Substrate transport apparatus with multiple movable arms utilizing a mechanical switch mechanism

A substrate transport apparatus including a frame, a drive section connected to the frame and including at least one independently controllable motor, at least two substrate transport arms connected to the frame and comprising arm links arranged for supporting and transporting substrates, and a mechanical motion switch coupled to the at least one independently controllable motor and the at least two substrate transport arms for effecting the extension and retraction of one of the at least two substrate transport arms while the other one of the at least two substrate transport arms remains in a substantially retracted configuration.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of U.S. Provisional Patent Application No. 60/916,781, filed on May 8, 2007, and is related to U.S. Provisional Patent Application No. 60/916,724 filed on May 8, 2007, the disclosures of which are incorporated by reference herein in their entirety.

BACKGROUND

The disclosed embodiments relate to a substrate transport apparatus and, more particularly, to substrate transport apparatus with multiple movable arms utilizing a mechanical switch mechanism.

2. Brief Description of Related Developments

In conventional multiple arm substrate transport apparatus, the arms or linkages of the transports are actuated by a complex arrangement of three or more motors, which for example may be configured in a coaxial manner and coupled to the linkages through concentrically arranged hollow shafts for providing the transport with movement having three degrees of freedom. Typically the outermost shaft may be coupled to a hub for rotating the multiple arms about, for example, a central axis of rotation. Two inner shafts, for example, may be connected to a respective one of the multiple arms through independent belt and pulley arrangements. As may be realized, the larger the number of motors employed for effecting movement of the transport, the greater the burden on the control system controlling the motion of the transport. Also, the larger number of motors employed increases the potential for motor failure as well as the cost of the transport.

The conventional multiple arm transport apparatus may be used in transport chambers or other substrate processing equipment where the transport apparatus and its drive system are located within and/or partially below the chamber/equipment so that the space available for other substrate processing components (e.g. vacuum pumps, etc.) is limited or otherwise constrained in some way. In conventional systems this may cause an increase in the size of the transport chamber to allow for mounting, for example, vacuum pumps at locations other than the bottom of the chamber/equipment. This results in incremental costs.

Conventional non-coaxial side-by-side dual SCARA (Selective Compliant Articulated Robot Arm) arms are offered for sale by several companies; the UTW and UTV series of robots by MECS Korea, Inc., the RR series of robots by Rorze Automation, Inc. and the LTHR, STHR and SPR series of robots by JEL Corp. An example of a side-by-side dual arm SCARA transfer device can be found in U.S. Pat. No. 5,765,444.

An exemplary configuration of a conventional non-coaxial side-by-side dual arm robot is shown inFIGS. 1 and 1A. The robot is built around a pivoting hub, which carries two SCARA arms or linkages. The left linkage has an upper arm, a forearm and an end effector coupled in series through revolute joints. A belt and pulley arrangement is used to constrain the motion of the left arm so that rotation of the upper arm with respect to the hub produces rotation of the forearm in the opposite direction (e.g. clockwise upper arm rotation causes counterclockwise forearm rotation). Another belt and pulley arrangement is used to maintain radial orientation of the end effector. The right linkage may be a mirror image of the left arm. The end effectors of the left and right arms move in different horizontal planes to allow for unrestricted motion of the two linkages of the robot. As can be seen inFIGS. 1B-1D, by rotating the left and right upper arms the respective linkages can be extended independently in a common radial direction with respect to the pivot point of the hub.

In the conventional side-by-side robots as shown inFIGS. 1,1A-D, the robot arms or linkages are actuated by a complex arrangement of three (or more) motors, which for example may be configured in a coaxial manner, coupled to the robot through hollow shafts to provide the robot with movement having three degrees of freedom. The outermost shaft may be coupled to the hub, while the two inner shafts may be coupled to the upper arms of the left and right linkages through independent belt and pulley arrangements. As may be realized, the larger the number of motors employed for effecting movement of the robot arm, the greater the burden on the control system controlling robot motion. Also, the larger the number of motors employed increases the potential for motor failure as well as the cost of the robot.

The conventional side-by-side robots as shown inFIGS. 1A-Dare used in transport chambers where the robot and drive section are located within the chamber so as to substantially prevent or at best encumber and limit the space envelope available for mounting of other components to the chamber such as atmosphere control systems (e.g. vacuum pumps to the bottom of the transport chamber). In conventional systems this may cause an increase in the size of the transport chamber for mounting of vacuum pumps at locations other than the bottom of the chamber. This results in incremental costs.

It would also be advantageous to have a robot manipulator with independently movable arms with reduced complexity, containment area and improved reliability and cleanliness of the robotic system.

SUMMARY

In one exemplary embodiment, a substrate transport apparatus is provided. The substrate transport apparatus includes a frame, a drive section connected to the frame and including at least one independently controllable motor, at least two substrate transport arms connected to the frame and comprising arm links arranged for supporting and transporting substrates, and a mechanical motion switch coupled to the at least one independently controllable motor and the at least two substrate transport arms, the mechanical motion switch including a pivoting member rotatably driven by the at least one independently controllable motor about a first axis, a first and second connecting links, each connecting link being rotatably coupled at one end to the pivoting member and rotatably coupled at a second opposite end to a respective drive link, the respective drive links being distinct from the arm links of the at least two substrate transport arms, the respective drive links being rotatably coupled to the frame about a second and third axis located side-by-side from each other and spaced apart from the first axis, each drive link being drivingly coupled to a respective upper arm link of the arm links of the at least two substrate transport arms for effecting the extension and retraction of one of the at least two substrate transport arms while the other one of the at least two substrate transport arms remains in a substantially retracted configuration.

In accordance with another exemplary embodiment a substrate transport apparatus is provided. The substrate transport apparatus includes a drive section and a SCARA arm operably connected to the drive section to move the SCARA arm, the SCARA arm comprising an upper arm and at least two forearms movably mounted on the upper arm and capable of holding a substrate thereon, wherein the upper arm is a substantially rigid link, and a mechanical motion switch located inside the upper arm and being operably connected to the drive section, the mechanical motion switch being operated by but one motor of the drive section and configured to selectably effect rotation of one of the at least two forearms substantially independent of other ones of the at least two forearms.

In accordance with still another exemplary embodiment, a substrate transport apparatus is provided. The substrate transport apparatus includes a frame, a drive section connected to the frame and including at least one independently controllable motor, at least two substrate transport arms connected to the frame and comprising arm links arranged for supporting and transporting substrates, and a compact mechanical motion switch coupled to the at least one independently controllable motor and the at least two substrate transport arms, the mechanical motion switch including a pivoting member rotatably driven by the at least one independently controllable motor about a first axis, a first and second drive link distinct from the arm links of the at least two substrate transport arms, each drive link being rotatably coupled at one end to the pivoting member at a respective first joint and rotatably coupled at a second opposite end to a respective upper arm link of the at least two substrate transport arms at a respective second joint, where the first drive link crosses over the second drive link, and wherein a distance between the first axis and the respective first joint is substantially equal to a distance from the respective first joint to the respective second joint.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT(S)

Although the embodiments disclosed will be described with reference to the embodiments shown in the drawings, it should be understood that the embodiments disclosed can be embodied in many alternate forms of embodiments. In addition, any suitable size, shape or type of elements or materials could be used.

Provided is a substrate transport apparatus with a manipulator having independently movable arms that utilize a mechanical switch mechanism to allow the two or more arms to have combined rotational and independent pick/place motion (e.g. each arm has two or more degrees of freedom with at least one degree of freedom of each arm substantially independent of the degrees of freedom of the other arms) with as few as two independently controllable motors. The drive for the two or more arms may be for example integrated into the vacuum transport chamber walls, which allows integration of vacuum system components (vacuum pumps, gauges, and valves) to the bottom of the chamber. In one exemplary embodiment, the shoulders of the arms may be positioned off center (closer to the processing station), resulting in articulated arms that have a SEMI (Semiconductor Equipment and Materials International) reach of the robot, but smaller than conventional arms.

Referring toFIGS. 2A-2D, there are shown a schematic views of substrate processing apparatus or tools incorporating features of the exemplary embodiments as disclosed further herein.

Referring toFIGS. 2A and 2B, a processing apparatus, such as for example a semiconductor tool station1090is shown in accordance with an exemplary embodiment. Although a semiconductor tool is shown in the drawings, the embodiments described herein can be applied to any tool station or application employing robotic manipulators. In this example the tool1090is shown as a cluster tool, however the exemplary embodiments may be applied to any suitable tool station such as, for example, a linear tool station such as that shown inFIGS. 2C and 2Dand described in U.S. patent application Ser. No. 11/442,511, entitled “Linearly Distributed Semiconductor Workpiece Processing Tool,” filed May 26, 2006, the disclosure of which is incorporated by reference herein in its entirety. The tool station1090generally includes an atmospheric front end1000, a vacuum load lock1010and a vacuum back end1020. In alternate embodiments, the tool station may have any suitable configuration. The components of each of the front end1000, load lock1010and back end1020may be connected to a controller1091which may be part of any suitable control architecture such as, for example, a clustered architecture control. The control system may be a closed loop controller having a master controller, cluster controllers and autonomous remote controllers such as those disclosed in U.S. patent application Ser. No. 11/178,615, entitled “Scalable Motion Control System,” filed Jul. 11, 2005, the disclosure of which is incorporated by reference herein in its entirety. In alternate embodiments, any suitable controller and/or control system may be utilized.

In the exemplary embodiments, the front end1000generally includes load port modules1005and a mini-environment1060such as for example an equipment front end module (EFEM). The load port modules1005may be box opener/loader to tool standard (BOLTS) interfaces that conform to SEMI standards E15.1, E47.1, E62, E19.5 or E1.9 for 300 mm load ports, front opening or bottom opening boxes/pods and cassettes. In alternate embodiments, the load port modules may be configured as 200 mm wafer interfaces or any other suitable substrate interfaces such as for example larger or smaller wafers or flat panels for flat panel displays. Although two load port modules are shown inFIG. 2A, in alternate embodiments any suitable number of load port modules may be incorporated into the front end1000. The load port modules1005may be configured to receive substrate carriers or cassettes1050from an overhead transport system, automatic guided vehicles, person guided vehicles, rail guided vehicles or from any other suitable transport method. The load port modules1005may interface with the mini-environment1060through load ports1040. The load ports1040may allow the passage of substrates between the substrate cassettes1050and the mini-environment1060. The mini-environment1060generally includes a transfer robot1013as will be described in greater detail below. In one embodiment the robot1013may be a track mounted robot such as that described in, for example, U.S. Pat. No. 6,002,840, the disclosure of which is incorporated by reference herein in its entirety. The mini-environment1060may provide a controlled, clean zone for substrate transfer between multiple load port modules.

The vacuum load lock1010may be located between and connected to the mini-environment1060and the back end1020. The load lock1010generally includes atmospheric and vacuum slot valves. The slot valves may provide the environmental isolation employed to evacuate the load lock after loading a substrate from the atmospheric front end and to maintain the vacuum in the transport chamber when venting the lock with an inert gas such as nitrogen. The load lock1010may also include an aligner1011for aligning a fiducial of the substrate to a desired position for processing. In alternate embodiments, the vacuum load lock may be located in any suitable location of the processing apparatus and have any suitable configuration.

The vacuum back end1020generally includes a transport chamber1025, one or more processing station(s)1030and a transfer robot1014. The transfer robot1014will be described below and may be located within the transport chamber1025to transport substrates between the load lock1010and the various processing stations1030. The processing stations1030may operate on the substrates through various deposition, etching, or other types of processes to form electrical circuitry or other desired structure on the substrates. Typical processes include but are not limited to thin film processes that use a vacuum such as plasma etch or other etching processes, chemical vapor deposition (CVD), plasma vapor deposition (PVD), implantation such as ion implantation, metrology, rapid thermal processing (RTP), dry strip atomic layer deposition (ALD), oxidation/diffusion, forming of nitrides, vacuum lithography, epitaxy (EPI), wire bonder and evaporation or other thin film processes that use vacuum pressures. The processing stations1030are connected to the transport chamber1025to allow substrates to be passed from the transport chamber1025to the processing stations1030and vice versa.

Referring now toFIG. 2C, a schematic plan view of a linear substrate processing system2010is shown where the tool interface section2012is mounted to a transport chamber module3018so that the interface section2012is facing generally towards (e.g. inwards) but is offset from the longitudinal axis X of the transport chamber3018. The transport chamber module3018may be extended in any suitable direction by attaching other transport chamber modules3018A,3018I,3018J to interfaces2050,2060,2070as described in U.S. patent application Ser. No. 11/442,511, previously incorporated herein by reference. Each transport chamber module3018,3019A,3018I,3018J includes a substrate transport2080as will be described in greater detail below for transporting substrates throughout the processing system2010and into and out of, for example, processing modules PM. As may be realized, each chamber module may be capable of holding an isolated or controlled atmosphere (e.g. N2, clean air, vacuum).

Referring toFIG. 2D, there is shown a schematic elevation view of an exemplary processing tool410such as may be taken along longitudinal axis X of the linear transport chamber416. In the exemplary embodiment shown inFIG. 2D, tool interface section12may be representatively connected to the transport chamber416. In this exemplary embodiment, interface section12may define one end of the tool transport chamber416. As seen inFIG. 2D, the transport chamber416may have another workpiece entry/exit station412for example at an opposite end from interface station12. In other alternate embodiments, other entry/exit stations for inserting/removing workpieces from the transport chamber may be provided. In the exemplary embodiment, interface section12and entry/exit station412may allow loading and unloading of workpieces from the tool. In alternate embodiments, workpieces may be loaded into the tool from one end and removed from the other end. In the exemplary embodiment, the transport chamber416may have one or more transfer chamber module(s)18B,18i. Each chamber module may be capable of holding an isolated or controlled atmosphere (e.g. N2, clean air, vacuum). As noted before, the configuration/arrangement of the transport chamber modules18B,18i, load lock modules56A,56B and workpiece stations forming the transport chamber416shown inFIG. 2Dis merely exemplary, and in alternate embodiments the transport chamber may have more or fewer modules disposed in any desired modular arrangement. In the embodiment shown, station412may be a load lock. In alternate embodiments, a load lock module may be located between the end entry/exit station (similar to station412) or the adjoining transport chamber module (similar to module18i) may be configured to operate as a load lock. As also noted before, transport chamber modules18B,18ihave one or more corresponding transport apparatus26B,26ilocated therein. The transport apparatus26B,26iof the respective transport chamber modules18B,18imay cooperate to provide the linearly distributed workpiece transport system420in the transport chamber. In this embodiment, the transport apparatus26B may have a general SCARA arm configuration as will be further defined herein (though in alternate embodiments the transport arms may have any other desired arrangement). In the exemplary embodiment shown inFIG. 2D, the arms of the transport apparatus26B may be arranged to provide what may be referred to as fast swap arrangement allowing the transport to quickly swap wafers from a pick/place location as will also be described in further detail below. The transport arm26B may have a suitable drive section for providing each arm with three (3) (e.g. independent rotation about shoulder and elbow joints with Z axis motion) degrees of freedom from a simplified drive system compared to conventional drive systems. As seen inFIG. 2D, in this embodiment the modules56A,56,30imay be located interstitially between transfer chamber modules18B,18iand may define suitable processing modules, load lock(s), buffer station(s), metrology station(s) or any other desired station(s). For example the interstitial modules, such as load locks56A,56and workpiece station30i, may each have stationary workpiece supports/shelves56S,56S1,56S2,30S1,30S2that may cooperate with the transport arms to effect transport or workpieces through the length of the transport chamber along linear axis X of the transport chamber. By way of example, workpiece(s) may be loaded into the transport chamber416by interface section12. The workpiece(s) may be positioned on the support(s) of load lock module56A with the transport arm15of the interface section. The workpiece(s), in load lock module56A, may be moved between load lock module56A and load lock module56by the transport arm26B in module18B, and in a similar and consecutive manner between load lock56and workpiece station30iwith arm26i(in module18i) and between station30iand station412with arm26iin module18i. This process may be reversed in whole or in part to move the workpiece(s) in the opposite direction. Thus, in the exemplary embodiment, workpieces may be moved in any direction along axis X and to any position along the transport chamber and may be loaded to and unloaded from any desired module (processing or otherwise) communicating with the transport chamber. In alternate embodiments, interstitial transport chamber modules with static workpiece supports or shelves may not be provided between transport chamber modules18B,18i. In such embodiments, transport arms of adjoining transport chamber modules may pass off workpieces directly from end effector or one transport arm to end effector of another transport arm to move the workpiece through the transport chamber. The processing station modules may operate on the substrates through various deposition, etching, or other types of processes to form electrical circuitry or other desired structure on the substrates. The processing station modules are connected to the transport chamber modules to allow substrates to be passed from the transport chamber to the processing stations and vice versa. A suitable example of a processing tool with similar general features to the processing apparatus depicted inFIG. 2Dis described in U.S. patent application Ser. No. 11/442,511, previously incorporated by reference in its entirety.

Referring toFIGS. 4A-C, a substrate transport apparatus300, having for example dual same side SCARA arms and incorporating a mechanical switch mechanism (see alsoFIGS. 3A-B). The transport chamber30may be generally similar to chamber modules18B,18ishown inFIG. 2. As seen best inFIGS. 4Band C, the transport apparatus may include independently articulated arms A and B, and is located within a transport chamber30. InFIG. 4B, the dual same side SCARA arms are indicated as Arm A41and Arm B43with the transport chamber not shown. The substrate for transport is indicated by S and is positioned on a forked shaped end effector32. The end effector may be of an alternative shape including, but not limited to, paddle shaped. One end effector is shown for example purposes, and in alternate embodiments the arm(s) may have any number of end effectors. The substrate S is representative and may be of any size, and shape such as a 200 mm, 300 mm, 450 mm or larger semiconductor wafer, a reticle or pellicle or panel for flat screen displays. As noted before, each arm may have for example a SCARA arrangement, though in alternate embodiments the transport arms may have any other desired arrangement. In the exemplary embodiment the transport arms are generally similar, though in alternate embodiments the arms may be different. The end effector32is pivotally connected at wrist joint34, to a forearm36for each Arm A41and B43. The forearm36is pivotally connected at an elbow joint38, to an upper arm40for each of Arm A41and Arm B43. In the exemplary embodiment, the upper arm40, for Arm A41and B43, are in turn mounted to a common base rotor42for the T2motor44via the arm shoulder joint46.

FIG. 4Dis a schematic partial elevation view of the transport chamber30and drive section of transport apparatus300. As seen inFIG. 4D, in the exemplary embodiment, the T1, T2motors may be any suitable type of motors and may be incorporated within the wall structure of the chamber30. For example the T1, T2motors may be brushless DC motors (though any other suitable motors may be used), with stator coils integrated into walls and isolated from the internal atmosphere of the chamber30. In other exemplary embodiments the drive may be a bearing drive system located at least partially below the chamber30as shown inFIG. 4Eand as will be described in greater detail below. In alternate embodiments the drive may be a combination of, for example, the bearing drive system and the drive located in the chamber walls. In other alternate embodiments, the drive may be any combination of the drive systems disclosed herein and any suitable conventional drive system.

Referring again toFIG. 4D, the motors may be housed in a common section302that is capable of Z axis motion, as shown inFIG. 4D, hence providing the arms with Z motion. A suitable flexible seal SC (such as a bellows seals may connect the drive belt to the adjoining wall structure to maintain the isolatable atmosphere in the transport chamber module. The drive section, may be operably connected to a suitable Z-drive T3illustrated substantially inFIG. 4D. The Z-drive may be of any suitable type, such as including windings (not shown) in the stator capable of moving the rotors42,50R in the Z direction. The Z-drive windings may also provide, in addition to Z location control, Z-stability for the motor rotors and arms holding the rotors and arms in a desired Z-location. The motors may be self bearing in both radial and Z-directions, or may have passive radial and Z bearing systems such as permanent magnets or mechanical bearings or a combination thereof for Z and radial bearing. In alternate embodiments, the Z-drive may include a Z-drive motor powering a lead screw connected to the section302to effect Z-motion of the transport arms. In the exemplary embodiments, the shoulder joint46of the arms41,43is coaxial, the respective upper arms40A,40B pivoting about a common shaft24that may be offset from the rotor axis of rotation22. In alternate embodiments, the arms may be mounted with offset shoulder joints, each rotating about a corresponding axis of rotation that are substantially parallel to each other. In the exemplary embodiments, the motor rotors42,50R are shown as being located on one side, such as in the bottom wall30L, of the chamber30for example purposes, though in alternate embodiments the rotors may be disposed in one or more of the transport chamber walls, such as one rotor on top (above the transport arms) and one on the bottom (below the arms). In the exemplary embodiment, the rotors may have a generally hollow ring structure, for reduced weight. In alternate embodiments, the rotors may have any suitable shape and configuration.

As seen best inFIGS. 4B,4D a crank link48connects the upper arm40A, B for each arm A41and B43to a revolute joint52on the rotor50R of T1motor50. As depicted inFIGS. 4A-D, the two crank links share a common convergent or pivot (e.g. shaft)52on the rotor50R of motor T1. As seen best in the plan views illustrated inFIGS. 4A and 4B, the locations of the revolute joints20A,20B of each link48A,48B to the respective upper arms40A,40B, are for example on substantially opposite sides of the X axis, along which the end effectors32of each arm is extended/retracted. In order to effect extension of Arm A41or Arm B43(e.g. for pick and place of a substrate S on the end effector32), the T1motor50may be rotated while the T2motor44is stationery. When the T1motor is rotated in one direction, one arm extends or retracts while the second arm practically does not move due to what may be called a mechanical switch or lost motion system that develops motion of one arm from another, generated by a common motor without physically decoupling the arms from the motor (see alsoFIGS. 3A-B).FIG. 4Cdepicts Arm A41in an extended position beyond the confines of the transport chamber30while Arm B is retracted within the transport chamber30. This movement of Arm A41allows for a substrate S to be picked up and placed in a storage chamber or processing station. In order to effectuate rotation of the arms, both the T2motor44and the T1motor50are rotated to the same degree. The T1motor50and T2motor44have independent drive shafts which necessitates that the center of rotation of T1is offset from T2.

Referring now toFIGS. 3A-B, the principle of operation of the mechanical switch mechanism10for arm motion disclosed herein will be described when used in a same side dual arm configuration.FIG. 3A-Bdepict the mechanical switch mechanism10of the same side dual SCARA arm configuration shown inFIGS. 4A-4D. As may be realized, the lines and connections thereof to the respective arms40A,40B and common motor T1, rotor50R are substantially mirror images of each other, and may be represented as shown inFIGS. 3A-3Bfor clarity to illustrate its operation. As noted before mechanical switch mechanism10may include upper arms40A,40B, in the exemplary embodiment sharing common revolute joint24, but shown as circular members (with diameter14) on opposing revolute joints24,24′, T1motor rotor50R, shown as opposing circular members with diameters12) on (common) axis of rotation22. These members may be linked together with crank links48A,48B at revolute joints18,18′ joints20A,20B (to respective upper arms) located on each side of the links48A,48B. Non-limiting exemplary bearings18,20include needle type, ball bearing type or bushing type. In the exemplary embodiment the center of rotation22of the rotor50,50′ and the center of rotation (e.g. shoulder joint) of the (upper arms) circle40A,40B,24,24′ may be offset with respect to one another in the exemplary embodiment. Thus as seen best inFIG. 3A, in the exemplary embodiment, each arm41,43may have a corresponding crank link48A,48B coupling the circle (T1) representing the motor rotor50R,50R′ with the smaller circle (T2) representing in the example the upper arms40A,40B of the corresponding arms. In alternate embodiments, the link coupling motor and articulated arm may be joined to any other desired section of the arm.

The resultant motions of the arms A, B (41,43) effected by motor T1(50) via the mechanical switch10are substantially depicted inFIG. 3Bby way of example, when T1rotates between 0 and −135 degrees (counterclockwise), Arm A (41) is changing extension angle or rotating (about shoulder24). In contrast, Arm B (43) is practically not moving. However, when T1rotates between 0 and +135 degrees (clockwise), Arm B is changing extension angle or rotating (about shoulder24) and Arm A is practically not moving. The relative motions illustrating the operation of the switch in the exemplary embodiment, are also depicted graphically in the graph ofFIG. 3Bwhich plots the extension angle of Arms A and B versus the rotation angle and direction of T1. As noted previously, in the exemplary embodiment, the two crank links48A,48B may be attached opposite of the axis of symmetry so when T1rotates in one direction, one link and arm combination are substantially locked, causing arm rotation with T1and the other link and arm combination is substantially released or free thus not undergoing movement with T1. Correspondingly, when T1rotates in the opposite direction, the previously locked arm releases to rotate with T1while substantially the previously free arm substantially locks to rotate with T1. This allows for independent extension of the two arms (depending on the direction and degree of rotation) from but one motor T1. As may be realized and as will be described in greater detail below, when both T1and T2rotate together, the two arms rotate relative to for example transport chamber30(e.g. about center of rotation22), as a unit.

As may be realized fromFIGS. 3A, and4A-D, in the exemplary embodiment, the T1, T2motors42,50may be rotary motors (such as brushless DC motors as noted before) that are coupled to the respective arms A, B (41,43) via what may be referred to as a shaft less drive coupling system. In the exemplary embodiment shown, the stators50S,44S of the T1, T2motors may be generally linearly distributed such as in a generally arcuate manner substantially around and proximate the periphery of the transport chamber30. The diameter of the T1, T2motors may be maximized relative to the space envelope of the transport chamber, which as may be realized may be minimized to the space envelope circumscribing the clearances for the motions of the arms A, B and wafers on the one or more end effector(s) of the arms. As may be realized, in the exemplary embodiment, the T1motor, for example, operates to impart a force on the arms A, B that is eccentric to the shoulder axis of rotation (e.g. revolute joint24) hence, by way of example the T1motor50output imparts a leverage force in the arms A, B that pivots the arms about a fulcrum defined for example by shoulder joint24. The coupling system between arms and motor50, that includes the previously described mechanical switch10, causes a resultant force to be applied by motor50to the arms that is eccentric to shoulder axis of rotation. In alternate embodiments, the motors and couplings delivering power from the motors to the arms may have any other suitable arrangement.

Referring now toFIGS. 5A-D, the extensional movement of Arm A41is depicted in four different extensional positions for the substrate transport apparatus300with dual same side SCARA arms incorporating the mechanical switch mechanism disclosed herein. InFIG. 5A, the two crank links48connecting the arm shoulder joints46on the T2motor mounting plate44to the T1motor50substantially converge at revolute joint62(similar to joint52inFIG. 4D) along the circumference of T150as noted before, in alternate embodiments, the links may be joined to the T1motor rotor at offset revolute joints. As rotor50R of T1motor50is rotated in the clockwise direction, the crank links48A,48B also rotate along the circumference of T1from position62to point B64in FIG.5B, which in turn causes Arm A41to extend outward toward the right while Arm B43remains essentially fixed in the retracted position. As T150is further rotated in the clockwise direction, the crank links48further rotate along the circumference of T1to point C66inFIG. 5C, which in turn causes Arm A41to further extend outward toward the right while Arm B43still remains essentially fixed in the retracted position. As T150is further rotated in the clockwise direction, the crank links48further rotate along the circumference of T1to point D68inFIG. 5D, which in turn causes Arm A41to further extend outward toward the right while Arm B43still remains essentially fixed in the retracted position. To retract Arm A41, the direction of T150is reversed along points C66, B64, and A62. In an alternative embodiment, the two crank links48for the two arms41,43need not converge on the same point on the circumference of T150.

Referring toFIGS. 6A-C, the extensional movement of Arm B43is depicted in three different extensional positions for the substrate transport apparatus300with dual same side SCARA arms incorporating the mechanical switch mechanism disclosed herein. InFIG. 6A, the two crank links48connecting the arm shoulder joints46(supported on the T2motor rotor44) to the T1motor by way of example50are positioned for example at point E72along the circumference of T1motor50. As T1motor50is rotated in the counterclockwise direction, the crank links48also rotate along the circumference of T1to point F74inFIG. 6B, which in turn causes Arm B43to extend outward toward the right while Arm A41remains essentially fixed in the retracted position. As T150is further rotated in the counterclockwise direction, the crank links48further rotate along the circumference of T1to point G76inFIG. 6C, which in turn causes Arm B43to further extend outward toward the right while Arm A41still remains essentially fixed in the retracted position. To retract Arm B43, the direction of T150is reversed along points F74, and E72.

Referring toFIGS. 7A-E, the rotational movement of Arm A41and Arm B43are depicted in five different rotational positions for the substrate transport apparatus300InFIG. 7A, the end effector(s)32are pointing along the positive x-axis. When both the T1and T2motors50,44are rotated in the same direction in equal amounts, Arms A and B,41,43will correspondingly rotate as a unit about axis of rotation22in the same direction along the continuum shown inFIGS. 7B,7C,7D and7E.

Referring now toFIGS. 8A-C, the extension/retraction movement of Arm B43in the exemplary embodiment is depicted in three different exemplary positions alongside with the corresponding positions of arm A41. As may be realized, in the embodiment shown inFIG. 8Aarm B is in an extended position and inFIG. 8Carm8is retracted. InFIG. 8A, the revolute joint for the two crank links48connecting the arm shoulders42on the T2motor mounting plate44to the T1motor50is located at point H82along the circumference of T1motor50. As T1motor50is rotated, for example in the clockwise direction, the crank links48also rotate along the circumference of T1to point184inFIG. 8B, which in turn causes Arm B43to retract inward toward the left while Arm A41remains essentially stationary in the retracted position. As T150is further rotated in the clockwise direction, the crank links48further rotate along the circumference of T1to point J86inFIG. 8C, which in turn causes Arm B43to further retract inward toward the right while Arm A41still remains essentially fixed in the retracted position.

The operation illustrated inFIGS. 5A-D,6A-C,7A-E and8A-C enables but two motors (T1and T2) to effectuate both substantially independent extension/retraction of each arm and rotation of the dual same side SCARA arms via the mechanical switch mechanism described herein. In comparison, standard dual same side SCARA arms require three (3) motors to effectuate the extension/retraction and rotation of the two arms. Hence, the mechanical switch mechanism disclosed herein allows for the elimination of one (1) motor and the corresponding cost savings and space reduction benefits.

As may be realized, the end effector, forearms and upper arms are linked by a synchro system so that rotation of the upper arm about the revolute joint at the shoulder generate relative movement between upper arm and forearms and between forearms and end effector so that the arm extension retraction causes end effector travel along an axis of travel such as along axis P shown inFIG. 9A.FIGS. 9A-Cillustrate an exemplary synchro system for the dual same side SCARA arms or arm assemblies in three different extensional positions in accordance with an exemplary embodiment that will be described below. The substrate transport apparatus300may include a drive section (T1and T2motors not shown), a coupling system between the drive section, and arms or arm assemblies491L,491R. In this example, the substrate transport300is shown having two SCARA arm assemblies, but in alternate embodiments the substrate transport may have any suitable configuration with any suitable number and/or configuration of arm assemblies. The drive section and coupling system, as previously described inFIGS. 3-8includes or defines what is referred to here as a mechanical switch mechanism that enables two drive motors (T1and T2) of the drive section to effect extension/retraction and rotation of more than one SCARA arm substantially independent of each other. The T1and T2motors may be constructed from two stacked rings (rotors) coupled with stator windings integrated in the transport chambers walls, possibly external to the vacuum, which may allow mounting of the vacuum system components to the bottom of the transport chamber. In addition, positioning of the upper arm shoulder off center of the transport chamber provides SEMI reach with significantly smaller arms than with respect to prior art SCARA arm design.

Referring again toFIGS. 9A-C, in the exemplary embodiment the arms491L,491R are substantially similar to arms A, B41,43of the transport apparatus300and include an upper arm member490L,490R, a forearm member460L,460R and an end effector430L,430R connected to each other through respective revolute joints492,493,494,495. In alternate embodiments, the arms may have more or fewer articulations. In the exemplary embodiment the upper arms490L,490R pivot about revolute joints402,401(e.g. shoulder joint24, seeFIG. 4A-4D). The proximate ends of the upper arms490L,490R are pivotally joined to the links422L,422R of the coupling system through revolute joints404,406as previously described. The distal ends of the upper arms490L,490R may for example be pivotally joined to respective proximate ends of the forearms460L,460R at revolute joints492,493. In the exemplary embodiment, the distal ends of the forearms460L,460R may be pivotally joined to the end effectors460L,460R at revolute joints494,495. The end effectors460L,460R may have a longitudinal axis running from the front of the end effector to the back of the end effector. The longitudinal axis of the end effectors may be aligned with a path of extension and retraction P of the arms as previously described inFIGS. 3-8. In alternate embodiments, the arms may have any desired configuration relative to the axis of extension/retraction P.

In this exemplary embodiment the links48A,48B (SeeFIGS. 3-8) of the coupling system may be incorporated into or are part of the upper arms490L,490R respectively so that links423L,423R form a portion or extension of their respective arm as previously described. In alternate embodiments, the arms may be configured to include the upper arm portions423L,423R in any suitable manner. As also noted before, the revolute joints402,401(mounted to motor T2) may be the pivot points of the upper arms490L,490R respectively. In other alternate embodiments, the upper arm portions423L,423R may be connected to a pulley or disk that is mounted to the upper arm so that as the respective disk rotates around point402or401thereby rotating a respective upper arm491L,491R. In still other alternate embodiments, the upper arm portions may depend from any portion of the arm for imparting torque to the upper arm. As may be realized, the relationship or orientation of the upper arm portions423L,423R to the rest of the upper arm as shown inFIGS. 9A-Cis merely exemplary and the upper arm portions423L,423R may have any suitable relationship/orientation to the upper arm.

In the exemplary embodiment shown, the arms491L,491R may also include a belt and pulley system for driving the forearm. For example, pulleys435L,435R may be coupled to a (stationary) fixture or hub at joints402,401(for example fixed to post24; seeFIG. 4D) so that as the upper arms rotate, their respective pulleys435L,435R remain stationary relative to the apparatus frame (e.g. upper arm motion effects relative movement between upper arm and corresponding pulley). A second (idler) pulley445L,445R may be coupled to the forearms460L,460R about joints492,493. The pulleys435L,445L and435R,445R may be connected by any suitable belt or bands440L,440R so that as the upper arms rotate490L,490R, relative motion with pulleys435L,435R causes the pulleys445L,445R to be drivingly rotated via the belts. In alternate embodiments, the pulleys may be connected by one or more metal bands that may be pinned or otherwise fixed to the pulleys. In other alternate embodiments, any suitable flexible band may connect the pulleys. In still other alternate embodiments, the pulleys may be connected in any suitable manner or any other suitable transmission system may be used. The pulleys435L,435R,445L,445R may be configured so that the movement of the arm members is constrained so that rotation of the upper arms490L,490R about joints402,401produces desired rotation of a respective one of the forearms460L,460R in the opposite direction. For example, to achieve this rotational relationship the ratio of the radii for pulleys450L,450R to pulleys445L,445R may be a 2:1 ratio.

In the exemplary embodiment, a second belt and pulley arrangement including pulleys450L,450R,465L,465R and belts455L,455R may be provided to drive the end effectors430L,430R so that the radial orientation or longitudinal axis of the end effectors430L,430R along the common path of travel P is maintained as the arms491L,491R are extended and retracted. The pulleys450L,450R may be coupled to their respective upper arm490L,490R about joints492,493and the pulleys465L,465R may be coupled to their respective end effectors430L,430R about joints494,495. In this example the ratio of pulleys450L,450R to pulleys465L,465R may be a 1:2 ratio. As can be seen inFIGS. 9A-C, pulleys450L,450R in the exemplary embodiment are mounted in line with a respective one of the pulleys445L,445R about joints492,493so that when the pulleys445L,445R are rotated with the forearms460L,460R the pulleys450L,450R remain stationary with respect to their respective upper arms490L,490R. Any suitable belt455L,455R may connect a respective pair of the pulleys so that as the forearms460L,460R are rotated the pulleys465L,465R are drivingly rotated. In alternate embodiments, the pulleys may be connected by one or more metal bands that may be pinned or otherwise fixed to the pulleys. In other alternate embodiments, any suitable flexible band may connect the pulleys. In still other alternate embodiments, the pulleys may be connected in any suitable manner.

The end effectors430L,430R may be coupled to a respective forearm at revolute joint494,495. The end effectors430L,430R may be drivingly coupled to a respective one of the pulleys465L,465R so that as the arms are extended or retracted the end effectors430L,430R stay longitudinally aligned with the common path of travel P as can be seen inFIGS. 9B,9C. It may be realized that the belt and pulley systems described herein may be housed within the arm assemblies491L,491R so that any particles generated may be contained within the arm assemblies. A suitable ventilation/vacuum system may also be employed within the arm assemblies to further prevent particles from contaminating the substrates. In alternate embodiments, the synchronization systems may be located outside of the arm assemblies. In other alternate embodiments, the synchronization systems may be in any suitable location.

Still referring toFIGS. 9A-Cthe operation of the substrate transport apparatus300is as was previously described inFIGS. 3-8utilizing the mechanical switch mechanism disclosed herein. As can be seen inFIG. 9A, the substrate transport300is at its initial or neutral position with both arms491L,491R in a retracted position. The coupling system and a portion of the arms may be located within a housing suitably configured to prevent particles generated by moving parts of the substrate transport from contaminating the substrates. For example slots may be provided in the housing for the arms to pass where any openings between the slots and the arms are sealed with a flexible seal. In alternate embodiments, the housing may have any suitable configuration to prevent substrate contamination from particulates that may be generated from moving parts of the transport. In other alternate embodiments, the coupling system may not be within a housing. InFIG. 9B, arm491L is in the extended position while arm491R is in its retracted position. InFIG. 9C, arm491R is in the extended position while arm491L is in its retracted position. The extension and retraction of arms491L,491R are effectuated using the drive and mechanical switch coupling system previously described inFIGS. 3-8.

Referring now toFIGS. 9C-D, rotation of the upper arm490L causes stationary pulley435L to drive pulley445L via belt440L so that as the arm is extended the forearm430L is rotated by substantially an equal amount in the opposite direction about revolute joint492. Rotation of the forearm490L in turn causes pulley450L to drive pulley465L via belt455L so that the end effector rotates about point494. Rotation of the end effector about point494is such that the radial orientation or longitudinal axis of the end effector430L is maintained along the common path of travel P as the arm491L is extended and retracted. Thus, as described above with respect toFIGS. 9A-C, the rotation of the forearm430L is slaved to the rotation of the upper arm490L about point492and the rotation of the end effector430L is slaved to the rotation of the forearm460L about point494. As a result the arm491L is extended radially while the arm491R remains substantially stationary in its retracted position. Retraction of the arm491L occurs in a substantially opposite manner.

Rotation of the upper arm490R causes stationary pulley435R to drive pulley445R via belt440R so that as the arm is extended the forearm460R is rotated an equal amount in the opposite direction about revolute joint493. Rotation of the forearm460R in turn causes pulley450R to drive pulley465R via belt455R so that the end effector430R rotates about point495. Rotation of the end effector430R about point495is such that the radial orientation or longitudinal axis of the end effector430R is maintained along the common path of travel P as the arm491R is extended and retracted. Thus, as described above with respect to arm491L, the rotation of the forearm460R is slaved to the rotation of the upper arm490R about point493and the rotation of the end effector430R is slaved to the rotation of the forearm460R about point495. As a result the arm491R is extended radially while the arm491L remains substantially stationary in its retracted position. Retraction of the arm491R occurs in a substantially opposite manner.

As may be realized, in the exemplary embodiment the end effectors430L,430R may travel along a common path of travel P, the end effectors may be configured in such a way so as to be in different planes along the path of travel P. In alternate embodiments, the arms491L,491R may be configured to be at different heights so that the end effectors can travel along the common path P. In other alternate embodiments, the transport may have any suitable configuration for allowing multiple end effectors to travel along a common path of travel. In yet other alternate embodiments, the end effectors may travel along different paths that may be generally parallel or angled relative to each other. The paths may be located in the same plane. The illustrated motions of the linkages of the coupling system are merely exemplary and in alternate embodiments the linkages may be arranged to provide and undergo any desired range of motion switching from driving the arms independently of each other.

In accordance with another exemplary embodiment, the substrate transport apparatus, with dual same side SCARA arms and the mechanical switch mechanism, may be powered from a drive section with a coaxial drive shaft assembly. For example, as can be seen inFIG. 4E, the drive system100may have coaxial inner and outer drive shafts101,102driven by motors104,103respectively. The motors103,104may each have a rotor103R,104R attached to their respective drive shaft102,101and a stator103S,104S for driving the rotor, the stator103S,104S being stationarily connected to a housing100H of the drive system100. In alternate embodiments the drive system may not be coaxial. It is noted that the housing100H of the drive system100may be coupled to chamber30(FIG. 4A) so that at least part of the drive system housing100H forms part of the interior of the chamber30. In one embodiment, the rotors103R,104R may be located within the atmosphere of the chamber30while the stators103S,104S are suitably isolated from the chamber atmosphere. Suitable examples of the coaxial drive100may be substantially similar to that described in U.S. Pat. Nos. 5,720,590, 5,899,658, 5,813,823, and 6,485,250 and/or Patent Publication Number 2003/0223853, which are incorporated herein by reference in their entirety. In alternate embodiments, any suitable drive section may be employed such as for example a non-coaxial drive assembly or a magnetic drive assembly.

The drive section may be housed within a housing of the substrate transport to prevent contamination or damage to the substrates from any particles that may been generated from the moving parts of the drive section. In this example, as noted above, the coaxial drive assembly may have an inner and outer drive shaft101,102. The outer drive shaft102may be connected to a housing of the substrate transport so that when the outer drive shaft102is rotated the arms491L,491R of the substrate transport apparatus are rotated about an axis of rotation of the outer drive shaft102. The inner drive shaft101may be connected to the coupling system at rotation point42so that when the inner drive shaft101is rotated the coupling system will rotate or pivot about an axis of rotation (i.e. rotation point42) of the inner drive shaft101. In the exemplary embodiment, the outer drive shaft102may be connected to the motor rotor (generally analogous to the T1motor powering arm extension/retraction) of the substrate transport apparatus so that when the outer drive shaft is rotated the dual arms may be independently extended/retracted in a similar manner to that previously described and shown inFIGS. 3-8. As may be realized the inner drive shaft101of the coaxial drive assembly may also rotate in the same direction and at substantially the same speed as the outer drive shaft to keep the arms of the transport apparatus from extending or retracting as the arms of the substrate transport apparatus are rotated substantially as a unit. The inner drive shaft101may be connected to a hub assembly (somewhat analogous to motor T2) via a coupling system at rotation point42so that when the inner drive shaft101is rotated the coupling system will rotate or pivot about an axis of rotation (i.e. rotation point42) of the inner drive shaft.

Referring now toFIGS. 10A-B, a substrate transport apparatus310with dual same side SCARA arms incorporating the mechanical switch mechanism with a coaxial drive assembly is depicted. InFIG. 10A, the transport apparatus with a coaxial drive assembly including Arms A141and Arm B143are located within a transport chamber130. InFIG. 10B, the dual same side SCARA arms are indicated as Arm A141and Arm B (only a portion of which is shown for clarity) with the transport chamber (also not shown). The arms and transport chamber are substantially similar to arms A, B in transport chamber30described previously. Similar features are similarly numbered. The substrate for the transport310is not shown, but would be positioned on an end effector132. In this example the end effector132is shown as having a forked shape but in alternate embodiments the end effector may be of an alternative shape including, but not limited to, paddle shaped. The end effector132is pivotally connected to a wrist or pivot joint134, which in turn is connected to a forearm136for each Arm A141and B143. The forearm136is pivotally connected to an elbow or pivot joint138, which in turn is connected to an upper arm140for each of Arm A141and Arm B143. The upper arm140for Arm A141and B143are in turn mounted to a common base or mounting plate142for the T1and T2motors150,144via their respective arm shoulder joints146. The center of the coaxial drive assembly for the T1and T2motors is also the center of the common base or mounting plate142. In this embodiment, an extension arm147extends radially outward from the coaxial drive shaft for T1motor150. In addition, a crank link148connects the arm shoulder joints146for each of Arm A141and B143to a revolute joint152on the extension arm147or motor T1. As depicted inFIGS. 10A-B, in the exemplary embodiment the two crank links148may share a common pivot point152offset from the center of the coaxial drive assembly142though in alternate embodiments the links may be joined to motor T1at offset revolute joints.

Referring again toFIGS. 10A-B, in order to effectuate extension of Arm A141or Arm B143for pick and place of a substrate S on the end effector132, the T1motor150is rotated while the T2motor144is stationery. When the T1motor is rotated in one direction, one arm extends or retracts while the second arm practically does not move in a similar manner to that previously described inFIGS. 3A-B.FIG. 10Adepicts Arm A141in an extended position for example beyond the confines of the transport chamber130while Arm B may be retracted within the transport chamber130. This movement of Arm A141allows for a substrate S to be picked up and placed in a storage chamber or processing station. In order to effectuate pure rotation of the arms, both the T2motor144and the T1motor150are rotated to the same degree. This maintains the crank links148for Arm A141and Arm B stationary relative to one another so as to not exert a torque on one of the two arms to effectuate extension or retraction. In this embodiment including a coaxial drive assembly, T1and the arm shoulder joints146rotate about a common axis of rotation.

Referring now toFIGS. 11A-D, the extensional movement of Arm A141is depicted in four different extensional positions for the substrate transport apparatus310with dual same side SCARA arms incorporating the mechanical switch mechanism with a coaxial drive assembly disclosed herein. InFIG. 11A, the two crank links148and extension arm147connecting the arm shoulder joints146on the T2motor mounting plate144to the T1motor150converge at point A162along the circumference of T1150. As T1150is rotated in the clockwise direction, the crank links148and extension arm147also rotate along the circumference of T1to point B164inFIG. 11B, which in turn causes Arm A141to extend outward toward the right (P direction) while Arm B143remains essentially fixed in the retracted position. As T1150is further rotated in the clockwise direction, the crank links148and extension arm147further rotate along the circumference of T1150to point C166inFIG. 11C, which in turn causes Arm A141to further extend outward toward the right while Arm B143still remains essentially fixed in the retracted position. As T1150is further rotated in the clockwise direction, the crank links148and extension arm147further rotate along the circumference of T1to point D168inFIG. 11D, which in turn causes Arm A141to further extend outward toward the right while Arm B143still remains essentially fixed in the retracted position. To retract Arm A141, the direction of T1150is reversed along points C166, B164, and A162. In an alternative embodiment, the two crank links148for the two arms141,143need not converge on the same point of the extension arm147to T1150.

In accordance with another exemplary embodiment of the substrate transport apparatus disclosed herein, a bisymmetric SCARA arm drive arrangement as can be seen inFIGS. 12A-12Band13A-13C may be utilized in place of a dual same side SCARA arm drive arrangement as was previously described inFIGS. 3-11. In a bisymmetric SCARA arm drive arrangement, two or more arms of the substrate transport apparatus may be arranged and/or oriented in different or opposite directions relative to each other. The substrate transport apparatus with a bisymmetric SCARA arm design utilizing a mechanical switch mechanism similar to that previously described allows for arm A and arm B to be positioned in the same plane and to correspondingly have a smaller envelope of motion. In turn, this may allow for the minimization of transport chamber volume, which in turn may decrease the possibility of substrate cross-contamination. Similar to the embodiments previously described for dual same side arms, with a bisymmetric arm arrangement utilizing the mechanical switch mechanism, independent extension/retraction and rotation of arm A and arm B may be effectuated with as few as two motors (T1and T2). The T1and T2motors may again be constructed from two stacked rings (rotors) coupled with stator windings integrated in the transport chambers walls, possibly external to the vacuum, which may allow mounting of the vacuum system components to the bottom of the transport chamber. In addition, positioning of the upper arm shoulder off center of the transport chamber provides SEMI reach with significantly smaller arms than with respect to prior art SCARA arm design.

Referring again toFIGS. 12A-B, there is shown respectively a schematic plan view of transport apparatus320having what may be referred to for example purposes only as a bisymmetric SCARA arm arrangement and a mechanical switch mechanism for substantially independent arm motion and a graph plotting the respective arm motions relating to motor displacement. The mechanical switch mechanism may be generally similar to that described previously, and may include two or more links247,248respectively connected by revolute joints on corresponding arm sections (e.g. upper arms of the SCARA arms). In the exemplary embodiment, each motor, such as T1motor250and T2motor244, has a link247,248pivotally connected thereto (e.g. link248to T1motor and link247to T2motor). In the exemplary embodiment shown, one crank link247connects the Arm B241elbow joint238to T2244. The other crank link248connects the Arm A244elbow joint238to T1250. T1and T2250,244may be motors substantially similar to that described before shown inFIG. 4D. In the exemplary embodiment, each SCARA arm is joined, via a corresponding revolute joint246A,246B at for example the shoulder joint to a respective rotor of the T1, T2motors. As seen best inFIG. 12A, in the exemplary embodiment, revolute joint246A (of arm A) is fixed to the T2motor rotor, and the link248joined at one end to upper arm240A (of arm A) is joined to the T1motor rotor. Conversely, the shoulder joint246B of arm B is fixed to the T1motor rotor, and the link247is pinned at the T2motor rotor.

In the exemplary embodiment shown inFIG. 12A, the dual bisymmetric SCARA arms are indicated as Arm A241and Arm B243with the transport chamber not shown. The substrate for the transport320is indicated by S and is positioned on end effector232. The end effector may be of any suitable shape including, but not limited to, fork and paddle shaped. The end effector232A, B is pivotally connected to a wrist joint234A, B, which in turn is connected to a forearm236A, B for each Arm A241and B243. The forearm236is pivotally connected to an elbow joint238, which in turn is connected to an upper arm240for each of Arm A241and Arm B243. As noted before, the upper arm(s)240A, B for Arm A241and B243are in turn respectively mounted to a corresponding rotor(s)244,250for the T1, T2motor(s) via respective arm shoulder joint(s)246A, B. As previously described, one crank link247connects the Arm B243elbow joint238to T2244. The other crank link248connects the Arm A241elbow joint238to T1250.

In order to effectuate extension of Arm A241or Arm B243for pick and place of a substrate S on the end effector232, the T1motor250is rotated while the T2motor244is stationery. Utilizing this type of switch type mechanism, by way of example when T1250rotates in one direction and when T2244is stationary, it effectuates extension and retraction of one arm. More particularly, when either the T1or T2motors are rotated causing relative movement between T2and T1motors in one direction, one arm extends or retracts while the second arm practically does not move due to the mechanical switch mechanism. When the relative movement of T2244and T1250motor is in the opposite direction, it effectuates extension of the other arm positioned opposite to the first arm. More particularly, when the T2motor is rotated in the opposite direction, the second arm extends or retracts while the first arm practically does not move due to the principle of operation of the mechanical switch mechanism. In the embodiment shown, the respective revolute joints (e.g. shoulder joint246A, B and link pivots) on the corresponding rotors250,244are depicted as being substantially coaxial for example purposes only, and in alternate embodiments the shoulder joint and link pivots on each rotor may be offset from each other. In order to effectuate rotation of the arms241,243substantially as a unit, both the T2motor244and the T1motor250are rotated to the same degree.

Referring toFIG. 12B, the principle of operation of the mechanical switch mechanism is depicted graphically, which plots the extension angle of Arms A and B versus the difference in rotation angle between T1and T2. There is a linear relationship between arm extension angle and the difference between T1and T2for the arm that extends/retracts. While one arm extends/retracts, the other arm practically does not extend/retract. Again with the mechanical switch mechanism used with dual bisymmetric SCARA arms, the two crank links247,248are attached opposite of the axis of symmetry so when T1rotates in one direction, one arm physically locks and the other arm is free to rotate with T1. Correspondingly, when T1rotates in the opposite direction, the previously locked arm releases and is free to rotate with T1while the previously free arm physically locks. This allows for independent extension of the two arms depending on the direction and degree of rotation of T1. In addition, when both T1and T2rotate together, the two arms rotate as opposed to extend.

Referring now also toFIG. 13A-C, the substrate transport apparatus320with dual bisymmetric SCARA arms incorporating the mechanical switch mechanism ofFIGS. 12A-Bis depicted. InFIGS. 13Aand C, the transport apparatus including Arms A and B is located within a transport chamber230. InFIG. 13B, the dual bisymmetric SCARA arms are indicated as Arm A241and Arm B243with the transport chamber not shown.

Referring now toFIGS. 14A-C, the extensional movement of Arm B243is depicted in three different extensional positions for the substrate transport apparatus320with dual bisymmetric SCARA arms incorporating the mechanical switch mechanism disclosed herein. InFIG. 14A, arm B243is shown slightly extended while arm A241is shown fully retracted with the crank link248effectuating arm B243movement at point A262along T1250. As depicted inFIG. 14B, as T1250is rotated in the clockwise direction (relative to T2motor rotor244), the crank link248connected to the T1rotor250moves with the circumference of the T1rotor250, which in turn causes Arm B243to extend outward toward the right while Arm A241remains essentially in the retracted position (but may be rotated as shown with rotation of rotor250). Correspondingly, the crank link247(for effectuating arm A241movement) is released at revolute joint240A causing no rotational motion of upper arm240A about shoulder joint246A. As depicted inFIG. 14C, as T1250is further rotated in the clockwise direction, the crank link,248connected to the T1rotor250further moves along with T1250, which in turn causes Arm B243to further extend outward toward the right while Arm A241still remains essentially fixed in the retracted position. Correspondingly, the crank link248effectuating arm B243movement moves from point B264to point C266along T1250. To retract Arm B243, the direction of T1250is reversed along points C266, B264, and A262.

Referring toFIGS. 15A-C, the extensional movement of Arm A241is depicted in three different extensional positions for the substrate transport apparatus320with dual bisymmetric SCARA arms incorporating the mechanical switch mechanism disclosed herein. As may be realized, the transport apparatus shown inFIGS. 15A-15Cmay be rotated 180 degrees from the orientation of the apparatus illustrated inFIGS. 14A-14C(such as for example when effecting a swap from a substrate holding station). InFIG. 15A, arm A241is shown slightly extended while arm B243is shown fully retracted with the crank link247effectuating arm A241movement at point D272along T1250. As depicted inFIG. 15B, as the T2rotor244is rotated relative to the T1rotor250in the counterclockwise direction, the crank link247, connected to the T2rotor244also moves with the circumference of the T2244rotor, which in turn causes Arm A241to extend outward toward the right while Arm B243remains essentially fixed in the retracted position (the crank link248being released). Correspondingly, the crank link247effectuating arm A241movement moves from point D272to point E274along T2244. As depicted inFIG. 15C, as T2244is further rotated in the counterclockwise direction, the crank link247connected to the T2rotor244further rotates along the circumference of T2244, which in turn causes Arm A241to further extend outward toward the right while Arm B243still remains essentially fixed in the retracted position. Correspondingly, the crank link247effectuating arm A241movement moves from point E274to point F276along T2244. To retract Arm A241, the direction of T2244is reversed along points F276, E274, and D272.

Referring toFIGS. 16A-D, the rotational movement of Arm A241and Arm B243are depicted in four different rotational positions for the substrate transport apparatus320with dual bisymmetric SCARA arms incorporating the mechanical switch mechanism disclosed herein. InFIG. 16A, the two arms241,243are pointing in opposite directions along P. When both the T1and T2motors250,244are rotated in the same direction (for example in the counterclockwise direction) in an equal amounts, Arms A and B,241,243will correspondingly rotate in, for example (depending on which direction T1and T2are rotated), the counterclockwise direction along the continuum shown inFIGS. 16B,16C, and16D. In another example, where T1and T2are rotated in a clockwise direction in equal amounts, Arms A and B,241,243will correspondingly rotate in, for example, the clockwise direction in a manner substantially opposite the counterclockwise rotation shown inFIGS. 16B,16C, and16D (i.e. the sequence of rotation would be fromFIGS. 16D to 16Arather than from16A to16D).

In another exemplary embodiment of the substrate transport apparatus with dual bisymmetric SCARA arms utilizing the mechanical switch mechanism disclosed herein, a coaxial drive shaft assembly may be used for coupling the T1and T2motors to the SCARA arms and mechanical switch. Hence in this embodiment, the center of rotation of T1and T2may be substantially the same. The coaxial drive may be substantially similar to that described above with respect toFIG. 4E. The outer drive shaft102may be connected to the T1motor rotor of the substrate transport apparatus so that when the outer drive shaft102is rotated the dual arms may be independently extended/retracted based on the principle of operation of the mechanical switch previously described inFIGS. 12-16. As may be realized the inner drive shaft101of the coaxial drive may also rotate in the same direction and at the same speed as the outer drive shaft102to keep the arms of the transport apparatus from extending or retracting as the arms of the substrate transport apparatus are rotated. The inner drive shaft101is connected to the T2hub assembly via a coupling system at rotation point242so that when the inner drive shaft101is rotated the coupling system will rotate or pivot about an axis of rotation (i.e. rotation point242) of the inner drive shaft101to effectuate rotation of T2.

Referring now toFIGS. 17A-B, a substrate transport apparatus380with dual bisymmetric SCARA arms incorporating the mechanical switch mechanism with a coaxial drive assembly is depicted. InFIG. 17A-B, the transport apparatus380with a coaxial drive assembly including Arms A341and Arm B343are located within a transport chamber330. In this example, the coaxial drive assembly may include stators integrated into the chamber330walls as described above with respect toFIGS. 3A, and4A-D. In other embodiments the coaxial drive may be similar to that shown inFIG. 4E. InFIG. 17C, the dual bisymmetric SCARA arms are indicated as Arm A341and Arm B (not shown) with the transport chamber (also not shown). The substrate S for transport is shown positioned on the forked end effector332inFIG. 17A, but is not shown inFIG. 17B-C. The end effector332may again be of an alternative shape including, but not limited to, paddle shaped. The end effector332is pivotally connected to a wrist or pivot joint334, which in turn is connected to a forearm336for each Arm A341and B343. The forearm336is pivotally connected to an elbow or pivot joint338, which in turn is connected to an upper arm340for each of Arm A341and Arm B343. The upper arm340for Arm A341and B343are in turn mounted to a common base or mounting plate342for the T1and T2motors350,344via their respective arm shoulder joints346. The center of the coaxial drive assembly for the T1and T2motors is also the center of the common base or mounting plate342. In this embodiment, two extension arms349a,349bextend radially outward from the coaxial drive shaft for T1and T2motors350,444. In addition, two crank links347,348connect the arm shoulder joints346for each of Arm A341and B343to a pivot point352(shown in dashed lines inFIG. 17C) on the extension arms349a,349b. The extension arms349a,349bconnect the arm shoulder346to the center or axis of rotation351of T1350and T2444. As depicted inFIGS. 17B-C, the two extension arms emerge from different shafts, but have the same axis of rotation351. The two crank links347,348do not share a common convergent or pivot point, but are offset from the center of the coaxial drive assembly351.

Referring again toFIGS. 17B-C, in order to effectuate extension of Arm A341or Arm B343for pick and place of a substrate S on the end effector332, the T1motor350is rotated while the T2motor344is stationery. When the T1motor is rotated in one direction, one arm extends or retracts while the second arm practically does not move due to the principle of operation previously described inFIGS. 12A-B. In particular, to extend arm A341, T1350is rotated counterclockwise which causes crank link348to rotate the upper arm340of arm A341in the counterclockwise direction, which in turn causes arm A341to extend.FIG. 17B depicts Arm A341in an extended position beyond the confines of the transport chamber330while Arm B343is retracted within the transport chamber330. This movement of Arm A341allows for a substrate S to be picked up and placed in a storage chamber or processing station. In order to effectuate rotation of the arms substantially as a unit, both the T2motor344and the T1motor350are rotated in the same direction and to the same degree. This maintains the crank links347,348and extension arms349a,bfor Arm A341and Arm B343stationary relative to one another so as to not exert a torque on one of the two arms to effectuate extension or retraction. In this embodiment including a coaxial drive assembly, T1and T2rotate about a common axis of rotation351.

Referring now toFIGS. 18A-D, the retractional movement of Arm A341is depicted in four different retractional positions (A through D) for the substrate transport apparatus380with dual bisymmetric SCARA arms incorporating the mechanical switch mechanism with a coaxial drive assembly disclosed herein.

The principle of operation of the substrate transport apparatus380with dual bisymmmetric SCARA arms incorporating the mechanical switch mechanism with a coaxial drive assembly as described inFIGS. 17-18is based on the two crank links being attached opposite of the axis of symmetry so when T1rotates in one direction, one arm physically locks and the other arm is free to rotate with T1. Correspondingly, when T1rotates in the opposite direction, the previously locked arm releases and is free to rotate with T1while the previously free arm physically locks. This allows for independent extension of the two arms depending on the direction and degree of rotation of T1. In addition, when both T1and T2rotate together, the two arms rotate together substantially as a unit as opposed to extend. Hence, the principle of operation of the substrate transport apparatus380with dual bisymmetric SCARA arms incorporating the mechanical switch mechanism with a coaxial drive assembly as described inFIGS. 17-18is the same as the substrate transport apparatus320(FIGS. 13-16) with dual bisymmetric SCARA arms incorporating the mechanical switch mechanism with independent drive assemblies for T1and T2

Referring now toFIGS. 19A-C, the retractional movement of Arm A341is depicted in three different positions (A through C) for the substrate transport apparatus380with dual bisymmetric SCARA arms incorporating the mechanical switch mechanism with a coaxial drive assembly disclosed herein. Arm B343is depicted on the left side of the schematics and Arm A341on the right side of the schematics. InFIG. 19A, arm A341is shown extended while arm B343is shown fully retracted with the crank link347effectuating arm A341movement at point A382along T1350. As depicted inFIG. 15B, as T1350is rotated in the clockwise direction, the crank link347connected along the circumference of T1350and the elbow joint338of arm A341also rotates in the clockwise direction along the circumference of T1350to point B384along T1350. This in turn causes Arm A341to retract inward in the P direction while Arm B343remains essentially fixed in the retracted position. The crank link348connected along the circumference of T1to the elbow joint338of arm B343remains fixed at point D388on the circumference of T1, which locks this arm in place. As depicted inFIG. 15C, as T1350is further rotated in the clockwise direction, the crank link347connected along the circumference of T1350and the elbow joint338of arm A341further rotates in the clockwise direction along the circumference of T1350to point C386along T1350. This in turn causes Arm A341to further retract fully inward in the P direction while Arm B343remains essentially fixed in the fully retracted position. Again, the crank link348connected along the circumference of T1to the elbow joint338of arm B343remains fixed at point D388on the circumference of T1, which keeps this arm locked in place.

Referring now toFIGS. 20A-20Lanother substrate transport apparatus2800is shown in accordance with an exemplary embodiment. In this example, the transport apparatus2800includes a first and second arm2891L,2891R, each having an upper arm2840L,2840R, forearm2855L,2855R, and end effector2830L,2830R. The arms2891L,2891R may be substantially similar to those described above with respect toFIGS. 9A-9B. In alternate embodiments, the arms2891L,2891R may have any suitable configuration. The shoulders2802L,2802R of each of the arms may be rotatably coupled to a mounting platform2801or any other suitable mounting structure. The shoulders may be mounted on the plate2801in a side by side arrangement as can be seen inFIG. 20A. In alternate embodiments the shoulders2802L,2802R may be mounted in a coaxial arrangement. The mounting platform2801may be fixedly coupled to drive motor T2so that as drive motor T2rotates (along with drive motor T1) clockwise or counter-clockwise the arms2891L,2891R with motor T2substantially as a unit to change an angular orientation of the path of extension and retraction with respect to, for example, a transfer chamber housing2880. The upper arms2840L,2840R of each arm2891L,2891R may be connected to drive motor T1through connecting links2899L,2899R. In this example, the connecting links2899L,2899R are shown as having a curvilinear shape but in alternate embodiments the connecting links2899L,2899R may have any suitable shape for connecting the arms2891L,2891R to the drive motor T1. The arms2891L,2891R may be connected to drive motor T1in any suitable manner for extending and retracting each of the arms. The motors T1, T2may be any suitable type of motors and may be incorporated within the wall structure of the chamber30as described above with respect toFIG. 4D. In alternate embodiments, the drive section may employ a coaxial drive shaft assembly. In still other alternate embodiments the motors T1, T2may have any suitable configuration, such as for example a non-coaxial drive assembly or a magnetic drive assembly.

Referring toFIGS. 20A-20Fanother exemplary embodiment of a dual same side SCARA arm is shown. The arms2891L,2891R may be substantially similar to those described above with respect toFIGS. 4A-4C. However, in this exemplary embodiment, the coupling between the arms and the drive section includes arcuate links2899L,2899R which are coupled at one end to a respective arm2891L,2891R and at the other opposite end to but one drive motor T1of the drive section. In this example the drive motors T1, T2are shown as being shaftless drives integrated into the walls of the chamber as described above with respect toFIG. 4Dbut in alternate embodiments the drives may be any suitable drives including, but not limited to, those described herein.

As can be seen inFIGS. 20A-20F, the extension of arm2891L is shown in several extensional positions. As can be seen in the figures, as the T1motor rotates in a counter-clockwise direction from the neutral position shown inFIG. 20A, the arm2891L is extended while the arm2891R remains in a substantially retracted position. As the motor T1is rotated in a counter-clockwise direction (the direction of arrow2870) as shown inFIGS. 20B-20Fthe connecting link2899L pushes on the upper arm2840L causing the upper arm to rotate about its shoulder axis also in a counter-clockwise direction. The pushing effect of the connecting link2899L on the upper arm2840L may be by virtue of the shape of the connecting link2899L. In alternate embodiments the pushing effect of the connecting link2899L may be provided in any suitable manner. Because the forearm2855L and end effector2830L are slaved to the upper arm2840L, as the upper arm rotates the forearm2855L and end effector2830L are extended along path P. As can be seen in the Figures as motor T1rotates in the counter-clockwise direction the connecting link2899R pivots about its coupling2880R with the upper arm2840R in a counter-clockwise direction without imparting any substantial motion to the upper arm2840R (i.e. the arm2891R remains in a retracted position). Retraction of the arm2891L is performed in a manner substantially opposite that described above such that connecting link2899L pulls the upper arm2840L in a clockwise direction thereby retracting the arm2891L from the position shown inFIG. 20Fto the position shown inFIG. 20A.

Referring toFIGS. 20G-20J, extension of the arm2891R may be performed in a manner substantially similar to the extension of arm2891L. For example, as the arm2891R is retracted and the motor T1is rotated in a clockwise direction (the direction of arrow2871) to the neutral position shown inFIG. 20G, the connecting link2899R begins pushing on the upper arm2840R while the connecting link2899L begins to rotate about its coupling2880L with upper arm2840L. As the motor T1continues to rotate in a clockwise direction the arm2891R is extended from the retracted position shown inFIG. 20Gto the extended position shown inFIG. 20L. Because connecting link2899L is free to rotate about coupling2880L, motor T1can rotate to extend arm2891R without imparting any substantial movement to arm2891L. Retraction of arm2891L can be performed in a manner substantially opposite to that described above with respect to its extension.

As noted above, when only the T1motor is rotated in a clockwise or counter-clockwise direction, one of the arms2891L,2891R are extended or retracted. When both the T1and T2motors are rotated in the same direction at substantially the same rate, both arms2891L,2891R are rotated as a unit to change the direction of extension and retraction P of the arms with respect to the, for example the transfer chamber housing2880.

Referring toFIG. 21A, there is shown a schematic plan view of a conventional transport apparatus with a two-by-two same side SCARA arm configuration. As may be realized, in this conventional configuration, three or more motors may be employed to effectuate independent extension/retraction of each arm and rotation of the four SCARA arms. It is noted that the dual end effectors located on each arm inFIG. 21Amay be incorporated onto the transport apparatus described above with respect toFIGS. 4A-4Bso that the mechanical switch with minimized number of drive motors can be utilized with the two-by-two same side SCARA arm configuration.

Referring now toFIG. 21Bthere is shown another exemplary embodiment of a substrate transport apparatus with double dual same side SCARA arm (e.g. a two by two SCARA arm (total of four arms) assembly) utilizing the mechanical switch mechanism disclosed herein. Hence a total of four arms may be configured within the substrate transport apparatus500. In contrast to conventional apparatus such as shown inFIG. 21A, in the embodiment shown inFIG. 21B, the two by two same side SCARA arm configuration for a substrate transport apparatus500utilizing the mechanical switch mechanism disclosed herein uses but two motors to effectuate independent extension/retraction of each pair of arms and rotation of the four SCARA arms. InFIG. 21B, arm1A541may be coupled to arm2A542via any suitable transmission541TA (such as belt/pulley system) and arm1B543may be coupled to arm2B544via another suitable transmission (not shown). The transport apparatus may be at least partly housed within a transport chamber530. The SCARA arms and mechanical switch may be generally similar to that previously described and depicted inFIGS. 3-11for the dual same side arm configuration (similar features are similarly numbered, and arm motions may be effected in a similar manner to that previously described. The T1and T2motors may be generally similar to T1and T2motors having two stacked rings (rotors)550R,544, respectively coupled with stator windings integrated in the transport chamber530, and for example external to the vacuum or chamber atmosphere. In alternate embodiments, the drive section for the double SCARA arms may employ a coaxial drive shaft assembly. In other alternate embodiments, any suitable drive section may be employed such as for example a non-coaxial drive assembly or a magnetic drive assembly. The drive section may be housed within a housing of the substrate transport to prevent contamination or damage to the substrates from any particles that may have been generated from the moving parts of the drive section. In comparison to the conventional design ofFIG. 21A, the double SCARA arm drive utilizing the mechanical switch mechanism depicted inFIG. 21Bprovides for positioning of the upper arm shoulders for example off center of the transport chamber, which correspondingly provides for station reach with significantly smaller and hence lighter arms.

As best seen inFIG. 21B, in the exemplary embodiment linkages548A,548B may be employed to define a mechanical switch generally similar to the mechanical switch described previously. As noted before, corresponding arms of each arm pair (e.g. A arms541,542, B arms543,544) are coupled, and hence the description below will refer generally to but one arm (e.g. A arm541, B arm543) of each arm pair. As seen inFIG. 21B, in the exemplary embodiment, the corresponding arm pairs541,544,542,543may be mounted with the shoulder joints offset from each other, though in alternate embodiments, the shoulder joints may be coaxial. In the exemplary embodiment, the arm pairs may be mounted on a support platform580that is substantially fixed to one motor (e.g. T2motor rotor544). The support platform shown has an exemplary configuration and in alternate embodiments the support platform may have any suitable shape, for example may be integrated with the motor rotor. Z-support and motion may be provided in a manner as described previously. As seen inFIG. 21B, linkages548A,548B may be connected by revolute joints (in the embodiment shown the joints are offset though in alternate embodiments the joints may have a common axis of rotation) to the rotor of the T1motor. In the exemplary embodiment, linkages548A,548B may be articulated each having first and second or crank link sections joined by a revolute joint. The crank link section of linkages548A,548B in the exemplary embodiment may be connected to the support platform580by revolute joints541R,543R. The crank link section of the linkages may be respectively coupled with a suitable transmission541T,543T (such as a belt/pulley system) to the corresponding upper arm of arms541,543. Hence, the crank link of linkage548A is coupled via transmission541T to the upper arm of A arm541, and crank link of linkage548B is coupled via transmission543T to the upper arm of B arm543. The crank links of linkages548A,548B are respectively free to rotate about corresponding revolute joints541R,543R. By way of example, in the exemplary embodiment, counter clockwise rotation of T1rotor550R causes linkage548A to articulate so that crank link of linkage548A is rotated about revolute joint541R hence causing extension/retraction of the A arm541,542via transmission(s)541T. The other linkage548B is substantially released so that articulation results in little or substantially no rotation of the corresponding crank link about revolute joint545R, and hence substantially no movement of the B arm543. Conversely, clockwise motion of the T1motor rotor550R, from an initial position causes extension of the B arm543,544from each arm pair.

Referring now toFIG. 22A, the extensional and retractional movement of the four arms are depicted in seven different extensional positions for the substrate transport apparatus500with double dual (two by two) same side SCARA arms incorporating the mechanical switch mechanism disclosed herein. Referring to the bottom row of schematics inFIG. 22A, the extensional movement of two of the arms (Arm1A541and Arm2A542) along the direction P is illustrated as the point595of the crank links548A,548B moves along T1550in the counter-clockwise direction based on counter-clockwise rotation of T1550. As T1550rotates counter-clockwise, the articulation of linkage548A causes link599A to rotate about revolute joint541R. Rotation of link599A about revolute joint541R in turn causes rotation of transmission541T for extending arm541. As noted above, arm541is coupled to arm542via transmission541TA such that as arm541extends/retracts, arm542extends/retracts with arm541. As can be seen inFIG. 22Awhen arms541,542are extended the link599B of linkage548B remains substantially rotationally fixed relative to, for example the support platform580such that arms543,544remain in a substantially retracted position. Referring to the top row of schematics inFIG. 22A, the extensional movement of the other two arms (Arm1B543and Arm2B544) along the P direction is illustrated as the point595of the crank links548A,548B move along T1550in the clockwise direction based on clockwise rotation of T1550. As T1550rotates clockwise, the articulation of linkage548B causes link599B to rotate about revolute joint543R. Rotation of link599B about revolute joint543R in turn causes rotation of transmission543T for extending arm543. As noted above, arm543is coupled to arm544via a suitable transmission such that as arm543extends/retracts, arm544extends/retracts with arm543. As can also be seen inFIG. 22A, as arms543,544are extended link599A of linkage548A remains substantially rotationally fixed with respect to, for example, the support platform580such that arms541,542remain in a substantially retracted position.

Referring now toFIG. 22B, a counter-clockwise rotational movement of the four arms541-544is depicted in eight different rotational positions for the substrate transport apparatus500with double dual (two by two) same side SCARA arms incorporating the mechanical switch mechanism disclosed herein. For exemplary purposes only the position of the transport apparatus500shown in the upper left corner ofFIG. 22Bwill be referred to as the start position with respect to the rotation of the arms541-544. In alternate embodiments, the start position for the rotation of the arms may be any suitable rotational orientation of the apparatus. As can be seen inFIG. 22Bthe transport arms are rotated as a unit by operating both the T1and T2motors such that they rotate in the same direction at substantially the same speed. In this example both the T1and T2motors are rotated in a counter-clockwise direction (i.e. the direction of arrow563). When the motors T1, T2are rotated in the same direction and at substantially the same speed, no relative motion is introduced between, for example, the support platform580and the linkages548A,548B. As such, the linkages548A,548B remain substantially in the same orientation throughout the rotation of the arms541-544as a unit without imparting any substantial extension or retraction of the arms541-544.

It should be understood that the substrate transport apparatus utilizing the mechanical switch mechanism disclosed herein is not limited to use with SCARA arms, which for example may include an upper arm, a band driven forearm and a band driven end effector. It should also be understood that the same side or bisymmetric SCARA arms described above may be of alternative designs and configurations.

In accordance with another exemplary embodiment, the transport apparatus may have a general SCARA arm arrangement that may incorporate a pair of independently actuated coaxial rings exposed at the circumference of the transport chamber. For example, the structural role of the upper arm is assumed directly by one of the actuation rings (motor rotors similar to motors214,50R shown inFIG. 4D). The second independently actuated coaxial ring is coupled to the arm by a coupling mechanism. Non-limiting, exemplary coupling mechanisms linking the second independently actuated coaxial ring coupled to the arm include a mechanical link (including one or more revolute joints), a band drive, a crossed band drive, and a magnetic coupling. The independently actuated coaxial rings may be, for example, two independent motor rotor rings, which may be concentric with one another. One or more pins may be attached to each of the coaxial rings for attaching revolute joints for the linkages connected to the two coaxial rings. The rotation and extension of the arm may be effected by the relative motion of one coaxial ring relative to the other coupled coaxial ring. This configuration shall be referred to herein, for description purposes only, as an arm with actuation rings. The arm with the actuation ring design may include one or two arms linked to the circumference of one coaxial ring. Various embodiments of this arm with the actuation ring design may be provided for through differing mechanical designs for the actuation of the remaining arm linkages. In single arm embodiments, both a left hand configuration and right hand configuration of the arm may be provided for. The pair of independently actuated coaxial rings may have the same or different diameters. The pair of independently actuated coaxial rings may also rotate in the same horizontal plane as depicted inFIGS. 23-28or may rotate in two different horizontal planes adjacent to one another (for example, on top of each other or side by side to each other). The linkage type and configuration between the two independently actuated coaxial rings will vary depending upon the relative diameter and the relative position of the two coaxial rings.

The arm with the actuation ring design may provide for one or more of the following non-limiting advantages: reduced complexity, lower cost, reduced size, improved utilization of torque and improved resolution. The arm with the actuation rings design eliminates one link and joint, including two pulleys and bands for each end effector. The arm with the actuation rings design also allows for the elbow joint of the arm to remain within the vacuum chamber as the arm extends, and hence for example the end effector or the end effector and wrist joint may pass through the slot valve to provide desired reach pursuant to the SEMI standard. The arm with the actuation rings design may for example also provide for a 1:1 pulley ratio though any suitable pulley ratio may be used. Various embodiments of this arm with the actuation ring design may be provided for through differing mechanical designs for the actuation of the remaining arm linkages for both single and dual end effector arms, which will be described in further detail below. It is noted that the housing, such as a vacuum or transfer chamber housing, for enclosing the transport apparatus described below with respect toFIGS. 23A-28Bis omitted from the figures for clarity purposes only.

Referring now toFIG. 23A, a single end effector arm600with actuation rings driven at least in part by, for example, a linkage is illustrated. In this embodiment, the arm600is installed on a pair of independently actuated coaxial rings601and602. The arm600includes a primary linkage603, an end effector604and a secondary linkage605. The two linkages603,605may be symmetrical or non-symmetrical depending upon their length and position along the circumference of the coaxial rings601,602. A substrate S is shown on the end effector604for exemplary purposes. The primary linkage603is coupled to one coaxial ring601through revolute joint606. End effector604is coupled to the primary linkage603through revolute joint607, and constrained to point radially along the path of extension/retraction P by band arrangement608. The band arrangement may include a first pulley608A and a second pulley608B and band608C. The first pulley608A may be drive pulley that is fixedly coupled to the first coaxial ring at joint606such that as the ring601rotates the pulley rotates along with the ring without any relative motion between the two. The second pulley608B may be a driven pulley that is fixedly coupled to the end effector604at joint610such that when the pulley608rotates the end effector604rotates with it. As can be seen inFIG. 23A, the pulleys608A,608B may have for example a 1:2 ratio so that as the arm600is extended/retracted the end effector604longitudinally remains along the path of travel P. In alternate embodiments, the pulleys may have any suitable ratio depending on a desired path of travel of the substrate and/or end effector. The band608C connecting the two pulleys608A,608B may be any suitable band arrangement, including but not limited to, one or more metal bands coupled to each of the pulleys (e.g. by pins or other suitable fastening device) and toothed bands. In alternate embodiments the band arrangement may have any suitable configurations. In still other alternate embodiments, the end effector604may be constrained to move along a predetermined path, such as path P, in any suitable manner. Secondary linkage605is coupled to the other coaxial ring602and end effector604through revolute joints609and610respectively.

The arm600may be rotated as a unit by rotating the coaxial rings601and602equally in the same direction. The arm600may be radially extended by moving coaxial rings601and602simultaneously in opposite directions. The symmetry of the primary linkage and the secondary linkage603,605may determine the amount of rotation or extension of the arm600relative to the rotation of the two coaxial rings601,602. Referring now toFIG. 23B, the radial extension of the single end effector arm600with actuation rings driven by a linkage with substrate S thereon is depicted in phased form in six different positions along the P direction. Beginning with the upper left diagram inFIG. 23Bfor exemplary purposes only, as coaxial ring601rotates in the clockwise direction and coaxial ring602rotates in a counterclockwise direction by equal amounts, the linkage603pulls on the end effector at revolute joint607while the linkage605pushes on the end effector at revolute joint610causing a radial extension of the arm600. As the coaxial rings continue to rotate in opposite directions the linkage603reaches a point where it begins to push on the end effector at revolute joint607as can be seen in the upper right diagram ofFIG. 23Bsuch that throughout the rest of the extension motion both linkages603,605are pushing the end effector through its path of extension as can be seen in the bottom row of diagrams inFIG. 23B. As described above the movement of the end effector is constrained by the band arrangement608such that it is longitudinally aligned with path P during extension and retraction. For example, as the coaxial ring602rotates clockwise the linkage603rotates counterclockwise relative to its pivot point606and the ring601. The band arrangement608in turn causes pulley608B to rotate clockwise (based on the relative motion between the linkage603and ring601) such that the end effector remains longitudinally aligned with the path of travel P (e.g. the rotation of the end effector about joint607counters the rotation of the linkage603about joint606). As may be realized the retraction of the arm600can be effected in a manner substantially opposite that described above with respect to the extension of the arm600.

Referring now toFIG. 24A, a single end effector arm620with actuation rings driven, for example, at least in part by straight bands is illustrated. In this embodiment, the arm620is again installed on a pair of independently actuated coaxial rings621and622. The two actuation rings621,622may be concentric with respect to each other as depicted inFIG. 24. The arm includes a linkage623, an end effector624and a straight band drive625. A substrate S is shown on the end effector624for exemplary purposes. Linkage623is connected at one end to both the coaxial ring621through revolute joint606and to the other coaxial ring622through the band drive625. In this exemplary embodiment, the straight band drive625includes a first drive pulley625A, a second driven pulley625B and a belt625C. The belt may be substantially similar to the belt described above with respect toFIG. 23A. The pulleys625A,625B in this example have a 1:1 ratio such that the rotation of the coaxial ring622is transferred to the arm linkage623without any reduction or increase in rotational speed. The drive pulley625A may be fixedly mounted to the coaxial ring622such that as the coaxial ring rotates the pulley625A rotates with it. In this example, the drive pulley625A is mounted substantially at the center of the inner actuation ring622, which may be in the form of a wheel. In alternate embodiments, the drive pulley625A may be mounted at a location other than the center of the inner actuation ring622. The driven pulley625B may be fixedly mounted to the arm linkage623about revolute joint628.

The end effector624is coupled to linkage623through revolute joint627and constrained to point radially by band arrangement628. The band arrangement628includes a first drive pulley628A, a second driven pulley628C and band628C. The band arrangement628may be substantially similar to the band arrangement608described above with respect toFIG. 23A. In alternate embodiments the band arrangement may have any suitable configurations. In still other alternate embodiments, the end effector624may be constrained to move along a predetermined path, such as path P, in any suitable manner.

The arm620may be rotated as a unit by rotating coaxial rings621and622by substantially equal amounts in the same direction (e.g. clockwise rotation of rings621,622produces a clockwise rotation of arm620about the center of rotation of the rings621,622). Radial extension of the arm620may be controlled by moving coaxial rings621and622simultaneously in opposite directions. In this example, to extend the arm620the rings621,622may be rotated by equal amounts in opposite directions as the band drive625is has a 1:1 pulley ratio. As may be realized, in alternate embodiments the rings621,622may be rotated in opposite directions by unequal amounts to extend the arm620depending on, for example, the ratio between the pulleys625A,625B. Referring now toFIG. 24B, the radial extension of the arm620with actuation rings621,622driven by straight bands is depicted in phased form in six different positions along direction P. Beginning with the upper left diagram inFIG. 24Bfor exemplary purposes only, the arm620is shown in a substantially retracted configuration. As the ring621rotates clockwise and the ring622rotates counterclockwise the arm extends along path P. As can be seen inFIG. 24B, rotation of ring621causes revolute joint628to travel along the circumference of the ring621without introducing any relative motion between the ring621and drive pulley628A. Rotation of the ring622in a counterclockwise direction causes band arrangement625to rotate the arm linkage623in a counterclockwise direction. The combined movement of ring621(moving the revolute joint) and ring622(rotating the arm linkage623) causes the arm linkage623to extend. As described above, the end effector624is constrained so that it is longitudinally aligned with path of travel P during extension and retraction. The combined rotation of the rings621,622in opposite directions produces relative movement between the linkage623and drive pulley628such that the linkage623is seen as rotating counterclockwise about joint628. This relative movement causes band assembly628to rotate the end effector624in a clockwise direction such that the end effector624remains longitudinally aligned with path P during extension and retraction of the arm620.

Referring now toFIG. 25A, a single end effector arm640with actuation rings driven at least in part by, for example crossed bands is illustrated. In this embodiment, the arm640is again connected to a pair of independently actuated coaxial rings641and642. The two actuation rings641,642may be concentric with respect to each other as depicted inFIG. 25A. The arm640includes a linkage643, an end effector644, a crossed band drive645and an end effector band arrangement648. In alternate embodiments the arm640may have any suitable configuration. A substrate S is shown on the end effector644for exemplary purposes. Linkage643is connected at one end to both the coaxial ring641through revolute joint646and the other coaxial ring642through the crossed band drive645. A driven pulley645B may be fixedly coupled to the linkage643so that as the pulley645B rotates the linkage643rotates with it about joint646. In this example, the inner coaxial ring645may be configured as a drive pulley such that the crossed band drive645may be positioned along the periphery of the inner coaxial ring642. In alternate embodiments the crossed band drive645may be positioned at another location where a wheel arrangement for the coaxial ring642may be utilized. In still other alternate embodiments the drive coupling between the coaxial ring642and linkage driven pulley645B may not be a crossed band drive. For example, the drive band may couple ring642and drive pulley645B in a manner substantially similar to that described above with respect to band625C andFIG. 24A. The end effector644is coupled to the other end of the linkage643through revolute joint647and is constrained to point radially by band arrangement648so that as the arm is extended/retracted the end effector644remains longitudinally aligned with the path of travel P. In this example, the end effector is constrained through band arrangement648. The band arrangement648may include a drive pulley648A, a driven pulley648B and band648C. The band arrangement648may be substantially similar to band arrangement608described above with respect toFIG. 23A.

The arm640may be rotated as a unit by rotating coaxial rings641and642by substantially equal amounts in the same direction (e.g. clockwise rotation of rings641,642rotates the arm640in a clockwise direction about, for example, a center of rotation of the rings). Radial extension of the arm640may be effectuated by moving coaxial rings641and642simultaneously in the same direction by unequal amounts. Referring now toFIG. 25B, the radial extension of the single end effector arm with actuation rings driven by crossed bands with substrate S thereon is depicted in phased form in six different positions along direction P. Beginning with the upper left diagram inFIG. 25Bfor exemplary purposes only, the arm640is shown in a substantially retracted configuration. As both coaxial rings641,642are rotated simultaneously in the same direction (in this example the rings are rotated in a clockwise direction) by unequal amounts, the revolute joint646travels along, for example, the circumference of the ring641. By rotating ring642at a different rate than ring641the crossed band645causes the arm linkage643to rotate in a counterclockwise direction relative to the revolute joint646. The combined rotation of the rings641,642causes the extension and rotation of the arm linkage643along the path of travel P. As described above the end effector644is constrained by band arrangement648such that as the linkage643extends the end effector remains longitudinally aligned with the path of travel in a manner substantially similar to that described above with respect toFIG. 23A. For example, as the arm linkage643rotates counterclockwise relative to the revolute joint646, the band arrangement648is configured to rotate the end effector644clockwise relative to revolute joint647. The rotation of the forearm644counteracts rotation of the linkage643and the forearm remains longitudinally aligned with the path of travel P as can be seen inFIG. 25B.

Referring now toFIG. 26A, a single end effector arm660with actuation rings driven at least in part by, for example, a magnetic coupling is illustrated. In this embodiment, the arm660is connected to a pair of independently actuated coaxial rings661and662. The two actuation rings661,662may be concentric with respect to each other as depicted inFIG. 25. The arm660includes a linkage663, an end effector664, a band arrangement668and a magnetic coupling665. The linkage663may be rotatably coupled to ring661through revolute joint666. A pulley666P may fixedly coupled to the linkage663at joint666such that as pulley666P rotates the linkage663rotates with it as will be described below. The end effector664is rotatably coupled to the linkage663by revolute joint667. The end effector may be constrained to travel along the path of travel (e.g. extension/retraction) by band arrangement668. The band arrangement includes a drive pulley668A fixedly coupled to the ring661, a driven pulley fixedly coupled to the end effector664and a band668C. The band arrangement668may be substantially similar to band arrangement608described above with respect toFIG. 23A. It is noted that a substrate S is shown on the end effector664for exemplary purposes.

In this exemplary embodiment, the inner coaxial ring622includes magnets662M located along its periphery. In alternate embodiments the magnets662M may be positioned at another location where, for example, a wheel arrangement for the inner coaxial ring662is utilized. As described above, linkage663is connected to coaxial ring661through revolute joint666. Pulley666P, which is also rotatable about joint666may magnetically couple the linkage663to the inner coaxial ring662. For example the pulley666P, which is fixedly coupled to linkage663, includes magnets666M located around its periphery. The magnets may be arranged so that each magnet has a different polarity. For example, as can be seen inFIG. 26Cthe magnets666M on the pulley666P are arranged so that the polarity alternates in a north-south-north-south pattern as can be seen with respect to magnets666MS,666MN. As can be also be seen inFIG. 26C, the magnets on the inner coaxial ring662alternate in a similar manner as can be seen with respect to magnets662MN,662MS. As may be realized, the magnets on the pulley666P and the magnets on the ring662may be arranged so that a magnets having a “north” polarity on the pulley666P are mated with a magnets having a “south” polarity on the ring662as shown inFIG. 26Cto form the magnetic coupling665. In alternate embodiments, the magnets may have any suitable configuration such that a magnetic coupling is formed between the ring662and the linkage663.

The arm660may be rotated as a unit by rotating coaxial rings661and662by substantially equal amounts in the same direction. Radial extension of the arm660may be controlled by rotating coaxial rings661and662simultaneously in the same direction by unequal amounts (e.g. clockwise rotation of rings641,642rotates the arm640in a clockwise direction about, for example, a center of rotation of the rings). Referring now toFIG. 26B, the radial extension of the single end effector arm660with actuation rings driven by a magnetic coupling with substrate S thereon is depicted in phased form in six different positions along direction P. Beginning with the upper left diagram inFIG. 26Bfor exemplary purposes only, the arm640is shown in a substantially retracted configuration. As both coaxial rings661,662are rotated simultaneously in the same direction (in this example the rings are rotated in a clockwise direction) by unequal amounts, the revolute joint666travels along, for example, the circumference of the ring661. By rotating ring662at a different rate than ring661the magnetic coupling665causes the arm linkage663to rotate in a counterclockwise direction relative to the revolute joint666. The combined rotation of the rings661,662causes the extension and rotation of the arm linkage663along the path of travel P. As described above the end effector664is constrained by band arrangement668such that as the linkage663extends the end effector664remains longitudinally aligned with the path of travel P in a manner substantially similar to that described above with respect toFIG. 23A. For example, as the arm linkage663rotates counterclockwise relative to the revolute joint666, the band arrangement668is configured to rotate the end effector664clockwise relative to revolute joint667. The rotation of the forearm664counteracts rotation of the linkage663and the forearm remains longitudinally aligned with the path of travel P as can be seen inFIG. 26B.

Referring now toFIG. 27A, a dual end effector arm arrangement700with actuation rings driven at least in part by, for example, a triangular multi-linkage is illustrated. In this embodiment, the dual end effector arm arrangement700is connected to a pair of independently actuated coaxial rings701and702. The left hand side arm700L includes a primary linkage703L, an end effector704L and a secondary linkage705L. A substrate S is shown on the end effector704L for exemplary purposes. The primary linkage703L is coupled to ring701through revolute joint706L. The arrangement of the triangular linkage703L shown inFIG. 27Ais merely exemplary and alternate embodiments the linkage may have any other suitable shape. End effector704L is coupled to the primary linkage703L through revolute joint707L, and constrained to point radially by band arrangement708L. The band arrangement708L includes a drive pulley711L that is fixedly coupled to ring701such that as ring701rotates the pulley711L rotates with it without any relative motion between the two. Driven pulley712L is fixedly coupled to the end effector704L such that as the end effector704L rotates the pulley712L rotates with it. The pulleys711L,712L are coupled together by band713L. The band arrangement and belt may be substantially similar to and operate in a substantially similar manner as band arrangement608inFIG. 23Aso that as the arm is extended the rotation of the end effector704L is slaved to the ring711L and remains substantially longitudinally aligned with a path P as the arm700L is extended and retracted. In alternate embodiments the end effector712L can be slaved to the ring711L in any suitable manner. Secondary linkage705L is coupled at one end to coaxial ring702and at the other opposite end to primary linkage703L through revolute joints709L and710L respectively.

Similarly, the right hand side arm700R includes a primary linkage703R, an end effector704R, a band arrangement708R and a secondary linkage705R. The primary linkage703R is coupled to coaxial ring701through revolute joint706R. End effector704R is coupled to the primary linkage703R through revolute joint707R, and constrained to point radially by band arrangement708R. The band arrangement708R includes a drive pulley711R fixedly coupled to ring701, a driven pulley712R fixedly coupled to end effector704R and a band713R coupling the pulleys711R,712R. The band arrangement708R may be substantially similar to band arrangement708L described above. Secondary linkage705R is coupled at one end to coaxial ring702and at the other opposite end to primary linkage703R through revolute joints709R and710R respectively.

In this embodiment, by way of example, when one of the arms700L or700R extends radially, the other arm700R or L rotates within a specified swing radius close to its retracted configuration. As may be realized, the arm700can be rotated as a unit by rotating coaxial rings701,702in the same direction at substantially the same rotational speed (e.g. clockwise rotation of rings701,702rotates the arms700L,700R in a clockwise direction about, for example, a center of rotation of the rings). One of the arms700L or700R may be extended by rotating, for example, ring701while ring702rotates a minimal amount. In alternate embodiments the ring702may remain substantially stationary or move any suitable amount to extend one of the arms. The arm700L,700R that is extended depends on the direction of rotation of ring701from the retracted or neutral position of the arms700R,700L. For example, in this exemplary embodiment, if both arms700R,700L are retracted and ring701is rotated clockwise, arm700L will be extended while arm700R is rotated in a substantially retracted configuration within a predetermined swing radius. If the ring701is rotated counterclockwise from the retracted position of the arms700R,700L, the arm700R will be extended while arm700L is rotated in a substantially retracted configuration within a predetermined swing radius.

Referring also toFIG. 27B, the radial extension of the left arm700L of the dual end effector arm with actuation rings driven, at least in part, by a triangular multi-linkage with substrate S thereon is depicted in phased form in six different positions along direction P. Beginning with the upper left diagram inFIG. 27B, for exemplary purposes only, the left and right arms700L,700R are shown in a substantially retracted configuration. In this example, to extend arm700L ring701is rotated in a clockwise direction (the direction of arrow A1) so that revolute joint travels along the circumference of ring701. The ring702may initially rotate counterclockwise (in the direction of arrow A2) such that the secondary linkage705L pulls on and rotates the primary linkage about revolute joint706L in a counterclockwise direction. The ring702may continue to rotate in a counterclockwise direction until the ring701can maintain the counterclockwise rotation of the primary linkage703L via its own rotation in the clockwise direction. Once the ring701is able to sufficiently rotate the primary linkage703L in the counterclockwise direction, the ring702may rotate clockwise (in the direction of arrow A3) to obtain a maximized extension of the arm700L. It is noted that secondary linkage705L constrains the primary linkage703L at revolute joint710L to effect, in part, the rotation of the primary linkage703L about revolute joint706L during extension and retraction of the arm700L. As described above, the rotation of the end effector704L is slaved to the ring701through and arrangement708L in a manner substantially similar to that described above with respect toFIGS. 23A and 23Bso that as the arm is extended the end effector704L remains substantially longitudinally aligned with the path of extension P.

Still referring toFIGS. 27A and 27Bthe rotation of arm700R in a substantially retracted configuration (during the extension of arm700L) will now be described. As the ring701rotates in the clockwise direction the revolute joint706R travels along the circumference of the ring701. As the revolute joint706R is moved along the circumference of ring701the primary linkage703R is constrained by secondary linkage705R such that the secondary linkage705R pulls on the primary linkage703R at revolute joint710R. The pulling action of the secondary linkage703R via the rotation of ring701(and ring702) causes rotation of the primary linkage703R about revolute joint706R in a clockwise direction such that there is little or no relative movement between the primary linkage703R and the ring701. Because there is little or substantially no relative movement between the primary linkage703R and the ring701slaved end effector704R of arm700R remains in a substantially retracted position while the arm is rotated (clockwise) substantially about a center of rotation of the rings701,702within a predetermined swing radius.

As described above, the direction of rotation of the rings701,702from the retracted position of the arms as shown in the upper left diagram inFIG. 27Bdetermines which arm is extended. As described above the simultaneous rotation of ring701in the direction A1and ring702in the direction of A2from the neutral position causes arm700L to extend. Conversely, the rotation of the rings701,702in the opposite manner from the neutral position causes the arm700R to extend. The extension of arm700R while arm700L is rotated in a substantially retracted position is effected in substantially the same manner as described above with respect to the extension of arm700L and rotation of arm700R. As such, the links shown inFIGS. 27A,27B are configured to transfer the extension motion from one arm to the other at the neutral or retracted position. For example, referring the lower right diagram ofFIG. 27B, the arm700L is shown in a substantially extended configuration. To retract the arm700L the ring701is rotated in the direction of A2(counterclockwise) and ring702is rotated in the direction of A1(clockwise). The retraction of arm700L, as can be seen inFIG. 27Boccurs in a substantially opposite manner than that described above with respect to the extension of the arm700L. When the arm700L is retracted to the neutral position the rings701,702may continue to rotate, such as during a fast substrate swap. During the continued rotation of the rings701,702in opposite directions, the links703L,705L,703R,705R cause a transfer of extension motion so that arm700R is extended while arm700L rotates in a substantially retracted configuration within the predetermined swing radius. As may be realized, the extension of arm700R while arm700L is rotated in a substantially retracted position is effected in substantially the same manner as described above with respect to the extension of arm700L and rotation of arm700R.

Referring now toFIG. 28A, a dual end effector arm arrangement720with actuation rings driven for example by a triangular multilinkage in a different geometric configuration with respect toFIGS. 27A-Bis illustrated. This geometric configuration results in substantially different kinematic characteristics of the mechanism. In this embodiment, the dual end effector arm arrangement720is connected to a pair of independently actuated coaxial rings721and722. The left hand side arm720L includes a primary linkage723L, an end effector724L and a secondary linkage725L. A substrate S is shown on the end effector724for exemplary purposes. The arrangement of the triangular linkage723L shown inFIG. 28Ais merely exemplary and alternate embodiments the linkage may have any other suitable shape. The primary linkage723L is coupled to one coaxial ring721through revolute joint726L. End effector724L is coupled to the primary linkage723L through revolute joint727L, and constrained to point radially by band arrangement728L. The band arrangement728L includes a drive pulley742L, a driven pulley741L and belt742L. The drive pulley740L may be fixedly coupled to ring721such that as ring721rotates the pulley742L rotates with it without any relative motion between the two. Driven pulley741L may be fixedly coupled to the end effector724L such that as the end effector724L rotates the pulley741L rotates with it. The pulleys740L,741L are coupled together by band742L. The band arrangement and belt may be substantially similar to and operate in a substantially similar manner as band arrangement608inFIG. 23Aso that as the arm is extended the rotation of the end effector724L is slaved to the ring721L and remains substantially longitudinally aligned with a path P as the arm720L is extended and retracted. In alternate embodiments the end effector724L can be slaved to the ring721in any suitable manner. Secondary linkage725L is coupled at one end to the other coaxial ring722through revolute joint729L and at the other opposite end to the primary linkage723L through revolute joint730L.

Similarly, the right hand side arm720R includes a primary linkage723R, an end effector724R and a secondary linkage725R. The primary linkage723R is coupled to coaxial ring721through revolute joint726R. End effector724R is coupled to the primary linkage723R through revolute joint727R, and constrained to point radially by band arrangement728R. The band arrangement728R includes a drive pulley740R fixedly coupled to ring721, a driven pulley741R fixedly coupled to end effector724R and a band742R coupling the pulleys740R,741R. The band arrangement728R may be substantially similar to band arrangement728L described above. Secondary linkage725R is coupled at one end to coaxial ring722through revolute joint729R and coupled at the other opposite end to primary linkage723R through revolute joint730R.

In this embodiment, by way of example, when one of the arms720L or720R extends radially, the other arm720R or720L rotates within a specified swing radius in substantially its folded or retracted configuration. Referring now toFIG. 28B, the radial extension of the left arm720L of the dual end effector arm with actuation rings driven by a triangular multilinkage with substrate S thereon is depicted in phased form in six different positions along direction P. In this exemplary embodiment the dual arm assembly720can be rotated as a unit (i.e. bot arm rotate substantially about a center of rotation of the rings721,722) by rotating both coaxial rings simultaneously in the same direction by equal amounts. One of the arms720R,720L can be extended by rotating the rings721,722in the same direction by unequal amounts. As may be realized the direction of rotation of the rings721,722may determine which arm is extended as will be described in greater detail below.

In this example, the radial extension of arm720R in the P direction will be described. Starting with the diagram in the upper left corner ofFIG. 28Bfor exemplary purposes only, the arms720L,720R can be seen in, for example, a substantially retracted or neutral position. In this example, to extend arm720R the rings721,722are rotated counterclockwise by unequal amounts. As can be seen inFIG. 28Bring722rotates through a larger angle than ring721to extend arm720R. In alternate embodiments, the arms may be configured so that ring721is rotated a greater distance than ring722to extend arm720R. As the rings721,722are rotated in the same direction by unequal amounts revolute joint726R travels along the circumference of ring721thereby moving the primary link723R in the direction of extension. Also, the greater rotational speed of ring722causes the secondary link725R to push on the primary link723R at revolute joint730R. The pushing force exerted on the primary link723R by secondary link725R causes the primary link723R to rotate about revolute joint726R in a clockwise direction further extending the primary link723R. As described above, band arrangement constrains the movement of the end effector such that as the primary link723R is rotated about revolute joint726R, the end effector724R remains longitudinally aligned with the path of travel P to pick or place the substrate S at a predetermined location.

As can be seen inFIG. 28B, as the arm720R is extended the arm720L rotates within a specified swing radius substantially in its retracted configuration. As the ring721rotates in the counterclockwise direction the revolute joint726L travels around the circumference of the ring721. The faster rotation rate of ring722causes secondary link725L to slightly pull on the primary link723L at revolute joint730L. The pulling force provided by the secondary link725L causes the primary link to rotate about revolute joint726L in a clockwise direction. As can be seen inFIG. 28Bthe configuration of the primary and secondary links723L,725L are such that the rotation of the primary link723L is minimized so that the arm720L rotates about the center of the rings721,722in a substantially retracted configuration within a predetermined swing radius.

As described above, the direction of rotation of the rings from the retracted position of the arms as shown in the upper left diagram inFIG. 28Bdetermines which arm is extended. As described above the counterclockwise rotation of the rings721,722from the neutral position causes arm720R to extend. Conversely, the rotation of the rings721,722in the clockwise direction from the neutral position causes the arm720L to extend. The extension of arm720L while arm720R is rotated in a substantially retracted position is effected in substantially the same manner as described above with respect to the extension of arm720R and rotation of arm720L. As such, the links shown inFIGS. 28A,28B are configured to transfer the extension motion from one arm to the other at the neutral position. For example, referring the lower right diagram ofFIG. 28B, the arm720R is shown in a substantially extended configuration. To retract the arm720R the rings721,722are rotated in a clockwise direction by unequal amounts. The retraction of arm720R, as can be seen inFIG. 28Boccurs in a substantially opposite manner than that described above with respect to the extension of the arm720R. When the arm720R is retracted to the neutral position the rings721,722may continue to rotate in the clockwise direction, such as during a fast substrate swap. This during the continued rotation of the rings721,722in the clockwise direction, the links723R,725R,723L,725L cause a transfer of extension motion so that arm720L is extended while arm720R rotates in a substantially retracted configuration within the predetermined swing radius.

The single and dual end effector arms described above and depicted inFIGS. 23A-28Bmay have alternative configurations. For example, each of the end effector arms, which are depicted in their left hand configurations, may be alternatively depicted and described in their right hand version. Alternatively, the pair of independently actuated coaxial rings, which are exposed at the circumference of the chamber to carry the arms, may have different diameters and rotate in the horizontal plane as shown inFIGS. 23A-28B. Alternatively, the pair of independently actuated coaxial rings may have the same diameters and operate on top of each other in two parallel horizontal planes as opposed to being concentric with one another.

Referring now toFIGS. 29A-29Da schematic illustration of a substrate transport apparatus3800is shown in accordance with an exemplary embodiment. The transport3800has a radius arm configuration (e.g. the upper arm portions of each of the arms rotate about an axis as a unit) and includes a manipulator having independently moveable arms3801,3802that are coupled to a mechanical switch mechanism to allow the two or more arms to have combined rotational and independent pick/place motion (e.g. each arm has two or more degrees of freedom with at least one degree of freedom of each arm substantially independent of the degrees of freedom of the other arms) with as few as two independently controllable motors as will be described in greater detail below.

The mechanical motion switch may be integrated into and/or housed by any suitable portion or portions of the transport3800such as, for example, the upper arm3810of the transport. At least a portion of the mechanical motion switch and/or a portion of the arms may be located within a housing suitably configured to prevent particles generated by moving parts of the substrate transport3800from contaminating the substrates S1, S2. For example slots may be provided in the housing for the arms3801,3802to pass where any openings between the slots and the arms3801,3802are sealed with a flexible seal. In alternate embodiments, the housing may have any suitable configuration to prevent substrate contamination from particulate that may be generated from moving parts of the transport3800. In still other alternate embodiments the transport3800may include a suitable vacuum system for collecting any particulate created by the movement of the transport3800. In other alternate embodiments, the mechanical motion switch may not be within a housing. It is noted that while the transport3800is shown in the Figures as having two arms, in alternate embodiments the transport3800may have more than two arms.

In one exemplary embodiment the transport apparatus3800includes a drive section3806(FIG. 30A) including two drive motors for driving a respective one of drive axes T1, T2. Examples of suitable drive sections3806include, but are not limited to, those described herein such as, for example, those described above with respect toFIGS. 3-8and10. In alternate embodiments, the transport can have any suitable drive section with more or less than two drive axes/motors and can be adapted to any suitable lost motion drive mechanism or mechanical motion switch.

As will be described in greater detail below, rotation of drive axes T1, T2in the same direction and at substantially the same speed results in rotation of the transport3800as a unit (e.g. both arms3801,3802rotate together for changing a direction of extension and retraction of the arms) about a central axis of rotation3805. Rotation of the drive axes T1, T2in opposite directions results in the extension or retraction of one of the arms3801,3802of the transport3800while the other one of the arms3801,3802rotates about axis3805in a substantially retracted configuration as can be seen inFIGS. 29B and 29C. Having only two drive axes T1, T2for effecting both the extension/retraction of the arms3801,3802as well as rotation of the transport3800as a unit may reduce costs associated with the transport in addition to increasing the reliability of the transport. For example, having only two drive axes T1, T2allows the number of drive motors, encoders and motor controls to be minimized. In alternate embodiments the transport apparatus3800may have more or less than two drive axes and any suitable number of encoders and/or motor controls.

As noted above, as few as two independently controllable motors may be used for driving axes T1, T2of the transport apparatus3800. In one embodiment, the motors may have any suitable configuration including, but not limited to, coaxial or side-by-side arrangements. Examples of suitable coaxial motor configurations can be found in U.S. Pat. Nos. 5,720,590, 5,899,658, 5,813,823, and 6,485,250 and/or Patent Publication Number 2003/0223853 the disclosures of which are incorporated by reference herein in their entirety. In another embodiment, the transport apparatus may have a shaftless coaxial drive system where the drive motors are integrated into the walls of, for example, a transport or vacuum chamber as described above with respect to FIGS.3A and4A-4D. For example, the stators of the T1, T2drive axes may be generally linearly distributed such as in a generally arcuate manner substantially around and proximate the periphery of the transport chamber3900. The diameter of the motors corresponding to the T1, T2drive axes may be maximized relative to the space envelope of the transport chamber3900, which as may be realized may be minimized to the space envelope circumscribing the clearances for the motions of the arms3801,3802and substrates S1, S2on one or more end effector(s) of the arms. As may be realized, in the exemplary embodiment, the T1(or T2) drive axis, for example, operates to impart a force on the arms3801,3802that is eccentric to the shoulder axis of rotation (e.g. revolute joint3805) hence, by way of example the T1drive axis output imparts a leverage force in the arms3801,3802that pivots the arms about a fulcrum defined for example by shoulder joint3805. Integrating the drive system in the walls of, for example, the transport or vacuum chambers allows, for example, the integration of vacuum system or other components (e.g. vacuum pumps, gauges, valves, etc.) to the bottom of the chamber.

As may be realized the drive of the transport apparatus3800may be a combination of the shaft driven and shaftless drive systems described above. As may also be realized, in one exemplary embodiment the drive motors may be coaxial with their respective drive axis T1, T2. In other exemplary embodiments the drive motors can be offset from their respective drive axis T1, T2where a drive system (e.g. gears, belts and pulleys or other suitable drive members) transfer motor torque to the respective drive axis T1, T2.

Referring also toFIGS. 30A and 30B, each arm3801,3802of the transport3800includes an upper arm portion3810L,3810R, a forearm portion3811L,3811R and a substrate support portion or end effector3812L,3812R. In alternate embodiments, the arms may have more or fewer articulations. In this example the end effectors3812L,3812R are shown as forked shaped end effectors for transporting substrates of any size, and shape such as a 200 mm, 300 mm, 450 mm or larger semiconductor wafer, a reticle or pellicle or panel for flat screen displays. In alternate embodiments the end effector may be of an alternative shape including, but not limited to, paddle shaped. While each arm is shown having one end effector for example purposes only, in alternate embodiments each of the arms may have any number of end effectors that may be arranged, for example, side by side or stacked one above the other. In this exemplary embodiment the upper arm portions3810L,3810R are pivotally joined to the drive section3806at a shoulder joint3820located at the central axis of rotation3805. In alternate embodiments the shoulder3820may be positioned off center (e.g. closer to a processing station) from rotational axis3805of the substrate transport3800enabling a Semiconductor Equipment and Materials International (SEMI) specified reach with arms that are smaller than conventional arms.

In this exemplary embodiment the upper arm portions3810L,3810R form a substantially rigid upper arm member3810. In one embodiment the upper arm3810may have a substantially V-shaped or boomerang shaped profile as can be seen best inFIG. 29B. In alternate embodiments, the upper arm portions3810L,3810R may form any suitable shape including, but not limited to, U-shapes and rectangular shapes. The dimensions of the upper arm portions3810L,3810R and the angle α (FIG. 30B) formed by the upper arm portions3810L,3810R may be any suitable dimensions and angle that allow the arms3801,3802to compactly fit within a transport chamber3900(FIG. 29) while providing a maximized reach or extension of the arm (e.g. the extension to containment ratio of the arm is maximized). In other exemplary embodiments the upper arm portions and their respective arms may form a double SCARA arm arrangement as will be described below. As can be seen best inFIG. 30Bthe upper arm3810is pivotally coupled to drive axis T2at axis3805so that as the drive axis T2rotates the upper arm3810rotates with it. The drive axis coupling between the upper arm3810and the drive axis T2is located at any suitable point along the arm3810between the elbow joints3821L,3821R. As can be seen inFIG. 30Bthe elbow joints3821L,3821R are located substantially at opposite ends of the arm3810. As noted above in this exemplary embodiment, the upper arm3810and the drive axis are joined at the shoulder joint3820for rotation about the axis3805. In alternate embodiments the elbow joints3821L,3821R can be located at any suitable point(s) on the upper arm3810.

In one exemplary embodiment, the upper arm member3810may be of a unitary construction (e.g. portions3810L,3810R are formed in a one-piece construction) so the elbow joints3821L,3821R are spatially fixed with respect to one another. In other exemplary embodiments the upper arm portions3810L,3810R may be separate links that are fixedly joined together using any suitable fasteners (e.g. welding, brazing, screws, adhesives, or any other suitable mechanical or chemical fastener) so that they rotate about the center of rotation3805as a unit. In still other embodiments the upper arm links3810L,3810R may be adjustably joined so the angle α is adjustable as described in greater detail in U.S. patent application Ser. No. 11/148,871, entitled “Dual Scara Arm” and filed on Jun. 9, 2005, the disclosure of which is incorporated by reference herein in its entirety. For example, the angle α may be adjusted by rotating one arm link3810L,3810R relative to the other arm link3810L,3810R about shoulder joint3820, where when a predetermined angle α is reached the arm links3810L,3810R can be suitably locked together so they rotate as a unit about the shoulder3820. In this example, the upper arm member3810is rotated about axis3805by a drive section motor corresponding to, for example, drive axis T2.

The forearm3811L is pivotally coupled at elbow joint3821L to upper arm portion3810L while forearm3811R is pivotally coupled at elbow joint3821R to upper arm portion3810R. The end effector3812L is pivotally coupled at a wrist joint3822L to forearm3811L and end effector3812R is pivotally coupled at wrist joint3822R to forearm3811R. Each of the end effectors3812L,3812R has a longitudinal axis running from the front of the end effector (the end distal from the wrist3822L,3822R) to the back of the end effector (the end proximate to the wrist3822L,3822R). In one exemplary embodiment, each arm3801,3802may include an end effector coupling or drive system for driving its respective end effector3812L,3812R. The end effector coupling system may be any suitable coupling system. For example, the end effector coupling system may be a slaved system so that the rotation of the end effectors3812L,3812R about a respective wrist3822L,3822R depends, at least in part, on rotation of their respective upper arm portions3810L,3810R in a manner substantially similar to that described above with respect to, for example,FIGS. 9A-9D.

For exemplary purposes only, referring toFIGS. 31A-31C, the slaved configuration of the end effector coupling system will be described. It is noted that the arms3801,3802are shown inFIGS. 31A-31Cas having separate upper arms for exemplary purposes only. In the exemplary embodiment shown, the arms3801,3802may include a belt and pulley system for driving the end effectors3812L,3812R. The belt and pulley system includes belts4555L,4555R and pulleys4550L,4550R,4565L,4565R. The pulleys4550L,4550R may be fixedly mounted to a respective upper arm portion3810L,3810R about elbow joints3821L,3821R. As the upper arm3810is rotated about axis3805and the forearms3811L,3811R are rotated about their respective elbow joint3821L,3821R (depending on which arm is being extended) the pulley4550L,4550R drivingly rotates a respective pulley4565L,4565R via the belt4555L,4555R for driving the end effector3812L,3812R so that the radial orientation or longitudinal axis of the end effector3812L,3812R along the common path of travel P1is maintained as each of the arms3801,3802are extended and retracted.

The pulleys4565L,4565R may be rotatably coupled to their respective forearms3811L,3811R while being fixedly coupled to their respective end effectors3812L,3812R about wrist joints3822L,3822R. In this example the ratio of pulleys4550L,4550R to pulleys4565L,4565R may be a 1:2 ratio so that as the forearms3811L,3811R rotate their respective end effector rotates in an opposite direction by a predetermined amount. In alternate embodiments the pulleys may have any suitable ratio for obtaining any suitable rotational characteristics of the end effectors relative to the forearm and/or upper arm. For exemplary purposes only, the end effector rotation about the wrist joint may be equal and opposite to the rotation of the forearm about the elbow joint. In alternate embodiments the forearms and end effectors may have any suitable rotational relationship(s). As can be seen inFIGS. 31A-31C, pulleys4550L,4550R are mounted about elbow joints3821L,3821R so that when the forearms3811L,3811R are rotated the pulleys4550L,4550R remain stationary with respect to their respective upper arm portions3810L,3810R. Any suitable belt4555L,4555R may connect a respective pair of the pulleys so that as the forearms2811L,2811R are rotated the pulleys4565L,4565R are drivingly rotated. In alternate embodiments, the pulleys may be connected by one or more metal bands that may be pinned or otherwise fixed to the pulleys. In other alternate embodiments, any suitable flexible band may connect the pulleys. In still other alternate embodiments, the pulleys may be connected in any suitable manner or any other suitable transmission system may be used.

The end effectors3812L,3812R may be coupled to a respective forearm at revolute joint3822L,3822R. The end effectors3812L,3812R may be drivingly coupled to a respective one of the pulleys4565L,4565R so that as one of the arms3801,3802is extended or retracted the respective end effector3812L,3812R stays longitudinally aligned with the common path of travel P1as can be seen in, for example,FIGS. 31B,31C while the other arm remains in a substantially retracted configuration as will be described in greater detail below. It may be realized that the belt and pulley systems described herein may be housed within the arm assemblies3801,3802so that any particles generated may be contained within the arm assemblies. A suitable ventilation/vacuum system may also be employed within the arm assemblies to further prevent particles from contaminating the substrates. In alternate embodiments, the synchronization systems may be located outside of the arm assemblies. In other alternate embodiments, the synchronization systems may be in any suitable location.

As may be realized, in the exemplary embodiment the end effectors3812L,3812R may travel along a common path of travel P1and be configured in such a way so as to be in different planes along the path of travel P1. In alternate embodiments, the arms3801,3802may be configured to be at different heights so that the end effectors can travel along the common path P1. In other alternate embodiments, the transport may have any suitable configuration for allowing multiple end effectors to travel along a common path of travel. In yet other alternate embodiments, the end effectors may travel along different paths that may be generally parallel or angled relative to each other. The paths may be located in the same plane. The illustrated motions of the linkages of the coupling system are merely exemplary and in alternate embodiments the linkages may be arranged to provide and undergo any desired range of motion switching from driving the arms independently of each other.

As noted above the arm drive section includes a mechanical motion switch that allows each of the arms3801,3802to be extended and retracted while using a minimum number of drive axes T1, T2. It is noted that while the disclosed embodiments are described herein with respect to a coaxial drive system (i.e. center of rotation of T1and T2are substantially in line with each other), in alternate embodiments the drive axes T1, T2may be located side by side or in any other suitable spatial configuration. It is noted that the drive motors for axes T1and T2may also be located coaxially or side by side and connected to drive axes T1, T2in any suitable manner. For example, drive axis T2may be located about the central axis of rotation3805while drive axis T1is located at axis of rotation3940(FIG. 32B). The rotation of the drive links T1A, T1B can be achieved when the drive axis T1is located at axis of rotation3940through suitable gearing, cams and/or belt and pulley systems so that the links T1A, T1B rotate as described herein using a single drive motor.

Referring to FIGS.29D and32A-32D, an exemplary mechanical motion switch will be described. In the exemplary embodiment shown inFIGS. 32A-32Dthe mechanical switch includes first drive links T1A, T1B, second drive links3910,3911and connecting links3920,3921. In alternate embodiments, the mechanical switch may include any suitable number of links coupled to each other and/or to the transport arms in any suitable manner and/or configuration.

The first drive links T1A, T1B may be connected to drive axis T1as will be described below. A first end of each of the drive links T1A, T1B may be pivotally connected to rotational axis3940in any suitable manner such that the links T1A, T1B are pivotable about axis3940. In this exemplary embodiment the axis3940may be offset by any suitable distance D from the center of rotation3805of the transport3800. In this example, the axis3940may lie substantially along the path of travel P1. In alternate embodiments the axis3940of the mechanical switch may not lie along the path of travel P1. In other alternate embodiments the mechanical switch may be configured so that the links T1A, T1B pivot about any suitable axis including, but not limited to axis3805. The axis3940may be located on, for example, a base of the transport3800such that the axis remains rotationally fixed or stationary with respect to the axis3805as the arms3801,3802are extended and retracted while at the same time being able to rotate about axis3805when the transport3800is rotated as a unit in the direction of arrow R.

As noted above, the mechanical switch may also include second drive links3910,3911. A first end of the drive link3910may be pivotally coupled to drive link T1B at revolute coupling3931. A first end of the drive link3911may be pivotally coupled to drive link T1A at revolute coupling3930. A second end of each of the drive links3910,3911may be pivotally coupled to drive axis T1in any suitable manner. For example in one exemplary embodiment, the drive links3910,3911may be pivotally coupled to a drive platform that may have any suitable shape and configuration. For exemplary purposes the drive platform is shown as a disk shaped member3960inFIG. 32Band as a triangular shaped member3960′ inFIG. 29Dthat is coupled to drive axis T1. In alternate embodiments the drive links3910,3911may be coupled to the drive axis through any suitably shaped member for transferring torque generated by the drive axis T1to the second ends of the drive links3910,3911such that the second ends rotate about axis3805. It is noted that the drive links T1A, T1B,3910,3911can have any suitable dimensions (e.g. length, cross section, etc.) for effecting the movement of the arms3801,3802as described herein. As can be seen in, for example,FIGS. 32B and 32Dthe second drive links3910,3911are arranged so that the drive links3910,3911cross one another. This crossed configuration, depending on the direction of rotation of drive axes T1, T2, may allow one of the drive links3910,3911to push on a respective one of drive links T1A, T1B while the other one of the drive links3910,3911rotates without imparting any substantial movement onto the other one of the respective drive links T1A, T1B as will be described in greater detail below. In alternate embodiments, the drive links3910,3911may have any other suitable configuration and spatial relationship.

The drive links T1A,3911, may be suitably connected to any suitable part of the arm3801in any suitable manner. In one exemplary embodiment, a connecting link3921may be pivotally joined at a first end to, for example, revolute joint3930while being pivotally joined at its second end to forearm3811L as can be seen inFIG. 32D. Similarly drive links T1B,3911may be connected to arm3802through connecting link3920. Connecting link3920may be pivotally joined at a first end to, for example, revolute joint3931while being pivotally joined at its second end to forearm3811R. It is noted that the connections between the drive links T1A,3910and T1B,3911and their respective arms3801,3802shown in the figures is merely exemplary in nature and that any suitable connecting links having any suitable shapes and sizes can be used. In alternate embodiments one or more the drive links T1A, T1B,3910,3911may be connected to their respective arms in any suitable manner, such as by belts and pulleys.

Referring toFIGS. 29E and 29Fanother exemplary mechanical motion switch will be described. In this example, the switch may be enclosed within the upper arm or housing3810. The mechanical motion switch includes a drive platform3960″ coupled to the drive axis T1and drive links3910′,3911′. Drive link3910′ may be rotatably coupled at a first end to a first end of the drive platform at revolute joint3965. A second end of the drive link3910′ may be connected to forearm drive pulley3970R in any suitable manner. For example, as can be seen inFIG. 29Fthe drive pulley3970R may include an arm3970RA that extends from the pulley such that drive link3910′ is coupled to the arm at revolute joint3966. Drive link3911′ may be rotatably coupled at a first end to a first end of the drive platform at revolute joint3967. A second end of the drive link3911′ may be connected to forearm drive pulley3970L in any suitable manner. For example, as can be seen inFIG. 29Fthe drive pulley3970L may also include an arm3970LA that extends from the pulley such that drive link3911′ is coupled to the arm at revolute joint3968. The forearm drive pulleys3970R,3970L may be rotatably supported within the upper arm3810in any suitable manner such as by bearings3980A,3980B about a respective axis CL1, CL2. The forearm drive pulleys3970R,3970L may be coupled to respective forearm pulleys3971R,3971L by belts/bands3981,3982for driving the rotation of the forearms3811R,3811L. In alternate embodiments the pulleys3970R,3971R and3970L,3971L may be coupled in any suitable manner for driving the forearms.

Referring toFIG. 29Ganother exemplary mechanical motion switch is shown. In this example, the motion switch is substantially similar to that described above with respect toFIG. 29Fbut in this embodiment the forearm pulleys3970R,3970L are coupled directly to their respective forearms3811R,3811L through connecting members3990R,3990L. As can also be seen inFIG. 29Gend effector pulleys3995R,3995L are connected to the upper arm2810for slavingly driving the end effectors as described above.

Referring now toFIGS. 32A-36Dthe operation of the transport3800will be described. As noted above, rotation of drive axes T1and T2in the same direction and at the same speed results in the transport3800rotating either clockwise or counter-clockwise as a unit about axis3805in the direction of arrow R. Rotating the drive axes T1, T2in opposite directions as can be seen inFIG. 33Aextends one of the two arms3801,3802. For example, the disclosed embodiments will be described with the extension of arm3801where T1rotates counter-clockwise and T2rotates clockwise. As may be realized, arm3802can be extended in a manner substantially similar to that described below where T2rotates counter-clockwise and T1rotates clockwise.

In the exemplary embodiments, T2rotates in the direction of arrow R2to correspondingly rotate the upper arm member3810about axis3805. At the same time T1rotates in the direction of arrow R1so that the second ends of drive links3910,3911rotate about axis3805. As can be seen when comparingFIGS. 32B and 33Bwhen T1rotates the drive links T1A, T1B,3910,3911are arranged such that drive link3911pushes on arm link T1A to rotate link T1A counter-clockwise about axis3940. It is noted that during rotation of T1in the direction R1, the drive links are further arranged so that drive link3910rotates about revolute joint3931so that link T1B remains substantially rotationally fixed with respect axis3940as can be seen when comparingFIGS. 32C,33C,34C,35C and36C. It is noted that two links (e.g. links T1B and3920) of the three-link configuration formed by, for example, drive links T1B,3910and connecting link3920may at least partially constrain revolute joint3931to allow the drive link3910to rotate without imparting any substantial motion to links T1B and/or3920.

FIGS. 32C,33C,34C,35C and36C graphically illustrate the angular rotation of the drive links T1A, T1B about axis3940with respect to the angular rotation of the drive axes T1, T2. As can be seen inFIGS. 32C,33C,34C,35C and36C the angular rotation of T1A and T1B is shown along the vertical axis of the graph and the angular rotation of T1is shown along the horizontal axis. It is noted that the graph ofFIGS. 32C,33C,34C,35C and36C is a “split” graph where values to the left of zero on the horizontal axis correspond to rotation of link T1A and the values to the right of zero correspond to the rotation of link T1B. The angular rotation of T1and the links T1A, T1B may be measured from the position of T1, T1A, T1B when in the retracted position shown inFIGS. 32A and 32B. As the rotational angle of T1increases (in the negative or counter-clockwise direction), the rotational angle of T1A also increases in the same direction. The rotational angle of T1B remains substantially zero as the rotational angle of T1increases in the counter-clockwise direction as can be seen best when comparingFIGS. 32C,33C,34C,35C and36C.

Referring now toFIGS. 33A-D, the forearm3811L is drivingly constrained by connecting link3921to links3911, T1A as described above. As drive link3911pushes on drive link T1A, connecting link3921is caused to pull on forearm3811L, which in turn causes forearm3811L to rotate about the elbow joint3821L. Connecting link3921continues to pull on forearm3811L by virtue of the combined rotation of drive axes T1and T2until the forearm3811L crosses over the upper arm portion3810L, at which point the connecting link3921starts to push on the forearm3811L as can be seen inFIGS. 34A-D. Drive axes T1, T2continue to rotate in opposite directions R1, R2respectively as can be seen inFIGS. 35A-Dand36A-D until the arm3801is extended such that the end effector3812L is positioned at a predetermined location for picking or placing the substrate S2. As may be realized, because the end effector3812L is slaved to the upper arm3810as described above, rotation of the upper arm3810in the direction R2and the rotation of the forearm3811L in an opposite counterclockwise direction causes the arm to extend while the end effector3812L remains longitudinally aligned with the path of travel X1. For example, as the upper arm3810rotates clockwise in the direction of R2and forearm3811L rotates counterclockwise in the direction of R1, the pulley4550L (which is fixedly connected to upper arm3810) is seen as rotating clockwise with respect to the forearm3811L. Pulley4550L drivingly rotates pulley4565L in a clockwise direction so that rotation of the end effector3812L is substantially equal and opposite to the rotation of the forearm3811L and the end effector remains longitudinally aligned with the path X1during extension (and retraction).

Still referring toFIGS. 32A-36D, as the arm3801is extended the arm3802remains substantially retracted and is rotated about axis3805. As described above, as the drive axis T1rotates in the direction of arrow R1the second end of drive link3910is caused to rotate in the same direction. In this exemplary embodiment, as can be seen in for exampleFIG. 32D, the drive link T1B is coupled to the forearm3811R through connecting link3920. This coupling between the forearm3811R and link T1B formed by the connecting link3920may constrain revolute coupling3931so that the drive link3910rotates about the revolute coupling3931without substantially causing movement of the drive link T1B or revolute coupling3931. As can be seen best inFIGS. 32D,33D,34D,35D and36D the links T1B,3910,3920are configured such that the revolute coupling3931is located proximate the axis of rotation3805of the upper arm3810during the extension of arm3801. Having the revolute coupling3931proximate the axis of rotation3805allows the arm3802to rotate about axis3805without any substantial retraction or extension movement as the arm3801extends and retracts.

To effect extension of the second arm3802the first arm3801may be retracted in a manner substantially opposite to that described above with respect to the extension of the arm3801. As the arm3801is retracted to a predetermined extent or position (e.g. the neutral position shown inFIGS. 29A,30A and32A) the mechanical switch switches motion of the drive system to arm3802so that the arm3802is extended while the arm3801remains in a substantially retracted configuration. The extension of arm3802occurs in a manner substantially similar to that described above with respect to arm3801. As may be realized, the mechanical motion switch operates when the rotational angle of T1passes substantially through zero degrees as can best be seen inFIG. 37.FIG. 37illustrates the angular rotation of the links T1A, T1B versus the angular rotation of T1when the arms3801,3802are extended. It is noted that inFIG. 37the value of the angular rotation of the links T1A, T1B is shown on the graph as a positive number when the arms3801,3802are extended regardless of whether the rotation of the link T1A, T1B is clockwise or counter-clockwise.

Referring now toFIGS. 38A-38E, another exemplary embodiment of a transport3800′ will be described. The transport3800′ in this example may be substantially similar to the transport3800described above with respect toFIGS. 29A-37except as otherwise noted. In this example transport3800′ has a double SCARA arm arrangement such that the upper arms3810R′,3810L′ of each arm are independently rotatable. The mechanical motion switch of the arm3800′ may be substantially similar to the switch described above with respect to transport3800in that the switch includes a includes a drive platform substantially similar to platform3960,3960′ described above that is connected to, for example drive axis T1. Drive links3910,3911are rotatably coupled to the drive platform at a first end and are rotatably coupled to a respective connecting link (not shown in the figures for clarity). In one embodiment the connecting link may be joined to a respective one of the upper arms3810R′,3810L′. In alternate embodiments the connecting links may be rotatably or movably joined to a respective upper arm. The connecting links directly couple a second end of each of the drive links3910,3911to a respective one of the upper arms3810R′,3810l′. As may be realized the connecting links may be rotatably or fixedly coupled to the respective upper arms at any suitable location. In alternate embodiments the connecting links may be of unitary construction with their respective upper arm. In other alternate embodiments, the mechanical switch may include any suitable number of links coupled to each other and/or to the transport arms in any suitable manner and/or configuration.

As can be seen inFIGS. 38A-38C, as drive axis T1rotates the drive platform in a counterclockwise direction such that drive platform causes the first end of the drive links3910,3911to travel in an arcuate path in the counterclockwise direction along with the drive platform. Drive link3911causes its connecting link to push on upper arm3810R′ causing the upper arm3910R′ to also rotate in the counterclockwise direction. In this example, the arm links may be slaved as described above so that as the upper arm3910R′ rotates counterclockwise, the forearm3811R′ rotates clockwise and a longitudinal axis of end effector3812R′ remains along the path of extension and retraction of the arm3801′. As can also be seen inFIGS. 38A-38C, as drive axis T1rotates counterclockwise, the drive link3910rotates such that its second end3910E remains substantially stationary so that arm3802′ remains is a substantially retracted configuration while arm3801′ extends to pick/place a substrate at point3870. As may be realized the retraction of the arm3801′ may occur in a substantially opposite manner to that described above with respect to the extension of the arm3801′. As can be seen inFIGS. 38D and 38E, the arm3802′ is extended by, for example, rotating drive axis T1in a clockwise direction such that drive platform causes the first end of the drive links3910,3911to travel in an arcuate path in the clockwise direction along with the drive platform. Here the drive link3910causes its connecting link to push on upper arm3810L′ for rotating the upper arm3810′ in a clockwise direction. As described above, the links of arm3802′ may be slaved so that the forearm3811L′ rotates counterclockwise and a longitudinal axis of end effector3812L′ remains along a path of extension and retraction. As can also be seen inFIGS. 38D and 38E, as drive axis T1rotates clockwise, the drive link3910rotates such that its second end3910E remains substantially stationary so that arm3801′ remains is a substantially retracted configuration while arm3802′ extends to pick/place a substrate at point3870. As may be realized the retraction of the arm3802′ may occur in a substantially opposite manner to that described above with respect to the extension of the arm3802′.

Referring now toFIG. 39another exemplary transport apparatus4000having a radius arm configuration and incorporating a mechanical motion switch will be described. In this exemplary embodiment the transport apparatus includes a side-by-side drive pulley arrangement which may result in a reduced or minimized height/thickness of the transport apparatus arm and shorter or minimized length belts/bands that drive the arm links of the transport apparatus. The minimized size of the arm and minimized length belts may provide for a corresponding reduction in the depth/volume of a vacuum/transport chamber in which the arm may be located and improved or maximized control, performance and speed of the arm due to, for example, improved structural properties of the transport apparatus.

In this example, the transport apparatus includes a housing or upper arm section4001. The upper arm section4001may have any suitable configuration and size and is shown in the figures as housing the mechanical switch4005. In alternate embodiments the upper arm section4001may not house the mechanical switch4005or house only a portion of the mechanical switch4005. The upper arm section4001is also configured to support one or more transport arms4055A,4055B. In alternate embodiments the arms4055A,4055B may be supported in any suitable manner such as by, for example, an arm support that is separate from but connected to the housing4000. Here there are two transport arms4055A,4055B shown but in alternate embodiments the transport apparatus4000may include any suitable number of transport arms. The upper arm section4001may be an assembly including a top and bottom (the bottom of which is shown inFIG. 39. In alternate embodiments the housing may have any suitable components and/or features (covers, doors, etc.) for allowing the assembly of the transport4000and access to the components of the transport4000that are located within the upper arm section4001, such as, for example, the components of the mechanical switch4005.

In this exemplary embodiment the transport apparatus4000may include any suitable drive section (not shown) such as, for example, the drive sections described above with respect toFIGS. 3-8and10. In one exemplary embodiment the drive section may be a coaxial drive section with, for example, two drive axes T1, T2. In alternate embodiments the drive section may have more or less than two drive axes. In other exemplary embodiments the drive section may also include a Z-axis drive for adjusting a height of the transport relative to, for example, substrate processing stations, load locks, or other substrate holding areas/apparatus that the transport apparatus4000serves. In this example the drive axis T1may be coupled to the housing and drive axis T2may be coupled to the mechanical motion switch4005for rotating the transport apparatus4000and arms as a unit and/or for extending and retracting the arms4055A,4055B as will be described in greater detail below.

As can be seen in FIGS.39and40A-C, each the arms4055A,4055B includes a forearm4055L,4055R that is rotatably coupled to the upper arm section4001at one end via a respective shoulder joint4055SR,4055SL and rotatably coupled to a respective end effector4056L,4056R at the other opposite end at a respective wrist joint4055W. It is noted that the distance LH between drive axis T2and the shoulder joint4055S is substantially equal to the length LA of the upper arm4055R,4055L from joint center to joint center (e.g. from the center of the shoulder joint to the center of the wrist joint)(see alsoFIG. 43C). In alternate embodiments the lengths LH, LA may be unequal and have any suitable lengths. The end effectors4056L,4056R may be slaved to the upper arm section4001so that a longitudinal axis of end effector4056L,4056R substantially follows a path of extension and retraction of its respective arm4055A,4055B. In alternate embodiments the end effectors may not be slaved to the upper arm section4001and may be rotatably driven in any suitable manner. The forearms4055L,4055R may be fixedly coupled to a respective pulley4051L,4051R for driving the forearms4055L,4055R as will be described below.

In the exemplary embodiments shown in FIGS.39and40A-C the mechanical motion switch4005includes a pivoting platform4021, two connecting links4022L,4022R and two drive links4023L,4023R. The pivoting platform4021is coupled to, for example, drive axis T2of the drive section in any suitable manner including, but not limited to a direct coupling or a transmission coupling such as through a pulley system. The pivoting platform4021may have any suitable shape and is shown in the figures for exemplary purposes only as having a boomerang or substantially V-shaped configuration. In alternate embodiments the platform4021may have a substantially straight elongated shape, triangular shape, circular shape or any other shape suitable for causing the extension and retraction of the transport arms as described herein. In this example, the platform4021includes a first portion or side that extends away from its axis of rotation CL (which may be same as drive axis T2) in a first direction and a second portion or side that extends away from axis of rotation CL in a second direction that is different than the first direction. The first end of connecting link4022L is rotatably coupled to the first portion at revolute joint4010. A second end of connecting link4022L is rotatably coupled to drive link4023L at revolute joint4012. In this example, the connecting link4022L is shown as a substantially straight elongated link but in alternate embodiments the connecting link4022L may have any suitable shape and/or configuration. The drive link4023L may include a pulley portion4024L that is rotatably coupled to, for example upper arm section4001at rotation axis CL1in any suitable manner such as by suitable bearings and an arm portion4024LA that extends from the pulley portion4024L for coupling with the connecting link4022L. In one embodiment the pulley portion4024L and arm portion4024LA of drive link4023L may be of a unitary one-piece construction. In alternate embodiments the pulley portion4024L and arm portion4024LA may be an assembly or have any other suitable configuration so that arm portion4024LA causes rotation of the pulley portion4024L. In still other alternate embodiments the drive link may be rotatably coupled directly to the pulley4024L. The drive link4023L is coupled to the forearm pulley4051L by, for example, a belt or band4050L for drivingly rotating the pulley4051L and the forearm4055L. In alternate embodiments the drive link4023L may be coupled to the forearm4055L in any suitable manner. Similarly, the first end of connecting link4022R is rotatably coupled to the second portion of the platform4021at revolute joint4011. A second end of connecting link4022R is rotatably coupled to drive link4023R at revolute joint4013. The connecting4022R may be substantially similar to connecting link4022L. The drive link4023R may be substantially similar to drive link4023L described above. For example, the drive link4023R may include a pulley portion4024R that is rotatably coupled to, for example upper arm section4001at rotation axis CL2in any suitable manner such as with suitable bearings and an arm portion4024RA that extends from the pulley portion4024R for coupling with the connecting link4022R. The drive link4023R is coupled to the forearm pulley4051R by, for example, a belt or band4050R for drivingly rotating the pulley4051R and the forearm4055R. In alternate embodiments the drive link4023R may be coupled to the forearm4055R in any suitable manner. As can be seen inFIG. 39, the links4022L,4022R,4023L,4023R form a pair of four-bar mechanisms coupled through the pivoting platform4021. As may be realized, the locations of the rotation axes CL, CL1, CL2relative to each other are shown in the drawings for exemplary purposes only and in alternate embodiments the rotation axes CL, CL1, CL2may have any suitable spatial relationship relative to each other.

Referring now toFIGS. 40A-44an exemplary operation of the transport apparatus4000will be described. As can be seen inFIGS. 40A-40Cthe mechanical switch mechanism4005is shown in greater detail. In this example, the axis of rotation CL of the platform4021is located on an opposite side of axes of rotation CL1, CL2than the revolute joints4010,4011when the switch4005is in a neutral or initial position/configuration as can be seen inFIG. 41A. The geometry of the links4021,4022L,4022R,40213L,4023R may be selected so that rotation of the platform4021from the neutral position in the clockwise direction produces a change of the angular orientation of the link4023L while the link4023R remains substantially stationary in its retracted configuration as can be seen inFIG. 41B. In the example shown inFIGS. 41A-41C, the mechanical motion switch4005is configured so that about a ninety degree rotation of the platform4021produces about a one hundred eighty degree motion of the link4023L (or4024L depending on the direction of rotation of the platform4021). In alternate embodiments the links4021,4022L,4022R,4023L,4023R may be configured to produce any desired angular change of links4023L,4023R for any desired rotation angle of platform4021. As may be realized when, for example, the platform4021is rotated in the counterclockwise direction the angular orientation of the link4023R changes while the link4023L remains substantially stationary in its retracted configuration as can be seen inFIG. 40C.

The angular orientations of the links4023L,4023R as a function of the angular position of the platform4021is graphed and shown inFIG. 41, where θ1denotes an angular position of the platform4021, θ3Land θ3Rare respectively angular orientations of the links4023L,4023R. It is noted that the angles θ1, θ3Land θ3Rare measured with respect to the initial configuration of links as shown inFIG. 40Awith θ1and θ3Rbeing positive in the counterclockwise direction and θ3Lbeing positive in the clockwise direction. The amount of residual motion by the stationary link4023R,4023L while the other one of the links4023R,4023L moves can be controlled by, for example, the ratio of L2over L1where L1is the distance between the pivoting point (axis CL) of the platform4021and the revolute joints4010,4011that couple the links4022L,4022R to the platform and L2is the length of the links4022L,4022R from joint center to joint center as shown inFIG. 40B. As can be seen inFIG. 41, the amount of residual motion decreases as the ratio L2/L1approaches the value of 1.

Referring toFIGS. 42A-42D,43and44, generally, in a substrate exchange sequence an empty arm4055B extends radially from a retracted position as shown inFIG. 39(see alsoFIG. 42A) to, for example, a workstation, or other suitable substrate holding location (not shown) as can be seen inFIG. 43, picks a processed substrate S2and retracts back to the folded position as shown inFIG. 39. The vertical position of the arm is adjusted (or the substrate holding position is adjusted where the transport apparatus does not have a Z-motion drive) so that the other arm4055A is able to enter the workstation. As may be realized, in one example, the Z-motion drive may compensate for the end effectors4056L,4056R being located one above the other in different planes. In alternate embodiments the end effectors may be located side by side in the same plane. The arm4055A extends radially, as shown inFIG. 44, carrying a fresh or unprocessed substrate S1, places the substrate at a workstation and returns to the retracted position shown inFIG. 39. The extension of arm4055A is shown inFIGS. 42A-42Din greater detail. As can be seen inFIG. 42B, both the T1and T2drive axes may rotate at, for example different rates to cause relative movement between the arm support (not shown, which may be substantially similar to upper arm section4001), carrying the arms4055A,4055B and the platform4021for causing an extension of one of the arms. In this example, to extend arm4055A the platform4021and arm support are initially rotated in opposite directions (arm support is rotated counterclockwise in the direction of arrow4200and platform is rotated clockwise in the direction of arrow4201) as shown inFIG. 42Bbut are later rotated in the same direction (in this example, counterclockwise in the direction of arrow4200) as shown inFIGS. 42C and 42D. It is noted that rotation of drive axes T1, T2in the same direction at substantially the same speed rotates the transport apparatus4000as a unit about, for example, axis CL. Here, rotation of the arm support moves the shoulder joint4055S of arm4055A along an arcuate path in a counterclockwise direction towards the workstation4070. The rotation of the platform4021causes connecting link4022R to pull on drive link4023R so the drive link4023R rotates clockwise. In alternate embodiments the platform4021may cause the connecting link to push on the drive link4023R. In still other alternate embodiments the platform4021may cause the drive link4021R to move in any suitable manner for extending the arm4055A. Drive link4023R causes a rotation of the forearm4055R (via belt4050R, drive pulley4024R and upper arm pulley4051R) in a clockwise direction to extend the arm4055A. As described above, the end effectors4056R,4056L may be slaved to the arm support by, for example, any suitable transmission such as belts/bands and pulleys so that as the forearm4055R rotates clockwise the end effector4056R is longitudinally aligned with and is extended along path4090. As may be realized retraction of the arm4055A may occur in a substantially opposite manner as described above. As may also be realized the extension and retraction of arm4055B may occur in a manner substantially similar to that described above with respect to arm4055A. As can be seen inFIGS. 42A-42D, as arm4055A is extended, the arm4055B remains in a substantially retracted configuration while rotating about axis CL and vice versa. In this example, the mechanical motion switch4005allows for both connecting links4022L,4022R to be driven by a single motor to simplify the transport apparatus drive system by, for example, eliminating the cost and complexity of a motor encoder assembly and the corresponding electronics.

Referring now toFIGS. 45A-46Danother exemplary transport apparatus4100will be described. The transport apparatus4100may be substantially similar to transport apparatus4000however, the mechanical motion switch4105has a different configuration as will be described below. As can be seen inFIG. 45Athe axis of rotation CL′ of the pivoting platform4131and revolute joints4110,4111connecting the platform4131to connecting links4132L,4132R are located on the same side of axes CL1′, CL2′. In this example, the platform4131may be coupled to drive axis T2in a manner substantially similar to that shown inFIGS. 39 and 40so that when drive axis T2rotates the platform4131rotates with it. It is noted that in one example the drive axis T2(and/or T1) may be coaxial with axis of rotation CL′. The platform4131has a first portion and a second portion each extending away from its axis of rotation CL′ in a manner substantially similar to that described above with respect to platform4021. The first portion of the platform4131is coupled to a first end of connecting link4132L by revolute joint4111and the second portion of the platform4131is coupled to a first end of connecting link4132R by revolute joint4110. The second opposite end of connecting links4132L,4132R are respectively coupled to drive links4133L,4133R by revolute joints4113,4112. As can be seen inFIG. 45Athe connecting links4132L,4132R cross over each other when the mechanical motion switch4105is in the initial or neutral position. The connecting links4132L,4132R may be substantially similar to connecting links4022L,4022R described above. The drive links4133L,4133R may also be substantially similar to drive links4023L,4023R described above with respect toFIGS. 39 and 40. For example, drive links4133L,4133R may each include a drive pulley4134L,4134R for driving a respective forearm pulley4151L,4151R for causing rotation of the forearms4155L,4155R. As described above with respect toFIGS. 39 and 40, the drive links4133L,4133R may be coupled to the forearm pulleys4151L,4151R by belts4150L,4150R. In alternate embodiments the drive links4133L,4133R may be drivingly connected to the forearms4155L,4155R in any suitable manner. As can be seen inFIG. 45B, as the platform4131is rotated in a counterclockwise direction (e.g. in the direction of arrow4600), drive link4133R also rotates in a counterclockwise direction while drive link4133L remains substantially in the initial position shown inFIG. 45A. Similarly, as can be seen inFIG. 45C, as the platform4131rotates in a clockwise direction (e.g. in the direction of arrow4601) the drive link4133L also rotates in a clockwise direction while drive link4133R remains substantially in the initial position shown inFIG. 45A. The motion profile of mechanical motion switch4105may be substantially similar to that shown inFIG. 41.

Referring now toFIGS. 46A-46Dthe extension of arm4155A of transport apparatus4100will be described. In this example, to extend arm4155A, drive axis may rotate the arm support (which may be substantially similar to upper arm section4001described above), in a counterclockwise direction (e.g. in the direction of arrow4600). Here, rotation of the arm support moves the shoulder joint4155S of arm4155A along an arcuate path in a counterclockwise direction towards the workstation4070. Drive axis T2may rotate pivoting platform4131initially in a clockwise direction (e.g. in the direction of arrow4601) and then in a counterclockwise direction. Rotation of the platform4131relative to the arm support causes platform4131to push on the drive link4133L via the connecting link4132L for causing the forearm4155L to rotate substantially in a clockwise direction for extending the arm4155A as shown inFIGS. 46A-46D. In alternate embodiments the platform4131may cause a pulling on the drive link4133L. In still other alternate embodiments the platform4131may cause the drive link4131L to move in any suitable manner for extending the arm4155A. It is noted that rotation of the drive axes T1, T2in the same direction at substantially the same speed may rotate the transport apparatus4100as a unit to change the angular orientation of a path of radial extension and retraction of the transport apparatus4100. In a manner substantially similar to that described above, the drive link pulley4134L drives the forearm pulley4151L via, for example, a belt/band4150L. The end effector4156L may be slaved to the arm support through, for example a suitable transmission such as belts and pulleys4159L,4157L in a manner substantially similar to that described above with respect toFIGS. 42A-42Dso that a longitudinal axis of end effector4156L remains substantially along an axis of extension and retraction4610(FIG. 46C) of the arm4155A. As may be realized retraction of arm4155A may occur in a manner substantially opposite that described above with respect to the extension of arm4155A. As may also be realized the extension and retraction of arm4155B (including forearm4155R, end effector4156R and pulleys4151R,4159R,4157R) may be substantially similar to that described above with respect to arm4155A.

In the examples shown inFIGS. 39-46Dthe forearms are driven by a respective drive link via belts and pulleys. However, in alternate embodiments, the transport apparatus may be configured so that the forearms are driven directly by a respective drive link in a manner substantially similar to that described above with respect toFIG. 29G.

In accordance with an exemplary embodiment a substrate transport apparatus is provided. The substrate transport apparatus includes a frame, a drive section connected to the frame and having a first motor driving a first axis of rotation and a second motor driving a second axis of rotation, a substantially rigid upper arm section rotatably connected to the frame, at least two forearms rotatably mounted to the substantially rigid upper arm section, each of the at least two forearms having at least one substrate support depending therefrom, a mechanical motion switch connecting the at least two forearms to the second motor so that the at least two forearms and the second motor are always connected and wherein the substantially rigid upper arm section is rotatably driven by the first motor and the at least two forearms are rotatably driven by the second motor via the mechanical motion switch which is configured such that the two motors driving but the first and second axes of rotation provide the substrate transport apparatus with at least three degrees of freedom.

In accordance with another exemplary embodiment a substrate transport apparatus is provided. The substrate transport apparatus includes a frame, at least two SCARA arms housed within the frame when the at least two SCARA arms are in a retracted configuration, each of the SCARA arms including at least one end effector for holding a substrate thereon, and a drive section having at least one independently controllable motor having a stator substantially linearly distributed arcuately around and proximate to a periphery of the frame, but one independently controllable motor of the at least one independently controllable motor being simultaneously connected to each of the at least two SCARA arms through a drive link, the but one independently controllable motor being configured to apply an eccentric driving force to rotate the drive link to extend and retract each of the at least two SCARA arms substantially independent of each other.

In accordance with yet another exemplary embodiment a substrate transport apparatus is provided. The substrate transport apparatus includes a drive section having at least two independently controllable motors, an articulated arm including a first SCARA arm being configured to extend in a first direction and a second SCARA arm being configured to extend in a second direction substantially opposite the first direction, each of the first and second SCARA arms having an end effector for holding a substrate thereon, and a coupling operably coupling each of the first and second SCARA arms to each other and to a respective one of the at least two independently controllable motors substantially continuously, the coupling being configured so that relative movement between the at least two independently controllable motors effects extension and retraction of a respective one of the first and second SCARA arms substantially independent of each other.

In accordance with still another exemplary embodiment a substrate transport apparatus is provided. The substrate transport apparatus includes a drive section having at least one independently controllable motor, an articulated arm operably connected to the at least one independently controllable motor, the articulated arm including a first pair of SCARA arms and a second pair of SCARA arms, each arm in the first and second pair of SCARA arms having an end effector for holding a substrate thereon, a coupling that couples each arm in the first and second pair of SCARA arms simultaneously and substantially continuously to the at least one independently controllable motor by a coupling, and the coupling being configured so that but one independently controllable motor of the at least one independently controllable motor effects a coordinated simultaneous extension and retraction of one arm in each of the first and second pair of arms substantially independent of the coordinated simultaneous extension and retraction of another different arm in each of the first and second pair of arms.

In accordance with another exemplary embodiment a substrate transport apparatus is provided. The substrate transport apparatus includes a drive section having at least a first and a second independently controllable motor, a first articulated arm having a first arm link and a first end effector connected to the first arm link for holding a substrate thereon, a second articulated arm having a second arm link and a second end effector connected to the second arm link for holding a substrate thereon, and each of the first and second arm links being rotatably joined to rotors of both of the first and second independently controllable motors such that simultaneous movement of the first and second independently controllable motors effects extension of one of the first and second articulated arms while the other one of the first and second articulated arms is rotated in a substantially retracted configuration.

In accordance with yet another exemplary embodiment a substrate transport apparatus is provided. The substrate transport apparatus includes a frame, a drive section connected to the frame including at least a first and a second independently controllable motors and an articulated arm including an arm link and an end effector for holding a substrate thereon, the arm link being rotatably joined at a first end of the arm link to a rotor of the first independently controllable motor and rotatably coupled at a second opposite end of the arm link to the end effector, and drivingly coupled at the first end of the arm link to the second independently controllable motor by a drive coupling.

The mechanical motion switch(es) described herein allows for a fast substrate swap capability with a minimized number of drives. The configuration of the mechanical motion switch also provides for a compact transport apparatus having a minimized containment for use in compact transport chambers while at the same time decreasing the cost of the transport and increasing its reliability.

It should be understood that the exemplary embodiments may be used individually or in any combination thereof. It should also be understood that the foregoing description is only illustrative of the embodiments. Various alternatives and modifications can be devised by those skilled in the art without departing from the embodiments. Accordingly, the present embodiments are intended to embrace all such alternatives, modifications and variances that fall within the scope of the appended claims.