Transfer system and transfer method

A transfer system includes a transfer chamber having transfer positions, a first robot provided in the transfer chamber to transfer articles between the transfer positions, a second robot provided in the transfer chamber to transfer articles between the transfer positions, and a retreat unit configured to move one robot among the first robot and the second robot to a retreat position by changing a height of the one robot such that the one robot does not interfere with an operating range of another robot among the first robot and the second robot.

BACKGROUND OF THE INVENTION

Field

A disclosed embodiment relates to a transfer system and a transfer method.

Background

A transfer system has conventionally been known in which a robot such as a horizontal articulated robot that includes a hand that holds a substrate is arranged in a locally-cleaned transfer chamber and the substrate is transferred to substrate housing cassettes installed on side walls of the transfer chamber or substrate processing chambers.

Furthermore, a technology is also proposed in which two robots for each processing chamber are installed in a transfer chamber so that a transfer process is continued even when one of the robots is broken down (for example, Japanese Patent Application Publication No. 2011-228559).

However, when two robots are simply installed for each processing chamber like the technology as described above, exclusive control to prevent the two robots from interfering with each other has to be executed and costs increase. That is, there is room for improvement in preventing an increase in costs of the conventional transfer system.

SUMMARY

According to an aspect of an embodiment, a transfer system includes a transfer chamber having transfer positions; a first robot provided in the transfer chamber to transfer articles between the transfer positions; a second robot provided in the transfer chamber to transfer articles between the transfer positions; and a retreat unit configured to move one robot among the first robot and the second robot to a retreat position by changing a height of the one robot such that the one robot does not interfere with an operating range of another robot among the first robot and the second robot.

According to another aspect of an embodiment, a transfer system includes a transfer chamber having first transfer positions and second transfer positions; a first robot provided in the transfer chamber to transfer articles between the first transfer positions; and a second robot provided in the transfer chamber to transfer articles between the second transfer positions and configured to transfer articles between the first transfer positions when the first robot does not transfer articles between the first transfer positions.

According to further aspect of an embodiment, a transfer method includes providing a first robot in a transfer chamber to transfer articles between the transfer positions in the transfer chamber; providing a second robot in the transfer chamber to transfer articles between the transfer positions in the transfer chamber; and moving one robot among the first robot and the second robot to a retreat position by changing a height of the one robot such that the one robot does not interfere with an operating range of another robot among the first robot and the second robot.

DESCRIPTION OF EMBODIMENTS

Hereinafter, a transfer system and a transfer method as disclosed in the present application will be described in detail with reference to the accompanying drawings. Additionally, the present invention is not limited by embodiments as described below.

Furthermore, in the embodiments described below, an expression of “parallel”, “perpendicular”, “horizontal”, “vertical”, “central”, or “symmetrical” may be used but does not have to satisfy such a condition strictly. That is, each expression as mentioned above allows a tolerance for manufacturing accuracy, installation accuracy, processing accuracy, detection accuracy, or the like.

First, an outline of a transfer system1according to an embodiment will be described by usingFIG. 1.FIG. 1is a schematic top view illustrating an outline of the transfer system1. Additionally, for the sake of better understanding of explanation,FIG. 1illustrates a three-dimensional Cartesian coordinate system with a Z-axis with a positive direction that is a vertically upward direction, an X-axis with a direction along a long side of a transfer chamber50, and a Y-axis with a direction along a short side of the transfer chamber50is illustrated. Such a Cartesian coordinate system may also be illustrated in other drawings that are used in the following description.

As illustrated inFIG. 1, the transfer system1includes the transfer chamber50, robots10, and supporting devices110. Additionally, as illustrated inFIG. 1, the transfer system1includes the two robots10, so that when the robots10are distinguished from each other, they are described as a robot10A and a robot10B. Furthermore, for the supporting devices110, the supporting device110that corresponds to the robot10A will be described as a supporting device (a lift or an additional lift)110A, and the supporting device110that corresponds to the robot10B will be described as a supporting device (a lift or an additional lift)110B.

The transfer chamber50is a so-called Equipment Front End Module (EFEM), and is a locally-cleaned casing where clean down-flow air flows into inside thereof. Furthermore, filling the transfer chamber50with nitrogen (N2 purge) is also executed. When N2 purge is executed in the transfer chamber50, once the transfer chamber50is opened, it takes time to restore the state of N2 purge, so that it is preferable to continue a transfer process without opening the transfer chamber50even when the robots10are broken down.

First, the transfer chamber50will be described. As illustrated inFIG. 1, the transfer chamber50has, for example, a rectangular shape with long sides in an X-axis direction and short sides in a Y-axis direction in the figure, where a first side wall51and a second side wall52that correspond to the long sides face each other. Furthermore, a third side wall53and a fourth side wall54that correspond to the short sides face each other. Additionally, in the following, a center line with respect to the Y-axis direction of the transfer chamber50is referred to as a center line CY, a center line with respect to the X-axis direction is referred to as a center line CX, and a point of intersection between the center line CY and the center line CX is referred to as a center point CC.

Additionally, althoughFIG. 1illustrates the transfer chamber50with a rectangular shape that is surrounded by the first side wall51and the second side wall52that face each other and the third side wall53and the fourth side wall54that face each other, a shape of the transfer chamber50is not limited thereby. That is, as long as at least the first side wall51and the second side wall52that face each other and the third side wall53and the fourth side wall54that face each other are included, other shapes such as a hexagonal shape may be provided.

Three cassettes C are arranged side by side outside each of the first side wall51and the second side wall52. Herein, the cassettes C are so-called Front-Opening Unified Pods (FOUPs), and are devices that house a substrate500in a multistage manner. The substrate500is housed in such a manner that a reference position (for example, a center) of the substrate500overlaps with a transfer position P11, for example. Herein, the transfer position P11is an example of a plurality of transfer positions P that are determined preliminarily in the transfer chamber50.

Two load lock chambers LL are arranged side by side on each of the third side wall53and the fourth side wall54. Herein, the load lock chambers LL correspond to chambers at a stage prior to processing chambers R1and R2, and the substrate500that is a processing target is transferred thereto one by one.

Herein, dimensions, such as positions, sizes, and intervals, of openings that are provided on the first side wall51and the second side wall52for mounting the cassettes C conform to the Semiconductor Equipment and Materials International (SEMI) standard. Furthermore, various dimensions of the cassettes C as described above also conform to the SEMI standard similarly.

Furthermore, dimensions, such as positions, sizes, and intervals, of openings that are provided on the third side wall53and the fourth side wall54for mounting the load lock chambers LL, and various dimensions of the load lock chambers LL also conform to the SEMI standard similarly.

As illustrated inFIG. 1, the transfer position P for the substrate500is determined preliminarily in each of the cassettes C. Additionally, althoughFIG. 1illustrates the transfer positions P as circular shapes similar to the substrate500, centers of the circular shapes may be provided as the transfer positions P.

Herein, the transfer positions P for the three cassettes C on the first side wall51are referred to as a transfer position P11, a transfer position P12, and a transfer position P13in a clockwise direction, respectively. Furthermore, a transfer position P21, a transfer position P22, and a transfer position P23are also provided on the second side wall52similarly.

Furthermore, the transfer positions P in the load lock chambers LL on the third side wall53are referred to as a transfer position P31and a transfer position P32in a clockwise direction, respectively. Furthermore, a transfer position P41and a transfer position P42are also provided on the fourth side wall54similarly.

Additionally, a transfer position P51and a transfer position P52are the transfer positions P that correspond to a pre-aligner PA (seeFIG. 7) that aligns a crystal orientation of the substrate500. Furthermore, the transfer position P51and the transfer position P52are arranged on the center line CY so as to be line-symmetric with respect to the center line CX. The transfer positions P51and52are not necessarily arranged on the center line CY.

Thus, each of the transfer positions P is determined preliminarily so as to be symmetric with respect to both of the center line CX and the center line CY. Additionally, althoughFIG. 1illustrates a case where the transfer positions P are arranged so as to be symmetric with respect to the center line CX and the center line CY, the symmetrical arrangement is an example of arrangement, and symmetrical arrangement does not have to be provided with respect to one or both of the center line CX and the center line CY. The same applies to arrangement of the robots10as described below.

Next, the robots10will be described. In the following, the robot10on the first side wall51side is referred to as the robot10A, and the robot10on the second side wall52side is referred to as the robot10B. Additionally, when both of them need not be distinguished from each other, they are described as the robots10. Each of the robots10transfers the substrate500between the cassettes C and the load lock chambers LL.

As illustrated inFIG. 1, the robots10include horizontal articulated arm parts19. Furthermore, each of the robots10is arranged in such a manner that a pivot axis of an arm on the proximal end of the arm part19is located on the center line CX. Then, the robot10A is arranged on the first side wall51side relative to the center line CY and the robot10B is arranged on the second side wall52side relative to the center line CY so as to be adjacent thereto while interposing the center line CY therebetween.

Herein, arm lengths of the arm parts19are to be capable of transferring the substrate500to all of the transfer positions P illustrated inFIG. 1. That is, the arm lengths of the arm parts19of the robots10A and10B are to be capable of transferring the substrate500to each of the transfer positions P on the first side wall51, the second side wall52, the third side wall53, and the fourth side wall54. Additionally, a detail of a configuration of the robots10will be described later by usingFIG. 3andFIG. 4.

The robot10A transfers the substrate500between the transfer positions P11, P12, and P13that correspond to the cassettes C on the first side wall51and the transfer positions P31and P32that correspond to the load lock chambers LL on the third side wall53. Furthermore, the robot10B transfers the substrate500between the transfer positions P21, P22, and P23that correspond to the cassettes C on the second side wall52and the transfer positions P41and P42that correspond to the load lock chambers LL on the fourth side wall54.

Thus, in normal times, the robot10A executes a transfer process related to the processing chamber R1, and the robot10B executes a transfer process related to the processing chamber R2. That is, the single robot10executes the transfer process for the single processing chamber R, so that the number of the robots10for the single processing chamber R is one. Thereby, it is possible to reduce costs for the single processing chamber R.

Additionally, for the sake of better understanding of explanation, the transfer positions P (the transfer positions P11, P12, P13, P31, P32, and P51) that are handled by the robot10A are hatched inFIG. 1. Furthermore, the transfer positions P (the transfer positions P21, P22, P23, P41, P42, and P52) without hatching are handled by the robot10B. Additionally, the transfer positions P that are handled by the robots10A and10B may be interchanged with each other. Furthermore, the robots10that handle the transfer positions P51and P52that correspond to the pre-aligners PA (seeFIG. 7) may be interchanged with each other. That is, the transfer position P51and the transfer position P52may be handled by the robot10B and the robot10A, respectively.

As illustrated inFIG. 1, the transfer positions P11, P12, P13, P31, P32, and P51that are handled by the robot10A and the transfer positions P21, P22, P23, P41, P42, and P52that are handled by the robot10B have point-symmetric relationships with respect to the center point CC. Furthermore, the transfer positions P11, P12, and P13and the transfer positions P23, P22, and P21have line-symmetric relationships with respect to the center line CY, and the transfer positions P31, P32, and P51and the transfer positions P42, P41, and P52have line-symmetric relationships with respect to the center line CX.

Next, the supporting devices110will be described. The supporting devices110are devices that change support heights of the robots10. Herein, the supporting devices (lifts)110are examples of a “retreat unit” that, when one of the robots10is broken down, causes the broken-down robot10to retreat to a height at which interference with an operating range of the other (normal) robot10is not caused.

Thus, the transfer system1causes the two robots10to execute transfer processes in normal times, and when one of the robots10is broken down, causes the broken-down robot10to retreat in a height direction (Z direction) so that the transfer processes are continued by the other (normal) robot10.

For example, when the robot10B that corresponds to the processing chamber R2is broken down, the supporting device110B lifts the robot10B down to a height at which interference with an operating range of the robot10A is not caused. Then, the robot10A that corresponds to the processing chamber R1also transfers the substrate500to the transfer positions P that corresponds to the processing chamber R2.

That is, the robot10A executes a transfer process that corresponds to the processing chamber R2in addition to a transfer process that corresponds to the processing chamber R1. Thus, the reason why the robot10A is able to additionally execute the transfer process of the robot10B is that the robot10A has the arm length capable of transferring the substrate500to all of the transfer positions P illustrated inFIG. 1as described above.

Additionally, although the case where the robot10B is broken down is described herein, when the robot10A is broken down, the supporting device110A causes the robot10A to retreat and the robot10B transfers the substrate500to all of the transfer positions P illustrated inFIG. 1.

Additionally,FIG. 1illustrates two independent devices such as the supporting device110A that supports the robot10A and the supporting device110B that supports the robot10B, for the supporting devices110. However, this is not limiting and the single supporting device110may separately change the respective support heights of the robots10A and10B. Furthermore, the functions of the supporting device110may be provided to each of the robots10.

Next, a retreat operation that is executed by the supporting devices110will be described by usingFIG. 2.FIG. 2is a side view of the supporting devices110. In particular,FIG. 2is a view in which the robots10and the supporting devices110are viewed from the third side wall53side (the negative direction side of the X-axis) inFIG. 1.

Additionally,FIG. 2illustrates a case where the supporting device110A supports the robot10A at a first height H1that is a height in normal times (height before retreat), and the supporting device110B supports the robot10B at a second height H2that is a height after retreat.

As illustrated inFIG. 2, the supporting devices110A and110B are installed on a floor surface50fof the transfer chamber50and respectively support the robots10A and10B, for example. The supporting devices110include lifting parts111, and upon receiving a lift-down instruction, lift top surfaces of the lifting parts111down from the first height H1to the second height H2. Herein, for an operating system of the lifting parts111, it is possible to use a pneumatic system or a hydraulic system.

For example, it is possible to close a valve by an actuator that operates against a biasing force to stop the lifting parts111at the first height H1when power is supplied, and open the valve by the biasing force to release pressure and lift down the lifting parts111to the second height H2when power supply is disconnected. Thus, it is possible to reduce the power consumption in normal times (when power is supplied). Additionally, it is possible to readily change a lift-down speed by adjusting the amount of opening of the valve.

Additionally, an electrical system may be used for the operating system of the lifting parts111. Furthermore, a manual system as well as an automatic system may be provided for the lifting parts111. For the manual system, it is possible to use a lifting mechanism, such as a jack, with an operating handle arranged outside the transfer chamber50, for example. The operating handle is arranged outside the transfer chamber50, so that, when the robot10is broken down, it is possible to cause the broken-down robot10to retreat without opening the transfer chamber50. Furthermore, a semi-automatic system may be provided in which an operating button is provided outside the transfer chamber50and a retreat operation is started by pushing the operating button. Thus, it is possible for the retreat unit to be an automatic system, a manual system, or a semi-automatic system.

As illustrated inFIG. 2, the second height H2is less than the first height Furthermore, it is sufficient that a lift-down width W that is a difference between the first height H1and the second height H2is an amount such that an upper edge height19T of the arm part19of the robot10B after retreat is less than a lower edge height19B of the arm part19of the robot10A before retreat.

Thus, even when the arm part19of the (normal) robot10A before retreat operates, interference with the (broken-down) robot10B after retreat is not caused. Therefore, it is also possible for the robot10A to access the transfer positions P21, P22, and P23on the robot10B side.

Additionally, althoughFIG. 2illustrates a case where the two supporting devices110A and110B respectively support the two robots10A and10B and cause them to retreat, the two lifting parts111that independently operate may be included in the single supporting device110. Furthermore, althoughFIG. 2illustrates a case where the lifting parts111is lifted up and down inside the supporting devices110, the supporting devices110may be configured in such a manner that the externally-exposed lifting parts111is lifted up and down.

Next, a configuration of the robots10will be described by usingFIG. 3andFIG. 4.FIG. 3is a perspective view of the robot10A, andFIG. 4is a side view of the robot10A. Additionally,FIG. 3corresponds to a view in which the robot10A is viewed from obliquely upward, andFIG. 4corresponds to a view in which the robot10A is viewed from the third side wall53side (the negative direction side of the X-axis). Furthermore, althoughFIG. 3andFIG. 4are diagrams relating to the robot10A by taking its orientation into consideration, in the case of the robot10B, it is sufficient to interchange positive and negative directions of the Y-axis inFIG. 3andFIG. 4.

As illustrated inFIG. 3, the robot10A includes a main body part15, a lifting part16, a first arm11, a second arm12, and hands13. Additionally, althoughFIG. 3illustrates a hand13A and a hand13B as the two hands13that coaxially pivot, the single hand13may be provided.

The main body part15is mounted on the supporting device110A (seeFIG. 2), and includes a built-in lifting mechanism (not illustrated) that lifts the lifting part16up and down. For the lifting mechanism, it is possible to use a mechanism that includes a ball screw oriented along the Z-axis, a slider that slides on the ball screw, and an actuator that rotates the ball screw, for example.

The lifting part16supports a proximal end of the first arm11to be rotatable around a first axis A1, and lifts it up and down along a lifting axis A0. Additionally, the lifting part16itself may be rotated around the first axis A1. Furthermore, the first axis A1is arranged on the negative direction side of the Y-axis on a top surface of the main body part15. This is because, when the first axis A1is arranged on the negative direction side in the figure, it is possible to increase the length of the first arm11in a range in which interference with the transfer chamber50is not caused.

The first arm11supports, at a distal end thereof, a proximal end of the second arm12to be rotatable around a second axis A2. The second aim12supports, at a distal end thereof, a proximal end of each of the hands13to be rotatable around a third axis A3.

Furthermore, each of the hands13includes a base part13aand a fork part13b. Proximal end sides of the base parts13aare supported by the second arm12to be rotatable around the third axis A3. The fork parts13bare provided on distal end sides of the base parts13a,and distal end sides thereof are bifurcated. Holding members that prevent the substrate500from sliding, such as O rings, are provided on top surfaces of the fork parts13b. Additionally, other holding mechanisms, such as gripping mechanisms or adsorbing mechanisms, may be provided instead of the holding members.

Thus, the robot10A is a three-link horizontal articulated robot with the first aim11, the second arm12, and the hands13. Furthermore, the robot10A includes the lifting mechanism as described above, so that it is possible to access each of the substrates500that are arranged in the cassettes C in a multistage manner. Additionally, the robot10A may be configured to have two links or four or more links.

Furthermore, the robot10A changes a height of the hands13by an operation of the lifting mechanism as described above, so that it is possible to access the transfer positions P in the load lock chambers LL as well as the transfer positions P in the pre-aligners PA. Additionally, a detail of such a matter will be described later by usingFIG. 7.

Additionally, for a driving source of the first arm11and the second arm12, it is possible to use a direct drive (DD) motor. Each of the first arm11and the second arm12is caused to pivot by the DD motor, so that it is possible to attain reduction of oscillation and improvement of transfer accuracy. Herein, when the DD motor is used for the driving source, it is preferable to use a rotation preventive brake in combination to prevent rotation that is caused by an external force.

As illustrated inFIG. 4, the second arm12is provided above the first arm11, and the hands13are provided above the second arm12. Additionally, the first aim11, the second arm12, and the hands13are collectively referred to as the arm part19(seeFIG. 1). Additionally, althoughFIG. 4illustrates a case where the lifting part16is entirely hidden by the main body part15as an example in which the aim part19is provided at the lowest position, a part of the lifting part16may protrude from the main body part15.

Next, a basic posture of the robot10will be described by usingFIG. 5.FIG. 5is an explanatory diagram of the basic posture. Additionally, althoughFIG. 5illustrates the robot10A and the robot10B, the robots10A and10B have a symmetrical relationship with respect to the center line CY, so that the basic posture of the robot10A will be described below.

As illustrated inFIG. 5, the basic posture of the robot10A is a posture in which a stretching direction of each of the first arm11, the second arm12, and the hands13is folded in the direction along the center line CX. That is, a posture is provided in which the first arm11, the second arm12, and the hand13are folded so as to overlap with one another and be perpendicular to the first side wall51. Additionally, it is also possible to provide a posture in which the first axis A1, the second axis A2, and the third axis A3illustrated inFIG. 3andFIG. 4are folded so as to overlap with the center line CX.

As the robot10A is caused to have the basic posture, interference with the robot10B is not readily caused. Furthermore, as the robot10A is forced to have the basic posture at the time of breakdown thereof, it is possible to prevent interference with the cassettes C or the load lock chambers LL that is involved with lift-down.

Additionally, for a method of forcing the robot10A to have the basic posture at the time of breakdown thereof, a method of continuing an operation until the basic posture is attained by using a battery that operates when a power supply is disconnected, or a method of having the basic posture by a driving system in a system different from that of a normal driving system. Furthermore, a method may be provided in which a biasing force toward the basic posture is added to each of the rotation axes of the robot10A and an operation is executed against such biasing force in normal times.

Additionally, as the broken-down robot10is caused to have the basic posture, it is possible for the normal robot10to access a part of the cassettes C (seeFIG. 1) on the broken-down robot10side without lifting the broken-down robot10down. For example, as the robot10B has the basic posture, it is possible for the robot10A to access the transfer positions P23and P21at both ends (seeFIG. 1). Furthermore, it is also possible to access the transfer positions P41and P42for the processing chamber R2(seeFIG. 1).

Next, a configuration of the transfer system1will be described by usingFIG. 6.FIG. 6is a block diagram of the transfer system1. Additionally,FIG. 6omits illustration of a controller that executes entire control of transfer chamber50(seeFIG. 1). Additionally, the above-described controller that executes entire control may implement functions of a retreat controller90illustrated inFIG. 6

As illustrated inFIG. 6, the transfer system1includes the robot10, a controller20that executes operation control of the robot10, the supporting device110, and the retreat controller90. Additionally, althoughFIG. 6illustrates the single robot10, the single controller20, and the single supporting device110from the viewpoint of simplicity of explanation, the two robots10, the two controllers20, and the two supporting devices110are present in practice.

In the following, a configuration of the retreat controller90will be mainly described. Additionally, a configuration of the controller20that executes operation control of the robot10will be described later by usingFIG. 8.

As illustrated inFIG. 6, the retreat controller90includes a control unit91and a storage unit92. Moreover, the control unit91includes a determining unit91a,a retreat instructing unit91b,and a changing unit91c.Furthermore, the storage unit92stores therein determination information92a.Furthermore, the retreat controller90is connected to the controller20and the supporting device110.

Herein, the retreat controller90includes a computer and various circuits that include, for example, a Central Processing Unit (CPU), a Read Only Memory (ROM), a Random Access Memory (RAM), a Hard Disk Drive (HDD), and an input-output port.

The CPU of the computer reads and executes a program stored in the ROM to function as the determining unit91a,the retreat instructing unit91b,and the changing unit91cof the control unit91, for example.

Furthermore, at least one or all of the determining unit91a, the retreat instructing unit91b, and the changing unit91cof the control unit91are also capable of being composed of hardware such as an Application Specific Integrated Circuit (ASIC) or a Field Programmable Gate Array (FPGA). The CPU, the ASIC, and the FPGA are examples of circuitry.

Furthermore, a storage unit22corresponds to a RAM or an HDD, for example. It is possible for the RAM or the HDD to store therein the determination information92a. Additionally, the retreat controller90may acquire the above-described program and various kinds of information via another computer or a portable recording medium connected by a wired or wireless network.

The control unit91of the retreat controller90executes control to cause the broken-down robot10to retreat. The determining unit91adetermines which of the two robots10is broken down on the basis of operation statuses of the robots10acquired from the two controllers20respectively and the determination information92a.Herein, the determination information92ais information that includes a condition under which the robots10are assumed to have been broken down.

For example, the determining unit91adetermines that the robot10that corresponds to the controller20that has acquired error information is broken down. Furthermore, the determining unit91amay determine that the robot10that corresponds to the controller20for which periodic communication has been disconnected is broken down. Additionally, it is possible to readily change contents of the determination of breakdown by changing the determination information92a.Then, the determining unit91anotifies the retreat instructing unit91band the changing unit91cof a determination result.

The retreat instructing unit91binstructs the supporting device110that corresponds to the determination result received from the determining unit91ato reduce the support height of the robot10. For example, in the case illustrated inFIG. 1, the retreat instructing unit91bthat has received, from the determining unit91a,the determination result indicating that the robot10B is broken down instructs the supporting device110B to execute lift-down.

The changing unit91cinstructs the controller20that corresponds to the determination result received from the determining unit91ato change the posture of the robot10. For example, in the case as illustrated inFIG. 1, the changing unit91cthat has received, from the determining unit91a,the determination result indicating that the robot10B is broken down instructs the controller20that corresponds to the robot10B to cause the robot10B to have the basic posture (seeFIG. 5).

Additionally, althoughFIG. 6illustrates a case where the changing unit91cprovides an instruction to change the posture of the robot10via the controller20, the changing unit91cmay directly instruct the robot10to change the posture thereof. In this case, it is assumed that the robot10is provided with a driving system of a system different from the driving system for normal operation, and the changing unit91cprovides an instruction to the driving system of the different system.

Next, a lifting range of the robot10will be described by usingFIG. 7.FIG. 7is an explanatory diagram of the lifting range. Additionally, althoughFIG. 7illustrates the lifting range of the robot10A, the same applies to the robot10B. Furthermore, inFIG. 7, the arm part19that is lifted down to the minimum height with respect to the main body part15by lifting the lifting part16down and the arm part19that is lifted up to the maximum height with respect to the main body part15by lifting the lifting part16up are indicated by a solid line and a broken line, respectively.

As illustrated inFIG. 7, the supporting device110A is arranged on the floor surface50fof the transfer chamber50(seeFIG. 1). A height of the floor surface50fis a “height61”. Furthermore, the main body part15of the robot10A is arranged on the lifting part111of the supporting device110A. Herein,FIG. 7illustrates a case where the top surface of the lifting part111is provided at the first height H1. A height of the first height H1is a “height62”.

Furthermore, a height of the top surface of the arm part19in a case where the aim part19of the robot10A is lifted down to the minimum height is a “height63”, and the height of the top surface of the arm part19in a case where the arm part19is lifted up to the maximum height is a “height67”. That is, a “lifting range W61” of the arm part19during a normal operation has a lower limit that is the height63and an upper limit that is the height67.

Herein, as a minimum value of a “housing range W62” of the substrates500that are housed in the cassettes C in a multistage manner as illustrated inFIG. 1is a “height64” and a maximum value thereof is a “height65”, the height64is greater than the height63and the height65is less than the height67. That is, the housing range W62is included in the lifting range W61. Furthermore, heights of the transfer positions P of the substrate500conveyed to the load lock chambers LL illustrated inFIG. 1are included in the housing range W62of the cassettes C.

Then, a “height66” of the substrate500mounted on the pre-aligner PA is greater than the housing range W62of the cassettes C and less than the height67that is the height of the top surface of the arm part19lifted up to the maximum height. Additionally, the pre-aligner PA aligns crystal orientations of the substrate500by rotating the substrate500around an axis along the Z-axis. Thus, the respective heights illustrated inFIG. 7have a relationship of “the height67>the height66>the height65>the height64>the height63>the height62>the height61”.

Next, a configuration of the controller20illustrated inFIG. 6will be described by usingFIG. 8.FIG. 8is a block diagram of the controller20. As illustrated inFIG. 8, the robot10and the retreat controller90are connected to the controller20. Furthermore, the controller20includes a control unit21and the storage unit22. The control unit21includes an operation control unit21aand a posture changing unit21b.The storage unit22stores therein teaching information22a.

Herein, the controller20includes a computer and various circuits that include, for example, a Central Processing Unit (CPU), a Read Only Memory (ROM), a Random Access Memory (RAM), a Hard Disk Drive (HDD), an input-output port, and the like.

The CPU of the computer reads and executes a program stored in the ROM to function as the operation control unit21aand the posture changing unit21bof the control unit21. Furthermore, at least a part or all of the operation control unit21aand the posture changing unit21bare also capable of being composed of hardware such as an Application Specific Integrated Circuit (ASIC) or a Field Programmable Gate Array (FPGA).

Furthermore, the storage unit22corresponds to a RAM or an HDD, for example. It is possible for the RAM or the HDD to store therein the teaching information22a. Additionally, the controller20may acquire the above-described program and various kinds of information via another computer or a portable recording medium connected by a wired or wireless network.

The control unit21executes operation control of the robot10. The operation control unit21aoperates the robot10based on the teaching information22a.Herein, the teaching information22ais information that is generated in a teaching stage for the robot10and includes a “job” that is a program for defining an operating path of the robot10. Additionally, the operation control unit21aconcurrently executes a process of improving operating accuracy based on a feedback value or the like from a built-in actuator of the robot10.

The posture changing unit21bexecutes a process of causing the robot10to have a retreat posture when receiving an instruction from the retreat controller90or the like. Herein, the retreat posture includes the “basic posture” as already described by usingFIG. 5. Additionally, for the evacuating posture, a posture may be provided to cause at least the hands13in the cassettes C or the load lock chambers LL to retreat to the outside of the cassettes C or the load lock chambers LL.

Next, retreat steps that are executed by the transfer system1will be described by usingFIG. 9.FIG. 9is a flowchart illustrating retreat steps that are executed by the transfer system1. Additionally, in the following, explanation will be provided with reference to the components illustrated inFIG. 6.

As illustrated inFIG. 9, the determining unit91aof the retreat controller90detects breakdown of the robot10(Step S101). Then, if breakdown of the robot10is detected (Step S101: Yes), the changing unit91cinstructs the corresponding controller20to release a brake of the broken-down robot10(Step S102). Additionally, if the determination condition at Step S101is not satisfied (Step S101: No), the process at Step S101is repeated.

Subsequently, the changing unit91cinstructs the controller20that corresponds to the broken-down robot10to cause the broken-down robot10to have the retreat posture (Step S103). Then, the retreat instructing unit91binstructs the supporting device110that corresponds to the broken-down robot10to cause the broken-down robot10to retreat to a retreat height (Step S104).

Furthermore, the changing unit91cinstructs the controller20that corresponds to the normal robot10to change a path in such a manner that the normal robot10additionally executes the transfer process of the broken-down robot10(Step S105), and terminates the process.

Additionally, such a path changing instruction is capable of being attained by changing the teaching information22aillustrated inFIG. 8from information on the path for the subject robot10to information including the paths for the subject robot10and the other robot10, for example. Paths for the subject robot10and the other robot10may be prepared preliminarily so as to disable the path for the other robot10in normal times and enable such a path when the other robot10is broken down.

Next, variations of the transfer system1will be described by usingFIG. 10A,FIG. 10B, andFIG. 10C.FIG. 10Ais an explanatory diagram of a first variation,FIG. 10Bis an explanatory diagram of a second variation, andFIG. 10Cis an explanatory diagram of a third variation. Herein,FIG. 10A,FIG. 10B, andFIG. 10Care schematic top views similar toFIG. 1, but the transfer positions P, the arm parts19of the robots10, etc., are omitted for the sake of better understanding of explanation. Additionally, the layout of the transfer positions P is similar to that ofFIG. 1.

First, the first variation will be described.FIG. 10Aillustrates a transfer system1A that is a variation of the transfer system1with respect to arrangement of the robots10A and10B. The transfer system1A is different from the transfer system1illustrated inFIG. 1in that the arrangement of the robots10A and10B illustrated inFIG. 1is rotated by 90 degrees in a counterclockwise direction with respect to the center point CC. That is, the first axis A1of the robot10A and the first axis A1of the robot10B are located on the center line CY at symmetrical positions with respect to the center line CX.

Even when the robots10A and10B are thus arranged, it is possible to execute a transfer process similar to that of the transfer system1. That is, the robot10A is capable of executing the transfer process for the transfer positions P11, P12, P13, P31, P32, and P51, and the robot10B is capable of executing the transfer process for the transfer positions P21, P22, P23, P41, P42, and P52.

Additionally, in the case illustrated inFIG. 10A, the transfer position P51among the transfer positions P51and P52that correspond to the pre-aligners PA (seeFIG. 7) is closer to the robot10A, so that the robot10A executes the transfer process for the transfer position P51and the robot10B executes the transfer process for the transfer position P52. Additionally, the robot10A may execute the transfer process for the transfer position P52and the robot10B may execute the transfer process for the transfer position P51.

Furthermore, althoughFIG. 10Aillustrates the transfer system1A in which the arrangement of the robots10A and10B illustrated inFIG. 1is rotated by 90 degrees in a counterclockwise direction with respect to the center point CC, the transfer system1A may be provided in which it is rotated by 90 degrees in a clockwise direction.

Next, the second variation will be described.FIG. 10Billustrates a transfer system1B that is a variation including an interchanging part TT that interchanges positions and orientations of the robots10A and10B. The transfer system1B is different from the transfer system1illustrated inFIG. 1in that the interchanging part TT is provided instead of the supporting devices110A and110B illustrated inFIG. 1.

Additionally, the first axis A1of the robot10A and the first axis A1of the robot10B are located on the center line CX at symmetrical positions with respect to the center line CY, similarly to the transfer system1illustrated inFIG. 1. Furthermore, the robots10A and10B are provided on the interchanging part TT.

The interchanging part TT is, for example, a disc-shaped turntable that rotates about the center point CC, for example. The interchanging part TT rotates by 180 degrees about the center point CC from the state illustrated inFIG. 10Bso that it is possible to interchange the positions and the orientations of the robot10A and the robot10B. That is, the interchanging part TT interchanges in-plane positions of the two robots10A and B.

For example, when the robot10B is broken down, the interchanging part TT is appropriately caused to reversely rotate so that it is possible to interchange, with respect to the robot10A, the position and the orientation of the robot10A with the position and the orientation of the robot10B illustrated inFIG. 10B.

Specifically, the robot10A executes the transfer process for the transfer positions P11, P12, P13, P31, P32, and P51assigned to the robot10A at the position indicated inFIG. 10B. Then, in a state in which the interchanging part TT is rotated by 180 degrees about the center point CC, the transfer process for the transfer positions P21, P22, P23, P41, P42, and P52that are originally assigned to the robot10B is executed.

Thus, the interchanging part TT is caused to rotate in increments of 180 degrees, so that even when the robot10B is broken down, it is possible for the robot10A to continuously execute the transfer process related to all of the transfer positions P in the transfer chamber50. Similarly, even when the robot10A is broken down, it is possible for the robot10B to continuously execute the transfer process related to all of the transfer positions P in the transfer chamber50.

Additionally, althoughFIG. 10Billustrates the turntable as an example of the interchanging part TT, it may be possible to use another moving mechanism such as a sliding mechanism may be used as long as the positions and the orientations of the robots10A and10B are interchangeable.

Next, the third variation will be described.FIG. 10Cillustrates a transfer system1C that is a variation of the transfer system1with respect to arrangement of the robots10A and10B. The transfer system1C is different from the transfer system1illustrated inFIG. 1in that the arrangement of each of the robots10A and10C illustrated inFIG. 1is closer to the first side wall51and the second side wall52, the first axis A1of the robot10A is closer to the first side wall51, and the first axis A1of the robot10B is closer to the second side wall52. Additionally, the first axis A1of the robot10A and the first axis A1of the robot10B are located on the center line CX at symmetrical positions with respect to the center line CY.

Even when the robots10A and10B are thus arranged, it is possible to execute a transfer process similar to that of the transfer system1. That is, the robot10A is capable of executing the transfer process for the transfer positions P11, P12, P13, P31, P32, and P51, and the robot10B is capable of executing the transfer process for the transfer positions P21, P22, P23, P41, P42, and P52.

Additionally, the robot10A may be arranged as illustrated inFIG. 10Cwhile the robot10B may be arranged as illustrated inFIG. 1. Furthermore, the robot10A may be arranged as illustrated inFIG. 1while the robot10B may be arranged as illustrated inFIG. 10C.

As described above, the transfer system1according to the present embodiment includes the transfer chamber50, the two robots10, and the supporting devices110as an example of the “retreat unit”. The plurality of transfer positions P are determined preliminarily in the transfer chamber50. Each of the two robots10is provided in the transfer chamber50, and includes the horizontal articulated arm part19that transfers the substrate500between the plurality of transfer positions P. The supporting devices110as an example of the retreat unit, when one of the robots10is broken down, cause the broken-down robot10to retreat to a height at which interference with an operating range of the other of the robots10is not caused.

Thus, the transfer system1causes the broken-down robot10to retreat in such a manner that interference with the normal robot10is not caused, so that it is possible to prevent an increase in costs and continue the transfer process even when the robot10is broken down.

Additionally, although the case where the supporting devices110that cause the broken robots10to retreat are separated from the robots10has been explained in the embodiment described above, the supporting devices110may be omitted by further extending the lifting range W61(seeFIG. 7) of the lifting parts16(seeFIG. 3) of the robots10by the lift-down width W of the supporting devices110(seeFIG. 2). In such a case, the lifting parts16of the robots10correspond to the “retreat unit”.

Additionally, in order to extend the lifting range W61of the aim parts19in the robots10, it is possible to provide the lifting mechanisms of the robots10that is configured as multi-tube telescopic systems or the lifting axis A0that is configured with a multi-stage system such as two-stage system. Thus, it is possible to reduce the height of the main body part15and extend the lifting range W61so as to allow retreat at the time of breakdown.

Furthermore, the “retreat unit” may be omitted from the transfer system1, so that if one of the robots10is broken down, the other of the robots10also transfers the substrate500to the transfer positions P that correspond to the broken-down robot10. That is, each of the robots10may be configured to operate so as to compensate for all of the transfer positions P that correspond to all of the robots10. Furthermore, when one of the robots10is stopped, the other of the robots10may also transfer the substrate500for the transfer positions P that corresponds to the stopped robot10.

It is possible for those skilled in the art to readily derive additional advantages and variations. Hence, broader aspects of the present invention are not limited to the specific details and representative embodiments as illustrated and described above. Therefore, it is possible to provide various modifications without departing from the spirit and scope of the general inventive concept as defined by the appended claims and equivalents thereof.