Abstract:
An airflow management system and/or method used in particle abatement in semiconductor manufacturing equipment. In particular, the apparatus disclosed is capable of creating and managing a carefully controlled particle free environment for the handling of semiconductor wafers or similar articles. The apparatus is particularly suited to be used as an interface between an equipment front end module (EFEM) and a vacuum loadlock chamber or other such article of process equipment. The apparatus also enables relative motion between enclosures while maintaining a particle free environment utilizing a moving air diffuser mounted to an interface panel.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to an apparatus and method for creating, managing, and maintaining a particle free environment for the handling of the semiconductor wafers or workpieces. More particularly, the present invention relates to an enclosed particle free interface and containment system between the EFEM and a wafer processing module. 
       BACKGROUND OF THE INVENTION 
       [0002]    Shortening cycle times to fabricate semiconductors is critical to the success of semiconductor manufacturing. A key factor in cycle time is the movement of workpieces from the equipment front end module (EFEM) into an air management system/load lock area. Shortened cycle times are critical to operational success allowing lean inventory, better yields, and the like. 
         [0003]    Semiconductor manufacturing requires an ultra clean environment for the silicon wafers or workpieces during the manufacturing process; therefore it is necessary to provide a filtered and controlled airflow of sufficient velocity to prevent airborne particles from migrating to the wafer surface, thereby contaminating the wafer and resulting in reduced production yields. Airflow recirculation near the wafer is significant source of airborne particles settling on the wafer surface. 
         [0004]    Customers often require that the implantation takes place at an angle, between zero degrees (0°) and ninety degrees (90°). In various implantation devices this requires that the process chamber rotate relative to the stationary ion implanter, for example. Current technologies and techniques allow for relative motion to occur between wafer handling apparatus and process modules, however when changing the implantation angle the process chamber often has to go back into a position so that new workpieces can be loaded into the load lock area or air management system. This results in reduced cycle times. 
         [0005]    Thus, it is desirable to provide an apparatus and method for allowing the relative motion between the process chamber and the air management system which allows for loading workpieces without the subsequent movement of the process chamber. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention overcomes the limitations of the prior art by providing an apparatus and method for controlling airflow while allowing for relative motion to occur between wafer handling and processing modules. The apparatus consists of a movable diffuser connected to the containment shroud by means of an interface panel. Airflow between the modules is controlled by the design of the diffuser and an adjustable exhaust damper panel at the airflow exit side of the shroud. 
         [0007]    To the accomplishment of the foregoing and related ends, the invention comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1A  illustrates an exemplary semiconductor implant system utilizing an air flow management component and movable air diffuser in accordance with one aspect of the present invention; 
           [0009]      FIG. 1B  illustrates a front perspective view of a reciprocating drive apparatus according to another aspect of the present invention; 
           [0010]      FIG. 1C  is a side view of an exemplary change in the ion implantation angle on a workpiece according to another aspect of the present invention; 
           [0011]      FIG. 1D  illustrates a side partial cross sectional view of an exemplary reciprocating drive apparatus system according to another aspect of the present invention; 
           [0012]      FIG. 1E  illustrates a front view of the reciprocating arm in accordance with still another aspect of the invention; 
           [0013]      FIG. 2A  is a top cross sectional view of a process chamber with an airflow management system in accordance with another aspect of the present invention; 
           [0014]      FIG. 2B  is a top cross sectional view of a process chamber with an airflow management system and a movable air diffuser according to an aspect of the invention; 
           [0015]      FIG. 2C  is a back perspective view of an interface panel with a movable diffuser in accordance with another aspect of the invention; 
           [0016]      FIG. 3  is a front view of an interface panel in accordance with another aspect of the invention; 
           [0017]      FIG. 4  is a top view of an interface panel in accordance with another aspect of the invention; 
           [0018]      FIG. 5  is a cross-sectional view of the vee bearing assembly according to an aspect of the invention; 
           [0019]      FIG. 6  is a top perspective view of the interface panel in accordance with another aspect of the invention; 
           [0020]      FIG. 7A  is a cross-sectional side view of the equipment front end module and the air management system in accordance yet another aspect of the invention; 
           [0021]      FIG. 7B  is a cross-sectional view of airflow within the equipment front end module and the air management system in accordance with another aspect of the present invention; 
           [0022]      FIG. 7C  is a cross-sectional view of the airflow within the air management system in accordance with still another aspect of the present invention; 
           [0023]      FIG. 8  is a graph of the average the filter of velocity versus the fan filter units power, in accordance with an aspect of the present invention; 
           [0024]      FIG. 9  is a graph of differential pressure versus the load lock damper opening percentage, according to yet another aspect of the present invention; 
           [0025]      FIG. 10  is a graph of differential pressure versus load lock damper opening with lower damper opened at 100%, in accordance with yet another aspect of the present invention; 
           [0026]      FIG. 11  is a graph of Zone  1  differential pressure relative to Zone  2  differential pressure with the floor damper opened 100%, in accordance with still another aspect of the present invention; 
           [0027]      FIG. 12  is a graph of Zone  1  differential pressure relative Zone  2  with the floor damper opened at 50%, in accordance with another aspect of the invention; 
           [0028]      FIG. 13  is a graph of flow velocity normal to the interface diffuser floor damper, according to yet still another aspect of the present invention; 
           [0029]      FIG. 14  is a graph of flow velocity normal to the interviews diffuser floor damper, according to another aspect of the present invention; 
           [0030]      FIG. 15  is a flow chart illustrating an exemplary air management technique according to yet another aspect of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0031]    The present invention is directed generally toward a reduced cycle time airflow management system and method for controlling particle abatement in semiconductor manufacturing equipment. Accordingly, the present invention will now be described with reference to the drawings, wherein like reference numerals may be used to refer to like elements throughout. It should be understood that the description of these aspects are merely illustrative and that they should not be interpreted in a limiting sense. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be evident to one skilled in the art, however, that the present invention may be practiced without these specific details. 
         [0032]    Referring now to the figures, in accordance with one exemplary aspect of the present invention,  FIG. 1A  illustrates an exemplary semiconductor implantation system  100  comprising an equipment front end module (EFEM)  102 , an air management system (AMS)  104  and an exemplary reciprocating drive system (RDS)  106 . The EFEM  102  is a component in semiconductor automation, moving work pieces between a “dirty” processing areas and “clean” areas, for example. Equipment front end modules  102  were developed in response to the requirement for higher yields, faster throughput, contamination reduction, and the like, while maintaining ever-shrinking geometries in the semiconductor industry. Contamination levels that were acceptable a short time ago are no longer acceptable for many products. 
         [0033]    The equipment/environmental front end module  102  can be configured with a shroud (not shown) defining a protected environmental area where work pieces may be reached and handled with minimum potential for contamination of the workpiece. In one embodiment the EFEM  102  comprises a robot  112  with robotic arms  114  for holding and moving a workpiece (not shown) and an air management system  104  for circulating air around a workpiece. The robot  112  in this embodiment can translate along a pathway, for example, linear, curvilinear, and the like, or the robot  112  in another embodiment can be stationary. In addition, robotic arms  114  can translate or rotate or both, for example. It will be understood that the EFEM  102  of  FIG. 1A  can be configured to move the workpiece from a “clean” zone  1  or first zone ( 108 ), illustrated in  FIG. 1A , as a dashed line, into a zone  2  or second zone ( 110 ) within the air management system  104 . 
         [0034]    The exemplary airflow management system  104  comprises a shroud  116 , an interface panel  118  configured with a moving diffuser  120 , and an adjustable damper  122 , wherein the moving diffuser  120  is generally configured with vanes  124 . The moving diffuser  120  provides an opening between Zone  1  ( 108 ) and inside the AMS  104  referred to as Zone  2  ( 110 ). The AMS  104  further comprises a support surface or platen  126  for supporting the workpiece, wherein the moving diffuser  120  is configured to move in order to align the translating robot  112  and the robotic arms  114 , the air diffuser  120  and the platen  126  within the chamber interior of Zone  2  ( 110 ). The air management system  104  can be fixedly attached to a rotating process chamber  128 , for example. 
         [0035]    According to the present invention, the reciprocating drive apparatus (RDS)  106  can be located within and extending through the process chamber  128 , for example.  FIG. 1A  illustrates the outside of the process chamber  128 , for example. The chamber  128  may comprise a generally enclosed vacuum chamber  128 , wherein an internal environment within the process chamber is operable to be generally isolated from an external environment outside the process chamber. For example, the vacuum chamber  128  can be configured and equipped so as to maintain the internal environment at a substantially low pressure (e.g., a vacuum). The process chamber  128  may be further coupled to one or more load lock chambers, well known by those of ordinary skill in the art, wherein the workpiece may be transported between the internal environment of the process chamber  128  and the external environment, Zone  1  ( 108 ) without substantial loss of vacuum within the process chamber  128 . The process chamber  128  may alternatively be comprised of a generally non-enclosed process space, wherein the process space is generally associated with the external environment. 
         [0036]      FIGS. 1B ,  1 D and  1 E illustrate simplified views of an exemplary reciprocating drive apparatus  130  operable within a process chamber  128  to reciprocally translate or oscillate a workpiece  132  along a predetermined first scan path  134 . The process chamber  128  is used with an exemplary air management system  104 , according to one aspect of the present invention. It should be noted that the reciprocating drive apparatus  130  of  FIGS. 1B ,  1 D and  1 E is illustrated to provide an upper-level understanding of the invention, and is not necessarily drawn to scale. Accordingly, various components may or may not be illustrated for clarity purposes. It shall be understood that the various features illustrated can be of various shapes and sizes, or excluded altogether, and that all such shapes, sizes, and exclusions are contemplated as falling within the scope of the present invention. Additionally, the air management system  104  can be configured to operate with the non-reciprocating drive system, for example, and is a key in the present invention. 
         [0037]    As implied by the use of the term “reciprocating drive apparatus”, in one example, the drive apparatus  130  of the present invention, illustrated in  FIG. 1B  is operable to reciprocally translate or oscillate the workpiece  132  in a reversible motion along the first scan path  134 , such that the workpiece translates alternatingly back and forth with respect to a generally stationary ion beam  147  or  148 , wherein the apparatus can be utilized with the air management system  104  in an ion implantation process, as will be discussed hereafter in greater detail. Alternatively, the air management system  104  and the reciprocating drive apparatus  130  may be utilized in conjunction with various other processing systems, which may include other semiconductor manufacturing processes such as, for example, a step-and-repeat lithography system. In yet another alternative, the air management system  104  can be utilized in various processing systems not related to semiconductor manufacturing technology, and all such systems and implementations are contemplated as falling within the scope of the present invention. 
         [0038]    According to one aspect of the present invention, the reciprocating drive apparatus  130  comprises a motor  136  operably coupled to a scan arm  138  wherein the scan arm is further operable to support the workpiece  132  thereon. The motor  136 , for example, comprises a rotor  140  and a stator  142 , wherein the rotor  140  and the stator  142  are dynamically coupled and operable to individually rotate about a first axis  144 . The rotor  140  is further operably coupled to a shaft  146 , wherein the shaft  146  generally extends along the first axis  144  and is operably coupled to the scan arm  138 . In the present example, the rotor  140 , the shaft  146 , and the scan arm  138  are generally fixedly coupled to one another, wherein rotation of the rotor  140  about the first axis  144  generally drives rotation of the shaft  146  and scan arm  138  about the first axis  144 , thus generally translating the workpiece  132  along the first scan path  134 . Alternatively, the rotor  140 , the shaft  146 , and the scan arm  138  may be otherwise coupled to one another, wherein the rotation of the rotor  140  and/or shaft  146  may drive an approximate linear translation of the scan arm  138  with respect to the first axis  144 , as will be further discussed infra. 
         [0039]    In one example, a process medium, such as the ion beam  148  ( FIG. 1C ), serves as the generally stationary reference, wherein the process chamber  128  is operable to move with respect to the process medium  148 , for example, rotate about a second axis  154  ( FIGS. 1B ,  1 D) and angle θ  149 . The process medium  148 , for example, may be alternatively associated with other semiconductor processing technologies. For example, the process medium  148  may comprise a light source associated with a lithography process. Accordingly, the present invention contemplates any process chamber  128  and process medium  148  operable to be utilized in processing the workpiece  132  ( FIG. 1D ), whether the process chamber  128  be enclosed, non-enclosed, fixed, or transitory, and all such process chambers and process mediums are contemplated as falling within the scope of the present invention. 
         [0040]    In accordance with another exemplary aspect of the invention, the motor  136  comprises a rotor  140  and a stator  142  ( FIG. 1D ), wherein the rotor  140  and the stator  142  are operable to individually rotate about a first axis  144 , and wherein an electromagnetic force between the rotor  140  and the stator  142  generally drives a rotation of the rotor  140  about the first axis  144 . For example, a control of the electromagnetic force between the rotor  140  and the stator  142  is operable to selectively drive the rotation of the rotor  140  in a clockwise or counter-clockwise direction about the first axis  144 , as will be discussed infra. In another example, the motor  136  further comprises a motor housing  156 , wherein the motor housing  156  is generally stationary with respect to the first axis  144 . The motor housing  156  in the present example generally encases the rotor  140  and stator  142  and further generally serves as the generally stationary reference for the rotation of the rotor  140  and stator  142 . A least a portion of the rotor  140  and stator  142  generally reside within the motor housing  156 , however, the motor housing  156  need not enclose the rotor  140  and the stator  142 . Accordingly, the rotor  140  and the stator  142  are operable to individually rotate with respect to the motor housing  156 , wherein the motor housing  156  is further operable to generally support the rotor  140  and the stator  142  therein. It should be noted that while the present example describes the motor housing  156  as being the generally stationary reference, other generally stationary references may be alternatively defined. 
         [0041]    The motor  136 , in one example, comprises a brushless DC motor, such as a three-phase brushless DC servo motor. The motor  136 , for example, may be sized such that a substantially large diameter of the motor (e.g., a respective diameter of the stator  140 , and/or the rotor  142 ) provides a substantially large torque, while maintaining a moment of inertia operable to provide rapid control of the rotation of the rotor  142 . The reciprocating drive system  130  further comprises a shaft  146  operably coupled to the motor  136 , wherein in one example, the shaft  146  is fixedly coupled to the rotor  140  and generally extends along the first axis  144  into the process chamber  128 . Preferably, the rotor  140  is directly coupled to the shaft  135 , as opposed to being coupled via one or more gears (not shown), wherein such a direct coupling maintains a substantially low moment of inertia associated with the rotor, while further minimizing wear and/or vibration that may be associated with the one or more gears. 
         [0042]    According to another example, the process chamber  128  comprises an aperture  157  therethrough, wherein the shaft  146  generally extends through the aperture  157  from the external environment  158  to the internal environment  159 , and wherein the motor  136  generally resides in the external environment  158 . Accordingly, the shaft  146  is operable to rotate about first axis  144  in conjunction with the rotation of the rotor  140 , wherein the shaft  146  is generally rotatably driven by the rotor  140  in alternating, opposite directions. In the present example, the shaft  146  may be substantially hollow, thereby providing a substantially low inertial mass. Likewise, the rotor  140  may be substantially hollow, further providing a substantially low rotational inertial mass. 
         [0043]    One or more low-friction bearings  150 , for example, are further associated with the motor  136  and the shaft  146 , wherein the one or more low-friction bearings rotatably couple one or more of the rotor  140 , the stator  142 , and the shaft  146  to a generally stationary reference  152 , such as the housing  146  or the process chamber base  160 . The one or more low-friction bearings  150 , for example, generally provide a low coefficient of friction between the respective rotor  140 , stator  142 , shaft  146 , and motor housing  156 . In another example, at least one of the one or more low-friction bearings  150  may comprise an air bearing (not shown), a liquid field environment, or other bearing known in the art. 
         [0044]    In accordance with another exemplary aspect of the invention, the reciprocating drive apparatus  130  is partitioned from the process chamber  128 , such that minimum wear and contamination occurs within the internal environment  162 . For example, the shaft  146  is generally sealed between the process chamber  128  and the external environment  158  by a rotary seal associated with the shaft and the process chamber, wherein the internal environment  162  within the process chamber is generally isolated from the external environment. 
         [0045]    The reciprocating drive apparatus system  160  further comprises a scan arm  138  operably coupled to the shaft  146 , wherein the scan arm  138  is operable to support the workpiece  132  thereon. According to another example, the scan arm  138  comprises an elongate arm  164  extending radially from the first axis  144 , wherein the elongate arm  164  is generally fixedly coupled to the shaft  146 , wherein the rotation of the shaft  146  about the first axis generally translates the workpiece  132  with respect to the first axis  144 . In one example, the scan arm  132  is coupled to the shaft  146  at a center of gravity of the scan arm  132 , wherein the scan arm  132  is substantially rotationally balanced about the first axis  144 . In another example, the scan arm  132  is comprised of a light weight material, such as magnesium or aluminum. 
         [0046]    The scan arm  138  may further comprise an end effector  135  operably coupled thereto, whereon the workpiece  132  is generally supported thereon. The end effector  135 , for example, comprises an electrostatic chuck (ESC) or other workpiece clamping device is operable to selectively clamp or maintain the workpiece  132  with respect to the end effector  135 . The end effector  135  may comprise various other devices for maintaining a grip of the workpiece  132 , such as a mechanical clamp or various other retaining mechanisms as may be known by those of ordinary skill in the art, and all such devices are contemplated as falling within the scope of the present invention. 
         [0047]    In another example, the scan arm  138  may further comprise a counterweight  166  operably coupled thereto, wherein the counterweight  166  generally balances a mass of the scan arm  138 , end effector  135 , and the workpiece  132  about the first axis  144 . Such a counterweight  166  may advantageously assist in centering the mass moment of inertia of the scan arm  138  about the first axis  144 , thus dynamically balancing the scan arm  138  about the first axis  144 . Accordingly, the scan arm  138 , shaft  144 , rotor  140 , and stator  142  are generally dynamically balanced about the first axis  144 , thus generally eliminating side load forces, other than gravitational forces. The counterweight  166 , for example, may be comprised of heavier metal than the scan arm  138 , such as steel. 
         [0048]    In the case where the reciprocating drive apparatus  130  of the present invention is utilized in an ion implantation system, the reciprocating drive apparatus  130  may further comprise a load lock chamber/air management system  104  associated with the process chamber  128 , wherein scan arm  138  is further operable to rotate and/or translate the end effector  135  to the load lock chamber/AMS  104  in order to insert or remove workpieces  132  to or from the process chamber. Furthermore, a Faraday cup  167  is provided within the process chamber  138  and positioned within a path of the ion beam  148 , wherein the Faraday cup  167  is operable to generally sense a beam current associated with the ion beam  148 . Accordingly, the sensed beam current can be utilized for subsequent process control. 
         [0049]    According to another exemplary aspect, the end effector  135  may be rotatably coupled to the scan arm  138  about a second axis  160 , wherein the end effector  135  is operable to rotate about the second axis. An end effector actuator  170  may be operably coupled to the scan arm  138  and the end effector  135 , wherein the end effector actuator  170  is operable to rotate the end effector  135  about the second axis  168 . The second axis  168 , for example, is generally parallel to the first axis  144 , wherein the process chamber  128  may be operable, for example, to selectively rotate the workpiece  132  relative to the ion beam  148  to vary the so-called “twist angle” of implant, as will be understood by those of ordinary skill in the ion implantation art. The process chamber  128  can be rotated about the third axis  172 , an angle θ  149 , for example, forty five degrees (45°) to implant the workpiece  132  at that angle as illustrated in  FIGS. 1B and 1C . Alternatively, the rotatable coupling of the end effector  136  to the scan arm  138  may be utilized to maintain a rotational orientation (e.g., a rotational orientation  174  of  FIG. 1E ) of the workpiece  136  with respect to the ion beam  148  by continuously controlling the rotation of the end effector  135  about the second axis  154 . The end effector actuator  176  of  FIG. 1D  may comprise a motor (not shown) or mechanical linkage (not shown) associated with the scan arm  138  operable to maintain the rotational orientation of the workpiece  132  with respect to the ion beam  148 . Alternatively, the end effector actuator  176  may comprise a pivot mount (not shown) associated with the second axis  154  ( 240 ), wherein inertial forces associated with the workpiece  132  are operable to maintain the rotational orientation of the workpiece  132  with respect to the ion beam  148 . Maintaining the rotational orientation of the workpiece  132  with respect to the ion beam  148  is advantageous when the ion beam  148  impinges on the workpiece  132  at a non-orthogonal angle θ  149 , and/or when a crystalline or other structure associated with the workpiece (e.g., a semiconductor substrate, or a substrate having structures formed thereon) plays a role in the uniformity of the ion implantation. 
         [0050]    According to another aspect of the present invention, a robot  112  can pick up a workpiece from a storage component (not shown) in the first zone  108  and translate it into a second zone  110 . The robot  112  can be stationary or it can translate along a linear or curvilinear path (not shown). The workpiece can be grasped utilizing robotic arms  114  that are able to translate or rotate, as is well known by those of ordinary skill in the art. 
         [0051]    Referring now to  FIG. 1E  an exemplary rotation  178  of the shaft  146  about the first axis  144  of  FIG. 1D  is illustrated, wherein the scan arm  138 , end effector  135 , and workpiece  132  are further rotated about the first axis  144 . Accordingly, the workpiece  132  can be reciprocally translated along a first scan path  180  with respect to the ion beam  148  (e.g., via one or more cyclical counter-rotations of the shaft  146  about the first axis  144 ), wherein the ion beam  148  of  FIGS. 1B ,  1 C and  1 D is illustrated as going into the page of  FIG. 1E . The rotation  178  (and counter-rotation) of the shaft  146  about the first axis  144  can be advantageously controlled in order to oscillate or reciprocate the end effector  135  along the first scan path  180  in a uniform manner, as will be discussed hereafter.  FIG. 1E  further illustrates a rotation  178  of the end effector  135  about the second axis  154  as discussed above, wherein the rotation  178  of the end effector  135 , and hence, the workpiece  132 , about the second axis  154  can be further controlled in order to maintain the rotational orientation  174  of the workpiece  132  with respect to the first axis  144  or ion beam  148  (e.g., rotational orientation of the workpiece  132  with respect to the ion beam  148  is indicated by a triangle  174  that is fixed with respect to the workpiece  132 ). 
         [0052]    In order to evenly process the workpiece  132 , such as providing an even implantation of ions into the workpiece  132  from the ion beam  148 , it is important to maintain a generally constant translational velocity of the end effector  135  when the workpiece  132  is subject to the ion beam  148  while traveling along the first scan path  180 . Maintaining a generally constant velocity of the end effector  135  while the workpiece  132  passes through the ion beam  148 , for example, provides a generally uniform dose of ions to the workpiece  132 , thus evenly processing the workpiece  132  as it travels along the first scan path  180  in a pendulum-type motion. 
         [0053]    Therefore, in one embodiment, a generally constant velocity is desired for a predetermined scanning range  182  associated with the movement of the workpiece  132  through the ion beam  148 . The predetermined scanning range  182  is generally associated with the physical dimensions of the workpiece  132  (e.g., greater than a diameter D of the workpiece). In the present example, the predetermined scanning range  184  is generally defined by the workpiece  132  traveling a distance greater than a total of the diameter D of the workpiece plus a width of the ion beam  148 , wherein the workpiece  132  travels through the ion beam  148  along the first scan path  180 , and wherein the ion beam  148  is relatively scanned between opposite ends  184  of the workpiece. 
         [0054]    According to another embodiment, a desired velocity profile for the workpiece  132  within the predetermined scanning range  182  may be defined, wherein the desired velocity profile generally depends on a configuration of the reciprocating drive apparatus  130 . For example, depending on whether the workpiece  132  is fixed or rotatable with respect to the scan arm  138 , a respective generally constant velocity or a variable velocity of the rotation  178  of the scan arm (and thus, a respective generally constant or variable velocity of the workpiece  132  along the first scan path  180 ) may be desired. If, for example, the workpiece  132  is rotated with respect to the scan arm  138  in order to maintain the rotational orientation  174  along the first scan path  180 , the rotational velocity of the scan arm about the first axis  144  may be varied when the ion beam  148  nears ends  184  of the predetermined scanning range  182  (e.g., an increase in velocity by about 10% near the ends  184  of the predetermined scan range  184 ) in order to provide a generally uniform dose of ions to the workpiece  132  along the curvilinear path  178 . As another alternative, or in addition to varying the velocity of the scan arm  138 , properties of the ion beam  148 , such as the ion beam current, can be varied in order to produce a generally uniform dosage of ions to the workpiece  132 . 
         [0055]      FIGS. 2A and 2B  illustrate simplified views of an exemplary process chamber system  200  and  250 , respectively operable to rotate the process chamber  128  around a process chamber axis  204 . It should be noted that the main difference between  FIG. 2A  and  FIG. 2B  is that the air diffuser  202  of  FIG. 2A  is illustrated as a fixed or stationary air diffuser  202 , whereas the air diffuser  120  of  FIG. 2B  is a moving air diffuser  120  illustrated to provide an upper-level understanding of the invention, and is not necessarily drawn to scale. Accordingly, various components may or may not be illustrated for clarity purposes. It shall be understood that the various features illustrated can be of various shapes and sizes, or excluded altogether, and that all such shapes, sizes, and exclusions are contemplated as falling within the scope of the present invention. 
         [0056]    As implied by the use of the term “moving air diffuser ”, in one example, the process chamber  128  of the present invention, illustrated in  FIGS. 2A and 2B  are operable to rotate about the process chamber axis  154 , such that the workpiece rotates with respect to a generally stationary ion beam, wherein the apparatus can be utilized with an air management system  104  in an ion implantation process, as will be discussed hereafter in greater detail. Alternatively, the air management system  104  and the moving air diffuser  120  may be utilized in conjunction with various other processing systems, which may include other semiconductor manufacturing processes such as, for example, a step-and-repeat lithography system. In yet another alternative, the air management system  104  can be utilized in various processing systems not related to semiconductor manufacturing technology, and all such systems and implementations are contemplated as falling within the scope of the present invention. 
         [0057]    According to one aspect of the present invention, the process chamber  130  of  FIGS. 2A and 2B  is driven by a motor operably coupled to a gearbox wherein the motor is further operable with a spur gear, for example, to rotate the process chamber, thereon. The air diffuser  202  of  FIG. 2A  is fixedly attached, for example, to the air management system  104  which is attached to and rotates with the process chamber  128 . In other words, in  FIG. 2A , the process chamber  128 , the air management system  128 , and the air diffuser  202  are generally fixedly coupled to one another, wherein rotation of the process chamber  128  about the axis  204  generally drives rotation of the AMS  104  and the air diffuser  202  about the axis  204 . As illustrated in  FIG. 2A , the center of the air diffuser  202  initially starts out at angle α  206  which in this example is zero degrees (0°), for example. A customer may request an ion implantation angle of forty five degrees (45°) as described supra. When the process chamber  128  in  FIG. 2A  is rotated clockwise forty five degrees (45°) (angle β  208 ) the air management system  104  and the air diffuser  202  rotate clockwise forty five degrees (45°), as well. 
         [0058]      FIG. 2A  illustrates a robot  112  having a robotic arm  114  for loading workpieces between an equipment/environmental front end module (EFEM)  102  and AMS  104 , that were described in detail supra. As illustrated, the robot is able to load the workpieces when the process chamber is at angle α (0°) however the robot  112  is unable to load workpieces at angle β (45°) because the air diffuser  202 , the interface opening between the EFEM  102  and the AMS  104 , is too far away. In this case the process chamber has to be rotated counterclockwise from angle β  208  to a predetermined angle that is less than angle β  208  and greater than or equal to angle α  206 . This additional movement of the process chamber  128  increases cycle times or the need for additional robots, for example, at a time when manufacturers are being driven to reduce cycle times for processing wafers and manufacturers want to limit the floor space allocated to robotics, process chambers and the like. Therefore a need clearly exists to reduce cycle time and allocated equipment space. 
         [0059]    Alternatively, the system  250  illustrated in  FIG. 2B  meets the goals outlined above utilizing a moving air diffuser  120 , as will be further discussed infra.  FIG. 2B  is a simplified top cross-sectional view of an exemplary process chamber system  250  similar to the one shown in  FIG. 2A , however, the air diffuser  120  is mechanically coupled to the process chamber  128  so that they rotate in opposite directions to each other. The mechanical coupling can be executed using a belt drive, a gear train, a mechanical linkage and the like. As seen in  FIG. 2B , the air diffuser  120  is generally integral to an air transfer system  104 , wherein the air diffuser  120  is generally configured to translate along a path allowing a process chamber to rotate relative to the equipment front end module. The translation in this embodiment is along an arcuate path, however any path is contemplated within this invention, for example, a linear path, a sinusoidal path, a predefined path, etc. The air diffuser  128  further comprises vanes  124  that are shaped and generally positioned to direct airflow in a controlled manner from the outside to the inside of the AMS  104  illustrated in  FIG. 2A . The air diffuser  120  is further configured with a moveable linkage configured to drive the air diffuser  120  in the direction opposite of the direction the process chamber  128  is being driven, for example. 
         [0060]    As illustrated in  FIG. 2B , the process chamber starts out, for example, at angle α (0°) and is rotated 45° clockwise, wherein the air diffuser  120  is driven counterclockwise 22.5°, for example. As illustrated in  FIG. 2B , in contrast to system  200  in  FIG. 2A , a robot  112  can load a workpiece into the air management system  104  when the process chamber  128  has been rotated clockwise  450  because the air diffuser  120  has rotated counterclockwise 22.5°, for example. In yet another alternative, the air diffuser  120  can be designed so that the air diffuser  120  rotates in the direction opposite of the process chamber  128  by the same number of degrees, or in various ratios, and the like. The ratio of the relative angular movement of the process chamber  128  and the air diffuser  120  can be adjusted by adjusting the gearing ratio, for example. Of course, those skilled in the art will recognize many modifications may be made to this configuration, without departing from the scope or spirit of what is described herein, and all such systems and implementations are contemplated as falling within the scope of the present invention. 
         [0061]      FIGS. 2C ,  3 ,  4 ,  5  and  6  illustrate various views of the exemplary interface panel  120  of  FIG. 1A . The interface panel  120  is shown in greater detail, wherein further exemplary aspects of the present invention can be appreciated.  FIG. 2C  illustrates a top front perspective view, wherein the interface panel  120  and a moving air diffuser  106  are illustrated, wherein the moving air diffuser  106  and the interface panel  260  are coupled to each other via respective vee wheels  126  ( FIG. 5 ) and cam followers  204 , wherein the wheels  126  translate along an arcuate track  230 . The vee wheels  126  and cam followers  204 , for example, are configured to rotate thereby translating the air diffuser  106  along the same arcuate path. The air diffuser  106  is connected to movable shields  134  on both sides of the diffuser  106 . The moveable shields  134  are preloaded in tension wherein the shield  134  is either pulled out of or retracted into a shield housing(s)  214 . Thus, the air diffuser  106  is movable about the interface panel  260  therein allowing access of a robotic arm from outside the air management system to enter the air management system illustrated in  FIG. 1A  after the process chamber  128  has been rotated. The shield  134  prevents air from passing through the interface panel  134  at locations where the shield  134  is located, for example. One or more motors, linkages or other force-producing mechanisms (not shown) may be further operably coupled to one or more of the interface panels  120  and the process chamber  128 , wherein controlled rotation of the process chamber  128  and the moving air diffuser  106  may be attained. For example, the controller  151  of  FIG. 1D  may be further configured to selectively position (e.g., rotate or translate) the process chamber  128  thirty five degrees (35°) clockwise and air diffuser  120  thirty five degrees (35°) counterclockwise (e.g., by controlling the motor(s) coupled to the linkage), therein generally controlling the position of the air diffuser  106  relative to the stationary robot, for example.  FIG. 3  illustrates a front view of the interface panel  300  illustrated in  FIG. 2C , for example.  FIG. 5  is a section view B-B as illustrated in  FIG. 4 . The vee wheel  126  is illustrated, wherein the vee wheel  126  rides on and is “captured” by the track  230 , for example. The vee wheel  126  can be flexibly held in place using a modified shoulder screw  235  preloaded with disc springs  231  and  232 , for example that are well known by those of ordinary skill in the art. It is to be appreciated that the interface panel  120  can be constructed in numerous ways, for example, utilizing folding panels, motors and wireless communication, and the like. 
         [0062]      FIG. 7A  illustrates an exemplary air management system  700  discussed above, wherein the air management system  700  comprises an interface panel and a moving air diffuser  120  of  FIG. 2C , for example. The diffuser  120  comprises vanes  124 , for example, configured to direct air entering the EFEM  102  from a fan unit  714  at the upper end of the EFEM  102 , wherein the air (e.g., illustrated as a dashed arrows) is directed through the air diffuser  120  by vanes  124  that direct the air over a platen  126 , wherein particles and/or contaminants are directed away from the workpiece  132 . In one embodiment, a first vane can be set at sixty degrees (60°, angle δ), to horizontal, the second vane can be set at twenty five degrees (60°, angle ε) to horizontal, a third vane can be set at minus sixty degrees (−60°, angle ζ), and the fourth vane may be set to minus twenty five degrees (−25°, angle η). The height of the opening  716  can be fabricated to 305 mm, for example, with the dimensions for the fourth vane  718  and  720 , as shown. As illustrated the dimension  718  is 40 mm and the dimension is 20 mm, for example. It is to be appreciated that of course, those of ordinary skill in the art will recognize many modifications may be made to this configuration, without departing from the scope or spirit of what is described herein, for example, six vanes, equal vane angles, etc. In addition other fluids than air are contemplated e.g., nitrogen, and the like in the present invention and may be utilized with other types and configurations of air management systems  104  without departing from the spirit and the scope of the invention. 
         [0063]      FIG. 7B  illustrates a cross-sectional view of the environmental front end module  102  as it interfaces with the air management system  104 . A moving air diffuser  120  is comprised of vanes  124  that are optimized to re-circulate air above the workpiece so that contaminants, coming in contact with the workpiece in Zone  2  ( 110 ), are minimized. A fan unit  714  supplies clean air to be EFEM  102  that passes through the air diffuser  120  and over at a workpiece platen  124  which then exits the air management system  104  through an adjustable damper  122 .  FIG. 7B  illustrates a flow optimization that was performed using a flow simulation, for example. The pressure between Zone  1  ( 108 ), Zone  2  ( 110 ) and Zone  3  ( 111 ) is maintained to ensure a desired air flow velocity of air that is well-known by one of ordinary skill in the art. 
         [0064]      FIG. 7C  illustrates a semi-transparent cross-sectional view of an air management system  104 . A moving air diffuser  120  is comprised of vanes  124  that are optimized to re-circulate air above the workpiece so that contaminants, coming in contact with the workpiece in Zone  2  ( 110 ), are minimized. A fan unit supplies clean air that passes through the air diffuser  120  and over at a workpiece platen  124  which then exits the air management system  104  through an adjustable damper  122 .  FIG. 7C  illustrates a flow optimization that was performed using a flow simulation, for example. The  FIG. 7C  illustrates that the flow of air over the top of the platen  124  is basically laminar which tends to drive contaminants away from the workpiece. The air flow/pressure tests agree with Computational Fluid Dynamics (CFD) models as a good approximation to be described infra. 
         [0065]    Referring to  FIG. 8 , in one embodiment of the present invention, is a graph at  800  that illustrates representative filter face velocities that were obtained, comparing both average filter velocity (fpm) and velocity uniformity (%) vs. fan filter units power (%). The graph illustrates the data, as plotted on a linear x-axis, and a linear y-axis. The graph  800  includes two different exemplary groupings of curves  802  and  804 , the first curve  802  was obtained by fixing the fan filter unit power at three different levels (e.g., 50%, 75% and 100%) of capacity. The average filter velocity was measure at each of those power levels. The second curve  804  is representative three data points plotted based on velocity uniformity at the three power points discussed supra. For example, it can be seen in the curve  802 ; the system can deliver a maximum of approximately 112 fpm average velocity. Also it is apparent that at approximately 90% of the FFU power and above the velocity uniformity is approximately about 10% or less which meets specification to prevent air flow recirculation. 
         [0066]    In yet another test, according to one embodiment of the present invention, three groups of data  902 ,  904  and  906  were obtained for an air management system, as shown in  FIG. 7C  as a graph  900 , for example. The graph illustrates Zone  1  ( 110 ) to ambient ( 111 ) differential pressure, utilizing a floor damper  777  (e.g.,  FIG. 7C ), for example, that is open 50%. The curves  902 ,  904 , and  906  illustrate the differential pressure (wg) obtained with the fan filter unit  714  ( FIG. 7B ) at 100%, 75% and 50%, respectively and the damper open at 0%, 25%, 50%, 75%, and 100%. Data  902  illustrates that with the floor damper 50% open and the load lock damper closed (0%). 
         [0067]    According to another embodiment a test, three groups of data  1002 ,  1004  and  1006  were plotted for an air management system, as shown in  FIG. 7C  as a graph  1000 , for example. The graph illustrates Zone  1  ( 110 ) to ambient ( 111 ) differential pressure, utilizing a floor damper  777  (e.g.,  FIG. 7C ), for example, that is open 100%. The curves  1002 ,  1004 , and  1006  illustrate the differential pressure (wg) obtained with the fan filter unit  714  ( FIG. 7B ) at 100%, 75% and 50% power, respectively and the damper open at 0%, 25%, 50%, 75%, and 100%. Data  902  illustrates that with the floor damper 50% open and the load lock damper closed (0%).  FIGS. 9 to 14  defines the range the tool operation which a desirable flow across the diffuser could be maintained. 
         [0068]    In yet an additional test, according to yet another embodiment of the present invention, three groups of data  1102 ,  1104  and  1106  were attained for graph  1100  for an air management system, as discussed supra. The graph  1000  illustrates Zone  1  ( 110 ) to Zone  2  ( 108 ) differential pressure, utilizing a floor damper  777  (e.g.,  FIG. 7C ), for example, that is 100% open. The curves  1102 ,  1104 , and  1106  illustrate the differential pressure (wg) obtained with the fan filter unit  714  ( FIG. 7B ) at 100%, 75% and 50%, respectively and the load lock damper open at 0%, 25%, 50%, 75%, and 100%.  FIG. 12  illustrates data similar to the data in  FIG. 11  except the floor damper is set at 50% open. 
         [0069]    Referring to  FIG. 13 , in yet another embodiment of the present invention, is a graph  1300  that illustrates representative flow velocity normal to the interface diffuser with the floor damper at 100% open, that were obtained, comparing both average interface flow velocity (fpm) and velocity (m/s) vs. load lock damper open (%). The graph illustrates the data, as plotted on a linear x-axis, and a linear y-axis. The graph  1300  includes three different exemplary groupings of curves  1302  and  1304 , and  1306 . The point  1308  on curve  1308  is the CFD modeled condition with an average horizontal velocity of 0.5 m/sec. In other words, at 1.0 Pa, the average interface velocity was calculated using the model to equal 0.502 m/sec, whereas the actual test result at 1.04 Pa was 0.502 m/sec. Therefore the theoretical and the test rest are approximately equal.  FIG. 14  is similar to  FIG. 13  except the floor damper, discussed supra is set at 50% open, for example. 
         [0070]    According to still another exemplary aspect of the present invention,  FIG. 15  is a schematic block diagram of an exemplary method  1500  illustrating a method of minimizing the contaminants that settle on a workpiece as the workpiece is moved from the EFEM to a load lock chamber while reducing the cycle time in loading the workpiece. The block diagram  FIG. 15  is according to an exemplary air management system e.g.,  FIGS. 1D and 7C . While exemplary methods are illustrated and described herein as a series of acts or events, it will be appreciated that the present invention is not limited by the illustrated ordering of such acts or events, as some steps may occur in different orders and/or concurrently with other steps apart from that shown and described herein, in accordance with the invention. In addition, not all illustrated steps may be required to implement a methodology in accordance with the present invention. Moreover, it will be appreciated that the methods may be implemented in association with the systems illustrated and described herein as well as in association with other systems not illustrated. 
         [0071]    As illustrated in  FIG. 15 , the method  1500  begins with rotating the semiconductor processing chamber to a desired angle to correspond to an ion implantation angle at  1502 , for example. The processing chamber, for example, comprises an air management system fixedly attached to the chamber for diffusing air across a workpiece loaded inside the air management system or Zone  2 . The air management system comprises a shroud, an interface panel configured with a moving diffuser, wherein the moving diffuser is generally configured with air deflecting vanes, and an adjustable damper configured to control the pressure within Zone  2 . The moving diffuser provides an opening between Zone  1 , the equipment/environmental front end module outside the air management system (AMS). The AMS further comprises a support surface or platen for supporting the workpiece, wherein the moving diffuser is configured to move in order to align a workpiece motion device, e.g., robot, the air diffuser and the platen within the chamber interior of Zone  2  resulting in a reduced workpiece loading time. 
         [0072]    At  1504  the air diffuser is translated along an arcuate path, for example. The air diffuser and process chamber can be driven separately using motors and wireless communication, for example, or the drive rotating the process chamber can also drive a linkage or a gear train for example that drive the air diffuser in a direction opposite to the process chamber. The inventors recognized the advantage of the moveable air diffuser (e.g.,  FIGS. 1D and 2C ) that allowed the movement of the process chamber and yet allowed the concurrent movement of the air diffuser so that transfer mechanisms within the EFEM had immediate access to the load lock chamber platen, for example, thereby reducing cycle times. At  1506  the transfer device, for example, a pick and place robotic arm transfers the workpiece from Zone  1  through the air diffuser opening and into Zone  2 . 
         [0073]    The robot at  1508  can then place the workpiece on a platen and clean air is then supplied by a fan filter unit passes from Zone  1  through the air diffuser opening and deflected by the vanes. The air exits through the adjustable load lock damper and/or a floor damper. The method ends at  1508 . 
         [0074]    Accordingly, the present invention provides a faster cycle time for ion implantation, especially in systems where moving the process chamber relative to the EFEM is performed. It should be further noted that although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described components (assemblies, devices, circuits, etc.), the terms (including a reference to a “means”) used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiments of the invention. In addition, while a particular feature of the invention may have been disclosed with respect to only one of several embodiments, such feature may be combined with one or more other features of the other embodiments as may be desired and advantageous for any given or particular application.