Patent Publication Number: US-7914248-B2

Title: Methods and apparatus for repositioning support for a substrate carrier

Description:
This application is a division of and claims priority to U.S. Non-Provisional patent application Ser. No. 11/180,029, filed Jul. 12, 2005, now U.S. Pat. No. 7,409,263 which claims priority to U.S. Provisional Patent Application Ser. No. 60/587,752, filed Jul. 14, 2004. Both of these patent applications are incorporated herein by reference in their entirety. 
     CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is related to the following commonly-assigned, co-pending U.S. Patent Applications, each of which is hereby incorporated by reference herein in its entirety: 
     U.S. patent application Ser. No. 10/650,310, filed Aug. 28, 2003 and titled “System For Transporting Substrate Carriers”; and 
     U.S. patent application Ser. No. 10/650,480, filed Aug. 28, 2003 and titled “Substrate Carrier Handler That Unloads Substrate Carriers Directly From a Moving Conveyor”. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to semiconductor device manufacturing, and more particularly to methods and apparatus for repositioning support for a substrate carrier. 
     BACKGROUND OF THE INVENTION 
     Manufacturing of semiconductor devices typically involves performing a sequence of procedures with respect to a substrate such as a silicon substrate, a glass plate, etc. These steps may include polishing, deposition, etching, photolithography, heat treatment, and so forth. Usually a number of different processing steps may be performed in a single processing system or “tool” which includes a plurality of processing chambers. However, it is generally the case that other processes are required to be performed at other processing locations within a fabrication facility, and it is accordingly necessary that substrates be transported within the fabrication facility from one processing location to another. Depending on the type of semiconductor device to be manufactured, there may be a relatively large number of processing steps required, to be performed at many different processing locations within the fabrication facility. 
     It is conventional to transport substrates from one processing location to another within substrate carriers such as sealed pods, cassettes, containers and so forth. It is also conventional to employ automated substrate carrier transport devices, such as automatic guided vehicles, overhead transport systems, substrate carrier handling robots, etc., to move substrate carriers from location to location within the fabrication facility or to transfer substrate carriers from or to a substrate carrier transport device. However, a need remains for improved methods and apparatus for supporting substrate carriers during transport operations. 
     SUMMARY OF THE INVENTION 
     In a first aspect of the invention, a first method is provided for repositioning support provided by an end effector. The first method includes the steps of (1) employing the end effector to support a substrate carrier by a bottom of the substrate carrier; (2) transferring the substrate carrier from the end effector to an intermediate support location, wherein the intermediate support location supports the substrate carrier by a bottom of the substrate carrier; (3) repositioning the end effector proximate an overhead transfer flange of the substrate carrier; (4) employing the end effector to support the substrate carrier by the overhead transfer flange of the substrate carrier; and (5) transferring the substrate carrier from the intermediate support location. 
     In a second aspect of the invention, a second method is provided for repositioning support provided by an end effector. The second method includes the steps of (1) employing the end effector to support a substrate carrier by an overhead transfer flange of the substrate carrier; (2) transferring the substrate carrier from the end effector to an intermediate support location, wherein the intermediate support location supports the substrate carrier by a bottom of the substrate carrier; (3) repositioning the end effector proximate the bottom of the substrate carrier; (4) employing the end effector to support the substrate carrier by the bottom of the substrate carrier; and (5) transferring the substrate carrier from the intermediate support location. 
     In a third aspect of the invention, a first substrate carrier transferring system is provided. The first substrate carrier transferring system includes (1) an end effector adapted to support a substrate carrier by a bottom of the substrate carrier and support the substrate carrier by an overhead transfer flange of the substrate carrier; (2) an intermediate support location; and (3) a controller coupled to the end effector and adapted to (a) employ the end effector to support the substrate carrier by the bottom of the substrate carrier; (b) transfer the substrate carrier from the end effector to the intermediate support location, wherein the intermediate support location supports the substrate carrier by the bottom of the substrate carrier; (c) reposition the end effector proximate the overhead transfer flange of the substrate carrier; (d) employ the end effector to support the substrate carrier by the overhead transfer flange of the substrate carrier; and (e) transfer the substrate carrier from the intermediate support location. 
     In a fourth aspect of the invention, a second substrate carrier transferring system is provided. The second substrate carrier transferring system includes (1) an end effector adapted to support a substrate carrier by a bottom of the substrate carrier and support the substrate carrier by an overhead transfer flange of the substrate carrier; (2) an intermediate support location; and (3) a controller coupled to the end effector and adapted to (a) employ the end effector to support the substrate carrier by the overhead transfer flange of the substrate carrier; (b) transfer the substrate carrier from the end effector to the intermediate support location, wherein the intermediate support location supports the substrate carrier by the bottom of the substrate carrier; (c) reposition the end effector proximate the bottom of the substrate carrier; (d) employ the end effector to support the substrate carrier by the bottom of the substrate carrier; and (e) transfer the substrate carrier from the intermediate support location. Numerous other aspects are provided, as are methods, systems, apparatus and computer program products in accordance with these and other aspects of the invention. Each computer program product described herein may be carried by a medium readable by a computer (e.g., a carrier wave signal, a floppy disc, a compact disc, a DVD, a hard drive, a random access memory, etc.). 
     Other features and aspects of the present invention will become more fully apparent from the following detailed description, the appended claims and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of a conventional front opening unified pod (FOUP) being supported by an end effector in accordance with an embodiment of the present invention. 
         FIG. 2  is a top view of the FOUP of  FIG. 1 . 
         FIG. 3  is a bottom view of the FOUP of  FIG. 1 . 
         FIG. 4  is an isometric view of the end effector and an intermediate support location of  FIG. 1  in accordance with an embodiment of the present invention. 
         FIG. 5A  is an isometric view of the bottom surface of the end effector of  FIG. 1  in accordance with an embodiment of the present invention. 
         FIG. 5B  is a side view of the end effector of  FIG. 1  in accordance with an embodiment of the present invention. 
         FIG. 6  illustrates an exemplary method for repositioning support provided by an end effector in accordance with an embodiment of the present invention. 
         FIG. 7  illustrates an end effector employed to support a substrate carrier by a bottom of the substrate carrier (e.g., FOUP) in accordance with an embodiment of the present invention. 
         FIG. 8  illustrates the end effector of  FIG. 7  directly above the intermediate support location in accordance with an embodiment of the present invention. 
         FIG. 9  illustrates the intermediate support location of  FIG. 7  employed to support the bottom side of the FOUP in accordance with an embodiment of the present invention. 
         FIG. 10  illustrates the end effector of  FIG. 7  positioned directly below the intermediate support location while the intermediate support location supports the FOUP in accordance with an embodiment of the invention. 
         FIG. 11  illustrates the end effector of  FIG. 7  positioned below the FOUP supported by the intermediate support location such that no portion of the end effector is underneath the FOUP in accordance with an embodiment of the present invention. 
         FIG. 12  illustrates the end effector of  FIG. 7  positioned slightly higher than the FOUP in accordance with an embodiment of the present invention. 
         FIG. 13  illustrates the end effector of  FIG. 7  positioned proximate the FOUP in accordance with an embodiment of the present invention. 
         FIG. 14  illustrates the end effector of  FIG. 7  supporting the FOUP by an OHT flange of the FOUP in accordance with an embodiment of the present invention. 
         FIG. 15  illustrates the end effector of  FIG. 7  supporting the FOUP directly above the intermediate support location in accordance with an embodiment of the present invention. 
         FIG. 16  illustrates the end effector and the FOUP of  FIG. 7  positioned higher than the intermediate support location and such that no portion of the end effector and the FOUP is over the intermediate support location in accordance with an embodiment of the present invention. 
         FIG. 17  illustrates the end effector and the FOUP of  FIG. 7  transferred from the intermediate support location in accordance with an embodiment of the present invention. 
         FIG. 18  illustrates a second exemplary method for repositioning support provided by an end effector in accordance with an embodiment of the present invention. 
         FIG. 19  is a schematic, front view of a system for transporting substrate carriers in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     A substrate carrier, such as a conventional front opening unified pod (FOUP), may store one or more substrates. During a semiconductor device manufacturing process, the substrate carrier is transferred from a first location to a second location of the semiconductor device manufacturing facility using a transporting device, such as an end effector of a robot arm. The transporting device may transfer (e.g., by lifting) the substrate carrier from the first location by supporting a first end (e.g., a top end) of the substrate carrier. In accordance with the present invention, however, the transporting device may then transfer the substrate carrier to the second location by supporting a second end (e.g., a bottom end) of the substrate carrier or vice versa. For example, the support provided to the substrate carrier may be repositioned from the first end to the second end of the substrate carrier during transfer. Accordingly, the present methods and apparatus provide for repositioning support of a substrate carrier. 
       FIG. 1  is an isometric view of a conventional front opening unified pod (FOUP)  101  being supported by an end effector  103  in accordance with an embodiment of the present invention. In one embodiment, the FOUP  101  may be a cube. Although shown as a cube in  FIG. 1 , the FOUP  101  may assume other shapes. The FOUP  101  may include a plurality of sides or surfaces including a top side  109  and a bottom side (not shown in  FIG. 1 ). The FOUP  101  may include a handle  105  on one or more sides, which may be used for manually carrying the FOUP  101 . The FOUP  101  includes an overhead transfer (OHT) flange  107  coupled to the top side or surface  109  of the FOUP  101 . The OHT flange  107  may include a plurality of flanges  111  on and/or extending from a base  114 . The OHT flange  107  or the bottom side (not shown in  FIG. 1 ) of the FOUP  101  are adapted to couple to a transporting device, such as the end effector  103 . 
     The end effector  103  includes a top side  113  and a bottom side  115 . Details of the top side  113  and the bottom side  115  of the end effector  103  are described below with reference to  FIGS. 4 and 5 , respectively. The end effector  103  may be employed for supporting the FOUP  101 , for example, during transfer. More specifically, the bottom side  115  of the end effector  103  may support the FOUP  101  using (e.g., by) a top side  109  of the FOUP  101  (e.g., the OHT flange  107 ). Alternatively, as shown in  FIG. 1 , the top side  113  of the end effector  103  may support the FOUP  101  using (e.g., by) the bottom side of the FOUP  101 . 
       FIG. 1  includes an isometric view of an intermediate support location  117  in accordance with an embodiment of the present invention. In one embodiment, the intermediate support location  117  may be a shelf. The intermediate support location  117  may include other types of supports. The intermediate support location  117  supports the FOUP  101  while the end effector  103  is repositioned from providing support to a first side (e.g., the bottom side) of the FOUP  101  to a second side (e.g., the top side  109 ) of the FOUP  101  (or vice versa). In the embodiment shown in  FIG. 1 , the intermediate support location  117  supports the FOUP  101  by the bottom side (not shown in  FIG. 1 ) of the FOUP  101 . In other embodiments, the intermediate support location  117  may support the FOUP  101  by another and/or additional sides of the FOUP  101 . 
       FIG. 2  is a top view of the FOUP  101  of  FIG. 1 . A top surface  201  of the OHT flange  107  may include one or more flange slots  203  for providing alignment with the end effector  103  or a support device, such as the intermediate support location  117  of  FIG. 1 . In one embodiment, the top surface  201  or bottom surface (not shown) of the OHT flange  107  includes three flange slots  203 . Other numbers of slots  203  may be employed. Further, different embodiments may include slots  203  of different lengths, depths and/or shapes and/or slot locations. 
       FIG. 3  is a bottom view of the FOUP  101  of  FIG. 1 . The bottom surface  301  of the FOUP  101  includes one or more FOUP slots  303  for providing alignment with the end effector  103  or a support device, such as the intermediate support location  117  of  FIG. 1 . In one embodiment, the bottom surface  301  of the FOUP  101  includes three FOUP slots  303 . Other numbers of FOUP slots  303  may be employed. Further, different embodiments may include FOUP slots  303  of different lengths, depths, shapes and/or slot locations. 
       FIG. 4  is an isometric view of the end effector  103  and the intermediate support location  117  of  FIG. 1  in accordance with an embodiment of the present invention. The top surface  113  of the end effector  103  may include one or more end effector pins  401 . The one or more end effector pins  401  couple to (e.g., are inserted in) corresponding FOUP slots  303  ( FIG. 3 ) included in the bottom surface  301  of the FOUP  101  when the end effector supports the bottom surface  301  of the FOUP  101 . The FOUP slots  303  and the one or more end effector pins  401  are designed such that coupling the one or more end effector pins  401  with corresponding FOUP slots  303  aligns the FOUP  101  with the end effector  103 . Similarly, the intermediate support location  117  may include one or more support location pins  403  (e.g., on a top side of the support location). The one or more support location pins  403  couple to (e.g., are inserted in) corresponding FOUP slots  303  when the intermediate support location  117  supports the bottom surface of the FOUP  101 . The FOUP slots  303  and the one or more support location pins  403  are designed such that coupling the one or more support location pins  403  with corresponding FOUP slots  303  aligns the FOUP  101  with the intermediate support location  117 . In the embodiment of  FIG. 4 , three end effector pins  401  and/or three support location pins  403  are employed, although other numbers of pins may be used. In one embodiment, the one or more end effector pins  401  and/or the one or more support location pins  403  are kinematic pins. Other types of pins may be employed. Further, the one or more end effector pins  401  and/or support location pins  403  may include sensors  405  (e.g., for detecting accurate carrier placement). Kinematic pins that employ sensors are described in U.S. Pat. No. 6,573,522 B2, filed Jun. 3, 2003 and titled “LOCATOR PIN INTEGRATED WITH SENSOR FOR DETECTING SEMICONDUCTOR SUBSTRATE CARRIER,” which is hereby incorporated by reference herein in its entirety. 
     The end effector  103  may be coupled to a controller  407 , which is adapted to move (e.g., control movement of) the end effector  103  in one or more directions. For example, the controller  407  may be adapted to move the end effector along the x-axis, y-axis and/or z-axis ( FIG. 4 ). The end effector  103 , the intermediate support location  117  and the controller  407  may form a substrate carrier transferring system  409 . 
     In the embodiment of  FIG. 4 , the shape of the end effector  103  and the positioning of the one or more end effector pins  401  are designed to compliment the shape of the intermediate support location  117  and the positioning of the of the one or more support location pins  403  thereon. More specifically, when the end effector  103  and the intermediate support location  117  are in the same plane (e.g., xy-plane), each of the end effector pins  401  of the end effector  103  and each corresponding support location pin  403  of the intermediate support location  117  may couple to (e.g., be inserted in) a respective FOUP slot  303 . During this time, both the end effector  103  and the intermediate support location  117  may support the FOUP  101  (e.g., via a bottom surface of the FOUP  101 ). 
       FIG. 5A  is an isometric view of the bottom surface  115  of the end effector  103  in accordance with an embodiment of the present invention. The bottom side  115  of the end effector  103  may include one or more end effector flanges  501 . As stated above, the bottom side  115  of the end effector  103  may support the FOUP  101  using the top side  109  of the FOUP  101 . More specifically, the one or more end effector flanges  501  are adapted to couple to the OHT flange  107 , for example, by sliding beneath the OHT flange  107 . In this manner, the end effector  103  supports the FOUP  101  using the OHT flange  107 . In one embodiment, the end effector  103  includes four end effector flanges  501 . Other numbers of end effector flanges  501  may be employed. Further, different embodiments may include end effector flanges  501  of different shapes, positions and/or sizes. In one embodiment, one or more of the end effector flanges may include and/or be coupled to an end effector sensor  503  for ensuring proper alignment of the end effector flanges  501  with the OHT flange  107 . For example, the end effector sensor  503  may indicate when the one or more end effector flanges  501  are properly positioned relative to the OHT flange  107 . 
       FIG. 5B  is a side view of the end effector  103  in accordance with an embodiment of the present invention. With reference to  FIG. 5B , a top surface  505  of one or more of the end effector flanges  501  may include one or more end effector pins  401 . The one or more end effector pins  401  on the top surface  505  of the end effector flanges  501  couple to (e.g., are inserted in) corresponding OHT flange slots (not shown) included in a bottom surface (not shown) of the OHT flange  107  when the end effector  103  supports the FOUP  101  by the OHT flange  107 . The OHT flange slots and the one or more end effector pins  401  on the top surface  505  of the end effector flanges  501  are designed such that coupling the one or more end effector pins  401  with corresponding OHT flange slots aligns the FOUP  101  with the end effector  103 . 
     Exemplary operation of the substrate carrier transferring system  409  ( FIG. 4 ) is now described with reference to  FIGS. 1-6  and with reference to  FIGS. 7-17 , which illustrate an exemplary method  601  for repositioning support provided by an end effector  101  in accordance with an embodiment of the present invention. More specifically, an exemplary method for repositioning support provided by the end effector  103  to a substrate carrier (e.g., FOUP  101 ) from a first side to a second side of the FOUP  101  is described. One or more of the steps of method  601  may, for example, be implemented via computer program code executed by the controller  407  and stored in a memory in, coupled to or otherwise associated with the controller  407  such as in any suitable computer readable medium (e.g., a carrier wave signal, a floppy disc, a compact disc, a DVD, a hard drive, a random access memory, etc.). 
     With reference to  FIG. 6 , in step  603 , the method  601  begins. In step  605 , an end effector  103  is employed to support a substrate carrier by a bottom side  301  of a substrate carrier (e.g., FOUP  101 ). The controller  407  may be employed to move the end effector such that the end effector pins  401  of the top surface  113  of the end effector  103  couple to the FOUP slots  303  included in the bottom surface  301  of the FOUP  101  thereby coupling the top surface  113  of the end effector  103  to the bottom side  301  of the FOUP  101 . In this manner, the end effector  103  supports the bottom side  301  of the FOUP  101 . The controller  407  may be employed to move the end effector  103  along one or more of the x, y and z axes to couple the end effector  103  to the FOUP  101  as described above.  FIG. 7  illustrates an end effector  103  employed to support a substrate carrier by a bottom of the substrate carrier (e.g., FOUP  101 ) in accordance with an embodiment of the present invention. For example, the end effector  103  may have removed the FOUP  101  from another support shelf that supports the FOUP  101  via the bottom thereof, or from an overhead conveyor system that supports the FOUP via the OHT flange thereof. As shown in  FIG. 7 , the FOUP  101  is fully supported by the end effector  103 . 
     In step  607 , the substrate carrier (e.g., FOUP  101 ) is transferred from the end effector  101  to an intermediate support location  117 . The intermediate support location  117  supports the bottom  301  of the substrate carrier (e.g., FOUP  101 ). For example, the controller  407  may move the end effector  103 , while the end effector is supporting a bottom side  301  of the FOUP  101 , along the z-axis (e.g., vertically upward or downward) such that the end effector is proximate (e.g., slightly higher) than the intermediate support location  117  (as shown in  FIG. 7 ). 
     The controller  407  then moves the end effector  103 , while the end effector  103  is supporting the bottom side  301  of the FOUP  101 , along the x-axis (e.g., horizontally left or right) such that the end effector  103  is directly above the intermediate support location  117 .  FIG. 8  illustrates the end effector  103  of  FIG. 7  directly above the intermediate support location  117  in accordance with an embodiment of the present invention. The end effector  103  fully supports the FOUP  101  by the bottom side  301  of the FOUP  101 . 
     The controller  407  then moves the end effector  103 , while the end effector  103  is supporting the bottom side  301  of the FOUP  101 , along the z-axis (e.g., vertically downward). While the end effector  103  moves downward along the z-axis, the end effector  103  fully supports the bottom side  301  of the FOUP  101 . However, as the end effector  103  approaches the position shown in  FIG. 9  (e.g., the position where the end effector  103  and the intermediate support location  117  are in the same xy-plane or where the xy-plane of the end effector  103  is slightly higher or lower than the xy-plane of the intermediate support location  117 , depending on the relative height of the pins  401 ,  403 ), the end effector  103  and the intermediate support location  117  may both support the bottom side  301  of the FOUP  101 . For example, each of the end effector pins  401  of the end effector  103  and each corresponding support location pin  403  of the intermediate support location  117  may couple to (e.g., insert into) a respective FOUP slot  303  supporting the bottom side  301  of the FOUP  101 . The amount of time that both the end effector  103  and the intermediate support location  117  support the bottom side  301  of the FOUP  101  may be brief (e.g., one second or less).  FIG. 9  illustrates the intermediate support location  117  employed to support the bottom side  301  of the FOUP  101  in accordance with an embodiment of the present invention. 
     As the controller  407  continues to move the end effector  103  vertically downward, the FOUP  101  continues to be supported from the bottom side  301  by the intermediate support location  117 , and the end effector pins  401  disengage from the FOUP slots  303 . Therefore, the end effector  103  no longer supports the FOUP  101  and the intermediate support location  117  may fully support the FOUP  101  by the bottom (e.g., bottom side) of the FOUP  101 . Thus, the FOUP  101  is successfully transferred from the end effector  103  to the intermediate support location  117  (as shown in  FIG. 10 ). 
     In step  609 , the end effector  103  is repositioned proximate an overhead transfer (OHT) flange  107  of the substrate carrier (e.g., FOUP  101 ). The controller  407  is employed for moving the end effector  103 , which is not supporting the FOUP  101 , along one or more of the x, y, and z axes to reposition the end effector  103  proximate the OHT flange  107 . For example, the controller  407  may move the end effector  103  vertically downward after the FOUP  101  is transferred from the end effector  103  to the intermediate support location  117 . Such vertically downward movement may be continuous with the vertically downward movement of step  607  or separate movements may be used. As a result of the vertically downward movement, the end effector  103  is directly below the intermediate support location  117  while the intermediate support location  117  supports the FOUP  101 .  FIG. 10  illustrates the end effector  103  positioned directly below the intermediate support location  117  while the intermediate support location  117  supports the FOUP  101  in accordance with an embodiment of the invention. The end effector  103  is far enough below the bottom surface  301  of the FOUP  101  such that the end effector pins  401  do not contact the intermediate support location  117  during any horizontal movement of the end effector  103  (a smaller or larger vertical distance than that shown in  FIG. 10  may be used, as may be a combination of vertical and horizontal movements). 
     The controller  407  may then move the end effector  103  horizontally, for example, along the x-axis. The controller  407  moves the end effector  103 , for example into an open region or tunnel (see, for example, open region  1911  in  FIG. 19 ), such that no portion of the end effector  103  is underneath the FOUP  101 , which is supported by the intermediate support location  117 . The tunnel defines an area in which the end effector may be moved along the z-axis (e.g., vertically), for example, without contacting other equipment or apparatus employed during the semiconductor device manufacturing process. For example, the tunnel may be a path between columns of shelves and/or load ports of a processing tool.  FIG. 11  illustrates the end effector  103  positioned below the FOUP  101  supported by the intermediate support location  111  such that no portion of the end effector  103  is underneath the FOUP  101  in accordance with an embodiment of the present invention. 
     The controller  407  then moves the end effector  103  along the z-axis (e.g., vertically in the tunnel) such that the end effector  103  is slightly higher than the FOUP  101 . More specifically, the end effector  103  is moved such that the bottom side  115  of the end effector  103  is higher (e.g., vertically) than the top surface of the FOUP&#39;s OHT flange  107  and such that the end effector flanges  501  of the end effector  103  and any raised features (such as the vertically oriented kinematic pins  401  shown in the side elevational view of  FIG. 5B ) are lower (e.g., vertically) than the OHT flange  107 . Because the end effector  103  is moving in an open region, the end effector  103  will not contact other equipment or apparatus employed during the semiconductor device manufacturing process.  FIG. 12  illustrates the end effector  103  positioned slightly higher than the FOUP  101 , as described above, in accordance with an embodiment of the present invention. 
     The controller  407  moves the end effector  103  horizontally (e.g., along the x and/or y axes) such that the bottom side  115  of the end effector  103  is directly above the top surface  201  of the OHT flange  107  and the end effector flanges  501  are directly below the OHT flange  107 . If the end effector  103  is moved upward along the z-axis, the end effector flanges  501  will couple to the OHT flange  107  (e.g., via kinematic pins  401  that provide final alignment between the end effector  103  and the FOUP  101  and that prevent the FOUP  101  from sliding during movement in the X-direction). In this manner, the end effector  103  is repositioned proximate the OHT flange  107  of the FOUP  101 .  FIG. 13  illustrates the end effector  103  positioned proximate the FOUP  101 , as described above, in accordance with an embodiment of the present invention. 
     In step  611 , the end effector  103  is employed to support the substrate carrier (e.g., FOUP  101 ) by the OHT flange  107  of the substrate carrier (e.g., FOUP  101 ). The controller  407  moves the end effector  103  upward along the z-axis (e.g., vertically). While the end effector  103  is moved upward along the z-axis, the end effector flanges  501  couple to and support the OHT flange  107 . As a result of the upward movement of the end effector  103 , the FOUP  101  is lifted upward along the z-axis from the intermediate support location  117 . Consequently the support location pins  403  of the support location  117  disengage from corresponding FOUP slots  303 . Therefore, the end effector  103  fully supports the FOUP  101  by the OHT flange  107  of the FOUP  101 .  FIG. 14  illustrates the end effector  103  supporting the FOUP  101  by the OHT flange  107  of the FOUP  101  in accordance with an embodiment of the present invention. 
     In step  613 , after the end effector  103  supports the substrate carrier by its OHT flange, the substrate carrier, (e.g., FOUP  101 ) is transferred from the intermediate support location  117 . For example, the FOUP  101  may be placed into a processing or load lock chamber (not shown). The end effector  103  is moved, and therefore the FOUP  101  is lifted upward along the z-axis such that the support location  117  pins do not contact the bottom side  301  of the FOUP  101  during any horizontal movement of the end effector  103  and the FOUP  101 . Thus, the end effector  101  supports the FOUP  101  directly above the intermediate support location  117 , as shown in  FIG. 15 . 
     The controller  407  moves the end effector  103  horizontally (e.g., along the x and/or y axes), for example into the open region or tunnel, such that no portion of the end effector  103  and the FOUP  101 , which is supported by the end effector  103 , is over (e.g., extends above) the intermediate support location  117 .  FIG. 16  illustrates the end effector  103  and the FOUP  101  positioned higher than the intermediate support location  117  and such that no portion of the end effector  103  and the FOUP  101  is over the intermediate support location  117  in accordance with an embodiment of the present invention. 
     The controller  407  moves the end effector  103  and the FOUP  101  supported by the end effector  103 , along the z-axis (e.g., vertically) to position the FOUP  101  relative to another component, such as a load lock chamber (not shown), docking station of a processing tool, or the like, included in the semiconductor device manufacturing facility. The controller  407  may move the end effector  103  and the FOUP  101  horizontally (e.g., along the x and/or y axis) to position the FOUP  101  relative to the component. In this manner, the FOUP  101  is transferred from the intermediate support location  117 .  FIG. 17  illustrates the end effector and the FOUP transferred from the intermediate support location  117  (e.g., and being transported to any other desired location such as a load lock chamber, a docking station of a processing tool, another support location, a storage shelf, a conveyer system, etc.) in accordance with an embodiment of the present invention. 
     In step  615 , the method  601  ends. Through the use of the method  601  of  FIG. 6 , support provided by an end effector  103  is repositioned. More specifically, the support provided by the end effector  103  to a substrate carrier (e.g., FOUP  101 ) may be repositioned from a first end (e.g., bottom side  301 ) of the FOUP  101  to a second end (e.g., a top side  109 ) of the FOUP  101  while the FOUP  101  is transferred from a first location to a second location in the semiconductor device manufacturing facility. The present method is advantageous when the FOUP  101  is more conveniently transferred from the first location using the first end of the FOUP  101  and more conveniently transferred to the second location using the second end of the FOUP  101 . 
     In one particular embodiment, the method  601  may be used as part of an operation to transfer a substrate carrier from an overhead conveyor system that supports substrate carriers via an overhead transfer flange, to a load port of a processing tool that supports substrate carriers via a bottom side of the substrate carriers. For example, the end effector  103  may be used to remove a substrate carrier from an overhead conveyor system as described in previously incorporated U.S. patent application Ser. Nos. 10/650,310 and 10/650,480, both filed Aug. 28, 2003 (e.g., while the conveyor system is in motion), by supporting the substrate carrier via a bottom of the substrate carrier. The end effector  103  then may be repositioned so that the end effector  103  supports the substrate carrier via the OHT flange of the substrate carrier (as described by method  601 ). The substrate carrier then may be positioned (lowered) onto a load port of a processing tool and docked/opened to allow processing of the substrates contained within the substrate carrier. The reverse operation may be performed to remove the substrate carrier from the load port by supporting the substrate carrier via its OHT flange, and loading the substrate carrier back onto the overhead conveyor system by supporting the substrate carrier via its bottom side. 
     Further exemplary operation of the substrate carrier transferring system  409  is now described with reference to  FIGS. 7-17 , and with reference to  FIG. 18 , which illustrates a second exemplary method  1801  for repositioning support provided by an end effector  103  in accordance with an embodiment of the present invention. More specifically, an exemplary method for repositioning support provided by the end effector  103  to a substrate carrier (e.g., FOUP  101 ) from a top side  109  (e.g., a second side) to a bottom side  301  (e.g., a first side) of the FOUP  101  is described. One or more of the steps of method  1801  may, for example, be implemented via computer program code executed by the controller  407  and stored in a memory in, coupled to or otherwise associated with the controller  407 , such as in any suitable computer readable medium (e.g., a carrier wave signal, a floppy disc, a compact disc, a DVD, a hard drive, a random access memory, etc.). 
     With reference to  FIG. 18 , in step  1803 , the method  1801  begins. In step  1805 , an end effector  103  is employed to support a substrate carrier (e.g., FOUP  101 ) by an overhead transfer (OHT) flange  107  of the substrate carrier (e.g., FOUP  101 ). As described above, the end effector flanges  501  may couple to and support the OHT flange  107 . Consequently, as shown in  FIG. 17 , the end effector  103  supports the FOUP  101  by the OHT flange  107  of the FOUP  101 . For example, the end effector  103  supports the FOUP  101  using the OHT flange  107  while transferring the FOUP  101  from a first location (e.g., a load lock chamber or docking station) of the semiconductor device manufacturing facility. 
     In step  1807 , the substrate carrier (e.g., FOUP  101 ) is transferred from the end effector  103  to an intermediate support location  117 . The intermediate support location supports the bottom side  301  of the FOUP  101 . The controller  407  may be employed for moving the end effector  103  along one or more of the x, y and z axes such that the FOUP  101  is transferred from the end effector  103  to the intermediate support location  117 . For example, the controller  407  may move the end effector  103  and therefore, the FOUP  101 , along the z-axis such that the FOUP  101  is proximate (e.g., slightly higher than) the intermediate support location  117 . More specifically, the controller  407  positions the end effector  103  and the FOUP  101  such that the bottom side  301  of the FOUP  101  does not contact the support location pins  403  when the end effector  103  and the FOUP  101  are moved horizontally (e.g., along the x and/or y axes). As shown in  FIG. 16 , the end effector  103  and the FOUP  101  are positioned higher than the intermediate support location  117 . 
     The controller  407  moves the end effector  103 , and therefore the FOUP  101 , horizontally (e.g., along the x and/or y axes) such that each FOUP slot  303  in the bottom side  301  of the FOUP  101  is positioned directly above a corresponding support location pin  403  of the intermediate support location  117 . As shown in  FIG. 15 , the end effector  103  and the FOUP  101  are positioned directly above the intermediate support location  117 . 
     The controller  407  moves the end effector  103 , and therefore the FOUP  101 , downward vertically (e.g., along the z-axis). When the bottom surface  301  of the FOUP  101  is positioned slightly higher than the intermediate support location  117 , the support location pins  403  begin to enter the corresponding FOUP slots  303  in the bottom side  301  of the FOUP  101 . As shown in  FIG. 14 , the FOUP  101  is positioned slightly higher than the intermediate support location  117 . 
     The controller  407  moves the end effector  103  and the FOUP  101 , downward vertically until the support location pins  403  engage or contact (e.g., couple to) the FOUP slots  303 . As described above, the support location pins  403  may include sensors  405  for indicating when and/or determining whether one or more end effector pins  401  and/or the one or more support location pins  403  are properly positioned relative to the FOUP slots  303 . When the support location pins  403  are properly positioned in (e.g., coupled to) the FOUP slots  303 , the end effector flanges  501  are not coupled to the OHT flange  107 . Consequently, the intermediate support location  117  fully supports the FOUP  101 , and the end effector  103  does not support the FOUP  101 . Therefore, the FOUP  101  is transferred from the end effector  103  to the intermediate support location  117 . As shown in  FIG. 13 , the intermediate support location  117  supports the FOUP  101 . 
     In step  1809 , the end effector  103  is repositioned proximate the bottom of the substrate carrier (e.g., FOUP  101 ). The controller  407  may be employed for moving the end effector  103  along one or more of the x, y and z axes so as to reposition the end effector  103  proximate the bottom side  301  of the FOUP  101 . For example, the controller  407  moves the end effector  103  horizontally along the x and/or y axes (e.g., into the tunnel) such that no portion of the end effector  103  is over (e.g., extends above) the FOUP  101 , which is supported by the intermediate support location  117 . As shown in  FIG. 12 , the end effector  103  is positioned such that no portion of the end effector  103  extends above the FOUP  101 . 
     The controller  407  then moves the end effector  103  downward along the z-axis (e.g., vertically in the tunnel) such that the end effector  103  is lower than the intermediate support location  117 . The end effector  103  is positioned such that the end effector pins  401  do not contact the intermediate support location  117  when the end effector  103  is moved horizontally (e.g., along the x and or y axes). As shown in  FIG. 11 , the end effector  103  is positioned lower than the intermediate support location  117 , as described above. 
     The controller  407  then moves the end effector  103  horizontally (e.g., along the x and/or y axes) such that the end effector  103  is directly below the intermediate support location  117  and FOUP  101 . More specifically, the end effector  103  is positioned such that the end effector  103  and the intermediate support location  117  may occupy the same plane (e.g., xy plane) when the end effector  103  is moved vertically, and the end effector pins  401  are positioned directly below corresponding FOUP slots  303  in the bottom side  301  of the FOUP  101 . As shown in  FIG. 10 , the end effector  103  is positioned directly below the intermediate support location  117  and FOUP  101 , as described above. In this manner, the end effector  103  is repositioned proximate the bottom side  301  of the FOUP  101 . 
     In step  1811 , the end effector  103  is employed to support the bottom of the substrate carrier (e.g., FOUP  101 ). The controller  407  moves the end effector  103  upward along the z-axis (e.g., vertically) such that the end effector pins  401  engage or couple to corresponding FOUP slots  303 . The end effector  103  then supports the FOUP  101  as shown in  FIG. 9 . As mentioned above, the end effector  103  and the intermediate support location  117  may briefly support the FOUP  101  at the same time. During the upward movement of the end effector  103 , the support location pins  403  disengage from the FOUP slots  303 . Consequently, the end effector  103  supports the bottom side  303  of the FOUP  101 ; the intermediate support location  117  does not support the bottom side  303  of the FOUP  101 . 
     In step  1813 , the substrate carrier (e.g., FOUP  101 ) is transferred from the intermediate support location  117 . The controller  407  may be employed for moving the end effector  103  along one or more of the x, y and z axes such that the FOUP  101  is transferred from the intermediate support location  117 . For example, the controller  407  moves the end effector  103 , which supports the bottom side  301  of the FOUP  101 , upward along the z-axis (e.g., vertically) to a position directly above the intermediate support location. More specifically, the end effector  103  is positioned such that the end effector  103  does not contact the intermediate support location  117  when the end effector  103  is moved horizontally (e.g., along the x and/or y axes). As shown in  FIG. 8 , the end effector  103  and the FOUP  101  are positioned above the intermediate support location  117 , as described above. 
     The controller  407  may move the end effector  103  horizontally (e.g., along the x and/or y axes) such that no portion of the end effector  103  and the FOUP  101  is over (e.g., extends above) the intermediate support location  117 . For example, the end effector  103 , and therefore the FOUP  103 , are moved into the tunnel or open region. As shown in  FIG. 7 , the end effector  103  and the FOUP  101  are positioned such that no portion of the end effector  103  and the FOUP  101  is over the intermediate support location  117 . The end effector  103 , and therefore the FOUP  101 , may be moved along the z-axis (e.g., vertically) such that the FOUP  101  is proximate a second location of the semiconductor device manufacturing facility (e.g., an overhead conveyor (not shown)). In this manner, the FOUP  101  is transferred from the intermediate support location  117 . 
     In step  1815 , the method  1801  ends. Through the use of the method  1801  of  FIG. 18 , support provided by an end effector  103  is repositioned. More specifically, the support provided by the end effector  103  to a substrate carrier (e.g., FOUP  101 ) may be repositioned from a top side  109  of the FOUP  101  to a bottom side  301  of the FOUP  101  while the FOUP  101  is transferred from a first location (e.g., a processing or load lock chamber) to a second location (e.g., an overhead conveyor) in the semiconductor device manufacturing facility. The present method is advantageous when the FOUP  101  is more conveniently transferred from the first location using the top side of the FOUP  101  and transferred more conveniently to the second location using the bottom side of the FOUP  101 . 
     The present invention is particularly advantageous when employed in a system such as that described in previously incorporated U.S. patent application Ser. No. 10/650,480, filed Aug. 28, 2003 and titled “SUBSTRATE CARRIER HANDLER THAT UNLOADS SUBSTRATE CARRIERS DIRECTLY FROM A MOVING CONVEYOR,”. 
     The foregoing description discloses only exemplary embodiments of the invention. Modifications of the above disclosed apparatus and methods which fall within the scope of the invention will be readily apparent to those of ordinary skill in the art. For instance, although exemplary sequences of movements for the end effector  103  were provided while describing one or more steps of the present methods  601 ,  1801 , different sequences of movement may be employed to perform any of the steps of the present methods  601 ,  1801 . In one or more embodiments, the controller  407  is adapted to perform one or more of the steps of the present methods  601 ,  1801 . Alternatively, other control devices may be employed to perform one or more steps of the present methods  601 ,  1801 . Although in one or more embodiments, the first end was a bottom side  301  of the FOUP  101  and the second end was the top side  109  of the FOUP  101 , or vice versa, the first end may be any side of the FOUP  101  and the second end may be any other side of the FOUP  101 . 
     Further, although the end effector  103  and/or intermediate support location  117  supports the bottom side  301  of the FOUP  101  by coupling pins  401 ,  403  to corresponding to (e.g., complementary to) slots  303 , the end effector  103  and/or the intermediate support location  117  and the FOUP  101  may be coupled using different complementary devices. Similarly, the end effector flanges  501  and the OHT flange  107  may be replaced by other complementary devices. In some embodiments, the intermediate support locations  117  may support a substrate carrier by its overhead transfer flange. 
       FIG. 19  is a schematic, front view of a system  1901  for transporting substrate carriers in accordance with the present invention. With reference to  FIG. 19 , the system  1901  includes an overhead conveyor system  1903  adapted to transport substrate carriers  1905  between a plurality of processing tools, including a first processing tool  1907  shown in  FIG. 19 . 
     In one or more embodiments of the invention, the overhead conveyor system  1903  may be configured as shown in previously incorporated U.S. patent application Ser. Nos. 10/650,310 and 10/650,480, both filed Aug. 28, 2003, and adapted to be continuously in motion. Other overhead conveyor systems, including conveyor systems that are not continuously in motion, may be used. In the embodiment of  FIG. 19 , the overhead conveyor system  1903  is adapted to support substrate carriers  1905  by the overhead transfer flange  1906  of each substrate carrier  1905 . 
     The processing tool  1907  includes the end effector  103 , which is adapted to support a substrate carrier  1905  via a bottom of the substrate carrier  1905  or via an overhead transfer flange  1906  of the substrate carrier  1905  (as shown in phantom). The processing tool  1907  includes a plurality of load ports  1909   a - f  separated into two columns as shown. Other configurations and/or numbers of load ports may be used. Each load port  1909   a - f  may be adapted to support, dock and/or open a substrate carrier  1905  (e.g., to allow substrates within the substrate carrier  1905  to be extracted and processed within the processing tool  1907 ), as well as to undock and/or close a substrate carrier  1905 . In the embodiment shown, each load port  1909   a - f  is adapted to support a substrate carrier  1905  by a bottom of the substrate carrier. 
     The processing tool  1907  also includes a plurality of support locations  117   a - f . Other numbers and/or arrangements of support locations  117   a - f  may be used. An open region or tunnel  1911  exists between the columns of support locations  117   a - f  and load ports  1909   a - f  that defines an area in which the end effector  103  may be moved along the z-axis (e.g., vertically) without contacting other support locations and/or load ports. 
     The controller  407  is coupled to the processing tool  1907  and may be adapted to control operation of the processing tool  1907 , including operation of the end effector  103  as previously described (e.g., so as to perform methods  601  or  1801 ). 
     During exemplary operation of the system  1901 , a substrate carrier  1905  may be unloaded from the overhead conveyor system  1903  using the end effector  103  to support the substrate carrier  1905  via a bottom of the substrate carrier  1905  (see, for example, U.S. patent application Ser. Nos. 10/650,310 and 10/650,480, both filed Aug. 28, 2003). The substrate carrier  1905  then may be placed on one of the support locations  117   a - f  and the end effector  103  may be repositioned to support the substrate carrier  1905  via its overhead transfer flange  1906  (as previously described). The substrate carrier  1905  then may be transferred from the support location  117   a - f  to one of the load ports  1909   a - f  and supported at the respective load port via a bottom of the substrate carrier  1905 . The substrate carrier  1905  then may be docked and opened at the load port, and the substrates of the substrate carrier  1905  may be processed within the processing tool  1907 . Thereafter, the substrate carrier  1905  may be closed and undocked at the load port. The end effector  103  then may transfer the substrate carrier  1905  from the respective load port to one of the support locations  117   a - f , supporting the substrate carrier  1905  via its overhead transfer flange. Thereafter, the end effector  103  may be repositioned (as previously described) to support the substrate carrier  1905  via the bottom of the substrate carrier  1905 . The substrate carrier  1905  then may be loaded onto the overhead conveyor system  1903  via the end effector  103  and transported to another processing tool (not shown) or other location within a fabrication facility. The controller  407  may include computer program code for performing any of the above steps. The steps of loading/unloading a substrate carrier onto/from the overhead conveyor system  1903  may be performed while the conveyor system is stopped or in motion. 
     While the present invention has been described primarily with reference to FOUPs, it will be understood that other types of substrate carriers may be employed (e.g., bottom opening substrate carriers, top opening substrate carriers, etc.). Likewise, the present invention may be used with small lot size or large lot size substrate carriers. As used herein, a “small lot” size substrate carrier refers to a substrate carrier that is adapted to hold significantly fewer substrates than a conventional “large lot” size substrate carrier which typically holds 13 or 25 substrates. As an example, in one embodiment, a small lot size substrate carrier is adapted to hold 5 or less substrates. Other small lot size substrate carriers may be employed (e.g., small lot size carriers that hold 1, 2, 3, 4, 5, 6, 7 or more substrates, but significantly less than that of a large lot size substrate carrier). For example, in one embodiment, each small lot size substrate carrier may hold too few substrates for human transport of substrates carriers to be viable within a semiconductor device manufacturing facility. 
     Accordingly, while the present invention has been disclosed in connection with exemplary embodiments thereof, it should be understood that other embodiments may fall within the spirit and scope of the invention as defined by the following claims.