Abstract:
A datum plate is provided for use in installations of substrate handling systems. The datum plate has a set of predetermined attachment locations adapted to couple the datum plate to a chamber; a set of predetermined attachment locations adapted to couple one or more automatic door opener platforms to the datum plate; and a set of predetermined attachment locations adapted to couple one or more substrate handlers contained within the chamber, to the datum plate. The attachment locations are positioned such that when the datum plate is coupled to the chamber, and the automatic door opener platform and the substrate handler are coupled to the datum plate, the substrate handler and automatic door opener platform are aligned for substrate transfer therebetween. Other apparatuses such as substrate storage locations, automation modules, substrate carrier handlers and/or shelves for storing substrate carriers may also be coupled to the datum plate, via sets of predetermined attachment locations. A substrate handling system that employs the datum plate, and a method for installing the substrate handling system are also provided. In one aspect the inventive datum plate may be coupled to a supporting frame rather than to a chamber. Numerous other aspects are provided.

Description:
[0001]    The present application claims priority from U.S. Provisional Patent Application Serial No. 60/302,114, filed Jun. 30, 2001, the contents of which are hereby incorporated by reference herein in their entirety. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The invention relates generally to fabrication systems and more particularly to an apparatus and method for installing and aligning various components of a substrate handling and/or processing system.  
         BACKGROUND OF THE INVENTION  
         [0003]    Conventional semiconductor fabrication systems transport a plurality of substrates in a sealed substrate carrier such as a sealed container or pod, thereby maintaining the substrates in a clean/controlled environment. Thus, conventional processing systems include one or more automatic door opener stations where sealed pods are opened, substrates are extracted therefrom and are loaded into the processing system. Typically each automatic door opener station comprises a docking platform adapted to receive a sealed pod which contains a plurality of substrates, and a pod door receiver adapted to engage and unlatch a door portion of the pod (hereinafter a pod door).  
           [0004]    In operation, the docking platform receives a pod and moves the pod horizontally toward the pod door receiver. Thereafter, the pod door receiver engages and unlatches the pod door, moves the pod door horizontally away from the docking platform, and then moves the pod door vertically downward to provide clear access to the substrates in the pod.  
           [0005]    Although automatic door openers generally provide reliable door opening, they typically require long installation and set up procedures. Accordingly a method and apparatus for facilitating automatic door opener installation and operation is needed.  
         SUMMARY OF THE INVENTION  
         [0006]    In a first aspect, a datum plate is provided for use in installations of substrate handling systems. The datum plate has a set of predetermined attachment locations adapted to couple the datum plate to a chamber; a set of predetermined attachment locations adapted to couple one or more automatic door opener platforms to the datum plate; and a set of predetermined attachment locations adapted to couple one or more substrate handlers contained within the chamber, to the datum plate. The attachment locations are positioned such that when the datum plate is coupled to the chamber, and the automatic door opener platform and the substrate handler are coupled to the datum plate, the substrate handler and automatic door opener platform are aligned for substrate transfer therebetween. Other apparatuses such as substrate storage locations, automation modules, substrate carrier handlers and/or shelves for storing substrate carriers may also be coupled to the datum plate, via sets of predetermined attachment locations. A substrate handling system that employs the datum plate, and a method for installing the substrate handling system are also provided. In one aspect the inventive datum plate may be coupled to a supporting frame rather than to a chamber. Numerous other aspects are provided.  
           [0007]    Further features and advantages of the present invention will become more fully apparent from the following detailed description of exemplary embodiments, the appended claims and the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 a systematic top plan view, in pertinent part, of a processing system having a factory interface substrate handler adapted to transport substrates between a plurality of automatic door opener stations and a processing tool;  
         [0009]    [0009]FIG. 2A is an exploded isometric view of the datum plate  41  taken from the factory interface side thereof;  
         [0010]    [0010]FIG. 2B is an isometric view of the datum plate taken from the automatic door opener side thereof showing factory interface substrate handlers coupled thereto;  
         [0011]    [0011]FIG. 2C is an exploded isometric view of the datum plate taken from the automatic door opener side thereof;  
         [0012]    [0012]FIG. 2D is an isometric view of the frame of the factory interface chamber showing the datum plate coupled thereto;  
         [0013]    [0013]FIG. 2E is a schematic side elevational view of the datum plate, shown coupled to various components of the processing system;  
         [0014]    [0014]FIG. 2F is a schematic side elevational view of the datum plate, shown coupled to various components of the processing system, and to one or more storage shelves positioned above the automatic door opener;  
         [0015]    FIGS.  3 A-B are side cross-sectional views of an inventive automatic door opener, shown in a pod exchange position, and a docked position respectively;  
         [0016]    [0016]FIG. 3C is a top plan view of the inventive door opener;  
         [0017]    FIGS.  4 A-C are schematic side views of a conventional pod door opener key, and two alternative embodiments of an inventive key, respectively;  
         [0018]    [0018]FIG. 5 is a front plan view of the pod door receiver;  
         [0019]    FIGS.  6 A-C are schematic side elevational views of the automatic door opener sequentially showing the horizontal and vertical motion of the pod door receiver; and  
         [0020]    FIGS.  7 A-C are schematic side elevational views showing the mechanism which controls the pod door receiver protrusion. 
     
    
     DETAILED DESCRIPTION  
       [0021]    Sinqle Datum Plane System Installation  
         [0022]    [0022]FIG. 1 is a schematic top plan view, in pertinent part, of a processing system  11  having a pair of factory interface substrate handlers  13  adapted to transport substrates between a plurality of automatic door opener stations  15   a - d  and a processing tool  17 . The exemplary processing system  11  shown in FIG. 1 includes an interface chamber  19  and a processing tool  17  which, in this example, comprises a pair of loadlock chambers  23 , a transfer chamber  25  coupled to the loadlock chambers  23 , and a plurality of processing chambers  27  coupled to the transfer chamber  25 .  
         [0023]    An interface wall  29  is positioned between the automatic door opener stations  15   a - d  and the processing system  11  for separating a “white area” clean room  31  from a less clean, “gray area” clean room  33 . The automatic door opener stations  15   a - d  are located in the “white area” clean room  31  and the processing system  11  is located in the less clean, “gray area” clean room  33 . The automatic door opener stations  15   a - d  are positioned adjacent pod access openings  35  in the interface wall  29 . The automatic door opener stations  15   a - d  comprise a docking platform P adapted to receive a sealed pod (not shown) and a pod door receiver  37  adapted to engage and unlatched a pod door from the remainder of the pod. The docking platform P is located on the white area side of the pod access opening  35  and the pod door receiver  37  is mounted on the grey area side of the pod access opening  35 .  
         [0024]    As previously stated, the interface chamber  19  contains one or more interface substrate handlers  13  adapted to extract substrates from an open pod positioned on the docking platform P and transport them to the loadlocks  23 . The transfer chamber  25  of the processing tool  17  contains a transfer substrate handler  39  adapted to transport substrates W between the loadlock chambers  23  and the processing chambers  27 . Note that a portion of the interface wall  29  located between the plurality of automatic door opener stations  15   a - d  and the interface chamber  19 , has openings (not shown) therein to allow the docking platform P of the automatic door opener stations  15   a - d  to be coupled to a datum plate  41 . Alternatively, the factory interface chamber  19  itself may act as the interface wall  29 , and the interface wall  29  may be omitted.  
         [0025]    As best shown in the views of FIGS.  2 A-E, the docking platform P and the pod door receiver  37  of the automatic door openers  15   a - d , and the interface chamber  19  (which supports the datum plate  41 ) are each coupled to the datum plate  41 . Thus the datum plate  41  provides a single frame of reference for each of these components, allowing them to be installed with reference only to the datum plate  41  and leveled and adjusted as a unit. The datum plate  41  may include pre-machined references, alignment pins, guides or attachment locations (for example predrilled openings) to allow the automatic door openers  15   a - d , the interface substrate handlers  13 , as well as the interface chamber  19  to be coupled thereto at predetermined locations (enabling these components to be fixed in all of the x, y and z axes). Thus the inventive system may be installed quickly and easily, and with components more precisely positioned relative to each other, such that substrate hand-off operations may be more reliable.  
         [0026]    The function of the datum plate  41  may be more fully understood with reference to FIGS.  2 A-E. FIG. 2A is an isometric view of the datum plate  41  taken from the factory interface  19  side thereof. As shown in FIG. 2A, substrate handler mounting blocks  43   a - b  are adapted to couple the factory interface substrate handlers  13  to the datum plate  41  and have holes drilled therethrough that correspond to predrilled holes on the datum plate  41  to allow the mounting blocks  43   a - b , and thus the factory interface substrate handlers  13 , to be coupled to the datum plate  41  at predetermined locations and orientations, as shown in the isometric view of FIG. 2B, which is taken from the automatic door opener side of the datum plate  41 .  
         [0027]    [0027]FIG. 2C is an isometric view of the datum plate  41  taken from the automatic door opener side thereof. As shown in FIG. 2C, factory interface mounting blocks  45  are adapted to couple the datum plate  41  to the frame of the factory interface chamber  19  and have holes drilled therethrough that correspond to predrilled holes on the datum plate  41  which allow the mounting blocks  45  to be coupled to the datum plate  41  at predetermined locations and with predetermined orientations. Thus, the datum plate  41  may be coupled to the frame of the factory interface chamber  19  via bolts  46  (or similar securing mechanisms that extend through the factory interface mounting blocks  45 , through the datum plate  41  and into the factory interface chamber  19 &#39;s frame (e.g., via predrilled mounting holes on the factory interface chamber&#39;s frame)) as shown in the isometric view of FIG. 2D which is taken from the automatic door opener side thereof. As will be apparent, the bolts  46  may be inserted from either the factory interface side, or from the automatic door opener side.  
         [0028]    As shown in both FIGS. 2B and 2D, automatic door opener posts  47  extend from the automatic door opener side of the datum plate  41  a sufficient distance such that they extend through the interface wall  29  (FIG. 1) to couple to predetermined locations (e.g., predrilled holes, not shown) on the front face of the automatic door opener  15 &#39;s frame and to thereby support the automatic door opener  15 , as best shown in the schematic side elevational view of FIG. 2E. As shown in FIGS.  2 A-C the datum plate  41  may have an integrated level finder  48 , such as a conventional liquid level finder.  
         [0029]    [0029]FIG. 2E schematically shows the various components which may couple to the datum plate  41 , including an optional substrate storage location  49  and an optional automation module  51 . The optional automation module  51  may comprise a substrate orienter, centerfinder, ID reader, or a metrology/inspection station.  
         [0030]    To install and align the components shown in FIGS.  2 A-E, the factory interface chamber  19  is first provided. The datum plate  41  is coupled (e.g., bolted) to the factory interface chamber  19  via the mounting brackets  45  (FIGS.  2 A-C), and is leveled by adjusting the factory interface chamber&#39;s mounting feet  53  while referring to the integrated level finder  47  (FIGS.  2 A-C). Thereafter, the remaining components may be added in any order. Because each component is coupled to the datum plate  41  via predefined mounting locations/alignment posts, etc., each component is inherently leveled via its support by the datum plate  41 . Further, aside from being leveled, each component occupies a specific position relative to each other component via its coupling to the datum plate  41 &#39;s predetermined mounting locations.  
         [0031]    Also, a support frame F having one or more pod storage shelves S coupled thereto may be coupled to the datum plate  41 , as shown in FIG. 2F. A substrate carrier handler H may also be coupled to the frame F, and may be adapted to move substrate carriers among the plurality of pod storage shelves S, and the one or more docking platforms P. The substrate carrier handler H may comprise a vertical and horizontal linear guide (not shown) movably coupled to the frame F, and an end effector E coupled to the vertical or horizontal linear guide. An apparatus for providing storage shelves above an automatic door opener is disclosed in U.S. patent application Ser. No. 09/201,737, filed Dec. 1, 1998, the entire disclosure of which is incorporated herein by this reference. The shelves, and/or the substrate carrier handler of the &#39;737 apparatus may be coupled directly to the datum plate  41 , or coupled thereto via the frame F such that the storage apparatus and the various components of the processing equipment may be more quickly and accurately aligned.  
         [0032]    In one aspect, the projected floor space occupied by the shelves S and the portion of the automatic door opener  15  located in the white area clean room  31  may be the same. That is, the portion of the automatic door opener  15  located in the white area clean room  31 , and the pod storage shelves S may occupy the same footprint.  
         [0033]    The support frame F may be supported via leveling feet  53  (like those that support the interface chamber  19 ) and coupled to the datum plate  41  (e.g., via coupling mechanism C) for alignment therewith. As will be apparent, coupling mechanism C may be a strut, bolt, or any similar mechanism adapted to ensure location in the X, Y and Z planes.  
         [0034]    As used herein the term “plate” is not to be limited to any particular shape or configuration, but is to be interpreted broadly to cover any structure that provides predetermined mounting locations, and functions as a datum point or plane, allowing coupling of the specified components in predetermined positions relative to each other.  
         [0035]    Similarly, predetermined mounting or attachment locations may be areas that are marked for drilling, or may be areas that are predrilled and/or have additional mounting mechanisms (brackets, bolts, screws, struts, etc.) coupled thereto.  
         [0036]    The datum plate may be coupled to any supporting structure (a chamber, a frame, etc.) or may be free standing in which case the datum plate may have adjustable leveling feet.  
         [0037]    Note that the automatic door opener described herein is merely exemplary. The inventive datum plate and installation method may be employed with any automatic door opener, regardless of the mechanism employed for door opening. Specifically, when an automatic door opener platform (e.g., any mechanism that holds a sealed or closed wafer carrier adjacent an opening mechanism) is coupled to the inventive datum plate, and a substrate handler for extracting a substrate from the opened substrate carrier is coupled to the inventive datum plate, the substrate handler will be properly aligned for substrate transfer to/from the opened substrate carrier. Thus, the inventive apparatus and method may be used advantageously with any automatic door opener.  
         [0038]    With use of the inventive datum plate and installation method, substrate and/or substrate carrier transfer between the various components coupled to the datum plate is facilitated as the datum plate&#39;s attachment/mounting locations are positioned such that when the various components are coupled to the datum plate, the various components are aligned for transfer of substrates or substrate carriers therebetween.  
         [0039]    Programmable Docking Platform Speed and Position Relative to Interface Wall  
         [0040]    FIGS.  3 A-B are side cross-sectional views of an inventive automatic door opener station  15 . The inventive automatic door opener station  15  comprises a docking platform P and a pod door receiver  37 . A pod  107  is shown positioned on alignment pins  109  which are connected to the docking platform P. A pod clamp  111  coupled to the docking platform P secures the aligned pod  107  in place on the docking platform P. The docking platform P is translatably mounted (via a horizontal actuator  119 ) to a base plate  115  which supports the docking platform P. An enclosure wall  117  encloses the horizontal actuator  119 . In the exemplary embodiment shown in FIG. 3, the horizontal actuator  119  comprises a lead screw  119   a  having a fitting  119   b  movably mounted thereto. The pod platform P fixedly mounts to the fitting  119   b  and translates therewith along the lead screw  119   a.    
         [0041]    A servo motor  121  (having an encoder  121   a ) is coupled to the lead screw  119   a  so as to rotate the same, causing the fitting  119   b  to move therealong. Specifically, the encoder  121   a  is coupled to the servo motor  121  and to a controller C. As is known in the art, the controller C provides to the encoder  121   a  a desired distance (e.g., a number of steps) and a direction the servo motor  121  is to travel. The encoder  121   a  then converts the distance/direction signals into appropriate current/voltage signals and drives the servo motor therewith. The controller C also may receive feedback information from the servo motor  121  (directly or via the encoder  121   a ) regarding the rotational resistance exhibited by the lead screw  119   a  (e.g., a current signal representative of the amount of torque applied to the lead screw  119   a ). In this manner, when the docking platform P (or a pod  107  positioned thereon) contacts the pod door receiver  37 , or any undesirable obstruction, the lead screw  119   a &#39;s resistance to rotation will increase and the controller C may use this information to control continued forward or backward motion of the docking platform.  
         [0042]    In accordance with the present invention, computer program code (e.g., one or more computer program products) is provided that allows the controller C to control the servo motor  121  such that:  
         [0043]    (1) the docking platform P moves at a slower speed during certain portions of its movement, such as while a pod positioned on the docking platform P contacts a surface surrounding the pod access port  23 ; and/or  
         [0044]    (2) the docking platform P (and/or a pod disposed thereon) is spaced from a surface surrounding the pod access port  23  when the docking platform P reaches its final position (e.g., so that a gap  24  shown in FIG. 3B exists therebetween).  
         [0045]    Option (2) may be accomplished, for example, by having the docking platform P contact the pod access port  23 &#39;s surrounding surface (e.g., as detected by an increase in rotational resistance of the lead screw  119   b ) and by then directing the servo motor  121  to “step back” by a predetermined distance so that a repeatable/predetermined gap  24  remains between the docking platform P (and/or the pod disposed thereon) and the surface surrounding the pod access port  23 . The step back may occur after the pod door has been removed.  
         [0046]    Pod ID Reader Mounted to Move with Docking Platform  
         [0047]    Mounted on the docking platform P is an ID reader  141 , mounted in a position with respect to the alignment pins  109  so as to allow the ID reader  141  to read the identification tag  143  of a pod  107  positioned on the docking platform P. Because the ID reader  141  is mounted to the docking platform P, the ID reader  141  travels with the docking platform P as the docking platform P moves between the pod exchange position (see FIG. 3A) and the docked position, adjacent the pod access port  35  (see FIG. 3B). Accordingly the inventive automatic door opener  15  may read a pod ID code  143  when a pod  107  is in the carrier exchange position (FIG. 3A), the docked position (FIG. 3B) or any position therebetween. A pod  107  properly positioned on the docking platform P (e.g. via the alignment pins  109 ) may be identified at any time by the ID reader  141 .  
         [0048]    Rotatable/Retractable Pod Clamp  
         [0049]    Also coupled to the docking platform P so as to move therewith, is a clamp  111  which secures the aligned pod  107  in place on the docking platform P. The clamp  111  comprises a post  145  having an elongated head portion  147 , as best seen from the top plan view of FIG. 3C. The clamp  111 &#39;s size and location relative to the alignment pins  109  is such that the clamp  111 , when in an initial, un-actuated position, will enter a corresponding opening  149  on the bottom of a standard pod  107  positioned on the alignment pins  109 . The clamp  111  is further coupled to an actuator  151  adapted to rotate and retract the clamp  111 . Rotation of the clamp  111  prevents the pod  107  from moving in the X-direction (see FIG. 3A). Retraction of the clamp  111  (see FIG. 3B) may more firmly hold the pod  107  in place and may prevent rocking, tilting or movement of the pod  107  in any direction.  
         [0050]    Pod Present Sensor  
         [0051]    Another feature found on the docking platform P side of the inventive automatic door opener  15  is a pod present detector (shown in FIGS.  3 A-B) comprising a light emitter  151  such as an LED, and a light detector  153  such as photodetector. The light emitter  151  may be coupled to an upper portion of the pod door opener&#39;s frame and may be positioned such that the beam of light emitted therefrom is directed across the vicinity of the docking platform P, to the light detector  153  which may be coupled to the docking platform P. The light emitter  151  and detector  153  are arrange such that the beam of light emitted by the emitter  151  is detected by the detector  153  unless a pod  107  or some other obstruction is present in the vicinity of the docking platform P. Accordingly when the detector  153  does not detect the emitted beam of light, the detector  153  sends a carrier present signal to a controller C coupled thereto. Note, in the exemplary embodiment shown, the controller C may control the operation of all the automatic door opener&#39;s sensors and moving parts.  
         [0052]    Retractable Pod Door Receiver Keys  
         [0053]    Specific features relating to the pod door receiver  37  side of the inventive automatic door opener  15  will now be described. As shown, the pod door receiver  37  defines a recess  173  into which a pod door  175  may be received. The recess  173  may be defined by a plate  177  and walls  179 . The plate  177  of the recess  173  may include a pod door key actuating mechanism which comprises a key  183  and a pneumatic actuator  185  coupled to the key  183  and adapted to rotate the key  183  so as to unlatch the pod door  175  from the remainder of the pod  107  and further adapted to retract the rotated key  183  so as to support the pod door  175 . Alignment pins  187  may also be provided on the plate  177  for aligning the pod door  175  with the pod door receiver  37  such that the pod door receiver key  183  enters a corresponding key hole  189  on the pod door  175  of a standard pod  107 .  
         [0054]    Pod Door Receiver Key Design  
         [0055]    Like the clamp  111 , the pod door receiver key  183  comprises a base portion  195 , and an elongated head portion  197  coupled thereto (as best seen with reference to FIGS.  4 A-C). The present inventors believe that a source of failure of conventional pod door opener keys  183  has been the fact that the key heads  197  contact and rub against the interior surface of the pod door  175  during key rotation. Thus the present inventors believe that conventional keys generate particles that may cause subsequent key failure or that may contaminate substrates transferred via conventional automatic door openers.  
         [0056]    Accordingly, the pod door key  183  of the inventive automatic door opener is designed such that the head portion  197  thereof will not contact the interior surface of the pod door  175 . This may be achieved by reducing the thickness of the key head  197 , or by lengthening the base portion  195  of the key. For example, when opening a standard pod  107 , if the overall length of the key  183  is equal to the current SEMI (Semiconductor Equipment and Materials International) specification, the key head  197 &#39;s thickness (represented by arrow t) should be less than the current SEMI specification therefore), as shown in FIG. 4B. Alternatively when opening a standard pod  107 , if the head portion  197  of the pod door receiver key  183  is as thick as that specified in the current SEMI specifications, the overall length of the key  183  should be longer than the SEMI specification, as shown in FIG. 4C.  
         [0057]    Surface Finish of Metal Parts  
         [0058]    The present inventors further believe that conventional pod door failure and/or substrate contamination may result from the use of turned parts, as turning results in rough surface finishes. Accordingly, any of the inventive automatic door opener  15 &#39;s metal parts may be polished mechanically or chemically so as to have a smooth surface finish. Particularly, the pod door receiver key  183  and alignment pins  182  may be polished, as may be the docking platform alignment pins  109  and clamp  111 , etc.  
         [0059]    Programmable Pod Door Receiver Retraction Speed  
         [0060]    Another feature of the pod door receiver side of the inventive automatic door opener  15  is the controller C&#39;s ability to provide programmable pod door receiver retraction speed. Specifically, with reference to the front elevational view of the pod door receiver  37  shown in FIG. 5, a servo motor  186  is coupled to the pod door receiver  37 , and the pod door receiver  37  and servo motor  186  are adapted such that the servo motor  186  can lift and lower the pod door receiver  37  between an elevated position wherein the pod door receiver  37  occludes the pod access opening  35  in the interface wall  23 , and a lowered position wherein the pod door receiver  37  does not occlude the pod access opening  35  in the interface wall  23  (FIG. 1). The pod door receiver  37  may be guided via one or more guide rails  201 .  
         [0061]    As shown in the front plan view of FIG. 5, the pod door receiver  37  may have an extended portion  37   a  that is mounted to a bracket  199 . The bracket  199  is slideably coupled between a pair of guide rails  201 , and is fixedly coupled to a nut  203  that is mounted to a lead screw  205 . The servo motor  186  is adapted to rotate the lead screws  205  causing the nut  203  to move up and down depending on the lead screw  205 &#39;s direction of rotation. The servo motor  186  coupled to the pod door receiver  37  is further coupled to the programmable controller C (FIG. 3A), and the programmable controller C is programmed so as to allow a user to specify the speed at which pod door receiver  37  lifts and lowers. In one aspect the program allows the user to select a slower speed during certain portions of the pod door receiver&#39;s movement, and to select a faster speed during other portions of the pod door receiver&#39;s movement.  
         [0062]    Single Actuation Dual Axis Motion Pod Door Receiver  
         [0063]    The components of the automatic door opener  15  that control the retraction of the substrate carrier door receiver  37  are described with reference to the side elevational views of FIGS.  6 A-C that sequentially show the operation of the pod door receiver.  
         [0064]    The vertical motion of the pod door receiver  37  may be translated into horizontal motion (e.g., pod door receiver motion toward and away from the pod access opening  35  in the interface wall  29 ), as described in U.S. patent application No. 60/217,147 (AMAT 5183), filed Jul. 7, 2000, the entire disclosure of which is incorporated herein by this reference. Specifically, a vertical motion stop  211  may be adapted to stop the vertical motion of the pod door receiver  37 , and a motion translator link  213  such as a four-bar link may be coupled to the vertical motion stop and to the pod door receiver  37 , so as to move the pod door receiver  37  forward after the pod door receiver&#39;s vertical motion has been stopped via the vertical motion stop.  
         [0065]    As shown in FIGS.  6 A-C, the automatic door opener  15  comprises a horizontally stationary member  215  (e.g., a member fixed against horizontal motion via a track  217  which allows vertical motion of the horizontally stationary member  215  but which prohibits horizontal motion), and a link  213  coupled between a substrate carrier door receiver  37  and the horizontally stationary member  215 , so as to allow vertical actuation to be translated into horizontal movement of the substrate carrier door receiver  37 , as described below.  
         [0066]    The link  213  may comprise an upper link  213   a  and a lower link  213   b,  both adapted to pivot between a retracted position (FIG. 6B) and an extended position (FIG. 6A). The upper link  213   a  comprises a first joint  219  and a second joint  221 . The first joint  219  is coupled to the horizontally stationary member  215  and the second joint  221  is coupled to the substrate carrier door receiver  37 . Similarly, the lower link  213   b  comprises a first joint  219  and a second joint  221 , which also are coupled to the horizontally stationary member  215  and the substrate carrier door receiver  37 , respectively. Thus, the substrate carrier door receiver  37 , the horizontally stationary member  215 , the upper link  213   a,  and the lower link  213   b  may be configured to comprise what is conventionally known as a four-bar link.  
         [0067]    The automatic door opener  15 &#39;s vertical motion stop  211  may comprise a cam follower  223  (such as a horizontal extension) coupled to the substrate carrier door receiver  37 , so that the cam follower  223  moves both vertically and horizontally with the substrate carrier door receiver  37 . The cam follower  223  is adapted so as to contact a vertically stationary mechanism (e.g., a cam  225 ) as the substrate carrier door receiver  37  moves vertically upward, thereby stopping further vertical motion of both the cam follower  223  and the substrate carrier door receiver  37 .  
         [0068]    The cam  225  is positioned such that when the cam follower  223  contacts the cam  225 , the substrate carrier door receiver  37  is in position to engage (e.g., at the same elevation as) the pod access port  35  and the door  175  of the pod located on the docking platform P. The cam  225  and the docking platform P may serve as datum points so as to properly position the substrate carrier door receiver  37  relative to the pod door  175 .  
         [0069]    A counterbalancing mechanism such as a spring (not shown) adapted to bias the substrate carrier door receiver  37  upwardly, may also be employed.  
         [0070]    The operation of the door receiver  37 &#39;s motion translator is now described with reference to the sequential views of FIGS.  6 A-C. The upper link  111  and the lower link  113  are initially in the extended position as shown in FIG. 6A. Because the horizontally stationary member  215  is positioned on the docking platform P side of the automatic door opener  15 , the extended position pushes the substrate carrier door receiver  37  horizontally away from pod access port  35 , as shown in FIG. 6A.  
         [0071]    In operation, the actuator  186  moves the pod door receiver  37  vertically upward so as to place the pod door receiver  37  in position to engage the pod door  175 . As the pod door receiver  37  moves vertically upward, the horizontally extending cam follower  223  contacts the cam  225  so as to prevent the cam follower  223  and the pod door receiver  37  from further moving vertically upward.  
         [0072]    The horizontally stationary member  215  continues to move vertically upward relative to the cam follower  223  and the pod door receiver  37  both of which remain vertically stopped by the cam  225 . As the horizontally stationary member  215  continues to move vertically upward, the first joints  219  of the upper link  213   a  and the lower link  213   b  move upward therewith. Because the horizontally stationary member  215  is restrained horizontally, this vertical motion positions the upper link  213   a  and the lower link  213   b  in the retracted position as shown in FIG. 6B, thereby retracting the pod door receiver  37  horizontally inward toward the pod access port  35 . Because the horizontally stationary member  215  is positioned on the docking platform P side of the pod access port  35 , the retracted position thus pulls the pod door receiver  37  toward the pod access port  35 .  
         [0073]    As the upper link  213   a  and the lower link  213   b  move to the retracted position, the cam follower  223  and the substrate carrier door receiver  37  coupled thereto, move horizontally in a straight line (e.g., due to the horizontally straight configuration of the cam follower  223  and the vertical fixation thereof when engaged with the cam  225 ) toward the pod access port  35  as shown in FIG. 6B, such that the pod door receiver may receive the pod door  175 . Thereafter the sequence is reversed and the pod door receiver  37  lowers, carrying the pod door  175  therewith.  
         [0074]    As is evident from the description above, the inventive pod door opener  15  may use a single actuator  186  to effect both vertical and horizontal movement of the pod door receiver  37 .  
         [0075]    Further, the cam  225  provides a convenient datum point that allows the position of the substrate carrier door receiver  37  to be accurately controlled relative to the pod access port  35 . Additionally, the preferred straight-line motion (e.g., which may result the straight surface of the cam follower  223  following the cam  225 ) of the pod door receiver  37  may reduce particle generation that may otherwise occur when the pod door receiver  37  contacts the pod door  175 .  
         [0076]    Programmable FIMS Gap  
         [0077]    Another feature found on the pod door receiver side of the inventive automatic door opener  15  is the ability to adjust the pod door receiver  37 &#39;s protrusion from the surface of the interface wall  29  toward the docking platform P.  
         [0078]    Specifically, the controller C which controls the servo motor  186  coupled to the pod door receiver can be programmed so as to stop the vertical motion of the horizontally stationary mechanism  215  at a predetermined position relative to the cam  211  which acts as a vertical motion stop. After the cam  211  is contacted, the farther the horizontally stationary mechanism  215  moves above the vertical motion stop (e.g., cam  211 ) the greater the horizontal distance the pod door receiver  37  moves toward the docking platform P.  
         [0079]    FIGS.  7 A-C are schematic side elevational views of the automatic door opener  15 . FIG. 7A shows the horizontally stationary mechanism  215  at the same elevation as the vertical motion stop (cam  211 ) causing the four bar link  213  to extend, pushing the pod door receiver  37  backward, away from the pod access port  35 . FIG. 7B shows the horizontally stationary mechanism  215  having traveled a small distance Y 1  above the vertical motion stop (cam  211 ), causing the four bar link  213  to pull the pod door receiver  37  a corresponding distance inward resulting in a small protrusion X 1 . FIG. 7C shows the horizontally stationary mechanism  215  having traveled a larger distance Y 2  above the vertical motion stop, causing the four bar link  213  to pull the pod door receiver  37  a corresponding distance inward resulting in a larger protrusion X 2 .  
         [0080]    In one aspect the programmable controller C allows a user to select a desired positive or negative gap between the surface of the docking platform side of the pod access opening  35 , and the surface of the pod door receiver  37  closest to the docking platform P (i.e., the factory interface surface or FIMS gap). The FIMS gap control program may include either a look up table that translates a user desired FIMS gap into a corresponding motor current, or may include an algorithm for translating the user&#39;s desired FIMS gap into the corresponding motor current.  
         [0081]    Automatic Door Opener Operation  
         [0082]    In operation after the inventive automatic door opener  15  and factory interface chamber  19  have been coupled to the datum plate  41  as described above, the horizontal actuator  119  coupled to the docking platform P is actuated causing the docking platform P to move away from the datum plate  41  to the pod receiving position shown in FIG. 3A. The light beam emitted by the pod present sensor&#39;s emitter  151  is received by the detector  153  thereof, and the pod present sensor sends a signal to the controller C indicating that the docking platform P is vacant and a pod  107  may be placed thereon. Thereafter a pod  107  is placed on the pod platform P via automatic or manual methods.  
         [0083]    Alignment pins  109  interface with features on the bottom of the standard pod  107  and kinimatically align the pod  107  on the docking platform P. Simultaneously therewith, the clamp  111  enters a corresponding opening  149  on the bottom of the standard pod  107 , and the pod present sensor senses that a pod is present on the docking platform P. The controller C receives the pod present signal, and in response thereto rotates and retracts the clamp  111  to securely hold the pod  107  in place on the docking platform P. Further, as previously stated, the ID reader  141  may read at any time, the identification tag of the pod  107  clamped to the docking platform P.  
         [0084]    The docking platform P may include three or more alignment pins adapted to interface with features on the bottom of a standard pod. A sensor may be positioned adjacent each alignment pin such that a standard pod would actuate all three sensors, and a controller coupled thereto would recognize that actuation of less than three sensors represents a pod is not properly positioned on the docking platform P. An alternative that may be employed comprises a pin having an integrated sensor such as a plunger that is depressed by a pod, and activates a sensor coupled to the plunger. Such an integrated sensor pin is described in U.S. patent application Ser. No. 09/894,383, filed Jun. 27, 2001 (AMAT No. 5770/ATD/BG), the entire disclosure of which is incorporated herein by this reference.  
         [0085]    The horizontal actuator  119  is then signaled to begin moving the docking platform P toward the pod access port  35  formed in the interface wall  29 . The rate at which the docking platform P moves is controlled by the controller C which maybe programmed to vary the speed, causing the docking platform P to slow down in the region adjacent the access port  35 , so as to gradually contact the pod door receiver  37  which may be flush with the surface of the pod access port  35 , may protrude therethrough or may be recessed from the surface of the pod access port  35 , as described previously. As the pod door enters the recess of the pod door receiver  37 , the pod door  175  is aligned by the alignment pins  187  contained in the recess thereof, and the key  133  enters the corresponding opening  139  on the door  125  of the sealed pod  107 . After the pod door  175  gently contacts the pod door receiver  37 , and is aligned within the recess thereof, the key  183  is rotated by the actuator so as to unlock the pod door  175  from the remainder of the pod. Because the key  183  has either a thinner head  197 , or a longer base  195 , both as described above, the key  183  does not rub against the inside of the pod door as the key  183  rotates.  
         [0086]    Thereafter the robot  13  contained in the interface chamber  19  may extract substrates from the pod access opening  35  and transport them into the processing tool  17 . During the entire process the pod  107  is securely held in place and is prevented from rocking or tilting via the retracted pod clamp  111 . Because of the datum plate  41  and the pod clamp  111  the position of each component, including the pod  107 , and the substrates contained therein, is accurate and repeatable. The inventive automatic door opener  15  provides much greater flexibility than prior art systems because of the programmed controller which allows control of the speeds of approach of the docking platform P, the speed at which the pod door receiver  37  is elevated and the protrusion of the pod door receiver (or FIMS gap). The programmed controller also allows contact between moving parts to be gentle yet provides faster motion during times when moving parts are not contacting.  
         [0087]    The computer program code used to perform these functions may be (1) developed by a person of ordinary skill in the art; (2) written in any computer programming language; and/or (3) stored in a memory location of the controller C or in another memory location (not shown).  
         [0088]    Magnetically Mounted Casing  
         [0089]    One final feature of the inventive automatic door opener  15  facilitates assembly, and provides ease of access to the moving parts for both assembly and repair. Specifically, the moving parts of conventional automatic door openers typically are encased in thin sheets of metal, which serve both to encase particles and to improve the aesthetic appearance of the automatic door opener. Conventionally these metal sheets are fastened in place with screws or bolts. The inventive automatic door opener  15 , however, may be encased with thin metal sheets (preferably burnished aluminum) that are secured in place via a plurality of magnets. The magnets may be fixedly mounted to a frame of the automatic door opener. Accordingly the metal sheets may be easily applied and removed from the inventive automatic door opener.  
         [0090]    The foregoing description discloses only a preferred embodiment of the invention; modifications of the above disclosed apparatus which fall within the scope of the invention will be readily apparent to those of ordinary skill in the art. For instance, it will be apparent that the automatic door opener described above has a number of inventive features, each of which can be employed independently of the others. The lead screw type motion system described is merely exemplary, and any number of motion systems, keys, detectors, etc., may be employed. Similarly the specific position of the datum plate relative to the various components coupled thereto may vary, without affecting the function of the datum plate. The specific shape of the plate is not limited, and the term “plate” is not intended to limit the datum plate to any specific shape or dimension. Any object which provides the above described functionality of the datum plate may be considered to be a datum plate.  
         [0091]    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 claim.