Abstract:
In a first aspect, a loadlock chamber is provided that includes: (1) a first chamber portion adapted to remain stationary; (2) a second chamber portion adapted to move relative to the first chamber portion; and (3) a substrate handler located between the first and second chamber portions. The loadlock chamber is adapted to assume: (a) a closed position wherein the first and second chamber portions contact one another so as to define a region capable of maintaining a vacuum pressure; (b) an opened position wherein the second chamber portion moves away from the first chamber portion so as to define an opening; and (c) a load position wherein at least a portion of the substrate handler extends through the opening. Systems and methods in accordance with these and other aspects also are provided.

Description:
[0001]    This application claims priority from U.S. Provisional patent application Ser. No. 60/217,144, filed Jul. 7, 2000, which is hereby incorporated by reference herein in its entirety. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to semiconductor device manufacturing, and more particularly to an inventive loadlock chamber for use during semiconductor device manufacturing.  
         BACKGROUND OF THE INVENTION  
         [0003]    [0003]FIG. 1 is a schematic top plan view, in pertinent part, of a conventional processing system  11  having a factory interface wafer handler  13  adapted to transport wafers between a plurality of wafer carrier loading stations  15   a - d  and a processing tool  17 . The exemplary processing system  11  shown in FIG. 1 includes an interface chamber  19  and the processing tool  17  which, in this example, comprises a pair of conventional loadlock chambers  23 , a transfer chamber  25  coupled to the conventional loadlock chambers  23 , and a plurality of processing chambers  27  coupled to the transfer chamber  25 .  
           [0004]    An interface wall  29  is positioned between the wafer carrier loading 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 wafer carrier loading 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 wafer carrier loading stations  15   a - d  are positioned adjacent sealable openings  35  in the interface wall  29 . The wafer carrier loading stations  15   a - d  each comprise a wafer carrier platform (not shown) adapted to receive a sealed pod (not shown) and a wafer carrier opener  37  adapted to engage and unlatch a pod door (not shown) from the remainder of the pod as is known in the art.  
           [0005]    The interface chamber  19  contains the interface wafer handler  13  mounted to a track (not shown). The transfer chamber  25  of the processing tool  17  contains a transfer chamber wafer handler  39  adapted to transport wafers (such as wafer W) between the loadlock chambers  23  and the processing chambers  27 .  
           [0006]    In operation, a pod (not shown), containing cassettes of wafers, is loaded onto one of the wafer carrier loading stations  15   a - d;  and the wafer carrier opener  37  engages and unlatches the pod door (not shown) of the pod. The wafer carrier opener  37  moves the pod door horizontally away from the wafer carrier platform (in the “X” direction in FIG. 1) and then moves the pod door vertically downward (into the page in FIG. 1) to provide clear access to the wafers in the pod. The interface wafer handler  13  of the interface chamber  19  then extracts a wafer from the pod and transports the wafer to one of the conventional loadlock chambers  23 . Thereafter, the transfer chamber wafer handler  39  of the processing tool  17  transports the wafer from the conventional loadlock chamber  23  to one of the processing chambers  27  wherein a processing step is performed on the wafer.  
           [0007]    While the conventional processing system  11  is highly effective, it is always desirable to reduce processing system footprint (e.g., to reduce clean room size requirements).  
         SUMMARY OF THE INVENTION  
         [0008]    In accordance with the present invention, an inventive loadlock chamber is provided that may reduce processing system footprint. In a first aspect of the invention, a loadlock chamber is provided that includes (1) a first chamber portion adapted to remain stationary; (2) a second chamber portion adapted to move relative to the first chamber portion; and (3) a substrate handler located between the first and second chamber portions. The loadlock chamber is adapted to assume (a) a closed position wherein the first and second chamber portions contact one another so as to define a region capable of maintaining a vacuum pressure; (b) an opened position wherein the second chamber portion moves away from the first chamber portion so as to define an opening; and (c) a load position wherein at least a portion of the substrate handler extends through the opening.  
           [0009]    In a second aspect of the invention, a load lock chamber is provided that includes (1) a top portion adapted to remain stationary and that includes a first opening adapted to allow a substrate to be transferred to and from the loadlock chamber; (2) a bottom portion adapted to raise and lower relative to the top portion; and (3) a substrate handler located between the top and bottom portions. The loadlock chamber is adapted to assume (a) a closed position wherein the top and bottom portions contact one another so as to define a region capable of maintaining a vacuum pressure; (b) an opened position wherein the bottom portion and the substrate handler lower as a unit away from the top portion so as to define a second opening; (c) a load position wherein at least a portion of the substrate handler extends through the second opening; and (d) an unload position wherein the top and bottom portions contact one another and wherein at least a portion of the substrate handler extends through the first opening. Systems and methods in accordance with these and other aspects of the invention also are provided.  
           [0010]    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  
       [0011]    [0011]FIG. 1 is a schematic top plan view, in pertinent part, of a conventional processing system as previously described;  
         [0012]    FIGS.  2 A-D are schematic side sectional views of a novel processing system, showing an inventive loadlock chamber in a closed position, an opened position, a load position and an unload position, respectively;  
         [0013]    [0013]FIG. 3 is a top view of the novel processing system of FIGS.  2 A-D taken along line  3 - 3  in FIG. 2B; and  
         [0014]    [0014]FIG. 4 is a top plan view of an exemplary embodiment of the transfer chamber of FIGS.  2 A- 3 . 
     
    
     DETAILED DESCRIPTION  
       [0015]    FIGS.  2 A-D are schematic side sectional views of a novel processing system  100 , showing an inventive loadlock chamber  101  in a closed position, an opened position, a load position and an unload position, respectively, and FIG. 3 is a top view of the novel processing system  100  taken along line  3 - 3  in FIG. 2B. The inventive loadlock chamber  101  contains a substrate handler  103  adapted to transfer a wafer (not shown) between a wafer carrier loading station  105  and a transfer chamber  107  of a processing tool (not shown).  
         [0016]    The inventive loadlock chamber  101  comprises a stationary top plate  109  and a vertically moveable bottom plate  111 . The top plate  109  and the bottom plate  111  are coupled so as to touch at an intersection surface  113  (FIG. 2A and FIG. 3). The top plate  109  and/or the bottom plate  111  may comprise an O-ring or the like (not shown) for forming a seal between the top plate  109  and the bottom plate  111  (e.g., a seal that is capable of withstanding/maintaining vacuum pressure in a region  114  formed between the top plate  109  and the bottom plate  111  as described below). The bottom plate  111  is mounted to the substrate handler  103 , so as to move vertically therewith, such that when the substrate handler  103  moves vertically downward, the bottom plate  111  moves downward (FIG. 2B). When the bottom plate  111  is in the lowered position (FIG. 2B), the loadlock chamber  101  is in an “opened” position, and a blade B of the substrate handler  103  is adjacent an opening  115  created between the stationary top plate  109  and the lowered bottom plate  111 . The substrate handler  103  may be raised and/or lowered via a vertical actuator such as a motor  117 .  
         [0017]    The operation of the inventive loadlock chamber  101  is described with reference to the sequential views of FIGS.  2 A-D, which show the inventive loadlock chamber  101  in the closed, opened, load and unload positions, respectively.  
         [0018]    In operation, from the closed position (FIG. 2A) the motor  117  is energized and moves the substrate handler  103  downward, carrying the bottom plate  111  therewith. As the substrate handler  103  moves downward, the opening  115  is created between the stationary top plate  109  and the bottom plate  111 , which is attached to and moves downward with the substrate handler  103 . The inventive loadlock chamber  101  is then in the opened position as shown in FIG. 2B. The blade B of the substrate handler  103  moves horizontally and extends to a position beneath a wafer (not shown) contained within a pod  121  positioned on the wafer carrier loading station  105 . The inventive loadlock chamber  101  is then in the load position as shown in FIG. 2C. The blade B of the substrate handler  103  lifts slightly (so as to pick up the wafer), retracts and carries the wafer into the inventive loadlock chamber  101  (FIG. 2B). Alternatively, the substrate handler  103  may remain stationary while the pod  121  (or a wafer support therein) indexes downward to place a wafer on the substrate handler  103 . The blade B of the substrate handler  103  then may retract so as to carry the wafer into the inventive loadlock chamber  101  (FIG. 2B).  
         [0019]    After a wafer is retrieved, the motor  117  elevates the substrate handler  103 , carrying the wafer and the bottom plate  111  vertically upward such that the bottom plate  111  again contacts and seals against the stationary top plate  109 . Thus, the opening  115  is closed, as shown in FIG. 2A (creating the sealed region  114 ). Thereafter, the inventive loadlock chamber  101  is pumped down to a desired vacuum level. An arm  123  of the substrate handler  103  rotates 180 degrees so as to place the blade B adjacent a slit valve  119 . The slit valve  119  then opens and the substrate handler  103  extends so as to transfer the wafer into the transfer chamber  107  through the slit valve  119  (placing the inventive loadlock chamber  101  in the unload position as shown in FIG. 2D).  
         [0020]    In one aspect, the opening  115  may be created at a lower elevation than the elevation of the slit valve  119 ; accordingly the wafer carrier loading station  105  may be positioned at a lower elevation than the transfer chamber  107 . Thus when the substrate handler  103  and the bottom plate  111  lower so as to open the inventive loadlock chamber  101 , the substrate handler  103  is positioned adjacent (e.g., at the same elevation as) the wafer carrier loading station  105 , and when the substrate handler  103  and the bottom plate  111  raise so as to close the inventive loadlock chamber  101 , the substrate handler  103  is positioned adjacent (e.g., at the same elevation as) the transfer chamber  107 .  
         [0021]    Alternatively, the opening  115  may be created at the same elevation as the slit valve  119  (so that the wafer carrier loading station  105  and the transfer chamber  107  may be located at the same level).  
         [0022]    As can be seen from FIGS.  2 A- 3 , the novel processing system  100  occupies a smaller footprint than the conventional processing system  11  of FIG. 1 (e.g., as the interface chamber  19  is not required).  
         [0023]    Note that the slit valve  119  may be, for example, the slit valve disclosed in U.S. Provisional patent application Ser. No. 60/216,868, filed Jul. 7, 2000 (AMAT Docket No. 4514/L/ATD/MBE titled “Automatic Slit/Gate Valve”) which is hereby incorporated by reference herein in its entirety, and the transfer chamber  107  may be, for example, the transfer chamber disclosed in U.S. patent application Ser. No. 09/611,549, filed Jul. 7, 2000 (AMAT Docket No. 1259/P2/ATD/DV titled “Method and Apparatus For Improved Substrate Handling”) which is hereby incorporated by reference herein in its entirety.  
         [0024]    [0024]FIG. 4 is a top plan view of a transfer chamber  411  containing a substrate carriage  413  and temperature adjustment plate  415  that represents one exemplary embodiment of the transfer chamber  107  of FIGS.  2 A- 3 . The transfer chamber  411  is described in further detail in previously incorporated U.S. patent application Ser. No. 09/611,549.  
         [0025]    With reference to FIG. 4, the transfer chamber  411  includes a central shaft  417  fixedly coupled to the temperature adjustment plate  415  and that extends therefrom through a center region of the substrate carriage  413 . Preferably the central shaft  417  is not in contact with the center region of the substrate carriage  413 , but rather is coupled to the substrate carriage  413  via a motor (not shown). The substrate carriage  413  comprises three equally spaced branches  419   a - c  which extend radially outward from the center region of the substrate carriage  413 . Each branch  419   a - c  comprises a pair of substrate supports  421   a - b  which face outwardly (i.e., away from each other) therefrom. The branches  419   a - c  are preferably machined from the same piece of material or may be made of two or more separate parts connected together using bolts, screws or other connectors including welding, such that they rotate and/or elevate together as a unit. The branches  419   a - c  and the substrate supports  421   a  (e.g., of a first branch  419   a ) and  421   b  (e.g., of a second branch  419   b ) are configured so as to define a plurality of substrate seats  423   a - c  each of which supports a substrate (not shown) by its edge. By placing a substrate (not shown) on a pair of substrate supports  421   a - b  secured to adjacent branches (e.g., branches  419   a,    419   b,  branches  419   a,    419   c  or branches  419   b,    419   c ) a passage is maintained for a substrate handler blade  424   a  of a substrate handler (not shown) to pass therethrough during substrate handoffs between the substrate carriage  413  and the substrate handler blade  424   a,  as described further below.  
         [0026]    The substrate supports  421   a - b  are preferably made of a ceramic such as alumina, quartz or any other hard material which is compatible with semiconductor substrates and does not produce particles or scratch a substrate during contact therewith. The substrate supports  421   a - b  are attached to the underside of the branches  419   a - c,  such that the substrate carriage  413  may lower the substrate supports  421   a - b  below the top surface of the temperature adjustment plate  415 , and below the substrate handler blade  424   a,  thus transferring a substrate supported by a substrate seat  423   a - c  to the temperature adjustment plate  415  and/or to the substrate handler blade  424   a,  while the remainder of the substrate carriage  413  (i.e., the branches  419   a - c ) remains above and does not contact either the temperature adjustment plate  415  and/or the substrate handler blade  424   a.    
         [0027]    The temperature adjustment plate  415  is configured to simultaneously support two substrates (not shown), when the substrate carriage  413  lowers the substrate supports  421   a - b  to an elevation below the top surface of the temperature adjustment plate  415 . In order to achieve uniform heating or cooling across the entire substrate surface, the temperature adjustment plate  415  is preferably coextensive with the substrates placed thereon. Thus, in order to allow the substrate supports  421   a - b  to lower to an elevation below that of the top surface of the temperature adjustment plate  415 , the temperature adjustment plate  415  includes four notches  425   a - d  placed to receive the substrate supports  421   a - b.  Preferably the temperature adjustment plate  415  also comprises a cut out region  426  in which the substrate handler (not shown) may be housed. The cut out region  426  is configured to provide sufficient space for the substrate handler to swing about a central axis when the substrate handler extends and retracts without interfering engagement with a heating plate  415   a.    
         [0028]    In operation the substrate carriage  413  positions one of the substrate support seats  423   a - c  adjacent the slit valve  119  and lowers. The slit valve  119  opens and the blade B of the substrate handler  103  extends therethrough carrying a wafer to a position above the substrate support seat  423   a - c  adjacent the slit valve  119 . The substrate carriage  413  elevates, lifting the wafer from the blade B onto the substrate support seat  423   a - c.  The blade B retracts, the loadlock chamber  101  assumes the closed position (FIG. 2A) and the substrate carriage  413  rotates to position the wafer adjacent a slit valve  427 . The substrate carriage  413  then lowers transferring the wafer to the blade  424   a.  The slit valve  427  opens and the blade  424   a  extends therethrough to place the wafer into another chamber (not shown) coupled to the transfer chamber  411 , such as a processing chamber. The wafer may be heated or cooled via the temperature adjustment plate  415  prior to wafer transfer as described in U.S. patent application Ser. No. 09/611,549.  
         [0029]    The foregoing description discloses only exemplary embodiments of the invention. Modifications of the above-disclosed apparatus and method which fall within the scope of the invention will be readily apparent to those of ordinary skill in the art. For instance, the inventive load lock chamber  101  may be configured such that the top plate  109  moves up and down rather than the bottom plate  111  and/or the substrate handler  103 . The particular shapes of the top plate  109  and the bottom plate  111  are merely exemplary, and other shapes may be employed. Other mechanisms may be employed to raise and lower the bottom plate  111  and the substrate handler  103 , and the bottom plate  111  and substrate handler  103  may be raised and lowered independently if desired. Other types of substrate handlers may be employed within the inventive loadlock chamber  101 .  
         [0030]    Accordingly, while the present invention has been disclosed in connection with the 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.