Abstract:
In certain aspects, a load lock chamber is provided that includes a body having at least one sealing surface wall including a sealing surface. The sealing surface wall has an opening adjacent the sealing surface adapted to input or output a substrate. The body further includes a plurality of side walls. The load lock chamber also includes a top coupled to the body. The top includes one or more openings that divide the top into a first portion and a second portion. The load lock chamber further includes one or more top sealing members adapted to cover each opening of the top. Each top sealing member absorbs a movement of the first portion of the top relative to the second portion of the top. Numerous other aspects are provided.

Description:
The present application claims priority to U.S. Provisional Patent Application Ser. No. 60/587,114, filed Jul. 12, 2004 and U.S. Provisional Patent Application Ser. No. 60/576,906, filed Jun. 2, 2004, which are hereby incorporated by reference herein in their entirety for all purposes. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to flat panel display and/or electronic device manufacturing, and more particularly to methods and apparatus for sealing a chamber. 
     BACKGROUND 
     To increase flat panel display and/or electronic device manufacturing device throughput, a second load lock may be stacked on a first load lock. Each load lock may include one or more load lock doors for sealing the load lock such that a vacuum may be formed inside the load lock. Pressure gradients (e.g., atmospheric pressure outside a load lock and/or vacuum pressures within the load lock) may cause a top or bottom of a load lock to move and thus one or more walls of the load lock to move. Movement of a load lock wall that includes a load lock door may cause friction between a sealing gasket, the load lock wall and the load lock door. Such friction may cause the gasket to wear and generate particulates that create defects during flat panel display and/or electronic device manufacturing. 
     Load locks may be designed with one or more walls, a top and/or a bottom of a large thickness such that the pressure induced movement of the walls that include sealing surfaces is reduced. However, increasing the thickness of walls, a top and/or a bottom of a load lock requires extra material, and therefore, increases the cost and weight of the load lock. Further, increasing the thickness of the top and/or bottom of one or more stacked load locks increases the pitch of the load locks, which increases the complexity and cost of a manufacturing facility which includes the stacked load locks by complicating and/or increasing the cost of transfer mechanisms that transfer substrates to and/or from the stacked load locks. 
     Accordingly, improved methods and apparatus for sealing a chamber (e.g., a load lock) are desired. 
     SUMMARY OF THE INVENTION 
     In certain aspects of the invention, a load lock chamber is provided that includes a body having at least one sealing surface wall including a sealing surface. The sealing surface wall has an opening adjacent the sealing surface adapted to input or output a substrate. The body further includes a plurality of side walls. The load lock chamber also includes a top coupled to the body. The top includes one or more openings that divide the top into a first portion and a second portion. The load lock chamber further includes one or more top sealing members adapted to cover each opening of the top. Each top sealing member absorbs a movement of the first portion of the top relative to the second portion of the top. 
     In some aspects of the invention, a method for sealing a first load lock chamber is provided that includes the steps of (1) defining a gap between a central portion of a top and a sealing surface wall of the first load lock chamber so as to reduce movement of the sealing surface wall caused by movement of the central portion of the top; and (2) sealing the gap with a flexible gap sealing member. 
     In certain aspects of the invention, a load lock system is provided that includes a plurality of stacked load lock chambers. Each load lock chamber includes a body having (1) at least one sealing surface wall including a sealing surface, the sealing surface wall having an opening adjacent the sealing surface adapted to input or output a substrate; and (2) a plurality of side walls. Each load lock chamber also includes (a) a top coupled to the body, wherein the top includes one or more openings that divide the top into a first portion and a second portion; (b) one or more top sealing members adapted to cover each opening of the top, wherein each top sealing member absorbs a movement of the first portion of the top relative to the second portion of the top; (c) a bottom coupled to the body, wherein the bottom includes one or more openings that divide the bottom into a first portion and a second portion; and (d) one or more bottom sealing members adapted to cover each opening of the bottom, wherein each bottom sealing member absorbs a movement of the first portion of the bottom relative to the second portion of the bottom. Numerous other aspects are provided. 
     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 FIGURES 
         FIG. 1  illustrates a side view of a first exemplary load lock system in accordance with an embodiment of the invention. 
         FIG. 2  illustrates a top view of the first load lock in the first exemplary load lock system in accordance with an embodiment of the invention. 
         FIG. 3A  illustrates an exploded view of portions of the first load lock in accordance with an embodiment of the invention. 
         FIGS. 3B and 3C  are a top view and a side cross-sectional view, respectively, of a second exemplary bottom for a first load lock. 
         FIG. 3D  is an enlarged, side cross-sectional view of the second exemplary bottom of  FIGS. 3B and 3C . 
         FIG. 3E  is an enlarged, side cross-sectional view of an alternative embodiment of the second exemplary bottom of  FIG. 3D . 
         FIG. 3F  is a side, partial cross-section view of a second exemplary load lock system in which the bottom of  FIGS. 3B-3E  is employed. 
         FIG. 3G  is an exploded, side partial cross-section view of the components of  FIG. 3F . 
         FIG. 3H  is a perspective, cross-sectional view of a portion of the bottom of  FIGS. 3B-3E  that shows an exemplary embodiment of a slot. 
         FIG. 3I  is a cross-sectional, perspective view of a portion of the bottom of  FIGS. 3B-3E  that illustrates an exemplary pumping channel that may be employed to evacuate the slot of  FIG. 3H . 
         FIG. 4  illustrates a side view of a second exemplary load lock system in accordance with an embodiment of the invention. 
         FIG. 5  illustrates a side view of a first exemplary load lock door in accordance with an embodiment of the invention. 
         FIG. 6  illustrates a side view of a second exemplary load lock door in accordance with an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention relates to reducing movement of a chamber (e.g., load lock) sealing surface due to a movement of a load lock chamber top and/or bottom caused by a pressure or pressure change in the load lock chamber or an adjacent load lock chamber stacked above or below the chamber. Further, an inventive chamber door (e.g., load lock chamber door) may couple to and move with a sealing surface wall of the load lock chamber. As described below, the sealing surface wall of the load lock chamber may move due to a pressure or pressure change in the load lock chamber and/or a pressure or pressure change in an adjacent load lock chamber. 
       FIG. 1  illustrates a side view of a first exemplary load lock system  101  in accordance with an embodiment of the invention. With reference to  FIG. 1 , the first exemplary load lock system  101  includes a plurality of load locks  103 - 107 , which are vertically stacked. The first exemplary load lock system includes a first load lock  103  stacked below a second load lock  105  and stacked on top of a third load lock  107 . The first load lock  103  includes a body  108  that defines a plurality of sealing surface walls  109 ,  111 . The sealing surface walls  109 ,  111  may be formed of stainless steel, aluminum or the like. One or more of the sealing surface walls  109 ,  111  of the first load lock  103  includes an opening  115 - 117  for inputting and/or removing a substrate (e.g., a glass substrate, a polymer substrate, a semiconductor wafer, etc.) during flat panel display and/or electronic device manufacturing. 
     A load lock door  119 - 121  may be coupled to a respective sealing surface wall  109 ,  111  (e.g., to a sealing surface  122  of the sealing surface wall  109 ,  111  around the opening  115 - 117  in the sealing surface wall  109 ,  111  [ 109 - 111 ]) to seal the load lock  103 . The load lock door  119 - 121  may be internal or external to the load lock  103 . For example, the first load lock  103  includes an external door  119  adapted to couple to the first sealing surface wall  109  and seal the first opening  115 , and an internal door  121  adapted to couple to the second sealing surface wall  111  and seal the second opening  117 . A larger or smaller number of doors and/or different door positions may be employed. Each load lock door  119 - 121  may couple to the sealing surface wall  109 ,  111  via a gasket  123 , such as an  0 -ring. 
     The first load lock  103  includes a top  113  coupled to the sealing surface walls (e.g., an upper perimeter of the sealing surface walls  109 ,  111 ). The top  113  of the first load lock  103  serves as the bottom of the second load lock  105 . Although, the top  113  shown in  FIG. 1  is a multi-piece top, a one-piece top (e.g., a plate) may be employed. The top  113  of the first load lock  103  includes one or more slots  125 - 127  that define a first portion  129  and a second portion  131  of the top  113 . Each of the one or more slots  125 - 127  defines openings in the top  113  (e.g., an opening in a top surface and a bottom surface of the top  113 ). 
     To seal the first load lock  103  from the second load lock  105 , a flexible gap sealing member, such as a gasket  133 , may be employed to cover the openings defined by each slot  125 - 127 . For example, a double gasket (e.g., differential) seal may be employed. The gasket  133  may be an elastomer or a metal bellows (although other gasket configurations and/or materials may be employed). Further, a frame  135  may be coupled to and support each gasket  133  (e.g., by attaching each gasket to the top  113 ). 
     The first load lock  103  includes a bottom  137  coupled to the sealing surface walls  109 - 111  (e.g. a lower perimeter of the sealing surface walls  109 - 111 ). The bottom  137  of the first load lock  103  serves as the top of the third load lock  107 . The bottom  137  of the first load lock  103  is similar to the top  113  of the first load lock  103  in structure and function and, therefore, will not be described in detail herein. 
     In a similar manner, additional load locks may be stacked above the second load lock  105  and/or below the third load lock  107 . Alternatively, the second load lock  105  may be the top of the stacked load lock system  101  and/or the third load lock  107  may be the bottom of the stacked load lock system  101 . In embodiments in which the third load lock  107  is the bottom of the stacked load lock system  101 , a bottom  139  of the third load lock  107  may be similar to the bottom  137  of the first load lock  103 . However, because the bottom  139  of the third load lock  107  does not need to accommodate a door of a load lock below the third load lock  107 , the bottom  139  of the third load lock  107  may be modified accordingly. For example, the bottom surface of the bottom  139  need not include a cut-out portion that accommodates door movement, such as the cut-out portion shown for the bottom  137  of the first load lock  103 . Further a single gasket seal may be used to seal the slots  125 ,  127  of the bottom  139 . Similarly, in embodiments in which the second load lock  105  is the top of the stacked load lock system  101 , a top  141  of the second load lock  105  may be similar to the top  113  of the first load lock  103 . However, because the top  141  of the second load lock  105  does not need to accommodate a door of a load lock above the second load lock  105 , the top  141  of the second load lock  105  may be modified accordingly. A single gasket seal may be used to seal the slots  125 ,  127  of the top  141  of the second load lock  105 . 
       FIG. 2  illustrates a top view of the first load lock  103  in the first exemplary load lock system in accordance with an embodiment of the invention. Portions of the load lock sealing surface walls  109 - 111  have been removed in this view. With reference to  FIG. 2 , the frame  135  is coupled to the second portion  131  of the top  113  (e.g., a top surface of the second portion  131 ) of the load lock  103 . A gasket (not shown in  FIG. 2 ;  133  in  FIG. 1 ) is below the frame  135  and seals an opening defined by a slot (not shown in  FIG. 2 ;  125  in  FIG. 1 ) in the second portion  131  of the top  113 . 
       FIG. 3A  illustrates an exploded view of portions of the first load lock  103  in accordance with an embodiment of the invention. With reference to  FIG. 3A , the load lock  103  includes the body  108  that includes the plurality of sealing surface walls  109 - 111 , and sidewalls  301 - 303 . The first and second sealing surface walls  109 - 111  include sealing surfaces (e.g., flapper door seal surfaces). In one embodiment, the load lock body  108  is a forged aluminum or stainless steel box. The length of the box is about 110 inches, the width of the box is about 88 inches and the height of the box is about 10.5 inches. Further, the thickness of the sealing surface walls  109 - 111  and/or the sidewalls  301 - 303  of the box is about 2 inches. The body  108  may be formed from other materials. Further, different load lock body configurations may be employed. For example, the load lock body  108  may include a larger or smaller number of sides and/or may be dimensioned differently. 
     In one embodiment, the width of the first opening  115  in the first sealing surface wall  109  is about 82.5 inches and the height of the first opening  115  in the first sealing surface wall  109  is about 5.6 inches. The second opening  117  in the second sealing surface wall  111  may be similarly sized. Other dimensions may be used. 
     The bottom  137  of first load lock  103  may be a one-piece assembly. For example, in the embodiment of  FIG. 3A , the bottom  137  is an aluminum separation plate, which includes a machined step (not shown). Other materials similar to aluminum, such as stainless steel or the like may be employed for the bottom  137 . In one embodiment, the length of the bottom  137  is about 110 inches, the width of the bottom  137  is about 88 inches and the thickness of the bottom  137  is about 2 inches. Therefore, the bottom  137  of the first load lock  103  may be susceptible to movement due to a pressure in the first load lock  103  and a pressure in the third load lock  107  ( FIG. 1 ). The bottom  137  of the first load lock  103  may be dimensioned differently. 
     The bottom  137  of the first load lock  103  includes two slots  125 ,  127  positioned such that the slots  125 ,  127  define a first portion  129  (e.g., an edge region) and a second portion  131  (e.g., a center portion) of the bottom  137 . For example, each slot  125 ,  127  may be oval-shaped, about 82 inches long and about 0.5 inches wide. Further, the slots  125 ,  127  define an edge region about 4 inches wide (to a center of the each slot  125 ,  127 ). The slots may be shaped, dimensioned and/or positioned differently. Further, a larger or smaller number of slots may be employed. 
     As stated one or more gaskets  133  may be employed to seal each of the slots  125 ,  127 . Accordingly, each gasket  133  is dimensioned such that the gasket  133  seals the opening defined by the slot  125 ,  127  to which the gasket  133  is coupled. Although not shown in  FIG. 3A , the top  113  of the first load lock  103  may be similar to the bottom  137  of the first load lock  103 . 
       FIGS. 3B and 3C  are a top view and a side cross-sectional view, respectively, of a second exemplary bottom  137 ′ for the first load lock  103 . The bottom  137 ′ is a multi-piece assembly which includes a stainless steel frame  305  and an aluminum insert  307  ( FIG. 3C ). Other materials may be used for the frame  305  and/or insert  307 . In one embodiment, the length of the bottom  137 ′ is about 110 inches, the width of the bottom  137 ′ is about 88 inches and the thickness of the frame  305  of the bottom  137 ′ is about 2 inches. Therefore, the bottom  137 ′ of the first load lock  103  may be susceptible to movement due to a pressure in the first load lock  103  and a pressure in the third load lock  107  ( FIG. 1 ). The bottom  137 ′ of the first load lock  103  may be dimensioned differently. 
       FIG. 3D  is an enlarged, side cross-sectional view of the second exemplary bottom  137 ′. As shown in  FIG. 3D , in one exemplary embodiment, the steel frame  305  has a width W 1  of about 3.7 to about 5.5 inches (depending on whether the steel frame  305  is a “central” or “outer” top or bottom of a load lock system as described below with reference to  FIG. 3F ), a first thickness T 1  of about 2 inches and a second thickness T 2  of about 4 inches, with a step  309  formed therein to accommodate the aluminum insert  307 . The step  309  has a width W 2  of about 1.8 inches, and a height H 1  of about 0.2 inches. The aluminum insert  307  may be sized to sit within the frame  305 , being supported by a flange  311  of the insert  307  that rests on the step  309  of the steel frame  305 . In one embodiment, the thickness of the flange  311  of the insert  307  may be about 1.1 to 2.4 inches, and the total thickness of the insert  307  may be about 4.5 inches. Other dimensions for the frame  305  and/or insert  307  may be employed. 
       FIG. 3E  is an enlarged, side cross-sectional view of an alternative embodiment of the second exemplary bottom  137 ′ that is similar to the embodiment of  FIG. 3D , but in which the thickness T of the frame  305  is uniform (e.g., about 2 inches in one embodiment, although other dimensions may be used). The remaining dimensions of the bottom  137 ′ of  FIG. 3E  may be similar to those of the bottom  137 ′ of  FIG. 3D . 
       FIG. 3F  is a side, partial cross-section view of a second load lock system  101 ′ in which the second exemplary bottom  137 ′ is employed. The body  108 , sealing surface walls  109 - 111 , openings  115 - 117  and/or load lock doors  119 - 121  of each load lock  103 - 107  are not shown in  FIG. 3F , but may be similar to those shown in  FIG. 1  (although other suitable components may be employed). 
     The load lock system  101 ′ of  FIG. 3F  employs a top  113 ′ of the first (center) load lock  103  that is similar to the bottom  137 ′ described with reference to  FIGS. 3B-3E . That is, the top  113 ′ includes a frame  305  and insert  307 . (The top  141 ′ of the second load lock chamber  105  is similar to the top  113 ′ of the first load lock chamber  103 , and the bottom  139 ′ of the third load lock chamber  107  is similar to the bottom  137 ′ of the first load lock chamber  103 .) Note that tops and bottoms similar to the bottom  137 ′ of  FIG. 3E  may be employed. 
       FIG. 3G  is an exploded, side partial cross-section view of the components of  FIG. 3F  that shows the inserts  307  separated from the frames  305  for each top  113 ′/bottom  137 ′. Note that in the embodiment of  FIGS. 3F and 3G , the “central” frames  305  of the load lock system  101 ′ extend further into the load lock system  101 ′ so as to allow (1) the insert  307  of the top  113 ′ of the first (center) load lock  103  to be passed through the frame  305  of the top  141 ′ of the second (top) load lock  105 ; and (2) the insert  307  of the bottom  137 ′ of the first (center) load lock  103  to be passed through the frame  305  of the bottom  139 ′ of the third (bottom) load lock  107 . In one embodiment of the invention, the inserts  307  of the top  113 ′ and bottom  137 ′ of the load lock  103  are about 88 inches by 73 inches, the insert  307  of the top  141 ′ of the second load lock  105  is about 95 inches by 81 inches and the insert  307  of the bottom  139 ′ of the third load lock  107  is about 95 inches by 81 inches. The inserts  307  have an overall thickness of about 4.5 inches. Other size inserts may be used. The inserts  307  may be coupled to the frames  305  via any suitable sealing mechanism (e.g., an o-ring) and/or fastening mechanism (e.g., bolts, screws, etc.). In one embodiment, the flange  311  of the two bottom inserts  307  is about 1.1 inches thick, and the flange  311  of the two top inserts  307  is about 2.4 inches thick (e.g., with both top and bottom inserts having a total thickness of about 4.5 inches). In one or more embodiments, the difference in the thicknesses of the top and bottom flanges  311  may allow the volumes of the three load locks  103 - 107  to be approximately equal. The frames  305  may be similar to the frame  305  of  FIG. 3D  or  FIG. 3E . Other flange/insert sizes and/or shapes may be used. 
     With reference to  FIGS. 3B-3G , the bottom  137 ′ of the first load lock  103  includes two slots  125 ,  127  positioned such that the slots  125 ,  127  define a first portion  129  (e.g., an edge region) and a second portion  131  (e.g., a center portion) of the bottom  137 ′ (within the frame  305 ). For example, each slot  125 ,  127  may be oval-shaped, about 82 inches long and about 0.5 inches wide. Further, the slots  125 ,  127  define an edge region about 4 inches wide (to a center of the each slot  125 ,  127 ). The slots may be shaped, dimensioned and/or positioned differently. Further, a larger or smaller number of slots may be employed. 
       FIG. 3H  is a perspective, cross-sectional view of a portion of the bottom  137 ′ of the load lock  103  that shows an exemplary embodiment of the slot  125 . The slot  127  may be similarly configured. 
     The slots  125  are shown within the frame  305  area of the bottom  137 ′. In one exemplary embodiment, the slot  125  has a width WS of about 0.5 inches. As stated, one or more gaskets  133   a - b  (e.g., rubber, a fluoroelastomer such as Viton® available from Dupont, metal or another suitable material) may be employed to seal the slot  125 . The gaskets  133   a - b  may be held against the frame  305  via a stainless steel or similar retaining plate  313  or suitable structure (e.g., via bolts, screws or other fasteners). The slot  125  may include steps which accommodate the gaskets  133   a - b  and/or the retaining plate  313  as shown. In one embodiment, the steps within the slot  125  may be about 0.1 inches in depth, as may be the thickness of the gaskets  133   a - b  and/or the retaining plate  313 . Other step, gasket and/or retaining plate sizes may be used. 
     The slot  125  may include radius features  315  to relieve pressure induced stress within the bottom  137 ′ (e.g., by avoiding sharp edges which serve as high stress locations). In one embodiment, the radius features  315  may each have a radius of about ⅜ of an inch, although other dimensions may be used. 
     As shown in  FIG. 3H , a cavity  317  is formed between the gaskets  133   a - b  within the slot  125 . In at least one embodiment, the cavity  317  may be evacuated (e.g., to about 500 milliTorr or another suitable pressure) during use of the load lock chamber  103 .  FIG. 3I  is a cross-sectional, perspective view of a portion of the bottom  137 ′ that illustrates an exemplary pumping channel  319  that may be employed to evacuate the slot  125 . Other pumping channel configurations may be used.  FIG. 3I  also illustrates that the slot  125  (and/or the slot  127 ) may have radiused ends  321  to relieve stress within the slot  125 . In one embodiment, the radiused ends  321  form a keyhole-shape having a diameter of about 1 inch, although other sizes may be used. 
     In operation, during flat panel display and/or electronic device manufacturing, a pressure inside two or more of the load locks  103 - 107  of the exemplary load lock system  101 ,  101 ′ may be different. For example, the first, second and third load locks  103 - 107  may include a first, second and third pressure, respectively. The pressure differential between adjacent load locks  103 - 107  (and additionally, the ambient pressure) may cause a top and/or bottom of one or more of the load locks  103 - 107  to move (e.g., deflect vertically). For example, a pressure differential between the first and second load locks  103 - 105  may cause one or more portions of the top  113 ,  113 ′ of the first load lock  103 , which serves as the bottom of the second load lock  105 , to move downward. Downward deflection of the second portion  131  (e.g., center portion) of the top  113 ,  113 ′ causes the first portion  129  (e.g., the edge region) to deflect (e.g., downward). The slots  125 ,  127  may cause the center portion of the top  113 ,  113 ′ to move (e.g., downwardly or upwardly) more than a conventional top which is subjected to the same pressure differential and may cause the edge region of the top  113 ,  113 ′ to move less than a conventional top which is subjected to the same pressure differential. In this manner, the top  113 ,  113 ′ of the first load lock  103  is adapted to diminish the movement of the first (edge) portion  129  caused by movement of the second (center) portion  131  of the top  113 ,  113 ′ of the first load lock  103 . 
     Further, movement of the load lock sealing surface wall  109 ,  111  ( FIG. 1 ) adjacent the first portion  129  of the top  113 ,  113 ′ of the first load lock chamber  103  is reduced. More specifically, movement (e.g., upward or downward) of the edge region  129  of the top  113 ,  113 ′ causes the load lock sealing surface wall  109 ,  111  adjacent the first portion  129  of the top  113 ,  113 ′ to move (e.g., upward or downward). However, by reducing the movement of the first portion  129  of the top  113 ,  113 ′ of the first load lock chamber  103 , the movement of the load lock sealing surface wall  109 ,  111  adjacent the first portion  129  of the top  113 ,  113 ′ of the first load lock chamber  103  is reduced. Likewise, movement of the load lock sealing surface  122  caused by movement of the first portion  129  of the top  113 ,  113 ′ of the first load lock  103  is also reduced. Consequently, rubbing is reduced between the gaskets  123 , the load lock sealing surface walls  109 - 111  and the load lock doors  119 - 121  coupled to the load lock sealing surface walls  109 - 111 . In this manner, wearing of the gaskets  123  and/or other contact surfaces is reduced as is particulate generation and any substrate defects associated therewith. 
     Through use of the present invention, the sealing surfaces  122  of the load lock  103  (as well as the load locks  105 - 107 ) may be isolated from movements of other portions (e.g., a center portion of the top  113 ,  113 ′) of the load lock  103  caused by a pressure differential between the load lock  103  and adjacent load locks  105 - 107  (e.g., resulting from pressure fluctuation in one or more load locks  103 - 107  in the load lock system  101 ,  101 ′). Thinner wall thicknesses thereby may be employed, reducing load lock system cost and/or complexity. 
       FIG. 4  illustrates a side view of a third exemplary load lock system  401  in accordance with an embodiment of the invention. The third exemplary load lock system  401  of  FIG. 4  is similar to the first exemplary load lock system  101  of  FIG. 1 . However, a top and/or bottom of the load locks in the third exemplary load lock system are different from the first exemplary load lock system. With reference to  FIG. 4 , a top  403  of a first load lock chamber  405  in the third exemplary load lock system  401  is adapted to define a gap  407  between a central portion  408  of the top  403  and a sealing surface wall  409  (e.g., a top of the sealing surface wall  409 ) of the first load lock chamber  405 . In one embodiment of the invention, the gap  407  may be about ¼ in. wide, a first portion of the top  403  adjacent the sealing surface wall  409  is at least about one inch thick and a second portion (e.g., a center portion) of the top  403  is about 4-5 inches thick (although, the top  403  and/or gap  407  may be dimensioned and/or shaped differently). 
     The top  403  of the first load lock chamber  405  may serve as a bottom of a second load lock chamber  410 . In such embodiments, in a manner similar to that described above, the top  403  of the first load lock chamber  405  is adapted to define a gap  407  between the top  403  and a sealing surface wall  411  (e.g., a bottom of the sealing surface wall  411 ) of the second load lock chamber  410 . Alternatively, the top  403  of the first load lock chamber  405  may serve as the top of the third exemplary load lock system  401  if the second load lock chamber  410  is not present. 
     The top  403  is coupled to the sealing surface wall  409 ,  411  via a flexible gap sealing member  412 , such as a gasket. More specifically, the flexible gap sealing member  412  seals the gaps  407  defined between the top  403  and the sealing surface wall  409 ,  411 . The flexible gap sealing member  412  is employed to reduce movement of the sealing surface walls  409 ,  411  caused by movement of the top  403 . Consequently, rubbing between a gasket  423 , which is coupled between the load lock sealing wall  409 ,  411  and a load lock door  425 ,  427  is reduced. 
     Similarly, a bottom  413  of the first load lock chamber  405  in the third exemplary load lock system  401  is adapted to define a gap  407  between the bottom  413  and the sealing surface wall  409  (e.g., a bottom of the sealing surface wall  409 ) of the first load lock chamber  405 . The bottom  413  of the first load lock chamber  405  may serve as a top of a third load lock chamber  415 . In such embodiments, in a manner similar to that described above, the bottom  413  of the first load lock chamber  405  is adapted to define a gap  407  between the bottom  413  and a sealing surface wall  417  (e.g., a top of the sealing surface wall  417 ) of the third load lock chamber  415 . Alternatively, the bottom  413  of the first load lock chamber  405  may serve as the bottom of the third exemplary load lock system  401  if the third load lock chamber  415  is not present. 
       FIG. 5  illustrates a side view of a first exemplary load lock door  501  in accordance with an embodiment of the invention. The first exemplary load lock door  501  may seal a load lock chamber during flat panel display and/or electronic device manufacturing. With reference to  FIG. 5 , the first exemplary load lock door  501  may couple to a sealing surface wall  503  of a load lock  505 , which includes a top  506  and a bottom  507 . More specifically, the first exemplary load lock door  501  may couple to a sealing surface  508  around an opening  509  in the sealing surface wall  503 . 
     The load lock door  501  includes a first stiffener  510  coupled to a first side (e.g., an outer side) of a bellows  511  (e.g., a bellows/basket) via a frame  513  (e.g., a flexible clamp frame, such as an aluminum or stainless steel frame). A second stiffener  515  is coupled to a second side (e.g., an inner side) of the bellows  511 . The first stiffener  510  may be coupled to the second stiffener  515  via one or more bolts  517  or similar connection means. The first and second stiffeners  510 ,  515  limit movement of the bellows  511 , and therefore, provide stiffness to the first exemplary door  501 . The first and second stiffeners  510 ,  515  may be formed from aluminum, stainless steel or the like. The second stiffener  515  is adapted to mate with the second side of the bellows  511 . 
     The bellows  511  is adapted to provide a flexible vacuum seal to the load lock  505 . The bellows  511  may include one or more curves R 1 . The bellows  511  may be formed from an elastomer or a flexible metal, such as stainless steel or the like, or from other materials. 
     A flexible sealing member  523  is coupled to the second side of the bellows  511 . More specifically, a first side of the flexible sealing member  523  is adapted to couple to a perimeter of the bellows  511  and is dimensioned accordingly. The second side of the flexible sealing member  523  is adapted to couple to and form a seal with the sealing surface wall  503  (e.g., at the sealing surface  508  of the sealing surface wall  503 ), for example, via a gasket  525 , such as an O-ring. The flexible sealing member  523  may be formed from aluminum or another suitable material. The flexible sealing member  523  may be coupled to the frame  513  via one or more bolts  527  or similar connection means. Further, the first exemplary door  501  is coupled to the load lock  505  via a shaft  529  which allows the first exemplary door  501  to pivot relative to the load lock  505 . 
       FIG. 6  illustrates a side view of a second exemplary load lock door in accordance with an embodiment of the invention. With reference to  FIG. 6 , the second exemplary load lock door  601  is similar to the first exemplary load lock door  501 . However, the number and shape of the stiffeners employed by the second exemplary load lock door  601  is different. Further, the shape of a bellows  603  employed by the second exemplary load lock door  601  is different. For example, edges  609  of the bellows  603  include curves R 2 . 
     The second exemplary load lock door  601  includes a stiffener  605  coupled to a first side of the bellows  603 . The stiffener  605  is adapted to mate with the bellows  603 . More specifically, edges  607  of the stiffener  605  facing the bellows  603  are rounded. A bolt  611  and corresponding nut  613  may be employed to couple the stiffener  605  to the bellows  603 , although other connection mechanisms may be employed. The remaining components of the second door  601  may be similar to the first door  501 . 
     The operation of a load lock door in accordance with an embodiment of the present invention is now described with reference to  FIG. 5 , which illustrates the first exemplary load lock door  501 . The second exemplary load lock door  601  operates in a similar manner. 
     A sealing force, such as ambient pressure, may be applied to the first exemplary load lock door  501 . The sealing force, which may be at an angle relative to the direction of movement of the load lock door  501  caused by movement of the top  506  of the load lock  505 , biases the load lock door  501  against the load lock sealing surface wall  503 . In accordance with the present invention, if the top  506  of the load lock  505  moves, the flexible sealing member  523  moves along with the load lock sealing surface wall  503  of the top  506 . Consequently, rubbing between the load lock sealing surface wall  503  and the gasket  525  and/or other contact surfaces is reduced. Therefore, wearing of the gasket  525  and/or other contact surfaces is reduced. 
     The first exemplary load lock door  501  may be coupled to and/or included in a load lock  505  of a stacked load lock system. For example, the load lock  505  may be stacked below an upper load lock (not shown) and stacked above a lower load lock (not shown). The top  506  of the load lock  505  may serve as a bottom for the upper load lock. The bottom  507  of the load lock  505  may serve as a top for the lower load lock. During flat panel display and/or electronic device manufacturing, pressures in the load lock  505 , upper load lock and lower load lock may cause the top  506  and/or bottom  507  of the load lock  505  to move (e.g., deflect) as previously described. For example, a portion of the top  506 , such as the perimeter  531 , may move due to differing pressures within the load locks. 
     Further, movement of the perimeter  531  of the top  506  causes the load lock sealing surface wall  503  to move (e.g., upward or downward). Consequently, the sealing surface  508  in the sealing surface wall  503  moves. 
     Through use of the present invention, one or more portions of a load lock door (e.g., sealing features of the load lock door)  501  move in conjunction with a load lock sealing surface wall  503  during flat panel display and/or electronic device manufacturing. Although the load lock door is rigid enough to seal the load lock chamber, the load lock door is flexible enough to move with the load lock sealing surface wall. 
     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. Although one or more of the above methods and apparatus are described with respect to a load lock chamber, in other embodiments the present methods and apparatus may be employed by other types of chambers employed during flat panel display and/or electronic device manufacturing. 
     In at least one embodiment of the invention, a method is provided that includes the steps of (1) providing one of the inventive load lock chambers described herein; (2) storing a substrate within the load lock chamber; (3) transferring the substrate from the load lock chamber to a processing chamber; and (4) processing the substrate within the processing chamber (e.g., by performing a flat panel display and/or electronic device manufacturing process on the substrate). For example, the load lock chamber may be coupled to the processing chamber by a transfer chamber, and the substrate may be transferred between the load lock chamber and the processing chamber via a vacuum robot positioned with the transfer chamber. The substrate may be returned to the load lock chamber after processing within the processing chamber. 
     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.