Abstract:
A wafer processing system which requires no isolation between the operational areas within the processing system. The system of the present invention includes operational areas, such as a loading area, a transport area, and a reactor or thermal processing area. Advantageously, since there are no isolation devices or gate valves separating the areas, the processing system effectively has each operational area combined into a “single” chamber. Preferably, the single chamber has a single slit valve, hinge door, or other vacuum sealable door disposed proximate to the loading area to allow for the removal/insertion of the wafers into the loading area. Once the door to the loading area has been closed the internal pressure within the chamber can be kept uniform throughout each operational area.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention generally relates to semiconductor device fabrication and more particularly to systems for processing a semiconductor wafer.  
           [0003]    2. Description of the Related Art  
           [0004]    Specialized wafer processing systems are used to process semiconductor wafers into electronic devices. In most wafer processing systems, a carrier containing wafers is loaded into a loading station and transferred to a loadlock. Subsequently, a robot picks up a wafer from the carrier and moves the wafer into a reactor. The wafer is processed in the reactor according to a recipe. Once the wafer has been processed, the robot picks up and transfers the wafer back to the carrier in the loadlock. The carrier is then moved out of the loadlock and back into the loading station.  
           [0005]    Gate valves are routinely employed in a variety of circumstances where wafers are moved from an area at a first pressure to an area at a different, second pressure. In general, the gate valve is a device which is used to isolate operational areas in a wafer processing environment, such that the internal pressures within the operational areas can be varied. The gate valve also reduces particulate contamination between operational areas, which may otherwise be problematic to certain wafer processes.  
           [0006]    Unfortunately, the use of gate valves in the processing system also has drawbacks. For example, gate valves generally include large numbers of exposed joints, bearings, hinges, and the like, which generate particulates whenever the gate valve is actuated. These particulates can deposit on the wafers and interfere with the processing operation. Moreover, such joints are difficult to lubricate in a low pressure environment, where the lubrication fluid quickly vaporizes. In addition, location of the gate valve within the processing system usually increases the size of the system. Typically, the increased size of the system, increases the time and power required to draw a vacuum, as well as increasing the capital costs associated with manufacturing the system.  
           [0007]    For these reasons, it would be desirable to provide a wafer processing system which does not require vacuum isolation between operational areas of the processing system.  
         SUMMARY OF THE INVENTION  
         [0008]    The present invention provides a wafer processing system which requires no isolation between the operational areas within the processing system. The system of the present invention includes operational areas, such as a loading area, a transport area, and a reactor or thermal processing area. Advantageously, since there are no isolation devices or gate valves separating the areas, the processing system effectively has each operational area combined into a “single” chamber. Preferably, the single chamber has a single slit valve, hinge door, or other vacuum sealable door disposed proximate to the loading area to allow for the removal/insertion of the wafers into the loading area. Once the door to the loading area has been closed the internal pressure within the chamber can be kept uniform throughout each operational area.  
           [0009]    In one aspect of the invention, a wafer processing apparatus is provided which includes a chamber. Within the chamber are a loading area, a thermal processing area; and a transport area. The loading area, the transport area, and the thermal processing area remain in environmental communication during performance of a wafer processing operation in said wafer processing area.  
           [0010]    In another aspect of the invention, a system is provided for processing a semiconductor wafer. The system includes a first compartment configured for receiving wafers to be processed. The system also includes a second compartment disposed adjacent to the first compartment, which includes a transport mechanism operable for transporting the wafers. A third compartment is disposed adjacent to the second compartment, which is used for thermally processing the wafers. The first compartment, the second compartment, and the third compartment are in environmental communication while the wafer is being thermally processed in the third compartment.  
           [0011]    A processing system which includes the operational areas combined together in effectively a single chamber removes the possibility of pressure fluctuations from occurring during processing. Because the operational areas in the chamber are under one pressure, the wafer throughput can be increased. Further, since there is one chamber volume there is no need for multiple pumps in the system. The present invention is particularly useful in thermal processes, such as annealing and some chemical vapor deposition processes.  
           [0012]    Other uses, advantages, and variations of the present invention will be apparent to one of ordinary skill in the art upon reading this disclosure and accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIGS. 1A and 1B show a side view and a top view, respectively, of a wafer processing system in accordance with the invention;  
         [0014]    [0014]FIGS. 2A and 2B show a side view and a top view, respectively, of a loading station in accordance with the invention;  
         [0015]    [0015]FIG. 3 shows a cross-sectional view of a bar used in the loading station shown in FIG. 2A;  
         [0016]    [0016]FIG. 4A shows a functional “x-ray” view of a wafer processing robot in accordance with the invention;  
         [0017]    [0017]FIG. 4B shows a magnified view of a portion of the robot shown in FIG. 4A;  
         [0018]    [0018]FIGS. 4C and 4D show top “x-ray” views of a robot in one embodiment of the invention;  
         [0019]    [0019]FIG. 5 shows in block diagram form a control system for controlling the wafer processing system shown in FIGS. 1A and 1B;  
         [0020]    FIGS.  6 A- 6 E illustrate in graphical form the movement of a platform in the loading station shown in FIGS. 2A and 2B;  
         [0021]    [0021]FIGS. 7A and 7B show side views of the loading station shown in FIGS. 2A and 2B;  
         [0022]    FIGS.  8 A- 8 F show side views of the wafer processing system shown in FIG. 1A illustrating the movement of a wafer from a carrier in a load lock to a reactor;  
         [0023]    [0023]FIG. 9 shows a functional diagram of a sensor configuration for tracking the position of a platform in the loading station shown in FIGS. 2A and 2B;  
         [0024]    [0024]FIGS. 10A and 10B show side views of a loading station and a load lock in one embodiment of the invention;  
         [0025]    [0025]FIG. 11A shows a perspective view of a load lock and a platform in accordance with the invention;  
         [0026]    [0026]FIG. 11B shows a side cross-sectional view of the load lock and platform shown in FIG. 11A;  
         [0027]    [0027]FIGS. 12A and 12B are simplified illustrations of a top plan view and a side view, respectively of an embodiment of the processing system of the present invention;  
         [0028]    [0028]FIG. 12C is a simplified illustration of a side view of an alternative embodiment of the present invention;  
         [0029]    [0029]FIG. 13A, is a simplified illustration of a partial cross-sectional side view of a first compartment (loading area) in accordance with the present invention;  
         [0030]    [0030]FIG. 13B is a simplified illustration of an alternative embodiment to the first compartment of FIG. 13A; and  
         [0031]    [0031]FIGS. 14, 14A, and  14 B are illustrations of various views of an embodiment of a cooling station in accordance with the present invention.  
     
    
     DETAILED DESCRIPTION  
       [0032]    [0032]FIGS. 1A and 1B show a side view and a top view, respectively, of a wafer  5  processing system  100  in accordance with the present invention. System  100  includes a loading station  10 , a load lock  12 , a transfer chamber  20 , a robot  21 , reactors  30  and  40 , and a cooling station  60 . Loading station  10  has platforms  11 A,  11 B, and  11 C for supporting and moving wafer carriers, such as a wafer carrier  13 , up into load lock  12 . While three platforms are used in this  10  embodiment, the invention is not so limited. Two platforms can also be used as can additional platforms to increase throughput. Carrier  13  is a removable wafer carrier which can carry up to 25 wafers at a time. Other types of wafer carriers, including fixed wafer carriers, can also be used. Wafer carriers are loaded onto platforms  11 A,  11 B, and  11 C either manually or by using automated guided vehicles (“AGV”).  
         [0033]    While the movement of a wafer carrier into load lock  12  is illustrated herein using carrier  13  on platform  11 A as an example, the same illustration applies to the movement of other wafer carriers using platforms  11 B and  11 C. Further, because platforms  11 A,  11 B, and  11 C are structurally and functionally the same, any reference to platform  11 A also applies to platforms  11 B and  11 C. Referring to FIGS. 2A and 2B, which show a side view and a top view of loading station  10 , platform  11 A includes a driving bar  209  which is coupled to a triangular block  207  via bearings  217 . A motor  205  is mechanically coupled to an adapter block  219  using a flexible coupler  206 . Adapter block  219  is fixedly attached to triangular block  207 . By rotating adapter block  219 , motor  205  can thus rotate triangular block  207  which, in turn, rotates platform  11 A about a pole  208 . The rotation of platform  11 A about pole  208  is illustrated in FIGS. 6A to  6 E. FIGS. 6A to  6 C sequentially show top views of platform  11 A as it is rotated from a position  610  to a position  611  in a direction indicated by an arrow  613 . FIG. 7A shows a side view of loading station  10  when platform  11 A is in position  611 . FIGS. 6C to  6 E show top views of platform  11 A rotating from position  611  to a position  612  in a direction indicated by an arrow  614 . FIG. 7B shows a side view of loading station  10  when platform  11 A is in position  612 .  
         [0034]    Referring to FIG. 2B, a belt  202  is wound through a fixed center pulley  204 , fixed platform pulleys  201 , and idlers  203  so that opening  601  of wafer carrier  13  through which wafers are inserted (FIGS.  6 A- 6 E) faces towards robot  21  as platform  11 A is rotated about pole  208 . Tension on belt  202  is set by adjusting idlers  203 .  
         [0035]    Referring to FIG. 9, the position of platform  11 A in loading station  10  is tracked using a sensor  901  and a flag  905 . Flag  905  is attached to a predetermined location on triangular block  207 . The position where flag  905  passes through sensor  901  is known as the “home”position. In one embodiment, the output of sensor  901  is coupled to a motor controller  902  via a line  903 . The output of motor  205 , which can be an encoder output, is also coupled to motor controller  902  via a line  904 . When flag  905  passes through sensor  901 , sensor  901  outputs a “home signal”to motor controller  902  indicating that triangular block  207  is in the home position. By monitoring line  904 , motor controller  902  determines the number of rotation that motor  205  makes after the receipt of the home signal. Because the location of platform  11 A relative to the home position is predetermined, the location of platform  11 A as it rotates about pole  208  can then be tracked by motor controller  902 .  
         [0036]    As shown in FIG. 7B, a cam  212  engages a slotted disk  213  when platform  11 A is in position  612 . Cam  212  is attached to driving bar  209  which, in turn, is attached to platform  11 A. Once motor controller  902  indicates that platform  11 A is in position  612 , air pressure is provided into a pneumatic cylinder  210  to push a piston  211  upwards. Consequently, slotted disk  213  engages cam  212  to push platform  11 A up into load lock  12  as shown in FIG. 2A. Bar  209  has a cross-section as shown in FIG. 3, which is taken along section III-III in FIG. 2A, to prevent rotation of platform  11 A during vertical motion. To avoid jarring wafer carrier  13  on platform  11 A, the air pressure provided to pneumatic cylinder  210  is regulated such that a high pressure is initially provided and then gradually decreased as platform  11 A approaches load lock  12 .  
         [0037]    The rotational movement of platforms  11 A,  11 B, and  11 C into position  612  minimizes the floor space occupied by loading station  10 . As is evident from FIG. 2B, loading station  10  occupies just enough area to accommodate the number of platforms used which, in the particular embodiment shown in FIG. 2B, is three.  
         [0038]    In one embodiment, the platforms of a loading station  10 A, which is shown in FIG. 10A, are not elevated into a load lock  1012 . In loading station  10 A, a motor  205 A, a flexible coupler  206 A, an adapter block  219 A, and a triangular block  207 A are functionally and structurally the same as their counterparts in loading station  10  (i.e. motor  205 A is the same as motor  205 , etc.). Except for a platform  1010 A not having a long driving bar such as driving bar  209  of platform  11 A, platform  1010 A is otherwise the same as platform  11 A. In contrast to the operation of platform  11 A in loading station  10 , platform  1010 A is not elevated into load lock  1012 . Instead, platform  1010 A is rotated into a position (“load lock position”) where platform  1010 A can be enclosed within load lock  1012 . In FIG.  
         [0039]    [0039] 10 A, the load lock position is just below load lock  1012 . Once platform  1010 A is in the load lock position, load lock  1012  is lowered to enclose platform  1010 A as shown in FIG. 10B. A robot (not shown) in transfer chamber  1020  can then access the wafers in a wafer carrier  1013 . Load lock  1012  is raised and lowered using conventional structures. For example, load lock  1012  can be fitted with a ball screw and then lifted by rotating the ball screw using a motor. As in loading station  10 , the rotational movement of platform  1010 A minimizes the floor space requirement of loading station  10 A.  
         [0040]    As shown in FIG. 2A, load lock  12  is bolted onto transfer chamber  20  and is further supported by pole  208  through hinges  215  and  216 . Pole  208  freely rotates through hinge  215 , hinge  216 , and bearings  218  to prevent vibrations from motor  205  from being transmitted into load lock  12 . FIG. 11A shows a perspective view of load lock  12 . In FIG. 11A, pole  208  and other components of system  100  are not shown for clarity. Load lock  12  includes a viewing port  1102  on a side  1105  to allow visual inspection of the insides of load lock  12 . Viewing port  1102  is made of a transparent material such as quartz. Referring to FIG. 11B, which shows a partial side cross-sectional view of load lock  12 , viewing port  1102  is bolted on load lock  12  with bolts  1103 . A surrounding seal  1106  (e.g. o-ring or lip seal) between viewing port  1102  and side  1105  is provided to create a vacuum seal. Similarly, load lock  12  is bolted on transfer chamber  20  with bolts  1104 . A surrounding seal  1107  between load lock  12  and transfer chamber  20  creates a vacuum seal. When platform  11 A is up in load lock  12 , a surrounding seal  214  on platform  11 A (FIG. 11B) contacts the bottom opening portion of load lock  12 . During processing which requires vacuum, pneumatic cylinder  210  pushes platform  11 A up into load lock  12  such that seal  214  is compressed against load lock  12  to create a vacuum seal. Also, vacuum within load lock  12  draws in platform  11 A into load lock  12 , further enhancing vacuum sealing. A saving in floor space is achieved by vertically mounting load lock  12  which, in this particular embodiment, is above loading station  10 .  
         [0041]    In accordance with the invention, robot  21  is provided for transporting wafers to and from the modules of system  100  such as reactors  30  and  40 , cooling station  60 , and load lock  12 . FIG. 4A shows an “x-ray”view of an embodiment of robot  21 . To improve the clarity of illustration by showing all the relevant parts of robot  21  in one view, FIG. 4A is a functional representation of robot  21  and does not depict actual parts placement. For example, the actual location of a ball screw  402  in relation to the location of linear guides  405 A and  405 B is depicted in the top view shown in FIG. 4C. Of course, the invention is not limited to the specific parts, structures, and parts placement shown in FIGS.  4 A- 4 C. As shown in FIG. 4A, a z-axis (i.e. vertical motion) motor  401  is mechanically coupled to and rotates ball screw  402  via a belt  451 . A collar  404  rides on and is driven by ball screw  402 . In this embodiment, z-axis motor  401  is the type Part Number SGM-04A314B from Yaskawa Electric (“Yaskawa Electric”) of Fukuoka, Japan (telephone no. 81-93-645-8800) while ball screw  402  is the type Part Number DIK2005-6RRG0+625LC5 from THK Corporation Limited (“THK”) of Tokyo, Japan (telephone no. 81-3-5434-0300). Other conventional ball screws and motors can also be used. A support unit  452  (e.g. THK Part Number FK15) supports ball screw  402 . A vertical driver  403 , which rides on collar  404 , can be moved up or down by using z-axis motor  401  to drive collar  404  via ball screw  402 . Vertical driver  403  slides against wear rings  453 . Wear rings, generally, prevent metal to metal contact and absorb transverse loads. In one embodiment, wear rings  453  are the type Part Number GR 7 300800-T51 from Busak+Shamban (“Busak+Shamban”) (Internet web site “www.busakshamban.com”). Robot  21  also includes a harmonic gear  461  which can be of the same type as Part Number SHF-25-100-2UH from Harmonic Drive Systems Inc. of Tokyo, Japan (telephone no. 81-3-5471-7800).  
         [0042]    As shown in FIG. 4B, which is a magnified view of a portion of robot  21  defined by dashed-lines IV-IV shown in FIG. 4A, seals  418  surround vertical driver  403  and a rotation driver  415  to create a vacuum seal. Seals  418  can be any type of seal which does not expand and compress with a moving part being vacuum sealed. For example, seals  418  can be o-rings, lip-seals, or t-seals (as opposed to bellows). In one embodiment, seals  418  are of the type Part Numbers TVM300800-T01S, TVM200350-T01S from Busak+Shamban. In the prior art, bellows have been used in wafer processing robots to create a vacuum seal around a moving part such as vertical driver  403 . Because bellows expand and compress with the moving part, bellows are necessarily made larger when used with moving parts having a long range of motion. This makes bellows impractical in a semiconductor processing robot having a range of motion greater than 200 mm. In one embodiment of robot  21 , the use of seals  418 , instead of bellows, allows vertical driver  403  to be raised up to 350 mm. Thus, robot  21  can access multiple vertically mounted modules. To keep seals  418  in place as vertical driver  403  is moved up and down, vertical driver  403  is stabilized using linear guides  405 A (FIGS. 4A and 4C) and  405 B (FIG. 4C) (e.g. THK Part Number HSR25LBUUC0FS+520LF-II).  
         [0043]    Referring to FIG. 4A, robot  21  includes an end-effector  406 , which is made of a heat resistant material such as quartz, for picking-up and placing a wafer. End-effector  406  is fixedly attached to an attachment block  407  which accepts a variety of end-effectors. Block  407  is attached onto an arm  408  and rotates about an axis  410 . Arm  408  rotates about an axis  411  and is attached onto an arm  409 . As shown in FIG. 4D, a conventional belt and pulley arrangement, which includes pulleys  455 - 458  and belts  459 - 460 , mechanically couples arm  409 , arm  408 , and block  407  (which is coupled to pulley  458 ) together. End effector  406 , which is attached to block  407 , can be extended or retracted along a straight line by rotating pulley  455  using an extension motor  413  (FIG. 4A) (e.g. Yaskawa Electric Part Number SGM-02AW12). The entire arm assembly consisting of arm  409 , arm  408 , block  407 , and end-effector  406 , can be rotated about an axis  412  by using a rotation motor  414  (FIG. 4A) (e.g. Yaskawa Electric Part Number SGM-02AW12) to rotate rotation driver  415  via a belt  454 . FIG. 4C is a top view showing the placement of z-axis motor  402 , linear guides  405 A and  405 B, extension motor  413 , rotation motor  414 , and ball screw  402  in an embodiment of robot  21 .  
         [0044]    Referring to FIG. 4A, inlets  416  are provided to allow a coolant to flow through cooling channel  417  (also shown in FIG. 4B) and cool robot  21  during high temperature processing such as RTP. Any conventional coolant may be used including water, alcohol, and cooled gas. The use of internal cooling and a heat resistant end-effector in robot  21  decreases the processing time of system  100  as robot  21  can transport a wafer in and out of a reactor without waiting for the reactor or the wafer to cool down.  
         [0045]    [0045]FIGS. 8A to  8 F show side views of system  100  illustrating the movement of a wafer  22  from carrier  13 , which is inside load lock  12 , to a reactor  30  (or  40 ). Once carrier  13  is inside load lock  12 , robot  21  in transfer chamber  20  rotates and lowers towards load lock  12  (FIG. 8A). Robot  21  extends end-effector  406  to pick up wafer  22  from wafer carrier  13  (FIG. 8B). Robot  21  then retracts (FIG. 8C), rotates towards reactor  30  (FIG. 8D), elevates to position wafer  22  in-line with reactor  30  (FIG. 8E), and places wafer  22  into reactor  30  through a gate valve  31  (FIG. 8F). Robot  21  then retracts and, subsequently, gate valve  31  closes to begin the processing of wafer  22 .  
         [0046]    Referring to FIG. IA, reactors  30  and  40  are rapid thermal processing (“RTP”) reactors in this particular embodiment. However, the invention is not limited to a specific type of reactor and may use any semiconductor processing reactor such as those used in physical vapor deposition, etching, chemical vapor deposition, and ashing. Reactors  30  and  40  may also be of the type disclosed in commonly-owned U.S. patent application Ser. No. 09/451,494 (Attorney Docket No. M-7773), entitled “Resistively Heated Single Wafer Furnace,”filed on Nov. 30, 1999, which is incorporated herein by reference in its entirety. Reactors  30  and  40  are vertically mounted to save floor space. Reactors  30  and  40  are bolted onto  5  transfer chamber  20  and are further supported by a support frame  32 . Process gases, coolant, and electrical connections are provided through the rear side of reactors  30  and  40  using interfaces  33 .  
         [0047]    A pump  50 , shown in FIG. 1A, is provided for use in processes requiring vacuum. In the case where the combined volume of reactors  30  and  40  is a lot less than the combined volume of load lock  12 , cooling station  60 , and transfer chamber  20 , a single pump  50  may be used to pump down the entire volume of system  100  (i.e. combined volume of load lock  12 , cooling station  60 , transfer chamber  20 , reactor  30 , and reactor  40 ) to vacuum. Otherwise, additional pumps such as pump  50  may be required to separately pump down reactors  30  and  40 . In this particular embodiment, a single pump  50  suffices because the combined volume of load lock  12 , cooling station  60 , and transfer chamber  20  is approximately 150 liters whereas the total volume of reactors  30  and  40  is approximately 2 liters. In other words, because the combined volume of reactors  30  and  40  is insignificant compared to the entire volume of system  100 , reactors  30  and  40  do not significantly affect the pressure within system  100 . Thus, a separate pump is not needed to control the pressure within reactors  30  and  40 .  
         [0048]    After wafer  22  is processed in a well known manner inside reactor  30  (or  40 ), gate valve  31  opens to allow robot  21  to move wafer  22  into cooling station  60  (FIG. 1A). Because newly processed wafers may have temperatures upwards of 200° C. and could melt or damage a typical wafer carrier, cooling station  60  is provided for cooling the wafers before placing them back into a wafer carrier in load lock  12 . In this embodiment, cooling station  60  is vertically mounted above load lock  12  to minimize the floor space area occupied by system  100 . Cooling station  60  includes shelves  61 , which may be liquid-cooled, to support multiple wafers at a time. While two shelves are shown in FIG. 1A, of course, a different number of shelves can be used, if appropriate, to increase throughput. Subsequently, wafer  22  is picked-up from cooling station  60  and replaced to its original slot in carrier  13  using robot  21 . Platform I IA lowers from load lock  12  and rotates out of position to allow another platform to move a next wafer carrier into load lock  12 .  
         [0049]    [0049]FIG. 5 shows a block diagram of a control system  530  used in system  100 . A computer  501  communicates with a controller  520  using an ethernet link  502  to an input/output (“I/O”) controller  521 . I/O controller  521  can accommodate a variety of I/O boards including: (a) serial ports  522  for communicating with robot, temperature, pressure, and motor controllers (e.g. motor controller  902  shown in FIG. 9); (b) digital P/O  523  for controlling digital I/O lines such as sensors; (c) analog I/O  524  for controlling analog signal activated devices such as mass flow controllers and throttle valves; and (d) relay boards  525  for making or breaking continuity of signal lines such as interlock lines. Components for building controller  520  are commercially available from Koyo Electronics Industries Co., Ltd., 1-171 Tenjin-cho, Kodaira Tokyo 187-0004, Japan, (telephone number: 011-81-42-341-3115). Control system  530  uses a conventional control software for activating and monitoring various components of system  100 . System  100  may also use any conventional control hardware and software such as those available from National Instruments Corporation of Austin, Tex. (internet website “www.ni.com”).  
         [0050]    [0050]FIGS. 12A and 12B show a side view and a top view, respectively, of another embodiment of the wafer processing system in accordance with the present invention. System  300  includes a loading station  310 , a first compartment or loading area  312 , a second compartment or transport area  314 , a third compartment or thermal processing area  316 , and a cooling station  318 . Loading station  310  has platforms  311 A,  311 B, and  311 C for supporting and moving wafer carriers, such as a wafer carrier  320 , up into loading area  312 . The structure and function of similar components of system  300  are the same as their counterparts in system  100 , except as described below.  
         [0051]    As shown in FIG. 12A, first compartment or loading area  312  can be mounted onto second compartment or transport area  314 . Referring to FIG. 13A, a partial cross-sectional side view of first compartment  312 , is shown. When platform  311 A is up in loading area  312 , a surrounding seal  322  on platform  311 A contacts the bottom opening portion of loading area  312 . During processing which requires vacuum, a pneumatic cylinder pushes platform  311 A up into contact with loading area  312 , such that seal  322  is compressed against the outside of first compartment  312  to create a vacuum seal. Also, vacuum within system  300  draws in platform  311 A to further enhance vacuum sealing. Optionally, wafer carriers may be loaded into loading area  312  from the side of loading area  312 . As shown in FIG. 13B, platform  311 A may be replaced with a side door  324 . Door  324  may include any door which can provide suitable sealing for processes conducted in a vacuum, such as a slit valve, a hinge door, or a conventional gate valve. In the embodiment illustrated in FIG. 12A, platform  311 A (or alternatively door  324 ) is the only isolation device used in system  300 .  
         [0052]    Referring again to FIGS. 12A and 12B, the movement of a wafer  326  from carrier  320  to a third compartment or process area  316  is shown. In this embodiment, once carrier  320  is inside loading area  312  and platform  311 A (or door  324 ) is sealed, robot  328  in transport area  314  rotates and lowers towards loading area  312  to pick up wafer  326  from wafer carrier  320 . Robot  328  then retracts, rotates towards third compartment  316  and places wafer  326  into process area  316 . Robot  228  then retracts so that the processing of wafer  326  may commence. In this embodiment, as robot  328  moves wafer  326  from loading area  312 , through transport area  314 , and into process area  316 , robot  328  need not pass through any gate valves or isolation devices. The combined loading area  312 , transport area  314 , and process area  316  effectively form a “single”chamber, which has no isolation devices between operational areas. In this manner, the combined volume of the single chamber may be serviced using a single pump, which may be used to pump down the entire volume of system  300  to vacuum.  
         [0053]    After wafer  326  is processed in a well known manner inside process area  316 , the newly processed wafers may have temperatures upwards of 200° C. and could melt or damage a typical wafer carrier. Cooling station  318  is provided for cooling the wafers before placing them back into wafer carrier  320 . As shown in the embodiment of FIG. 12B, cooling station  318  is vertically mounted above loading area  312  to minimize the floor space area occupied by system  300 . FIG. 12C shows an alternate position for cooling station  318 , which may be between second compartment  314  (transport area) and third compartment  316  (process area).  
         [0054]    [0054]FIGS. 14, 14A and  14 B show an embodiment of cooling station  318 . Cooling station  318  may include shelves  332 , which may be liquid-cooled, to support a plurality of wafers simultaneously.  
         [0055]    The description of the invention given above is provided for purposes of illustration and is not intended to be limiting. The invention is set forth in the following claims.