Abstract:
Embodiments of substrate handling systems capable of heating and/or cooling batches of substrates being transferred into and out of various substrate processing chambers are provided. Methods of substrate handling are also provided, as are numerous other aspects.

Description:
RELATED APPLICATIONS 
       [0001]    The present application claims priority to U.S. Provisional Patent Application Ser. No. 61/800,595, filed Mar. 15, 2013 and entitled “WAFER HANDLING SYSTEMS AND METHODS FOR SMALL BATCHES OF WAFERS”, (Attorney Docket No. 20667/L/FEG/SYNX), which is hereby incorporated herein by reference in its entirety for all purposes. 
     
    
     FIELD 
       [0002]    The invention relates generally to electronic device manufacturing, and more particularly to temperature control systems and methods for small batch substrate handling systems. 
       BACKGROUND 
       [0003]    Within an electronic device manufacturing process, a substrate handling system may move substrates into and out of various chambers to undergo processing. Some chambers may simultaneously batch process a relatively small number of substrates (e.g., about six substrates). Some conventional substrate handling systems may be capable of transferring substrates through a manufacturing process at a high throughput, but may only transfer substrates one at a time. This may slow substrate production and, thus, increase the cost of manufacture. Accordingly, improved substrate handling systems and methods capable of transferring small batches of substrates into and out of various chambers are sought. 
       SUMMARY 
       [0004]    In some aspects of embodiments of the invention, a substrate handling system is provided. The substrate handling system includes a robot configured to transfer a plurality of substrates into or out of a substrate processing chamber; a carousel configured to position the substrates for transfer by the robot; and a temperature control system configured to heat or cool substrates on the carousel. 
         [0005]    In other aspects, a method of transferring substrates in a substrate process is provided. The method includes providing a substrate handling system including a robot configured to transfer a plurality of substrates into or out of a substrate processing chamber, a carousel configured to position the substrates for transfer by the robot, and a temperature control system configured to heat or cool substrates on the carousel; loading substrates onto the carousel; heating the substrates on the carousel; and loading the heated substrates into the processing chamber. 
         [0006]    In yet other aspects, a substrate processing system is provided. The substrate processing system includes a processing chamber; a substrate handing system coupled to the processing chamber and including a robot configured to transfer a plurality of substrates into or out of the substrate processing chamber, a carousel configured to position the substrates for transfer by the robot, and a temperature control system configured to heat or cool substrates on the carousel; and a factory interface disposed to deliver substrates to the substrate handing system and to receive substrates from the substrate handing system. 
         [0007]    Other features and aspects of the invention will become more fully apparent from the following detailed description of example embodiments, the appended claims, and the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a schematic diagram illustrating an example substrate processing system including side-by-side substrate handling carousel style platforms according to embodiments of the present invention. 
           [0009]      FIG. 2  is a schematic diagram illustrating an example substrate handling carousel style platform according to embodiments of the present invention. 
           [0010]      FIG. 3  is a perspective view diagram illustrating an example substrate handling carousel style platform according to embodiments of the present invention. 
           [0011]      FIG. 4  is a perspective view cut-away diagram illustrating an example substrate heating system within a substrate handling carousel style platform according to embodiments of the present invention. 
           [0012]      FIG. 5  is a schematic diagram illustrating an example substrate handling carousel style platform including a substrate cooling system according to embodiments of the present invention. 
           [0013]      FIG. 6  is a schematic diagram illustrating an example substrate cooling plate for a substrate handling carousel style platform according to embodiments of the present invention. 
           [0014]      FIG. 7  is a schematic diagram illustrating an example substrate processing system with a substrate handling carousel style platform including a substrate cooling system and a load lock function according to embodiments of the present invention. 
           [0015]      FIG. 8  is a schematic diagram illustrating a substrate processing system with a substrate handling carousel style platform including a substrate heating system and a load lock function according to embodiments of the present invention. 
           [0016]      FIG. 9  is a magnified view of the substrate handling carousel style platform of  FIG. 8 . 
           [0017]      FIG. 10  is a flowchart depicting an example method according to embodiments of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Embodiments of the present invention relate to temperature control methods and systems for use within substrate handling systems. These substrate handling systems are configured to transfer small batches of substrates (e.g., 5 or 6 substrates) for concurrent processing into or out of a substrate processing chamber or between at least two substrate processing chambers in an electronic device processing system. The substrate processing chambers are capable of processing small batches of substrates simultaneously. Efficient loading and unloading of the substrate batches from the processing chambers is achieved using a carousel style substrate handling system housed in a transfer chamber disposed adjacent the processing chamber(s). Note that in some embodiments, the housing or chamber (e.g., transfer chamber) is considered part of the substrate handling system. 
         [0019]    Some embodiments of the substrate handling systems include pre-processing pre-heating and/or post-processing cooling of the substrates within the transfer chamber while the substrates are being moved to or from the processing chamber. Further, some embodiments provide both (a) substrate handing systems with substrate temperature control systems and (b) load lock functions that eliminate the need for a load lock between the substrate handling system/transfer chamber and the factory interface. 
         [0020]    Some of the substrate handling system embodiments described herein have a smaller footprint and can also increase substrate throughput over conventional substrate handling systems. These benefits can be achieved via improved load lock utilization since the design decouples operation of the load lock from process chamber loading. In addition, throughput can be improved by providing substrate pre-heating and/or post-process cooling during transfer that does not requiring additional time (e.g., the heating and/or cooling is removed from the “critical path” time calculation because it is performed in parallel with transferring the substrates). Further, some embodiments can provide improved pre-heating control by applying the pre-heating continuously up to the time of entry into the process chamber. Some embodiments described herein are applicable to atomic layer deposition (ALD) carousels. 
         [0021]    Turning now to  FIGS. 1 and 2 , an example embodiment of a substrate processing system  100  including two side-by-side substrate handling carousel style platforms  102  is depicted. The example system  100  includes two small batch processing chambers  104  that are served by the substrate handling carousel style platforms  102 , wherein one substrate handling carousel style platform  102  is dedicated to one processing chamber  104 . The substrate handling carousel style platforms  102  each include a transfer chamber  106  housing a carousel type substrate handling system  108 . As can be more clearly seen in  FIG. 2 , the substrate handling system  108  includes a transfer robot  110  (e.g., a selective compliance articulated robot arm (SCARA)) supporting an end effector  112  (e.g., a blade) for handing the substrates and a substrate carousel  114  for rotating substrates into position for loading into and unloading from the processing chamber  104  using the transfer robot  110 . Note that in some embodiments, a linear extension axis robot arm can be used in place of an articulated robot arm. The substrate carousel  114  is also configured to position the substrates to be passed through a load lock  116  to or from a factory interface robot  118  within a factory interface  120 . In some embodiments, the system  100  can also include cooling stations  122  in the factory interface  120 . 
         [0022]      FIG. 2  depicts a magnified view and  FIG. 3  depicts a perspective view of one of the example substrate handling carousel style platforms  102  of  FIG. 1 . Note that the top of the transfer chamber  106  is removed from  FIG. 3  to more clearly show particular features. As shown in  FIG. 2 , the carousel  114  can include multiple substrate supports  202  (e.g., 5, 6, or 7 supports) that are rotated as the carousel  114  rotates and substrates  302  on one or more of the substrate supports  202  can be heated by one or more stationary heating systems  204  whenever the supports  202  pass proximate to the heating systems  204 . 
         [0023]    In some embodiments, radiant heating systems can be disposed directly over and/or under substrates  302  on the substrate supports  202  at, e.g., positions immediately proximate to the processing chamber  104 . An example of a suitable radiant substrate pre-heater is the RAYMAX® model panel heater commercially available from Watlow Electric Manufacturing Company of St. Louis, Mo. Other practicable heating systems including different types (e.g., conduction or convection) of heaters can be used such as the ULTAMIC® Advanced Ceramic heaters, the Thick Film Conduction heaters, and the Coil &amp; Cable heaters also from Watlow Electric Manufacturing Company. For example, the substrate carousel  114  can include embedded resistive heating elements within one or more of the substrate supports  202  and thus the heating system moves as the carousel  114  rotates. Therefore, the system  100  can be configured to selectively heat substrates  302  in supports  202  rotating toward the processing chamber  104  and not heat the substrates  302  in supports  202  rotating away from the processing chamber  104 . 
         [0024]    The configuration of the system  100  provides substantial flexibility in the location and use of heaters. Conventionally, preheating was done in the load lock  116 . This added time to the process of bringing a substrate  302  to a processing chamber  104 . Embodiments of the present invention decouple the load lock function and pre-heating and allow pre-heating to be performed off the critical path timeline. The configuration also allows the use of fewer heaters and the addition or removal of heaters in the field, e.g., for different applications. Further, the system  100  provides improved substrate temperature control by allowing the substrate  302  to be heated until the last moment before loading into the process chamber  104  because the heating system  204  can located directly in front of the process chamber  104 . This minimizes the temperature change from the preheat location to the process chamber  104 . 
         [0025]      FIG. 4  is a perspective view cut-away diagram illustrating an example substrate heating system  204  within a substrate handling carousel style platform  102 . The particular example heating system  204  embodiment depicted is positioned as indicated in  FIG. 3 , above a substrate support  202  of the carousel  114  and adjacent the processing chamber  104 . In some embodiments, a radiant heating system  204  that uses and infrared or other wavelength bulb can be used as the heat source  402 . In some embodiments, reflectors  404  disposed below the heat source  402  can be used to direct and focus the radiant heat directly at a substrate  302  positioned below the heating system  204  on its way toward the processing chamber  104 . 
         [0026]      FIG. 5  is a schematic diagram illustrating an example substrate handling carousel style platform  500  including a substrate cooling system  502  according to alternative embodiments of the present invention. The substrate cooling system  502  includes a rotatable carousel  504  supporting one or more cooling plates  506  that act like heat sinks to draw heat away from a substrate  302  resting on one of the cooling plates  506  of the carousel  504 . A transfer robot  110  using an end effector  112  is operative to place substrates  302  on the cooling plates  506  after they are unloaded from the processing chamber  104 . The carousel  504  can then rotate the cooling substrates  302  to an appropriate position to be loaded into another processing chamber  104 ′ or into a load lock  116  leading to a factory interface. 
         [0027]      FIG. 6  depicts details of an example cooling system  502  including a set of substrate cooling plates  506  mounted on a carousel  504  for use in a substrate handling carousel style platform  500 . The cooling plates  506  each include notches  602  and grooves  604  to accommodate features of the end effector  112  when substrates  302  are placed on and removed from the cooling plates  506 . In some embodiments, the cooling plates  506  can be made from aluminum, aluminum with copper tubing potted or swaged into the aluminum, nickel plated aluminum, stainless steel or such other materials that have relatively high thermal conductivity. In some embodiments, the plates can include channels for flowing liquid coolant (e.g., water) to further help remove heat. 
         [0028]    Likewise, the supporting carousel  504  can also be made from similar materials to help draw away heat from the substrates  302 . The dimensions and mass of the cooling plates can be selected to maximize surface contact with the substrates  302  and to provide sufficient heat dissipation/absorption to reduce the temperature of a supported substrate to a desired target temperature within a desired time period. In some embodiments, additional heat sinks can be coupled to the cooling plates  506  and/or the carousel  504 . In some embodiments, active cooling systems (e.g., circulated water cooling systems) coupled to the cooling plates  506  and/or the carousel  504  can be used to further enhance cooling. 
         [0029]      FIG. 7  is a schematic diagram illustrating an alternative example substrate processing system  700 . This example system  700  includes a substrate handling carousel style platform  702  with a substrate cooling system  704  and a load lock function  706  that seals the platform  702  (e.g., using slit valves) and provides a vacuum within the platform  702 . In other words, the transfer chamber  708  of the substrate handling carousel style platform  702  is configured to serve as a load lock in addition to being operative to transfer substrates into and out of a processing chamber  710 . Note that there is no separate load lock between the factory interface  712  and the transfer chamber  708  of the substrate handling carousel style platform  702 . Note that in the example system  700  depicted, a substrate heating station  714  within the factory interface  712  can be used to pre-heat substrates before they enter the transfer chamber  708  and the cooling system  704  can be used to cool substrates after they are removed from the processing chamber  710 . 
         [0030]    Further note that the example substrate handling carousel style platform  702  of  FIG. 7  also includes a linear extension axis robot arm  716  instead of an articulating robot arm. The use of a carousel to position the substrates for loading allows the use of the linear extension axis robot arm  716  that has a lower profile relative to an articulating robot arm. This allows the use of a smaller volume combined load lock and transfer chamber  708  with a shorter pump-down time and thus higher throughput. 
         [0031]    Similar to  FIG. 7 ,  FIG. 8  depicts a substrate processing system  800  including a substrate handling carousel style platform  802  with a load lock function  804  but instead of a cooling system  704 , the embodiment includes a substrate heating system  806 .  FIG. 9  provides a magnified view of the substrate handling carousel style platform  802  of  FIG. 8 . Note that the size of transfer chamber  808  of the substrate handling carousel style platform  802  is reduced to minimize the interior dimensions of the chamber  808 . This reduces the amount of time required to pump down air pressure in the transfer chamber  808  when the transfer chamber  808  is performing the load lock function. Reduced pump down time results in higher throughput. Note that in the example system  800  depicted, a substrate cooling station  814  within the factory interface  812  can be used to cool substrates after they exit the transfer chamber  808  and the heating system  806  can be used to pre-heat substrates before they are loaded into the processing chamber  810 . 
         [0032]    Embodiments of the present invention provide methods for controlling the temperature of substrates while transferring the substrates to and from a processing chamber.  FIG. 10  depicts an example method  1000  of transferring substrates in a substrate process. The method  1000  includes providing a substrate handling system including a robot configured to transfer substrates into or out of a substrate processing chamber, a carousel configured to position the substrates for transfer by the robot, and a temperature control system configured to heat or cool substrates on the carousel. ( 1002 ) Next, the substrates are loaded onto the carousel. ( 1004 ) The loaded substrates on the carousel are then pre-heated. ( 1006 ) Finally, the heated substrates are loaded into the processing chamber. ( 1008 ) 
         [0033]    In some embodiments, pre-heating can be performed in the load lock or in the factory interface and post-cooling can be performed in the substrate handling carousel style platform. In alternative embodiments, pre-heating can be performed in the substrate handling carousel style platform and post-cooling can be performed in the load lock or in the factory interface. In yet other embodiments, pre-heating can be performed on a first subset of the substrate supports within the substrate handling carousel style platform and post-cooling can be performed on a second subset of the substrate supports within the substrate handling carousel style platform. 
         [0034]    Accordingly, while the invention has been disclosed in connection with example embodiments thereof, it should be understood that other embodiments may fall within the scope of the invention, as defined by the following claims.