Abstract:
A reaction system for processing semiconductor substrates is disclosed. In particular, the invention discloses an arrangement of a susceptor and a baseplate for when a substrate is placed into a reaction region. Magnets are embedded into the susceptor and the baseplate in order to create a gap between the two. As a result of the gap, the invention prevents an accumulation of gaseous materials that would exist in prior art systems as well as particle generation due to physical contact between parts.

Description:
FIELD OF INVENTION 
       [0001]    The present disclosure generally relates to semiconductor processing tools. More particularly, the disclosure relates to a wafer handling mechanism comprising a susceptor and a baseplate. 
       BACKGROUND OF THE DISCLOSURE 
       [0002]    Semiconductor processing typically involves fabrication of devices, such as transistors, diodes, and integrated circuits, upon a thin piece of semiconductor material called a substrate. The semiconductor processing takes place in a reaction region, where gases are passed over the substrate, resulting in a controlled deposit of material upon the substrate. The substrate is lifted into the reaction region by a susceptor. 
         [0003]    A gap is formed between the susceptor and a baseplate of the reaction region during processing. The purpose of the gap is to allow fluid communication between the inside of the reaction region and outside the susceptor. With the gap, extraneous gas containing the reactive material can exit the reaction region. In addition, the gap is used to control the flow of gas into or out of the reaction region in a controlled and uniform manner. 
         [0004]    In addition, the gap is necessary as direct physical contact between the susceptor and the baseplate could result in particle generation. The direct physical contact results in the release of particles from either the susceptor or the baseplate. Particle generation is problematic as the smallest particles can contaminate and potentially cause defects in the processed substrate. 
         [0005]    A uniform gap between the susceptor and the baseplate has been desired to avoid issues of particle generation. In addition, a uniform gap will keep the gas flow into or out of a reactor chamber uniform around the entire seal. Prior art approaches to semiconductor processing have utilized pads disposed between the susceptor and the baseplate in order to maintain a uniform gap. The pads prevent direct physical contact between the susceptor and the baseplate. The height of the pads can range between 0.001 inches (approximately 25 μm) and about 0.05 inches (approximately 1275 μm). 
         [0006]    Over time, continued processing can lead to a deposit of reactive materials on and around the pads of the susceptor. This deposition build-up can lead to the reduction in size of the gap between the susceptor and the baseplate. Similar to the particle generation, a deposition build-up can cause issues of contamination and defects in the processed substrate. Thus, it is desired to have a uniform gap between the susceptor and the baseplate arranged without the deposition build-up of reactive materials and the particle generation. 
       SUMMARY OF THE DISCLOSURE 
       [0007]    Embodiments of the present disclosure relate to a reaction system for processing substrates including: a susceptor configured to hold a substrate, a baseplate of a reaction region, at least one susceptor magnet, and at least one baseplate magnet. An interaction of the at least one susceptor magnet and the at least one baseplate magnet creates a repelling force to maintain a gap between the susceptor and the baseplate. 
         [0008]    Embodiments of the present disclosure also relate to a reaction system for processing substrates including: a reaction region, a substrate loading region, a movement element, a reactant distribution system, a baseplate, a first susceptor magnet, and a first baseplate magnet. An interaction of the first susceptor magnet and the first baseplate magnet creates a repelling force to maintain a gap between the susceptor and the baseplate. 
         [0009]    For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught or suggested herein without necessarily achieving other objects or advantages as may be taught or suggested herein. 
         [0010]    All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments will become readily apparent to those skilled in the art from the following detailed description of certain embodiments having reference to the attached figures, the invention not being limited to any particular embodiment(s) disclosed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
         [0011]    These and other features, aspects, and advantages of the invention disclosed herein are described below with reference to the drawings of certain embodiments, which are intended to illustrate and not to limit the invention. 
           [0012]      FIG. 1  schematically shows an embodiment of a reaction system including a susceptor in a substrate loading position. 
           [0013]      FIG. 2  schematically shows an elevation view of a susceptor and a substrate. 
           [0014]      FIG. 3  schematically shows an elevation view of a baseplate. 
           [0015]      FIG. 4  schematically shows an embodiment of a reaction system including a susceptor in a substrate processing position. 
           [0016]      FIG. 5  schematically shows a zoomed view of a baseplate and a susceptor in a substrate processing position as shown in  FIG. 4 . 
           [0017]      FIG. 6  schematically shows an embodiment of a reaction system including a susceptor in a substrate loading position. 
           [0018]      FIG. 7  schematically shows an elevation view of a susceptor and a substrate. 
           [0019]      FIG. 8  schematically shows an embodiment of a reaction system including a susceptor in a substrate processing position. 
           [0020]      FIG. 9  schematically shows a zoomed view of a baseplate and a susceptor in a substrate processing position as shown in  FIG. 8 . 
           [0021]      FIG. 10  schematically shows an embodiment of a reaction system including a susceptor in a substrate loading position. 
           [0022]      FIG. 11  schematically shows an embodiment of a reaction system including a susceptor in a substrate processing position. 
           [0023]      FIG. 12  schematically shows a zoomed view of a baseplate and a susceptor in a substrate processing position as shown in  FIG. 11 . 
           [0024]      FIG. 13  illustrates a reaction system in accordance with additional exemplary embodiments of the disclosure. 
           [0025]      FIG. 14  illustrates a portion of the reaction system of  FIG. 13  in greater detail. 
       
    
    
       [0026]    It will be appreciated that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of illustrated embodiments of the present disclosure. 
       DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0027]    Although certain embodiments and examples are disclosed below, it will be understood by those in the art that the invention extends beyond the specifically disclosed embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the invention disclosed should not be limited by the particular disclosed embodiments described below. 
         [0028]    The embodiments of this invention are directed to reaction systems that are used to process substrates. The reaction systems include a susceptor for holding a substrate. As used herein, a “substrate” refers to any material having a surface onto which material can be deposited. The reaction systems also include a reaction region defined in part by a baseplate. The susceptor will be loaded with the substrate and then bring the substrate into the reaction region for processing. During processing, deposition of materials may take place on the substrate. In embodiments of the invention, magnets may be used in both the susceptor and the baseplate in order to form a gap between the susceptor and the baseplate. The gap allows for materials to pass out from the reaction region. In addition, the gap allows for a uniform controlled flow of gas into and out of the reaction region. The size of the gap can be monitored through the use of force gauges to ensure a consistent and repeatable gap. 
         [0029]    Embodiments of this invention will allow an adjustment to the size of the gap without disassembling the reactor to change to different-sized pads to either tune the process or to compensate for the change in the gap due to deposition of reactant materials. In addition, embodiments of this invention eliminate any physical contact between the pads and the baseplate. Even though the pads take up a small area, the pads still contact the baseplate physically, resulting in particle generation. Finally, embodiments of this invention may allow continuous rotation of the susceptor during processing of the semiconductor substrate. 
         [0030]      FIG. 1  illustrates a first embodiment of a reaction system  100  for processing substrates. The reaction system  100  includes a reaction region  105  and a substrate loading region  110 . A baseplate  115  separates the reaction region  105  from the substrate loading region  110 . The reaction region  105  is defined in part by a reaction region housing  120  and a reactant distribution system  125 . The substrate loading region  110  is defined in part by a substrate loading housing  130 . 
         [0031]    The reactant distribution system  125  is responsible for providing materials that would be deposited upon the substrate. While the reactant distribution system  125  is shown to be a showerhead distribution system, one of ordinary skill in the art would understand that the reactant distribution system  125  can take another form as a cross-flow distribution system. Such a cross-flow distribution system is disclosed in U.S. Pat. No. 8,216,380 to White et al, entitled GAP MAINTENANCE FOR OPENING TO PROCESS CHAMBER, the contents of which are hereby incorporated by reference to the extent such content does not conflict with the present disclosure. 
         [0032]    As previously stated, a substrate  135  is loaded onto a susceptor  140 . The susceptor  140  is able to move with the operation of a movement element  145 . Movement element  145  may be configured to move the susceptor  140  and the substrate  135  up and down. As shown in  FIG. 1 , the movement element  145  has the susceptor  140  in a substrate loading position. The movement element  145  may also be configured to rotate the susceptor  140  and the substrate  135 . In addition, the susceptor  140  may also have a lift-pin  150  for loading and unloading the substrate  135  from the susceptor  140 . Such a movement element and a lift-pin are disclosed in U.S. Pat. No. 8,216,380, the contents of which are hereby incorporated by reference to the extent such content does not conflict with the present disclosure. 
         [0033]    The susceptor  140  has several surfaces: a lower surface  140 A, a radial surface  140 B, and an upper surface  140 C. Within the lower surface  140 A of the susceptor  140 , a susceptor magnet  160  is disposed. In a corresponding location on a lower surface  115 A of the baseplate  115 , a baseplate magnet  170  is disposed. The susceptor magnet  160  and the baseplate magnet  170  will enable a gap to be formed between the susceptor  140  and the baseplate  115 . 
         [0034]      FIG. 2  is a top elevation view of the substrate  135  loaded onto the susceptor  140 . The substrate  135  is loaded onto a portion of the susceptor  140  defined by the upper surface  140 C. As stated previously, the susceptor magnet  160  is disposed within the lower surface  140 A of the susceptor  140 . While the susceptor magnet  160  is illustrated as a circular ring, one of ordinary skill in the art would recognize that the susceptor magnet  160  could be a series of magnets disposed along various points in the lower surface  140 A. For example, the susceptor magnet  160  could be four separate magnets equally spaced apart. 
         [0035]      FIG. 3  is an elevation view of the baseplate  115  of the reaction region  105 . The baseplate magnet  170  is embedded within the lower surface  115 A of the baseplate  115 . Similar to the susceptor magnet  160 , while the baseplate magnet  170  is illustrated as a circular ring, one of ordinary skill in the art would recognize that the baseplate magnet  170  could be a series of magnets disposed along various points in the lower surface  115 A. For example, the baseplate magnet  170  could be four separate magnets equally spaced apart, each of which can correspond to four separate magnets equally spaced apart in the susceptor  140 . 
         [0036]      FIG. 4  illustrates the reaction system  100  shown in  FIG. 1 , where the susceptor  140  is lifted from a substrate loading position in the substrate loading region  110  into a substrate processing position in the reaction region  105  by the movement element  145 . The substrate  135  is now within the reaction region  105 , such that the reactant distribution system  125  can deposit material onto the substrate  135  in either a showerhead or cross-flow arrangement. 
         [0037]      FIG. 5  shows a zoomed view of  FIG. 4 . The susceptor magnet  160  is embedded within the susceptor  140  such that a positive pole (+) of the susceptor magnet  160  can interact with a corresponding positive pole (+) of the baseplate magnet  170  embedded in the baseplate  115 . Although it is illustrated that the positive poles of the two magnets interact, one of ordinary skill in the art would understand that the susceptor magnet  160  and the baseplate magnet  170  can be arranged so that their negative poles can interact. 
         [0038]    The repulsion between the two positive poles of the magnets results in the creation of a gap  180 . The gap  180  can range between 0.001 and 0.05 inches. One of ordinary skill in the art will recognize that the size of the gap will depend on the strength of the magnets and the size and mass of the reactor parts. The absence of pads within the gap  150  provides a benefit by preventing the deposition build-up of reactant materials within the gap  150 . In addition, the absence of pads will eliminate all mechanical contact between the parts, potentially reducing the probability of mechanical defect generation. As previously stated, the size of the gap  150  may be monitored with the use of force gauges (not shown in the figure). 
         [0039]    The susceptor magnet  160  and the baseplate magnet  170  both must be able to withstand the high temperatures and caustic chemicals in a reaction region during the processing of the substrate  135 . Temperatures within the reaction region  105  during processing can range between 150° C. and 550° C. Samarium Cobalt magnets are capable of withstanding these high temperatures as having an operable temperature range of 400° C. and 550° C. Neodymium may also be used as it has an operable temperature range of 80° C. and 200° C. One of ordinary skill in the art can recognize that other high temperature magnets could potentially be used. 
         [0040]      FIG. 6  illustrates another embodiment of a reaction system  200  for processing substrates. The reaction system  200  includes a reaction region  205  and a substrate loading region  210 . A baseplate  215  separates the reaction region  205  from the substrate chamber  210 . The reaction region  205  is defined in part by a reaction region housing  220  and a reactant distribution system  225 . The reactant distribution system  225  is responsible for providing materials that would be deposited upon the substrate. One of ordinary skill in the art would understand that the reactant distribution system  225 , which is shown as a showerhead arrangement, can take another form as a cross-flow distribution system. The substrate loading region  210  is defined in part by a substrate loading housing  230 . 
         [0041]    As previously stated, a substrate  235  is loaded onto a susceptor  240 . The susceptor  240  has several surfaces: a lower surface  240 A, a radial surface  240 B, and an upper surface  240 C. Susceptor  240  is able to move with the operation of a movement element  245 . The movement element  245  may be configured to move the susceptor  240  and the substrate  235  up and down. As shown in  FIG. 6 , the movement element  245  has the susceptor  240  in a substrate loading position. Movement element  218  may also be configured to rotate the susceptor  240  and the substrate  235 . In addition, the susceptor  240  may also have a lift-pin  250  for loading and unloading the substrate  235  from the susceptor  240 . Such a movement element and a lift-pin are disclosed in U.S. Pat. No. 8,216,380, the contents of which are hereby incorporated by reference to the extent such content does not conflict with the present disclosure. 
         [0042]      FIG. 7  illustrates a top elevation view of the susceptor  240 . Within the lower surface  240 A of the susceptor  240 , a first susceptor magnet  260  and a second susceptor magnet  265  are disposed. The upper surface  240 C of the susceptor  240  defines an area in which the substrate  235  sits during processing. 
         [0043]      FIG. 8  illustrates the embodiment of  FIG. 6  with the susceptor  240  in a substrate processing position. A baseplate magnet  270  is disposed in a location on a lower surface  215 A of the baseplate  215 . The location of the baseplate magnet  270  corresponds to the location of first susceptor magnet  260  and second susceptor magnet  265 . The first susceptor magnet  260 , the second susceptor magnet  265 , and the baseplate magnet  270  will enable a gap to be formed between the susceptor  240  and the baseplate  215 . While it is preferable that the first susceptor magnet  260 , the second susceptor magnet  265 , and the baseplate magnet  270  be in a ring shape, the invention is not limited and contemplates utilizing a series of magnets within the baseplate  215  and the susceptor  235 . 
         [0044]    As shown in  FIG. 9 , the baseplate magnet  270  is disposed in a location such that it can interact with both the first susceptor magnet  260  and the second susceptor magnet  265 . The positive pole (+) of the baseplate magnet  270  interacts with the positive poles (+) of the first and second susceptor magnets to create a repulsive force. The repulsive force results in the formation of a gap  280 . The gap  250  can range between 0.001 and 0.05 inches. The absence of pads within the gap  280  provides a benefit by preventing the deposition build-up of reactant materials within the gap  280 . Furthermore, the absence of pads will eliminate all mechanical contact between the parts, potentially reducing the probability of mechanical defect generation. 
         [0045]    As illustrated, the baseplate magnet  270  can be located in between the first susceptor magnet  260  and the second susceptor magnet  265  such that the baseplate magnet  270  can interact equally with both susceptor magnets. However, the location of the baseplate magnet  270  is not so limited to be between the first susceptor magnet  260  and the second susceptor magnet  265 . The location of the baseplate magnet  270  can vary in order to obtain a desired size for the gap  280 . As previously stated, the size of the gap  280  may be monitored with the use of force gauges (not shown in the figure). 
         [0046]      FIG. 10  illustrates another embodiment of another embodiment of a reaction system  300  for processing substrates. The reaction system  300  includes a reaction region  305  and a substrate loading region  310 . A baseplate  315  separates the reaction region  305  from the substrate chamber  310 . The reaction region  305  is defined in part by a reaction region housing  320  and a reactant distribution system  325 . The reactant distribution system  325  is responsible for providing materials that would be deposited upon the substrate. One of ordinary skill in the art would understand that the reactant distribution system  325 , which is shown as a showerhead arrangement, can take another form as a cross-flow distribution system. The substrate loading region  310  is defined in part by a substrate loading housing  330 . 
         [0047]    As previously stated, a substrate  335  is loaded onto a susceptor  340 . The susceptor  340  has several surfaces: a lower surface  340 A, a radial surface  340 B, and an upper surface  340 C. Susceptor  340  is able to move with the operation of a movement element  345 . Movement element  345  may be configured to move the susceptor  340  and the substrate  335  up and down. As shown in  FIG. 10 , the movement element  345  has the susceptor  340  in a substrate loading position. The movement element  345  may also be configured to rotate the susceptor  340  and the substrate  335 . In addition, the susceptor  340  may also have a lift-pin  350  for loading and unloading the substrate  335  from the susceptor  340 . Such a movement element and a lift-pin are disclosed in U.S. Pat. No. 8,216,380, the contents of which are hereby incorporated by reference to the extent such content does not conflict with the present disclosure. 
         [0048]      FIG. 11  illustrates the embodiment of  FIG. 10  with the susceptor  316  in a substrate processing position. Within the lower surface  340 A of the susceptor  340 , a first susceptor magnet  360  is disposed. Within the radial surface  340 B of the susceptor  340 , a second susceptor magnet  365  is disposed. The upper surface  340 C of the susceptor  340  defines an area in which the substrate  335  sits during processing. A baseplate magnet  370  is disposed in a location on a lower surface  315 A of the baseplate  315 . The location of the baseplate magnet  340  corresponds to the location of first susceptor magnet  360  and second susceptor magnet  365 . The first susceptor magnet  360 , the second susceptor magnet  365 , and the baseplate magnet  370  will enable a gap to be formed between the susceptor  340  and the baseplate  315 . While it is preferable that the first susceptor magnet  360 , the second susceptor magnet  365 , and the baseplate magnet  370  be in a ring shape, the invention is not limited and contemplates utilizing a series of magnets within the baseplate  315  and the susceptor  340 . 
         [0049]    As shown in  FIG. 12 , the baseplate magnet  370  is disposed in a location such that it can interact with both the first susceptor magnet  360  and the second susceptor magnet  365 . The positive pole (+) of the baseplate magnet  370  interacts with the positive pole (+) of the first susceptor magnet  360  to create a repulsive force. The repulsive force results in the formation of a gap  380  between the lower surface  340 A of the susceptor  340  and the lower surface  315 A of the baseplate  315 . The gap  380  can range between 0.001 and 0.05 inches. The absence of pads within the gap  380  provides a benefit by preventing the deposition build-up of reactant materials within the gap  380 . Furthermore, the absence of pads will eliminate all mechanical contact between the parts, potentially reducing the probability of mechanical defect generation. 
         [0050]    At the same time, the negative pole (−) of the baseplate magnet  370  interacts with the negative pole (−) of the second susceptor magnet  365  to create a repulsive force. The repulsive force allows for centering of the susceptor  340  with respect to the baseplate  315  to maintain a gap between the radial surface  340 B of the susceptor and a radial surface  315 B of the baseplate  315 . A gap size is set by the diameter of the susceptor relative to the diameter of the baseplate opening. In certain reactor chambers, the gap size can be approximately 1.5 mm. 
         [0051]      FIG. 13  illustrates another embodiment of another embodiment of a reaction system  400  for processing substrates. The reaction system  400  includes a reaction region  405  and a substrate loading region  410 . A baseplate  415  separates the reaction region  405  from the substrate chamber  410 . The reaction region  405  is defined in part by a reaction region housing  420  and a reactant distribution system  425 . The reactant distribution system  425  is responsible for providing materials that would be deposited upon the substrate. One of ordinary skill in the art would understand that the reactant distribution system  425 , which is shown as a showerhead arrangement, can take another form as a cross-flow distribution system. The substrate loading region  410  is defined in part by a substrate loading housing  430 . 
         [0052]    As previously stated, a substrate  435  is loaded onto a susceptor  440 . The susceptor  440  has several surfaces: a lower surface  440 A, a radial surface  440 B, and an upper surface  440 C. Susceptor  440  is able to move with the operation of a movement element  445 . Movement element  445  may be configured to move the susceptor  440  and the substrate  435  up and down. As shown in  FIG. 13 , the movement element  445  has the susceptor  440  in a substrate processing position. The movement element  445  may also be configured to rotate the susceptor  440  and the substrate  435 . In addition, the susceptor  440  may also have a lift-pin  450  for loading and unloading the substrate  435  from the susceptor  440 . Such a movement element and a lift-pin are disclosed in U.S. Pat. No. 8,216,380, the contents of which are hereby incorporated by reference to the extent such content does not conflict with the present disclosure. 
         [0053]    Within the lower surface  440 A of the susceptor  440 , a susceptor magnet  460  is disposed. The upper surface  440 C of the susceptor  440  defines an area in which the substrate  435  sits during processing. A baseplate magnet  470  is disposed in a location on a lower surface  415 A of the baseplate  415 . The location of the baseplate magnet  440  corresponds to the location of the susceptor magnet  460 . The susceptor magnet  460  and the baseplate magnet  470  will enable a gap to be formed between the susceptor  440  and the baseplate  415 . While it is preferable that the susceptor magnet  460  and the baseplate magnet  470  be in a ring shape, the invention is not limited and contemplates utilizing a series of magnets within the baseplate  415  and the susceptor  440 . 
         [0054]    As shown in  FIG. 14 , the baseplate magnet  470  is disposed in a location such that it can interact with the susceptor magnet  460 . The orientation of the magnets is such that both the susceptor magnet  460  and the baseplate magnet  470  are disposed at an angle. The positive pole (+) of the baseplate magnet  470  interacts with the positive pole (+) of the susceptor magnet  460  to create a repulsive force. The repulsive force creates a gap  480  between the lower surface  440 A of the susceptor  440  and the lower surface  415 A of the baseplate  415 . The repulsive force creates a gap  485  between the radial surface  440 B of the susceptor  440  and the radial surface  415 B of the baseplate  415 . Both the gap  480  and the gap  485  can range between 0.001 and 0.05 inches. The absence of pads within the gaps provides a benefit by preventing the deposition build-up of reactant materials within the gaps. Furthermore, the absence of pads will eliminate all mechanical contact between the parts, potentially reducing the probability of mechanical defect generation. 
         [0055]    The particular implementations shown and described are illustrative of the invention and its best mode and are not intended to otherwise limit the scope of the aspects and implementations in any way. Indeed, for the sake of brevity, conventional manufacturing, connection, preparation, and other functional aspects of the system may not be described in detail. Furthermore, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and/or physical couplings between the various elements. 
         [0056]    Many alternative or additional functional relationship or physical connections may be present in the practical system, and/or may be absent in some embodiments. 
         [0057]    It is to be understood that the configurations and/or approaches described herein are exemplary in nature, and that these specific embodiments or examples are not to be considered in a limiting sense, because numerous variations are possible. The specific routines or methods described herein may represent one or more of any number of processing strategies. Thus, the various acts illustrated may be performed in the sequence illustrated, in other sequences, or omitted in some cases. 
         [0058]    The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various processes, systems, and configurations, and other features, functions, acts, and/or properties disclosed herein, as well as any and all equivalents thereof.