Abstract:
A method and apparatus for processing substrates includes a chamber defining a plurality of processing regions, a heater disposed centrally within each pair of processing regions, each heater having a first major surface and a second major surface opposing the first major surface, each of the first major surfaces defining a first substrate receiving surface and each of the second major surfaces defining a second substrate receiving surface, and a showerhead positioned in an opposing relationship to each of the first substrate receiving surfaces and each of the second substrate receiving surfaces of the heaters.

Description:
BACKGROUND 
       [0001]    Field 
         [0002]    Embodiments of the disclosure generally relate to semiconductor substrate processing, and more particularly, to etch and plasma related semiconductor substrate manufacturing processes and related hardware. 
         [0003]    Description of the Related Art 
         [0004]    A chip manufacturing facility is composed of a broad spectrum of technologies. Cassettes containing semiconductor substrates (e.g., wafers) are routed to various stations in a facility where they are either processed or inspected. Semiconductor processing generally involves the deposition of material onto and removal (“etching” and/or “planarizing”) of material from substrates. Typical processes include chemical vapor deposition (CVD) plasma enhanced CVD (PECVD), physical vapor deposition (PVD), electroplating, chemical mechanical planarization (CMP), etching, among others. 
         [0005]    One concern in semiconductor processing is substrate throughput. Generally, the greater the substrate throughput, the lower the manufacturing cost and therefore the lower the cost of the processed substrates. In order to increase substrate processing throughput, conventional batch processing chambers have been developed. Batch processing allows several substrates to be processed simultaneously using common fluids, such as process gases, chambers, processes, and the like, thereby decreasing equipment costs and increasing throughput. Ideally, batch-processing systems expose each of the substrates to an identical process environment whereby each substrate simultaneously receives the same process gases and plasma densities for uniform processing of the batch. Unfortunately, the processing within batch processing systems is hard to control such that uniform processing occurs with respect to every substrate. Consequently, batch processing systems are notorious for non-uniform processing of substrates. To achieve better process control, single chamber substrate processing systems were developed to conduct processing on a single substrate in a one-at-a-time-type fashion within an isolated process environment. Unfortunately, single chamber substrate processing systems generally are not able to provide as high a throughput rate as batch processing systems, as each substrate must be sequentially processed. 
         [0006]    Therefore, there is a need for a substrate processing system configured to provide controllable uniformity of a single substrate system and improved throughput characteristics of a batch processing system. 
       SUMMARY 
       [0007]    Embodiments of the disclosure generally provide a substrate processing system having one or more chambers, each chamber capable of processing four substrates. The one or more chambers comprise a plurality of processing regions, and a heater is disposed centrally within each of the processing regions. Each heater includes a disk-shaped member having a first major surface and a second major surface opposing the first major surface. Each of the first major surfaces define a first substrate receiving surface and each of the second major surfaces define a second substrate receiving surface. Each heater may be an electrostatic chuck or a vacuum chuck configured to chuck a substrate to the major surfaces thereof. Each heater may be an electrode for RF plasma generation within the respective chambers. Each chamber includes two showerheads configured to flow precursor gases toward substrates positioned on the respective heaters, which are positioned between the showerheads. In some embodiments, heaters in each dual processing zone function as a single electrode that interacts with two showerheads. Each heater is fixed relative to the chambers but the showerheads may move relative to the heater in each chamber. Substrates may be transferred into or out of the processing regions by a robot blade configured to grip an edge of a substrate or a major surface of the substrate utilizing electrostatic attraction. 
         [0008]    A method and apparatus for processing substrates is disclosed and may include a chamber defining a plurality of processing regions, a heater disposed centrally within each pair of processing regions, each heater having a first major surface and a second major surface opposing the first major surface, each of the first major surfaces defining a first substrate receiving surface and each of the second major surfaces defining a second substrate receiving surface, and a showerhead positioned in an opposing relationship to each of the first substrate receiving surfaces and each of the second substrate receiving surfaces of the heaters. 
         [0009]    In another embodiment, a quad processing chamber system is provided and includes a first quad processing chamber defining a first plurality of isolated processing regions, comprising a first substrate support and a second substrate support positioned in the first quad processing chamber, a first gas distribution assembly disposed at an upper end and a lower end of a first processing region and a second processing region of the plurality of isolated processing regions, and a second gas distribution assembly disposed at an upper end and a lower end of a third processing region and a fourth processing region of the plurality of isolated processing regions, wherein each of the gas distribution assemblies are independently movable relative to the respective substrate support. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    So that the manner in which the above recited features of the disclosure are attained can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to the embodiments thereof, which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure, and are therefore, not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments. 
           [0011]      FIGS. 1A and 1B  illustrate plan views of opposing sides of an exemplary quad chamber system. 
           [0012]      FIG. 2  illustrates a perspective view of the exemplary quad chamber system of  FIGS. 1A and 1B . 
           [0013]      FIG. 3A  is a side cross-sectional view of one embodiment of a quad processing chamber that may be used in the system of  FIGS. 1A and 1B . 
           [0014]      FIG. 3B  is a perspective cross-sectional view of a portion of the quad processing chamber of  FIG. 3A . 
           [0015]      FIG. 4  is a perspective view of one embodiment of a substrate support member that may be used in the transfer chamber of  FIGS. 1A and 1B . 
           [0016]      FIGS. 5A and 5B  are various views of a processing chamber showing one example of a substrate transfer process. 
           [0017]      FIGS. 6A-6D  are various views of a processing chamber showing another example of a substrate transfer process. 
       
    
    
       [0018]    To facilitate understanding, common words have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation. 
       DETAILED DESCRIPTION 
       [0019]    Embodiments of the disclosure generally provide a plasma processing system adapted to concurrently process multiple substrates. The substrate processing system is configured to combine the advantages of single substrate process chambers and multiple substrate handling for high quality substrate processing, high substrate throughput and a reduced system footprint. 
         [0020]      FIGS. 1A and 1B  illustrate upper and lower plan views, respectively, and  FIG. 2  illustrates a perspective view of an exemplary quad chamber system  100 . The system  100  may be used to perform deposition processes, etch processes, annealing processes or other thermal processes, or combinations thereof. The system  100  is generally self-contained having the necessary processing utilities supported on a mainframe structure  105  (shown in  FIG. 2 ). The system  100  can be easily installed and provides a quick start up for operation. 
         [0021]    The system  100  generally includes four different regions, namely, a front-end staging area  110 , a load lock chamber  112 , and a transfer chamber  114  in communication with a plurality of quad processing chambers  115  through isolation valves  120 . Each of the quad processing chambers  115  may be configured to process four substrates simultaneously or near simultaneously, such that the system  100  may process twelve substrates simultaneously or near simultaneously. 
         [0022]    The front-end staging area  110 , which is generally known as a factory interface or mini environment, generally includes an enclosure having at least one substrate containing cassette  125  positioned in communication therewith via a pod loader, for example. The system  100  may also include one or more front-end substrate transfer robots  130 , which may generally be single-arm robots configured to move substrates between the front-end staging area  110  and the load lock chamber  112 . The front-end substrate transfer robots  130  are generally positioned proximate to cassettes  125  and are configured to remove substrates therefrom for processing, as well as position substrates therein once processing of the substrates is complete. 
         [0023]    The front-end staging area  110  is selectively in communication with the load lock chamber  112  through, for example, a selectively actuated valve (not shown). Additionally, load lock  112  may also be selectively in communication with the transfer chamber  114  via another selectively actuated valve, for example. Therefore, the load lock chamber  112  may operate to isolate the interior of the substrate transfer chamber  114  from the interior of the front-end staging area  110  during the process of transferring one or more substrates into the transfer chamber  114  for processing. The load lock chamber  112  may be a side-by-side substrate type chamber, a single substrate type chamber, or multi-substrate-type loadlock chamber, for example, as is generally known in the art. 
         [0024]    The system  100  includes a utility supply unit  135  (shown in  FIG. 2 ), which may be positioned in any location that is generally proximate to system  100 . However, to maintain a smaller footprint, the utility supply unit  135  may be disposed below the load lock chamber  112 . The utility supply unit  135  generally houses the support utilities needed for operation of system  100 , such as a gas panel, a power distribution panel, power generators, and other components used to support semiconductor etch processes. The utility supply unit  135  generally includes RF power, bias power, and electrostatic power sections for each quad processing chamber  115 . 
         [0025]    The system  100  may include a process controller  138  in order to control one or more substrate processing functions. In one embodiment, the process controller  138  includes a computer or other controller adapted to analyze and display data input/output signals of the system  100 . The process controller  138  may display the data on an output device such as a computer monitor screen. In general, the process controller  138  includes a controller, such as programmable logic controller (PLC), computer, or other microprocessor-based controller. The process controller  138  may include a central processing unit (CPU) in electrical communication with a memory, wherein the memory contains a substrate processing program that, when executed by the CPU, provides control for at least a portion of the system  100 . As such, the process controller  138  may receive inputs from the various components of the system  100  and generate control signals that may be transmitted to the respective components of the system  100  for controlling the operation thereof. 
         [0026]    As illustrated in  FIG. 1A , a substrate transfer robot  140  may be centrally positioned in the upper interior portion of the transfer chamber  114 . The substrate transfer robot  140  is generally configured to receive substrates from the load lock chamber  112  and transport the substrates received therefrom to one of the quad processing chambers  115  positioned about the perimeter of the transfer chamber  114 . Additionally, the substrate transfer robot  140  is generally configured to transport substrates between the respective quad processing chambers  115 , as well as from the quad processing chambers  115  back into the load lock chamber  112 . The substrate transfer robot  140  generally includes a single quad-blade  145  having four substrate support members  148  configured to support up to four substrates  150  thereon simultaneously (only two are shown in  FIGS. 1A and 1B ). For example, the blade  145  may include two substrate support members  148  that are stacked vertically, and each of the two substrate support members  148  are generally aligned in a respective horizontal plane. The substrate support members  148  may have an edge grip configuration to hold the substrates  150  thereon. Additionally, the blade  145  of the substrate transfer robot  140  is selectively extendable, while the base is rotatable, which may allow the blade access to the interior portion of any of the quad processing chambers  115 , the load lock chamber  112 , and/or any other chamber positioned around the perimeter of the transfer chamber  114 . 
         [0027]    As illustrated in  FIG. 1B , a substrate transfer robot  140  may be centrally positioned in the lower interior portion of the transfer chamber  114 . The substrate transfer robot  140  is generally configured to receive substrates from the load lock chamber  112  and transport the substrates received therefrom to one of the quad processing chambers  115  positioned about the perimeter of the transfer chamber  114 . Additionally, the substrate transfer robot  140  is generally configured to transport substrates between the respective quad processing chambers  115 , as well as from the quad processing chambers  115  back into the load lock chamber  112 . The substrate transfer robot  140  generally includes a single quad-blade  145  having four substrate support members  148  configured to support up to four substrates  150  thereon simultaneously (only two are shown in  FIG. 1B ). For example, the blade  145  may include two substrate support members  148  that are stacked vertically, and each of the two substrate support members  148  are generally aligned in a respective horizontal plane. The substrate support members  148  may have an edge grip configuration to hold the substrates  150  thereon. Additionally, the blade  145  of the substrate transfer robot  140  is selectively extendable, while the base is rotatable, which may allow the blade access to the interior portion of any of the quad processing chambers  115 , the load lock chamber  112 , and/or any other chamber positioned around the perimeter of the transfer chamber  114 . 
         [0028]      FIGS. 3A and 3B  are various views of one embodiment of a quad processing chamber  300  that may be utilized as one or more of the quad processing chambers  115  of  FIGS. 1A, 1B, and 2 .  FIG. 3A  is a side cross-sectional view of the quad processing chamber  300  and  FIG. 3B  is a perspective cross-sectional view of a portion of the quad processing chamber  300  of  FIG. 3A . 
         [0029]    The quad processing chamber  300  includes a first processing chamber  302 A coupled to a second processing chamber  302 B, and each the first processing chamber  302 A and the second processing chamber  302 B are configured to process two substrates  150  simultaneously or near simultaneously. The first processing chamber  302 A and the second processing chamber  302 B may be operated in parallel such that up to four substrates will be processed similarly in the same amount of time. Thus, the quad processing chamber  300  increases throughput by at least a factor of 2, while minimally increasing footprint of a system such as the system  100  of  FIGS. 1A, 1B, and 2 . 
         [0030]    The quad processing chamber  300  includes a plurality of process volumes  305 A- 305 D contained within a chamber body  310 . The quad processing chamber  300  includes two substrate supports  315 , each of which may support two substrates  150  thereon on major surfaces thereof. Each of the process volumes  305 A and  305 B share one of the substrate supports  315 , and each of the process volumes  305 C and  305 D share another one of the substrate supports  315 . The quad processing chamber  300  includes four gas distribution plates or showerheads  320 . Each of the showerheads  320  are disposed in a respective process volume  305 A- 305 D. The chamber body  310  includes a lid plates  325  and walls  330  that contains the process volumes  305 A- 305 D. In some embodiments, the lid plates  325  may be hinged such that the showerheads  320  may be positioned away from the substrate supports  315  in a clamshell manner to facilitate substrate transfer. A pumping channel  340  at least partially surrounds the process volumes  305 A- 305 D. The pumping channel  340  may be symmetrical about the circumference of the dual process volumes  305 A and  305 B as well as the dual process volumes  305 C and  305 D. The pumping channel  340  is in fluid communication with the process volumes  305 A- 305 D and a central channel  345  that is coupled to a vacuum pump  350 . Pumping may be circumferential from the outside of the faceplate of the showerheads  320  but through a labyrinth structure such that deposition in or on the faceplate and/or openings in the showerheads  320  does not fall onto the substrates  150 . 
         [0031]    One or more valves  355  may control a conductance path within the dual process volumes  305 A and  305 B as well as the dual process volumes  305 C and  305 D. While the quad processing chamber  300  is shown in an orientation to process the substrates  150  in a horizontal plane, the chamber body  310  may be oriented such that the substrates  150  are processed vertically. 
         [0032]    Also shown in  FIG. 3A  is a process gas supply  392  that provides precursor gases to each of the process volumes  305 A- 305 D. The process gas supply  392  may be coupled to a gas flow splitting device  393  configured to control gas flow to each of the process volumes  305 A- 305 D. In some embodiments, the gas flow splitting device  393  includes a gas flow controller  395  and/or a gas flow meter  397 . The gas flow meter  397  and the gas flow controller  395  may be used to control the gas flow between each of the plurality of processing regions (e.g., process volumes  305 A- 305 D). In some embodiments, the gas flow splitting device  393  comprises a flow resistive element  399  to provide a substantially equal gas flow to each of the plurality of processing regions (e.g., process volumes  305 A- 305 D). 
         [0033]    In  FIG. 3B , the first processing chamber  302 A of the quad processing chamber  300  is described in more detail. However, the second processing chamber  302 B may be configured similarly to the first processing chamber  302 A. 
         [0034]    The substrate support  315  may be fixed to the wall  330  of the chamber body  310  by fasteners (not shown) in a cantilevered manner, in one embodiment. In some embodiments, the substrate support  315  bifurcates the first processing chamber  302 A such that the process volumes  305 A and  305 B are substantially equal in size. The substrate support  315  includes a first major surface  362  and an opposing second major surface  364 , each of which configured to receive and secure a substrate  150  thereon. 
         [0035]    In one aspect, the substrate support  315  includes a heater  360 . Alternatively or additionally, the substrate support  315  is coupled to a power supply  366  to function as an electrostatic chuck. In one example, the substrate support  315  is a bi-polar chuck that selectively chucks the substrates  150  on the respective first major surface  362  and second major surface  364 . In other embodiments, the substrate support  315  may be a heated vacuum chuck that selectively chucks the substrates  150  on the respective first major surface  362  and second major surface  364 . The process controller  138  (shown in  FIG. 1B ) may be coupled to the quad processing chamber  300  (shown in  FIG. 3A ) in order to control substrate processing parameters in the respective process volumes  305 A- 305 D (shown in  FIG. 3A ). The process controller  138  may be utilized to control RF power and/or tuning thereof to each of the process volumes  305 A- 305 D. For example, the process controller  138  may be a RF tuning device that may be utilized to lock output signals of the RF power supplies (e.g., power supply  374  shown in  FIG. 3B ). The process controller  138  may also be utilized to lock the output frequency of each of the RF power supplies using at least one of a phase lock and a frequency lock. The process controller  138  may be utilized to control actuation of the valves  355 . The process controller  138  may also be utilized to control temperature of the substrate supports  315 , among other functions. 
         [0036]    Each of the showerheads  320  include perforated plates having openings  370  in an output face  372  (e.g., a faceplate). Each of the output faces  372  oppose the first major surface  362  and the second major surface  364  of the substrate support  315 . Each of the showerheads  320  may be fabricated from a conductive material, such as a metal, and may function as an electrode within the process volumes  305 A and  305 B. The showerheads  320  may be coupled to a power supply  374 , which may be a radio frequency applicator, and utilized to form a plasma of process gases between the output faces  372  and the substrate support  315 . As such, the substrate support  315  may be fabricated from a conductive material to function as an electrode that is shared by the showerheads  320 . 
         [0037]    Each of the showerheads  320  may be coupled to a translation system  376  that moves the respective perforated plates relative to the first major surface  362  and the second major surface  364  of the substrate support  315 . The translation systems  376  may include an actuator  378  that controls a spacing between the output faces  372  and the first major surface  362  and the second major surface  364  of the substrate support  315 . In one example, the actuator  378  may be coupled to a lid cover plate  380  by a rod  382 . The rod  382  may be a screw-like member that is coupled to a ring  384  which maintains the orientation of the showerheads  320  during movement. For example, the ring  384  may be coupled the actuator  378  by a support member  385 , and one or more guide rods  386  interface with the ring  384  during movement of the showerheads  320 . The support member  385  may also be coupled with a central shaft  388  that is disposed in an opening  390  in the lid cover plate  380 . The central shaft  388  may be fixed to the showerheads  320 . The central shaft  388  may also serves as a gas conduit for the showerheads  320  such that gases from the process gas supply  392  may be delivered to the showerheads  320 . In some embodiments, the first processing chamber  302 A may include a RF shield  394  positioned between the first processing chamber  302 A and the second processing chamber  302 B (shown in  FIG. 3A ). The RF shield  394  may include materials adapted to absorb or reflect RF energy. For example, RF shield  299  may include metals such as steel and aluminum, and may also include electromagnetic insulating materials. 
         [0038]      FIG. 4  is a perspective view of one embodiment of a substrate support member  400  that may be used as the substrate support members  148  in the transfer chamber  114  of  FIGS. 1A, 1B, and 2 . The substrate support member  400  includes support arms  405  each having one or more edge gripping members  410 . While only two edge gripping members  410  are shown, the substrate support member  400  may include more edge gripping members  410 , such as three edge gripping members  410 . One or both of the support arms  405  and the edge gripping members  410  may move laterally in the direction of arrows (toward and away from the edge of the substrate  150 ). In other embodiments, the edge gripping members  410  may be a clamp device that selectively engages an edge of the substrate  150 . 
         [0039]    The support arms  405  include a first surface  415  and a second surface  420  opposing the first surface  415 . Likewise, the edge gripping members  410  include a first surface  425  and an opposing second surface  430 . Depending on whether the substrate support member  400  transfers the substrate  150  to the first major surface  362  or the second major surface  364  of the substrate support  315  (both shown in  FIG. 3B ), the respective planes of the first surface  415  and the second surface  420 , as well as the planes of the first surface  425  and the second surface  430  do not extend beyond a plane of a first major surface  435 , or the second major surface  440 , of the substrate  150 . For example, if the substrate  150  is to be placed or removed from the second major surface  364  of the substrate support  315  shown in  FIG. 3B , the first surface  415  of the support arms  405  and the first surface  425  of the edge gripping members  410  are coplanar with, or slightly recessed from (below as shown in  FIG. 4 ), a plane of the first major surface  435  of the substrate  150 . In some embodiments (not shown), the first major surface  362  and the second major surface  364  of the substrate support  315  (both shown in  FIG. 3B ) may include recesses or cut-outs that correspond to the positions of the edge gripping members  410  about a circumference of a substrate  150  receiving surface of the substrate support  315 . The recesses or cut-outs are configured to allow space for the edge gripping members  410  to support the substrate  150  when the planes of the first surface  425  and/or the second surface  430  of the edge gripping members  410  is not coplanar with the first major surface  435  or the second major surface  440  of the substrate  150 . 
         [0040]      FIGS. 5A and 5B  are various views of a processing chamber  500  showing one example of a substrate transfer process using the substrate support member  400  of  FIG. 4 . The processing chamber  500  may be the first processing chamber  302 A or the second processing chamber  302 B of the quad processing chamber  115  of  FIG. 3A . The processing chamber  500  depicted is a portion of the quad processing chamber  115  of  FIG. 3A  and includes two process volumes, such as a first process volume  505 A and a second process volume  505 B. While another processing chamber of the quad processing chamber  115  is not shown, the substrate transfer process described in  FIGS. 5A and 5B  may be similar and/or occur simultaneously in another processing chamber coupled to the processing chamber  500 . 
         [0041]      FIG. 5A  is a schematic cross-sectional view of the processing chamber  500 .  FIG. 5B  is a schematic isometric cross-sectional view of the processing chamber  500 . A substrate  150  is shown on the first major surface  362  of the substrate support  315 . The substrate support member  400  is shown extending into the first process volume  505 A through a substrate transfer port  510 . The support arms  405  (only one is shown in  FIG. 5B ) surrounds a portion of the peripheral edge of the substrate  150  where the substrate  150  can be gripped. 
         [0042]      FIGS. 6A-6D  are various views of a processing chamber  500  showing another example of a substrate transfer process using the substrate support member  400  of  FIG. 4 . While another processing chamber of the quad processing chamber  115  of  FIG. 3A  is not shown, the substrate transfer process described in  FIGS. 6A and 6B  may be similar and/or occur simultaneously in another processing chamber coupled to the processing chamber  500 . 
         [0043]      FIGS. 6A and 6B  are schematic cross-sectional views of the processing chamber  500  where a substrate  150  is supported on the substrate support member  400 . The substrate support member  400  enters the process volume  505 B through the substrate transfer port  510  in the X direction as shown. A backside  600  of the substrate  150  is slightly spaced apart from the second major surface  364  of the substrate support  315  (in the Z direction) such that the substrate  150  does not contact the substrate support  315 . 
         [0044]      FIG. 6C  is a schematic cross-sectional view of the processing chamber  500  and  FIG. 6D  is a schematic isometric cross-sectional view of the processing chamber  500 . In  FIG. 6C , the substrate support  315  is energized (e.g., electrostatically or applying vacuum) such that the substrate is attracted to the second major surface  364  of the substrate support  315 . The edge gripping members  410  (only one is shown) release the substrate  150  and the substrate  150  is effectively clamped onto the second major surface  364  of the substrate support  315  as shown in  FIG. 6D . While not shown, a substrate may be transferred to the first major surface  362  of the substrate support  315  simultaneously with the transfer of the substrate  150  onto the second major surface  364 . After clamping of the substrate  150 , the substrate support member  400  may retract out of the processing chamber  500  via the substrate transfer port  510 . The substrate transfer port  510  may be sealed and processing may commence. Additionally, while not shown, substrates for other processing volumes of the quad processing chamber, such as the quad processing chamber  115  of  FIG. 3A , may be transferred to all process volumes simultaneously. A transfer process to remove processed substrates from the process volumes may be a substantial reversal of the process described in  FIGS. 6A-6D . The removal process may be performed simultaneously. 
         [0045]    While the foregoing is directed to embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.