Patent Publication Number: US-2023162999-A1

Title: External substrate system rotation in a semiconductor processing system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/588,959, filed Sep. 30, 2019, which is a divisional of U.S. patent application Ser. No. 15/091,260, filed Apr. 5, 2016, which claims priority to U.S. Provisional Application No. 62/151,799, filed Apr. 23, 2015, each of which are hereby incorporated by reference in their entireties. 
    
    
     FIELD 
     The present disclosure generally relates to a method and apparatus for film uniformity in semiconductor processing. More specifically, a processing system having a rotation module coupled between two transfer chambers to increase film uniformity in semiconductor processing. 
     BACKGROUND 
     Semiconductive device performance is determined by a variety of factors. One factor of importance is the uniformity of films deposited on a substrate. It is desirable to deposit films uniformly such that thickness variation is minimized across the surface of the substrate. For example, it may be desirable to form films having thickness variation of less than about 5% across the surface of the substrate. 
     However, film uniformity may be adversely affected by several factors, including heater temperature, chamber geometry, process gas flow non-uniformity, and plasma non-uniformity, among others. These factors may result in the deposition of non-uniform films on the surface of the substrate, which may ultimately reduce device performance. 
     Rotating the substrate during processing provides improved uniformity. However, rotating the substrate during processing requires expensive equipment, such as slip rings and rotary unions. 
     Therefore, there is a need for an improved apparatus and method for film uniformity in semiconductor processing. 
     SUMMARY 
     In one embodiment, a method for processing a substrate is provided, the method including depositing a first portion of a film on the substrate in a processing chamber, transferring the substrate to a rotation module, rotating the substrate a predefined amount, transferring the substrate to the processing chamber, and depositing a second portion of the film on the substrate in the processing chamber. 
     In another embodiment, a method for processing a substrate is provided, the method including depositing a first portion of a film on the substrate in a first processing chamber, transferring the substrate to a rotation module, rotating the substrate a predefined amount, transferring the substrate to a second processing chamber, and depositing a second portion of the film on the substrate in the second processing chamber. The depositing a first portion and the depositing a second portion include the same deposition process. 
     In yet another embodiment, a processing chamber for semiconductor processing configured to be coupled between two transfer chambers is provided, the processing chamber including a chamber body defining an interior volume having an opening at a first and a second end, a substrate support, and a rotation module. The substrate support includes a substrate platform. The substrate support extends beyond the opening at the first end and the second end of the chamber body. The substrate support is configured to rotate a substrate. The rotation module includes a measurement module. The measurement module includes an ellipsometer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of 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. 
         FIG.  1    illustrates a top view of a processing system that includes at least one rotation module according to one embodiment. 
         FIG.  2    illustrates a side view of the rotation module of  FIG.  1    according to one embodiment. 
         FIG.  3    illustrates a side view of another embodiment of a rotation module portion of the processing system of  FIG.  1   , according to one embodiment. 
         FIG.  4    illustrates a method of processing a substrate, according to one embodiment. 
         FIGS.  5 A- 5 C  illustrate a side view of the rotation module of  FIG.  1   , according to one embodiment, depicting how a substrate is placed on the substrate support assembly. 
         FIG.  6    illustrates a top view of a processing system having a rotation module, according to one embodiment. 
         FIG.  7    illustrates a top view of a processing system having a rotation module, according to one embodiment. 
     
    
    
     For clarity, identical reference numerals have been used, where applicable, to designate identical elements that are common between figures. Additionally, elements of one embodiment may be advantageously adapted for utilization in other embodiments described herein. 
     DETAILED DESCRIPTION 
       FIG.  1    illustrates a schematic view of a processing system  100  for processing a substrate (not shown). The processing system  100  includes two transfer chambers  104   a ,  104   b , a rotation module  106 , and one or more processing chambers  108 . The processing system  100  may also include a load lock chamber  110 , a factory interface  112 , and a controller  113 . The factory interface  112  is configured to load and unload substrates from the processing system  100 . The factory interface  112  may include various robots and load ports adapted to load substrates to be processed and to store substrates that have been processed. 
     The load lock chamber  110  couples the transfer chamber  104   a  to the factory interface  112 . The load lock chamber  110  is selectively in fluid communication with transfer chamber  104   a , such that a substrate may be transferred between the atmospheric environment of the factory interface  112  and the load lock chamber  110 . Transfer chamber  104   a  includes a robot  114   a . The robot  114   a  is configured to transfer the substrates into and out of chambers  106 ,  108 . Transfer chamber  104   b  includes a robot  114   b . The robot  114   b  is configured to transfer the substrates into and out of chambers  106 ,  108 . 
     The processing chambers  108  are coupled to the transfer chambers  104   a ,  104   b . In one embodiment, the processing chambers  108  may be a deposition chamber or a treatment chamber. Examples of suitable deposition chambers include, but are not limited to, a chemical vapor deposition (CVD) chamber, a spin-on coating chamber, a flowable CVD chamber, a physical vapor deposition (PVD) chamber, an atomic layer deposition (ALD) chamber, an epitaxial deposition chamber, and the like. Examples of treatment chambers include, but are not limited to, a thermal treatment chamber, an annealing chamber, a rapid thermal anneal chamber, a laser treatment chamber, an electron beam treatment chamber, a UV treatment chamber, an ion beam implantation chamber, an ion immersion implantation chamber, or the like. It is also contemplated that one or more of the processing chambers  108  may be another type of vacuum processing chamber. 
     The rotation module  106  is coupled to the transfer chambers  104   a ,  104   b . The rotation module  106  separates transfer chamber  104   a  from transfer chamber  104   b . The rotation module  106  allows for fluid communication between transfer chambers  104   a ,  104   b , such that a substrate being transferred from  104   a  to  104   b  passes through the rotation module  106 . The rotation module  106  is configured to rotate a substrate. The rotation module  106  is discussed in more detail in  FIG.  2   . 
     Continuing to refer to  FIG.  1   , the processing chambers  108 , the rotation module  106 , the transfer chambers  104   a ,  104   b , and the load lock chamber  110  are connected to form a vacuum tight platform  116 . One or more pump systems  118  are coupled to the load lock chamber  110 , the transfer chambers  104   a ,  104   b , the rotation module  106 , and the processing chambers  108 . In  FIG.  1   , a single pump system  118  is shown coupled to the load lock chamber  110  to avoid drawing clutter. The pump system  118  controls the pressure within the processing system  100 . The pump system  118  may be utilized to pump down and vent the load lock chamber  110  as needed to facilitate entry and removal of substrates from the vacuum tight platform  116 . 
     The processing system  100  is coupled to the controller  113  by a communication cable  120 . The controller  113  is operable to control processing of a substrate within the processing system  100 . The controller  113  includes a programmable central processing unit (CPU)  122  that is operable with a memory  124  and a mass storage device, an input control unit, and a display unit (not shown), such as power supplies, clocks, cache, input/output (I/O) circuits, and the like, coupled to the various components of the processing system  100  to facilitate control of the processes of processing a substrate. The controller  113  may also include hardware for monitoring the processing of a substrate through sensors (not shown) in the processing system  100 . 
     To facilitate control of the processing system  100  and processing a substrate, the CPU  122  may be one of any form of general purpose computer processors for controlling the substrate process. The memory  124  is coupled to the CPU  122  and the memory  124  is non-transitory and may be one or more of readily available memory such as random access memory (RAM), read only memory (ROM), floppy disk drive, hard disk, or any other form of digital storage, local or remote. Support circuits  126  are coupled to the CPU  122  for supporting the CPU  122  in a conventional manner. The process for processing a substrate is generally stored in the memory  124 . The process for processing a substrate may also be stored and/or executed by a second CPU (not shown) that is remotely located from the hardware being controlled by the CPU  122 . 
     The memory  124  is in the form of computer-readable storage media that contains instructions, that when executed by the CPU  122 , facilitates the operation of processing a substrate in the processing system  100 . The instructions in the memory  124  are in the form of a program product such as a program that implements the operation of processing a substrate. The program code may conform to any one of a number of different programming languages. In one example, the disclosure may be implemented as a program product stored in computer readable storage media for use with a computer system. The program(s) of the program product define functions of the embodiments. Illustrative computer-readable storage media include, but are not limited to: (i) non-writable storage media (e.g., read-only memory devices within a computer such as CD-ROM disks readable by a CD-ROM drive, flash memory, ROM chips or any tope of solid-state non-volatile semiconductor memory) on which information is permanently stored; and (ii) writing storage media (e.g. floppy disks within a diskette drive or hard-disk drive or any type of solid-state random-access semiconductor memory) on which alterable information is stored. Such computer-readable storage media, when carrying computer-readable instructions that direct the functions of the methods described herein, are embodiments of the present disclosure. 
       FIG.  2    illustrates one embodiment of the rotation module  106 . The rotation module  106  includes a chamber body  202  and a substrate support assembly  212 . The chamber body  202  includes sidewalls  204 , a ceiling  206 , and a bottom  208 . The sidewalls  204 , the ceiling  206 , and the bottom  208  define an interior volume  210 . The substrate support assembly  212  is disposed in the interior volume  210 . The substrate support assembly  212  includes a platform  290 , a shaft  216 , and a rotary actuator  218 . The platform  290  has a substrate receiving surface  214  that is configured to receive a substrate. The shaft  216  extends through the bottom  208  of the chamber body  202  through an opening  224 . The opening  224  is sealed by a bellows  226 . A plate  294  is coupled to the bellows  226  and surrounds the shaft  216 . A shaft seal  292  is a sliding seal that provides a vacuum-tight coupling between the plate  294  and the shaft  216  during actuation of the shaft. The shaft  216  is coupled to the platform  290 . In one embodiment, the substrate support assembly  212  further includes a plurality of lift pins  222 . The plurality of lift pins  222  are configured to extend through the substrate receiving surface  214  to raise and/or lower the substrate to facilitate robotic transfer. 
     The rotary actuator  218  may be a stepper motor, a servomotor, or the like. In one embodiment, the substrate support assembly  212  further includes a rotation sensor  223 . The rotary actuator  218  is coupled to the shaft  216  of the substrate support assembly  212 . The rotary actuator  218  may be configured to rotate the substrate support assembly  212 . The rotation sensor  223  is coupled to the rotary actuator  218 . The rotation sensor is configured to measure the rotation of the substrate support assembly  212 . The rotation sensor  223  may be coupled to the controller (not shown) to provide real time feedback to the controller. In one embodiment, the rotation sensor  223  may be an encoder. 
     In one embodiment, the substrate support assembly  212  further includes a vertical actuator  220 . The vertical actuator  220  is configured to move the shaft  216  vertically, in a z-direction, so that the platform  290  is raised and or lowered. In  FIG.  2   , the platform  290  is shown in a raised position. 
     A measurement device  228  is coupled to the ceiling  206  of the rotation module  106 . In one embodiment, the measurement device  228  may be an ellipsometry device, configured to detect the dielectric properties of the film deposited on the substrate through a window  230  formed in the ceiling  206  of the chamber body  202 . Dynamic metrology can provide a real-time feedback on the effectiveness of the rotation of the substrate on film property uniformity. 
     In the embodiment shown in  FIG.  2   , the substrate support assembly  212  is entirely within the interior volume  210  of the rotation module  106 . The substrate support assembly  212  does not extend into an interior volume  280  of the first transfer chamber  104   a  or the interior volume  282  of the second transfer chamber  104   b.    
       FIG.  3    illustrates a side view of a portion of the processing system  100  of  FIG.  1   , according to one embodiment.  FIG.  3    includes the first transfer chamber  104   a , the second transfer chamber  104   b , and the rotation module  106 . The rotation module  106  is coupled to both the first transfer chamber  104   a  and the second transfer chamber  104   b . The rotation module  106  allows for fluid communication between the first transfer chamber  104   a  and the second transfer chamber  104   b , such that the substrate can be transferred between the first transfer chamber  104   a  and the second transfer chamber  104   b . In the embodiment shown in  FIG.  3   , the substrate support assembly  212  is not entirely within the interior volume  210  of the rotation module  106 . Rather, the substrate support assembly  212  extends partially into the interior volume  280  of the first transfer chamber  104   a  and the interior volume  282  of the second transfer chamber  104   b . For example, the platform  290  may extend into the transfer chambers  104   a ,  104   b . Thus, in the embodiment shown in  FIG.  3   , the rotation module  106  has a smaller interior volume  210  than the interior volume  210  of the rotation module  106  shown in  FIG.  2   . 
       FIG.  4    illustrates a method  400  of processing a substrate in the processing system  100 , such as that described in  FIG.  1   . The method  400  begins at block  402  by performing a first portion of the film deposition process on the substrate in the first processing chamber  108 . The substrate is transferred to the first processing chamber  108  by the robot  114   a  disposed in the first transfer chamber  104   a . The robot  114   a  is configured to move the substrate between the transfer chamber  104   a  and the processing chamber  108 . The robot  114   a  transferred the substrate into the first transfer chamber  104   a  from the load lock chamber  110 . The first processing chamber  108  may be a deposition chamber, such as a CVD chamber, a spin-on coating chamber, a flowable CVD chamber, a PVD chamber, and ALD chamber, or any other deposition chamber suitable for depositing thin films on a substrate. In the first processing chamber  108 , a first portion of the film deposition process is performed on the substrate. 
     At block  404 , the substrate is transferred from the first processing chamber  108  to a rotation module  106  by the robot  114   a , as illustrated by  FIGS.  5 A- 5 B .  FIGS.  5 A- 5 B  illustrate the rotation module  106  at block  404  of method  400 .  FIG.  5 A  illustrates the rotation module  106  as the robot is positioning a substrate  501  on the substrate support assembly  212 . The vertical actuator  220  actuates the substrate support assembly  212  in a downwards z-direction to allow the robot  114   a  to place the substrate  501  on the substrate support assembly  212 . The lift pins  222  of the substrate are formed through the platform  290  of the support assembly  212 . The lift pins  222  are actuated in an upward z-direction, such that the lift pins  222  extend out above the substrate receiving surface  214 , when the substrate support assembly  212  is lowered. In the lowered position, the lift pins  222  contact the bottom  208  of the chamber body  202 . As a result, the lift pins  222  extend out above the substrate receiving surface  214 . A robot blade  550  from the robot  114   a  extends from the transfer chamber  104   a  through an opening to position the substrate  501  in the interior volume  210 . Actuating the lift pins  222  allows the substrate receiving surface  214  to receive the substrate  501  from the robot blade  550  without obstructing the passage of the robot blade  550 . The lift pins  222  may actuate in a downwards z-direction to position the substrate  501  on the substrate receiving surface  214  of the platform  290 , when the blade is removed from beneath the substrate  501 . To actuate the lift pins  222  in a downwards z-direction, the substrate support assembly  212  is actuated in an upward z-direction, such that the lift pins  222  no longer contact the bottom  208  of the chamber body  202 . 
       FIG.  5 B  illustrates the rotation module  106  having the substrate support assembly  212  elevated in an extended position. The vertical actuator  220  actuates the substrate support assembly  212  to the extended position. In the extended position, the rotary actuator  218  is configured to rotate the substrate support assembly  212  (illustrated in  FIG.  5 C ). As illustrated, the lift pins  222  are disengaged from contact with the substrate. The substrate is now resting on the substrate receiving surface  214 . In an extended position, properties of the film deposited on the substrate in the first processing chamber  108  may be measured using the measurement device  228 . Measuring the properties of the film allows for a better n, m, mx bunderstanding of the film uniformity during stages of the deposition process. 
     Referring back to  FIG.  4   , at block  406 , the rotation module  106  is rotated a predefined degree, as illustrated  FIG.  5 C .  FIG.  5 C  illustrates the rotation of the substrate  501  via the rotary actuator  218  as described in block  406 . The rotary actuator  218  rotates the shaft  216  of the substrate support assembly  212  so that the platform  290  and the substrate  501  are rotated with the shaft  216 . The rotation of the substrate  501  changes the position of the substrate  501  relative the substrate&#39;s original position. In one embodiment, the rotary actuator  218  may rotate about a central axis of the substrate  501  between about 1 and 360 degrees. For example, the rotary actuator  218  may rotate the substrate  501  between about 90 and 180 degrees. Once the substrate  501  is rotated, the processes illustrated in  FIGS.  5 A- 5 C  are performed in reverse order, such that the robot  114   a  can remove the substrate  501  from the rotation module  106 . 
     Continuing to refer to  FIG.  4   , at block  408  the substrate  501  is transferred from the rotation module  106  to the second processing chamber  108 . In the second processing chamber  108  the substrate  501  undergoes a second portion of film deposition process, as illustrated by block  410 . The robot  114   b  transfers the substrate  501  from the rotation module  106  to the second transfer chamber  104   b , and then to the second processing chamber  108 . The second portion of the film deposition process may be the same film deposition process as the first portion of the film deposition process. For example, the second portion of the film deposition process may be a CVD chamber, a spin-on coating chamber, a flowable CVD chamber, a PVD chamber, and ALD chamber, or any other deposition chamber suitable for depositing thin films on a substrate. 
     Processing of the substrate may proceed by repeating the method  400  described in  FIG.  4    until a satisfactory film has been formed on the substrate. The substrate may then be removed from the processing system  100 . In one embodiment, the substrate may be rotated about 90 degrees four times such that the substrate undergoes four film deposition processes and is transferred to the rotation module  106  four times. The substrate may thus be processed in the processing chambers  108  when the substrate is in four distinct orientations in the processing chamber  108 . The properties of the film may also be measured four separate times using the measurement device  228  atop the rotation module  106 . 
       FIG.  6    illustrates a processing system  600  for processing substrates, according to one embodiment. The processing system  600  is similar to the processing system  100 . Accordingly, like numerals have been used to designate like components described above with reference to  FIG.  1   . The processing system  600  includes transfer chambers  104 , a rotation module  606 , and one or more processing chambers  108 . The processing system  600  may also include a load lock chamber  110 , a factory interface  112 , and a controller  113 . The one or more processing chamber  108  and the rotation module  606  are coupled to the transfer chamber  104 . 
     The rotation module  606  is similar to the rotation module  106 . Accordingly, like numerals have been used to designate like components described above with reference to  FIGS.  1 ,  2 , and  3   . The rotation module  606  is in fluid communication with the transfer chamber  104 . The rotation module  606  is configured to rotate a substrate. The rotation module  606  further includes a substrate support assembly  612 . The substrate support assembly  612  includes a platform  690 . The rotation module  606  is sized such that the rotation module  606  has a length, L, that is less than the diameter D of the platform  690 . Thus, the substrate support assembly  612  extends partially into the transfer chamber  104 . The length, L, of the rotation module  606  compared to the diameter D of the platform  690  has several advantages. The processing volume, V, of the rotation module  606  is decreased resulting in less time needed for pumping down the rotation module  606 . Additionally, moving parts, such as a slit valve door between the transfer chamber and the rotation module are removed because the platform  690  extends into the rotation module  606 . 
       FIG.  7    illustrates a processing system  700  for processing substrates, according to one embodiment. The processing system  700  is similar to the processing system  100 . Accordingly, like numerals have been used to designate like components described above with reference to  FIG.  1   . The processing system  700  includes a transfer chamber  104 , a rotation module  706 , and one or more processing chambers  108 . The rotation module  706  is positioned at a load lock position. The rotation module  706  is configured to rotate a substrate. The rotation module  706  and the one or more processing chamber  108  are in fluid communication with the transfer chamber  104 . 
     While the foregoing is directed to embodiments of the present 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.