Patent Publication Number: US-2022238355-A1

Title: Hyperbaric clean method and apparatus for cleaning semiconductor chamber components

Description:
FIELD 
     Embodiments of the present disclosure generally relate to substrate processing equipment. 
     BACKGROUND 
     Components for use in a process chamber for semiconductor substrate processing are typically cleaned prior to being installed in the process chamber. However, parts with complex geometries may be challenging to clean due to small openings and other hard to reach areas. Conventional methods of cleaning the components include sprays or agitation, which may be inadequate for cleaning parts with complex geometries and present the additional challenge of removing chemical byproducts. 
     Accordingly, the inventors have provided improved methods and apparatus for cleaning chamber components for use in semiconductor substrate processing equipment. 
     SUMMARY 
     Embodiments of methods and apparatus for cleaning components for use in substrate processing equipment are provided herein. In some embodiments, a cleaning system for cleaning components for use in substrate processing equipment includes: a boiler having a heater configured to heat a fluid; a clean chamber fluidly coupled to the boiler via at least one of a gas line and a liquid line, wherein the clean chamber includes one or more fixtures in an interior volume therein for holding at least one component to be cleaned, and wherein the clean chamber includes a heater for heating the interior volume; and an expansion chamber fluidly coupled to the clean chamber via a release line for evacuating the clean chamber, wherein the release line includes a release valve to selectively open or close a flow path between the expansion chamber and the clean chamber, and wherein the expansion chamber includes a chiller for cooling the expansion chamber and a vacuum port configured to couple the expansion chamber to a vacuum pump. 
     In some embodiments, a method of cleaning components for use in substrate processing equipment includes: loading at least one component to be cleaned into a clean chamber; heating a fluid in a boiler fluidly coupled to the clean chamber to a first temperature; delivering the heated fluid to a clean chamber to cover the at least one component with the heated fluid; increase a pressure in the clean chamber to a threshold pressure; and opening a release valve disposed in a release line that fluidly couples the clean chamber to an expansion chamber when the threshold pressure is reached to boil the fluid and evacuate the boiled fluid from the clean chamber into the expansion chamber. 
     In some embodiments, a non-transitory computer readable medium having instructions stored thereon that, when executed by a processor, perform a method of cleaning components for use in substrate processing equipment, the method including: loading at least one component to be cleaned into a clean chamber; heating a fluid in a boiler fluidly coupled to the clean chamber to a first temperature; delivering the heated fluid to a clean chamber to cover the at least one component with the heated fluid; increase a pressure in the clean chamber to a threshold pressure; and opening a release valve disposed in a release line that fluidly couples the clean chamber to an expansion chamber when the threshold pressure is reached to boil the fluid and evacuate the boiled fluid from the clean chamber into the expansion chamber. 
     Other and further embodiments of the present disclosure are described below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present disclosure, briefly summarized above and discussed in greater detail below, can be understood by reference to the illustrative embodiments of the disclosure depicted in the appended drawings. However, the appended drawings illustrate only typical embodiments of the disclosure and are therefore not to be considered limiting of scope, for the disclosure may admit to other equally effective embodiments. 
         FIG. 1  depicts a schematic view of a cleaning system for cleaning components for use in substrate processing equipment in accordance with some embodiments of the present disclosure. 
         FIG. 2  depicts a schematic cross-sectional view of a clean chamber in accordance with some embodiments of the present disclosure. 
         FIG. 3  depicts a flow chart of a method of cleaning components for use in substrate processing equipment in accordance with some embodiments of the present disclosure. 
     
    
    
     To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. The figures are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. 
     DETAILED DESCRIPTION 
     Embodiments of hyperbaric clean methods and apparatus for cleaning components for use in substrate processing equipment are provided herein. The components may be any components suitable for use in substrate processing equipment, for example, but not limited to, gas distribution plates, showerheads, process kit components, chamber liners, or the like. The components may also be any component(s) for use in substrate processing equipment that has a complex geometry, which may be difficult to clean using conventional cleaning methods. 
     The novel cleaning system generally includes a boiler fluidly coupled to a clean chamber, and the clean chamber fluidly coupled to an expansion chamber. A liquid is heated in the boiler to a suitable temperature. The hot steam or fluid from the boiler is introduced into the clean chamber, covering any component(s) disposed in the clean chamber with moisture. The clean chamber is pressurized to a high internal pressure. The expansion chamber is kept at a lower pressure, such as atmospheric or vacuum. When a release valve disposed between the clean chamber and the expansion chamber is opened, all of the moisture collected on the component(s) rapidly boils or cavitates due to the rapid pressure drop and evacuates from the clean chamber into the expansion chamber, along with unwanted particles or impurities on the component(s), which cleans the component(s). This process may be repeated until a desired cleanliness or desired particle count on the component is achieved. 
     The cleaning system provided herein advantageously controls the thermal energy by controlling the operation temperature. Further, the dynamics of the clean chamber can advantageously be controlled by adjusting the opening size of the release valve. The control of the thermal energy and dynamics of the clean chamber greatly enhance the clean process precision, efficiency, and repeatability. 
       FIG. 1  depicts a schematic view of a cleaning system  100  for cleaning components for use in substrate processing equipment in accordance with some embodiments of the present disclosure. The cleaning system  100  includes a boiler  110  fluidly coupled to a clean chamber  120  to deliver a fluid to the clean chamber. The cleaning system  100  includes an expansion chamber  130  fluidly coupled to the clean chamber  120  via a release line  102  to rapidly evacuate moisture and unwanted particles from the clean chamber  120 . 
     The boiler  110  is generally a closed vessel having a heater  112  configured to heat a fluid disposed in the boiler  110 . The fluid may be supplied or derived from a liquid supply  104  coupled to the boiler  110 . A supply valve  148  may be disposed between the liquid supply  104  and the boiler  110  to control a flow of the liquid from the liquid supply  104  into the boiler  110 . The liquid supply  104  may supply a suitable liquid such as water or deionized water. The boiler  110  may heat the liquid to generate steam. For example, the boiler  110  may heat the liquid to a temperature of about 300 degrees to about 550 degrees Fahrenheit. In some embodiments, a first temperature sensor  114  is coupled to the boiler  110  to measure a temperature inside the boiler  110 . In some embodiments, a first pressure sensor  111  is coupled to the boiler  110  to measure a pressure inside the boiler  110 . 
     [owls] In some embodiments, the boiler  110  is coupled to the clean chamber  120  via a gas line  103  to supply steam to the clean chamber  120  to saturate or cover one or more components disposed in the clean chamber  120  are to be cleaned. In some embodiments, the gas line  103  extends from an upper portion of the boiler  110  or a lid of the boiler  110 . In some embodiments, the gas line  103  includes a gas line valve  152  to control a flow of gas through the gas line  103 . In some embodiments, the gas line  103  includes a filter  154  configured to reduce particle contamination passing from the boiler  110 , through the gas line  103 , and into the clean chamber  120 . In some embodiments, the filter  154  is disposed between the gas line valve  152  and the boiler  110 . 
     The cleaning system  100  may also advantageously allow for introduction of process gasses during the cleaning process to enhance or retard material surface condition in the fully dried state. In some embodiments, the gas line  103  includes a second gas line valve  155  for mixing one or more process gases from a process gas supply  160  via a process gas supply line  159  into the gas line  103 . In some embodiments, the second gas line valve  155  is a three-way valve. In some embodiments, the second gas line valve  155  is disposed downstream of the gas line valve  152 . The process gas supply  160  may include one or more process gases suitable for performing a drying process, a passivation process, a seasoning process, or the like. For example, the process gas supply  160  may include one or more of nitrogen gas (N 2 ), oxygen gas (O 2 ), nitrogen trifluoride (NF 3 ), ozone (O 3 ), or ammonia (NH 3 ). 
     In some embodiments, a liquid line  118  extends from the boiler  110  to the clean chamber  120  to saturate or cover the one or more components disposed in the clean chamber  120  with liquid from the boiler  110 . The liquid line  118  may include a liquid line valve  115  to control a liquid flow through the liquid line  118 . In some embodiments, the liquid line  118  extends from a lower portion of the boiler  110 . In some embodiments, the clean chamber  120  is coupled to the boiler  110  via both the gas line  105  and the liquid line  118 . The boiler  110  may include a first drain line  117  coupled to a system drain (not shown) having a first drain valve  113  for draining liquid disposed in the boiler  110 . 
     The clean chamber  120  is generally a closed vessel configured to hold at least one component to be cleaned. The clean chamber  120  may be sized to accommodate at least one component  212  disposed therein. In some embodiments, the clean chamber  120  includes a heater  124  configured to heat an interior volume of the clean chamber  120 . The clean chamber  120  may include a second drain line  125  coupled to a drain (not shown) having a second drain valve  127  for draining liquid disposed in the clean chamber  120 .  FIG. 2  depicts a simplified schematic cross-sectional view of a clean chamber in accordance with some embodiments of the present disclosure. The clean chamber  120  includes a chamber body  202  and a lid  204  coupled to the chamber body  202  to at least partially define an interior volume  210  of the clean chamber  120 . The heater  124  may be disposed inside the interior volume  210 , or as depicted in  FIG. 2 , may be disposed outside of the interior volume. The heater  124  may comprise any suitable heating element such as heater jackets, resistive heating elements, heater rods, or the like. The heater  124  is configured to maintain or increase a temperature of heated fluid  230  disposed in the clean chamber  120 . In use, the heated fluid  230  in the form of steam, a heated liquid, or a combination of steam and heated liquid covers the at least one component  212  with droplets  232 , or moisture. In some embodiments, a second temperature sensor  126  is coupled to the clean chamber  120  to measure a temperature inside the clean chamber  120 . In some embodiments, a second pressure sensor  128  is coupled to the clean chamber  120  to measure a pressure inside the clean chamber  120 . 
     The chamber body  202  may include a port or opening to facilitate transfer of the at least one component  212  to be cleaned into or out of the interior volume  210 . In some embodiments, the clean chamber  120  includes a door  208  opposite a sidewall of the chamber body  202  configured to selectively open or close for transferring the at least one component  212  into or out of the interior volume  210 . In some embodiments, the clean chamber  120  includes a viewing element  218  to observe the at least one component  212 . In some embodiments, the viewing element  218  is coupled to or disposed in the lid  204 . In some embodiments, the viewing element  218  is a viewport or camera. In some embodiments, the lid  204  includes a gas inlet  226  coupled to at least one of the gas line  103  or the liquid line  118 . Alternatively, the lid  204  may include two gas inlets  226  coupled to the gas line  103  and the liquid line  118 , respectively. 
     The clean chamber  120  may include a suitable support for holding or supporting the at least one component  212 . In some embodiments, the suitable support may comprise one or more fixtures  216  disposed in the interior volume  210 . In some embodiments, the one or more fixtures  216  may include one or more holders  222  extending from a floor  214  of the chamber body  202 , where the at least one component is configured to rest on the one or more holders  222 . In some embodiments, the one or more holders  222  may comprise a single support. 
     In some embodiments, the one or more fixtures  216  include a one or more walls supports  220  extending from sidewalls of the chamber body  202 . In some embodiments, the one or more walls supports  220  comprise a plurality of wall supports that are spaced along the chamber body  202  at a common vertical height from the floor  214 . In some embodiments, the one or more walls supports  220  comprise a continuous ring along the chamber body. In some embodiments, the one or more wall supports  220  may be arranged along multiple vertically spaced apart rows, where each row is configured to hold a component of the at least one component  212  ( FIG. 2  depicts two vertically spaced rows). Accordingly, the one or more fixtures  216  may be configured to hold multiple components in a vertically spaced apart orientation. While the one or more fixtures  216  are depicted as one or more wall supports  220  or one or more holders  222  in  FIG. 2 , the clean chamber  120  may include any suitable structure, such as hooks, ledges, protrusions, or the like, for holding the at least one component  212 . 
     Referring back to  FIG. 1 , a return line  156  may extend from the clean chamber  120  to the boiler  110  to recycle excess liquid from the clean chamber  120  to the boiler  110 . The return line  156  may include a return line valve  158  for controlling a flow through the return line  156 . In some embodiments, the return line  156  and the second drain line  125  are coupled to the floor  214  of the chamber body  202 . 
     The release line  102  extending between the clean chamber  120  and the expansion chamber  130  facilitates evacuation of gas disposed in the interior volume  210  of the clean chamber  120 . The release line  102  includes a release valve  108  to selectively open or close a flow path between the expansion chamber  130  and the clean chamber  120 . In some embodiments, the release valve  108  is a control valve. In some embodiments, the release valve  108  is an on-off valve and the release line  102  further includes a flow control element  140 . In some embodiments, the flow control element  140  comprises at least one of a fixed orifice, a variable orifice, or a metering valve for controlling a flow through the release line  102 . In some embodiments, the flow control element  140  is disposed downstream of the release valve  108 . 
     The expansion chamber  130  is generally a closed vessel sized to evacuate high pressure gas from the clean chamber  120 . The expansion chamber  130  is configured to maintain a negative pressure with respect to the clean chamber  120  during evacuation of the clean chamber  120 . The negative pressure, for example, may be maintained by increasing an internal volume of the expansion chamber  130 , reducing a temperature of the expansion chamber  130 , or reducing pressure of the expansion chamber  130 . In some embodiments, the expansion chamber  130  has a larger internal volume than the clean chamber  120 . In some embodiments, the expansion chamber  130  includes a vacuum pump  132  coupled to the expansion chamber to regulate a pressure inside the expansion chamber  130 . In some embodiments, the vacuum pump  132  is configured to create vacuum pressure inside the expansion chamber  130  advantageously creating a larger pressure differential between the expansion chamber  130  and the clean chamber  120 . 
     In some embodiments, the expansion chamber  130  is coupled to a chiller  134  configured to cool the expansion chamber  130 . Cooling the expansion chamber  130  may reduce a required internal volume of the expansion chamber while maintaining the negative pressure with respect to the clean chamber  120 . The chiller  134  may also advantageously cool the expansion chamber  130  after hot gas is evacuated from the clean chamber  120 , decreasing cool down time between cleaning cycles on the at least one component  212  and increasing cleaning efficiency. The expansion chamber  130  may include a third drain line  135  coupled to a drain (not shown) having a third drain valve  136  for draining liquid disposed in the expansion chamber  130 . In some embodiments, the first drain line  117 , the second drain line  125 , and the third drain line  135  are coupled downstream to a common drain. 
     In some embodiments, the cleaning system  100  includes a condensation particle counter (CPC)  116  disposed downstream of the clean chamber  120  and upstream of the expansion chamber  130 . The CPC  116  is configured to measure a particle count from a portion of the gas that is evacuated from the clean chamber  120 . In some embodiments, the CPC  116  is disposed along a bypass line  163  that extends from the release line  102  to the expansion chamber  130 . In some embodiments, a three-way valve  106  disposed in line with the release line  102  may divert some flow from the release line  102  into the bypass line  163 . 
     A controller  180  controls the operation of the cleaning system  100  using a direct control of the boiler  110 , the clean chamber  120 , and the expansion chamber  130 , or alternatively, by controlling the computers (or controllers) associated with each of the boiler  110 , the clean chamber  120 , and the expansion chamber  130 . In operation, the controller  180  enables data collection and feedback from the cleaning system  100  to optimize performance of the cleaning system  100 . The controller  180  generally includes a Central Processing Unit (CPU)  182 , a memory  184 , and a support circuit  186 . The CPU  182  may be any form of a general-purpose computer processor that can be used in an industrial setting. The support circuit  186  is conventionally coupled to the CPU  182  and may comprise a cache, clock circuits, input/output subsystems, power supplies, and the like. Software routines, such as a method as described below may be stored in the memory  184  and, when executed by the CPU  182 , transform the CPU  182  into a specific purpose computer (controller  180 ). The software routines may also be stored and/or executed by a second controller (not shown) that is located remotely from the cleaning system  100 . 
     The memory  184  is in the form of computer-readable storage media that contains instructions, when executed by the CPU  182 , to facilitate the operation of the cleaning system  100 . The instructions in the memory  184  are in the form of a program product such as a program that implements the method of the present principles. 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 on a computer-readable storage media for use with a computer system. The program(s) of the program product define functions of the aspects (including the methods described herein). Illustrative computer-readable storage media include, but are not limited to: 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 type of solid-state non-volatile semiconductor memory) on which information is permanently stored; and writable 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 aspects of the present principles. 
       FIG. 3  depicts a flow chart of a method  300  of cleaning components (e.g., at least one component  212 ) for use in substrate processing equipment in accordance with some embodiments of the present disclosure. The substrate processing equipment may be deposition chambers, etch chambers, clean chambers, or the like. At  302 , the method  300  includes loading at least one component to be cleaned into a clean chamber (e.g., clean chamber  120 ). The at least one component may be at least one of a gas distribution plate, a showerhead, a process kit component, a chamber liner, or the like. 
     At  304 , the method  300  includes heating a fluid in a boiler (e.g. boiler  110 ) fluidly coupled to the clean chamber to a first temperature. In some embodiments, the first temperature is about 300 degrees to about 550 degrees Fahrenheit. The fluid may be delivered to the boiler via a liquid supply (e.g., liquid supply  104 ). The liquid may be, for example, water. 
     At  306 , the method  300  includes delivering the heated fluid to a clean chamber to cover the at least one component with the fluid. In some embodiments, the heated fluid is delivered as a steam via a gas line valve (e.g., gas line valve  152 ). In some embodiments, the heated fluid is delivered as a heated liquid via a liquid line valve (e.g., liquid line valve  115 ). In some embodiments, once a desired amount of heated fluid is delivered to the clean chamber, at least one of the liquid line valve and the gas line valve are closed. 
     At  308 , the method  300  includes increasing a pressure in the clean chamber to a threshold pressure. In some embodiments, the threshold pressure is about 100 to about 450 pounds per square inch (psi). In some embodiments, the pressure in the clean chamber may be increased by heating the clean chamber using a heater (e.g., heater  124 ). 
     At  310 , the method  300  includes opening a release valve disposed in a release line that fluidly couples the clean chamber to an expansion chamber when the threshold pressure is reached to boil the fluid and evacuate the boiled fluid from the clean chamber into the expansion chamber. In some embodiments, the release line includes a flow control element (e.g., flow control element  140 ) to control a release of the pressure from the clean chamber and therefore the rate of evacuation of the boiled fluid. In some embodiments, the boiled fluid is evacuated from the clean chamber into the expansion chamber in about 5 milliseconds to about 10 seconds. In some embodiments, an internal pressure of the expansion chamber is reduced to a vacuum pressure prior to opening the release valve to create a larger pressure differential between the clean chamber and the expansion chamber. 
     In some embodiments, the release valve is closed after the boiled fluid is evacuated from the clean chamber. In some embodiments, the at least one component in the clean chamber is conditioned after evacuating the boiled fluid from the clean chamber. In some embodiments, conditioning the at least one component comprises performing at least one of a drying process, a passivation process, or a seasoning process by introducing suitable process gases for the desired process via a process gas supply (e.g., process gas supply  160 ). For example, suitable process gases may include one or more of nitrogen gas (N 2 ), oxygen gas (O 2 ), nitrogen trifluoride (NF 3 ), ozone (O 3 ), or ammonia (NH 3 ). 
     In some embodiments, a particle counter (e.g., CPC  116 ) disposed downstream of the clean chamber is used to detect a number of particles flowing therethrough. In some embodiments, at  312 , the method  300  at  306 ,  308 , and  310  is optionally repeated until desired, for example, until the number of particles detected by the particle counter is at or below a predetermined amount. That is, in some embodiments, the method  300  includes delivering additional heated fluid to the clean chamber to cover the at least one component with the additional heated fluid, increasing the pressure in the clean chamber to the threshold pressure and reopening the release valve when the threshold pressure is reached. Once the at least one component is sufficiently cleaned or processed, the at least one component may be removed from the clean chamber and installed in suitable substrate processing equipment. 
     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.