Downstream exhausting of gases during maintenance of substrate processing chambers

Abstract

An exhaust system for a process chamber of a substrate processing system includes: a primary exhaust path connected to the process chamber and including a first one or more valves and a first pump, where the first pump is configured to pump gases from the process chamber; a secondary exhaust path connected to at least one of the process chamber and the primary exhaust path, where the secondary exhaust path includes a second one or more valves; and at least one controller configured to open the first one or more valves and run the first pump to pump out and purge the process chamber during a pump out and purge mode and open the second one or more valves to remove gases from the process chamber during a maintenance exhaust mode.

Description

DOWNSTREAM EXHAUSTING OF GASES DURING MAINTENANCE OF SUBSTRATE PROCESSING CHAMBERSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 662,564, filed on June 21 , 2024. The entire disclosure of the application referenced above is incorporated herein by reference.FIELD

[0002] The present disclosure relates to exhaust systems of substrate processing chambers.BACKGROUND

[0003] The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

[0004] A process chamber of a substrate processing system typically includes a plurality of process stations to perform deposition, etching, and other treatments of substrates such as semiconductor wafers. For example, deposition may be performed to deposit conductive film, dielectric film, or other types of film using chemical vapor deposition (CVD), plasma enhanced CVD (PECVD), atomic layer deposition (ALD), plasma enhance ALD (PEALD), and / or other deposition processes. As an example, etching may be performed to remove material from one or more layers and include atomic layer etching (ALE), high aspect ratio (HAR) etching, plasma etching, and / or other etch processes. During deposition, a substrate is arranged on a substrate support (e.g., a pedestal) and one or more precursor gases may be supplied to a process chamber using a gas distribution device (e.g., a showerhead) during one or more process steps. In a PECVD or PEALD process, plasma is used to activate chemical reactions within the process chamber during deposition. Additional examples of processes that may be performed on a substrate include, but are not limited to, dielectric etching, chemical etching, plasma etching, reactive ion etching, and cleaning processes. During thedeposition and etching processes, gas mixtures are introduced into the process chamber via showerheads, and plasma is struck to activate chemical reactions. During the cleaning processes, gases may also be introduced via the showerheads.SUMMARY

[0005] An exhaust system for a process chamber of a substrate processing system is disclosed. The exhaust system includes: a primary exhaust path connected to the process chamber and including a first one or more valves and a first pump, where the first pump is configured to pump gases from the process chamber; a secondary exhaust path connected to at least one of the process chamber and the primary exhaust path, where the secondary exhaust path includes a second one or more valves; and at least one controller configured to open the first one or more valves and run the first pump to pump out and purge the process chamber during a pump out and purge mode and open the second one or more valves to remove gases from the process chamber during a maintenance exhaust mode.

[0006] In other features, the secondary exhaust path is dedicated for exhaust gases from the process chamber during the maintenance exhaust mode. In other features, the secondary exhaust path is in a closed state when the exhaust system is not operating in the maintenance exhaust mode.

[0007] In other features, the secondary exhaust path includes a second pump, where the second pump is configured to remove gases from the process chamber during the maintenance exhaust mode. In other features, the second pump has at least one of a lower maximum capacity, a lower maximum flow strength, and a lower maximum power rating than the first pump. In other features, the at least one controller is configured to operate the first pump and the second pump independently.

[0008] In other features, the at least one controller does not run the first pump when the second pump is running and does not run the second pump when the first pump is running. In other features, the at least one controller is configured to maintain the second one or more valves in an open state and the second pump in a running state during cleaning of an interior of the process chamber when the process chamber is open.

[0009] In other features, the primary exhaust path includes a first input receiving gases from the process chamber, and a first output supplying gases to a third pump. The secondary exhaust path includes a second input receiving gases from the processchamber or a conduit of the primary exhaust path, and a second output supplying gases to a facilities channel, which supplies gases to a blow and scrubber. In other features, the third pump is a roughing pump.

[0010] In other features, the exhaust system further includes: a first sensor configured to detect levels of one or more substances within the process chamber; and a second sensor configured to detect pressure within the process chamber. The at least one controller is configured to change states of the first one or more valves, the first pump, and the second one or more valves based on outputs of the first sensor and the second sensor.

[0011] In other features, the exhaust system further includes a fume sensor, which is implemented as part of fab safety monitoring, and remains active during the maintenance exhaust mode as fumes are continuously exhausted by the secondary exhaust path to avoid triggering an alarm. The at least one controller monitors the fume sensor during the maintenance exhaust mode.

[0012] In other features, the at least one controller is configured to maintain the second one or more valves in a closed state during the pump out and purge mode and close the first one or more valves and stop running the first pump during the maintenance exhaust mode.

[0013] In other features, the exhaust system further includes an upstream exhaust system including: a hood to draw gases from a top side of the process chamber; and a third one or more valves. The at least one controller is configured to open the third one or more valves to draw gases from the process chamber via the hood during the maintenance exhaust mode.

[0014] In other features, the at least one controller is configured to close the third one or more valves and maintain the second one or more valves in an open state during cleaning of the process chamber when the process chamber is open.

[0015] In other features, the exhaust system further includes a vent valve configured to vent air into the process chamber when the process chamber is closed. The at least one controller is configured to open the vent valve for the pump out and purge mode. In other features, the at least one controller is configured to close the vent valve for the maintenance exhaust mode.

[0016] In other features, a method of performing maintenance on a process chamber of a substrate processing system is disclosed. The method includes: opening a first one or more valves and running a first pump to draw gases from the process chamber via a primary exhaust path during a pump out and purge mode; closing the first one or more valves and ceasing to run the first pump at an end of the pump out and purge mode; at the end of the pump out and purge mode, opening a second one or more valves to draw gases from the process chamber via a secondary exhaust path and during a maintenance exhaust mode; determining whether one or more conditions are satisfied; in response to the one or more conditions being satisfied, permitting opening of the process chamber for maintenance on an interior of the process chamber; and continuing to draw gases from the process chamber via the second one or more valves during the maintenance on the interior of the process chamber.

[0017] In other features, the method further includes running a second pump during the maintenance exhaust mode. In other features, the method further includes running the second pump during the maintenance on the interior of the process chamber.

[0018] In other features, the method further includes: determining at least one of whether a level of a substance is less than a predetermined level and an amount of time operating in the pump out and purge mode is greater than a predetermined threshold; and in response to at least one of the level being less than the predetermined level and the amount of time being greater than the predetermined threshold, transitioning from the pump out and purge mode to the maintenance exhaust mode.

[0019] In other features, the method further includes: determining at least one of whether a level of a substance is less than a predetermined level and an amount of time operating in the maintenance exhaust mode is greater than a predetermined threshold; and in response to at least one of the level being less than the predetermined level and the amount of time being greater than the predetermined threshold, permitting performance of maintenance on the interior of the process chamber.

[0020] In other features, the method further includes: determining whether pressure in the process chamber is at atmospheric pressure; and, in response to the pressure in the process chamber being at atmospheric pressure, enabling the maintenance exhaust mode.

[0021] In other features, the method further includes in response to the pressure in the process chamber being at atmospheric pressure, closing the first one or more valves andceasing to run the first pump. In other features, the method further includes opening the second one or more valves based on whether the pressure in the process chamber is at atmospheric pressure.

[0022] In other features, the method further includes, when the process chamber is closed, opening a vent valve to vent air into the process chamber during the pump out and purge mode. In other features, the method further includes: subsequent to opening the process chamber, receiving an input indicating that maintenance on the interior of the chamber is completed; subsequent to receiving the input, determining whether the process chamber is closed; and in response to the process chamber being closed, ceasing operation in the maintenance exhaust mode including closing the second one or more valves.

[0023] Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0025] FIG. 1 is a functional block diagram of an example substrate processing system including a primary exhaust path and a secondary (or maintenance) exhaust path in accordance with an example of the present disclosure;

[0026] FIG. 2 is a functional block diagram of an example downstream exhaust system of a process chamber in a closed state in accordance with an example of the present disclosure;

[0027] FIG. 3 is a functional block diagram of the downstream exhaust system of FIG. 2 in an open state in accordance with an example of the present disclosure;

[0028] FIG. 4 is a functional block diagram of example exhaust system of a process chamber configured for both downstream and upstream exhausting of gases in accordance with an example of the present disclosure;

[0029] FIG. 5 is a timing diagram illustrating timing for performing a maintenance process including downstream and optionally upstream exhausting of gases in accordance with the present disclosure; and

[0030] FIGs. 6A and 6B (collectively FIG. 6) is a maintenance method including pump out, purge, and exhausting of gases in accordance with the present disclosure.

[0031] In the drawings, reference numbers may be reused to identify similar and / or identical elements.DETAILED DESCRIPTION

[0032] Maintenance is periodically performed on process chambers of substrate processing systems. The maintenance can include, for example, cleaning deposits off surfaces in the chambers. In order to perform cleaning operations on a chamber, the chamber is pumped out and purged and then opened. A lid of the chamber is removed to provide access to an interior of the chamber. A hood is disposed over the chamber and draws gases from within the chamber. The hood and corresponding exhaust system is referred to as an upstream exhaust system. Subsequent to opening the chamber, the interior of the chamber is wet cleaned. This may be a manual job that includes a technician scrubbing an interior of the chamber, or may be a manual assisted, semiautomated, or fully-automated wet cleaning process of the interior of the chamber. The technician needs to use both hands to adjust positioning of the hood and to clean the interior of the chamber. The hood is used to draw waste including flakes and particles from the chamber during wet cleaning. The use of both hands as stated is inefficient because the operator has only one hand available for scrubbing the interior of the chamber, which results in intermittent operation because of handling of upstream exhaust hood with the other hand.

[0033] The pump out and purge operation, the upstream exhausting of gases, and the wet cleaning can take 3-4 hours to perform. The upstream exhausting of gases can take more than 2 hours to perform. The upstream exhausting of gases is performed until a level of certain substances within the chamber is less than, for example, 1 parts per billion (ppb). For example, when there is less than 1 ppb of hydrogen chloride (HCL) and hydrogen fluoride (HF) in the chamber, then the interior is wet cleaned. As a result, there is considerable downtime to perform the operations associated with wet cleaning the interior of a process chamber, which leads to loss of productivity.

[0034] In addition, the chamber may include multiple sensors, such as a fume sensor, an particle sensor, and a residual gas analyzer (RGA). The fume sensor may be disposed external to and above the chamber and the particle sensor may be disposed in the chamber. The fume and particle sensor may be used to detect certain gases and levels thereof above and within the chamber. The fume sensor may be used to monitor air quality for safety reasons. The RGA may be used to determine whether wet cleaningmaintenance activity can be performed. During wet cleaning, isopropyl alcohol (IPA) can be used to remove the deposits off the surfaces within the chamber. When the IPA mixes with the deposits, a toxic byproduct can be produced in the form of fumes. These fumes may be detected by the fume and particle sensors. The fumes can include, for example, HCL and HF. A false alarm can be generated one or more times based on an output of, for example, the fume sensor during cleaning. The false alarm can result in a system shutdown. The false alarm and the system shutdown can be perceived as a nuisance to a technician. As a result, the technician may override and / or shut off the alarm and / or disable the fume sensor to deactivate fume sensing and to avoid nuisance alarm triggering and a potential system shutdown. This can result in a potentially hazardous condition.

[0035] The examples set forth herein include a downstream independently operated exhaust system, which provides a positive displacement of exhaust gases downstream from a process chamber. This downstream draw of gases prevents a gas sensor from triggering an alarm. The downstream exhaust system is operated prior to and during wet cleaning operations. This substantially reduces time associated with performing a cleaning operation. The time to exhaust gases is reduced to less than a half an hour (or 30 minutes). In addition, an auto vent valve is provided, which may be used to aid in pumping out and purging the process chamber. This can further reduce time associated with pump out and purge operations.

[0036] FIG. 1 shows a substrate processing system 100 including a process chamber 101 having a substrate support 102, shown as an electrostatic chuck, a showerhead assembly 103, and an exhaust system 104. The exhaust system 104 may include a primary exhaust path 105 and a secondary (or maintenance) exhaust path 106, which is independent of the primary exhaust path 105. Although FIG. 1 shows a capacitive coupled plasma (CCP) system, the embodiments disclosed herein are applicable to transformer coupled plasma (TCP) systems, inductively coupled plasma (ICP) systems and / or other processing systems.

[0037] The substrate support 102 is enclosed within the processing process chamber 101 . The processing process chamber 101 also encloses other components, such as an upper electrode (or showerhead faceplate) 108, and contains RF plasma. During operation, a substrate 109 is arranged on and electrostatically clamped to the substrate support 102.

[0038] The showerhead assembly 103 includes a gas distribution plate 1 10 that introduces and distributes gases via the showerhead faceplate 108. The showerhead assembly 103 further includes a stem portion 1 1 1 including one end connected to a top surface of the processing process chamber 101 . The gas distribution plate 1 10 and the showerhead faceplate 108 are collectively cylindrical-shaped and may be referred to as the showerhead. A substrate-facing surface of the showerhead faceplate 108 includes holes through which process or purge gas flows. In an embodiment, the substrate support 102 may include one or more gas channels 113 for flowing backside gas to a backside of the substrate 109.

[0039] An RF generating system 120 generates and outputs RF voltages to the upper electrode 108 and one or more lower electrodes 1 19 in the substrate support 102. One of the upper electrode 108 and the substrate support 102 may be DC grounded, AC grounded or at a floating potential. For example only, the RF generating system 120 may include one or more RF generators 122 (e.g., a capacitive coupled plasma RF power generator, a bias RF power generator, and / or other RF power generator) that generate RF voltages, which are fed by one or more matching and distribution networks 124 to the upper electrode 108 and / or the substrate support 102. An electrode that receives an RF signal, an RF voltage and / or RF power is referred to as a RF electrode. As an example, a plasma RF generator 123, a bias RF generator 125, a plasma RF matching network 127 and a bias RF matching network 129 are shown. The plasma RF generator 123 may be a high-power RF generator producing, for example, 6-10 kilo-watts (kW) of power or more. The bias RF matching network supplies power to RF electrodes, such as the lower electrodes 119.

[0040] A gas delivery system 130 includes one or more gas sources 132-1 , 132-2,..., and 132-N (collectively gas sources 132), where N is an integer greater than zero. The gas sources 132 supply one or more precursors and gas mixtures thereof. The gas sources 132 may also supply etch gas, carrier gas and / or purge gas. Vaporized precursor may also be used. The gas sources 132 are connected by valves 134-1 , 134-2, ..., and134-N (collectively valves 134) and mass flow controllers 136-1 , 136-2, ..., and 136-N (collectively mass flow controllers 136) to a manifold 140. An output of the manifold 140 is fed to the processing process chamber 101. For example only, the output of the manifold 140 is fed to the showerhead.

[0041] The substrate processing system 100 may also include a power source 144 that provides power, including a high voltage, to clamping electrodes 131 to electrostatically clamp the substrate 109 to the substrate support 102. Clamping electrodes receive power to electrostatically clamp down the substrate 109 to the substrate support 102 and may receive RF signals, RF voltages and / or RF power. The power source 144 may be controlled by the system controller 160.

[0042] The substrate processing system 100 may further include a backside vacuum controller 152. The backside vacuum controller 152 may receive gas from the manifold 140 and supply the gas to channels 1 13 and / or to a pump 158. This improves transfer of thermal energy between the substrate support 102 and the substrate 109. The backside gas may also be provided to improve substrate peripheral edge purging and vacuum tracking of a location of the substrate. The channels 113 may be fed by one or more injection ports. In one embodiment, multiple injection ports are included for improved cooling. As an example, the backside gas may include helium.

[0043] The backside vacuum controller 152 controls flow rate of backside gas (e.g., helium) to the channels 1 13 for cooling the substrate 109 by controlling flow from one or more of the gas sources 132 to the channels 1 13. The backside vacuum controller 152 controls pressure and flow rates of gas supplied to channels 1 13 based on detected parameters from the temperature sensors 143. During a deposition process, the substrate 109 may be heated in presence of high-power plasma. Flow of gas through the gas channels 113 may reduce temperatures of the substrate 109.

[0044] The primary exhaust path (or line) 105 may include a valve 156 and a pump 158. The maintenance exhaust path (or line) 106 may include a valve 157 and a pump 159. The primary exhaust path 105 including the valve 156 and the pump 158 may be used to evacuate reactants from the process chamber 101 prior to, during and / or subsequent to substrate processing. The primary exhaust path 105 may also be used to remove gases from the process chamber 101 during a pump out and purge mode, as further described below.

[0045] The valves and 156, 157 and pumps 158, 159 are provided as examples, other examples are shown in FIGs. 2-4. The pump 158 may be a turbo molecular pump (TMP) or a roughing pump. In an embodiment, the primary exhaust path 105 has a ‘Y’-shaped configuration where gases can be drawn via a TMP and / or a roughing pump. Examples of this configuration are shown in FIGs. 2-4. The pump 159 may be a booster pump that has a lower drawing force than the roughing pump. In an embodiment, the pump 159 is implemented as a second roughing pump. In another embodiment, the pump 159 is not included and gases are drawn from the process chamber 101 via the exhaust path 106 using a facilities vacuum draw line. The pump 159 may have at least one of a lower maximum capacity, a lower maximum flow strength, and a lower maximum power rating than the pump 158.

[0046] The system controller 160 may control components of the substrate processing system 100 including controlling supplied RF power levels, pressures and flow rates of supplied gases, RF matching, etc. The system controller 160 controls states of the valves 156, 157 and the pumps 158, 159.

[0047] The substrate processing system 100 further includes a user interface 170, which may receive inputs from a user. For example, the user interface may receive inputs to operate in a maintenance mode, a wet clean mode, a downstream maintenance exhaust mode, an upstream maintenance exhaust mode, etc. The maintenance mode may refer to a process during which the process chamber 101 is opened to perform maintenance on the process chamber 101 . The wet clean mode may refer to a process during which the interior of the process chamber 101 is cleaned, as further described below. The downstream maintenance exhaust mode refers to when the maintenance exhaust path 106 is used to exhaust gases from within the process chamber 101. The upstream maintenance exhaust mode refers to when an upstream exhaust system, an example of which is shown in FIG. 4, is used to exhaust gases from the process chamber 101 . The inputs may be requests to open and / or close valves and / or to turn on or off pumps. The interface may include a touchscreen display, a keyboard, a keypad, a mouse, etc.

[0048] FIG. 2 shows an example downstream exhaust system 200 of a process chamber 201 . The downstream exhaust system 200 may be implemented as part of the substrate processing system 100 of FIG. 1 . The process chamber 201 is in a closed state with a top plate (or lid) 202 disposed on the process chamber 201 . Although not shown, when the top plate 202 is removed a corresponding showerhead assembly (e.g., theshowerhead assembly 103 of FIG. 1 ) may also be removed. The downstream exhaust system 200 includes a primary exhaust path 203 and a secondary (or maintenance) exhaust path 204. The primary exhaust path 203 is used during normal processing operations of the process chamber. The maintenance exhaust path 204 is used during and dedicated for performing maintenance operations.

[0049] The primary exhaust path 203 has a ‘Y’-shaped configuration and includes: a TMP 210 that draws gases from within the process chamber 201 ; a valve 212; and a conduit 214 that directs gases from the TMP 210 and valve 212 to a main conduit 216. The primary exhaust path 203 further includes: a conduit 217 that receives gases from the process chamber 201 ; a pair of valves 218, 219; and a roughing pump 220. The roughing pump 220 draws gases from the conduit 214 and the conduit 217. The valves 218, 219 control flow of gases from the conduit 217 to the roughing pump 220 via the main conduit 216. The valves 218 and 219 may respectively be referred to as a chamber soft valve and a rough valve. The valves 218, 219 may be closed and the valves 236, 238 may be opened to exhaust gases via the maintenance exhaust path 204. This prevents particles and / or flakes from being received at the roughing pump 220.

[0050] The maintenance exhaust path 204 includes conduits, 230, 232, 234 and one or more valves, such as a first valve 236 and a second valve 238. The second valve 238 may not be included. A pump 240 may also be included. The pump 240 may be a boosting pump or a roughing pump, which is isolated from the primary exhaust path via the valves 236, 238. In an embodiment, the pump 240 is not included and gases are drawn via a blower and scrubber 250 of a facility. The conduit 230 may be connected to the conduit 217, as shown. The valve 238 may be used as a redundant or backup valve to the first valve 236. A conduit 252 may supply gases from the pump 240 to a facilities channel 254, which supplies the gases to the blower and scrubber 250.

[0051] In an embodiment, the maintenance exhaust path 204 is used to draw gases from the process chamber 201 when the primary exhaust path 203 is disabled (i.e., not drawing gases from the process chamber 201 . By using the maintenance exhaust path 204 to draw gases from the process chamber 201 during maintenance operations, service life of components and devices, such as the roughing pump 220, of the primary exhaust path 203 is increased. This prevents deposits removed from the process chamber from being passed through and degrading operation of the roughing pump 220. The passage of deposits at the high draw force of the roughing pump can degradecomponents of the roughing pump over time. This is not the case with a booster pump that has a lower drawing force than a roughing pump. As stated, the pump 240 may be a booster pump. The booster pump 240 is responsible for controlling vacuum by operating in a close-loop with particle sensor 264. A subsystem of the booster pump 240 may trigger an alarm if there is no vacuum available from facility and / or blower and scrubber 250. The booster pump 240 is able to maintain a set vacuum level even when there is low vacuum available from blower and scrubber unit 250.

[0052] Since the pump 240 is dedicated for performing maintenance operations, the pump 240 is minimally used. Maintenance operations may be performed, for example, once every 3-6 months. The dedicated maintenance exhaust path 204 also reduces the potential for deposits and / or flakes removed during cleaning from flowing back into the process chamber 201 , which could occur if the primary exhaust path 203 were used for maintenance operations. The pump 240 may have at least one of a lower maximum capacity, a lower maximum flow strength, and a lower maximum power rating than the roughing pump 220.

[0053] The downstream exhaust system 200 may further include a controller 260, a solenoid bank 262, a fume sensor 263, a particle sensor 264, and a RGA 265, a pressure sensor (or switch) 266, and a vacuum sensor (or switch) 268. The controller 260 may be implemented as the system controller 160 of FIG. 1 . The controller 260 controls the states of the valves 212, 218, 219, 236, 238, an auto vent valve (AVV) 269, and the pumps 210, 220, 240. The controller 260 may control the states of the valves 212, 218, 219, 236, 238, 269 and the pumps 210, 220, 240 based on states of one or more of the sensors 264, 266, 268. The controller 260 may control states of the valves 236, 238, 269 via solenoids of the solenoid bank 262.The fume sensor 264 is external to the chamber 200 and is used to continuously monitor air quality.

[0054] In an embodiment, the AVV 269 is included and opened during a pump out and purge operating mode during which the process chamber 201 is pumped out and purged, as further described below. As an example, the AVV 269 may be opened to draw constituents of air 270, which may include oxygen, from outside the process chamber 201 into the process chamber to react with deposits on surfaces in the process chamber. Concurrently with drawing air 270 into the process chamber, gases within the process chamber 201 may be drawn from the process chamber via the TMP 210 and the roughingpump 220 via conduits 214, 216 with valve 212 open and valves 218, 219 closed. The AVV 269 is connected to the process chamber 201 via a conduit 272.

[0055] Each of the valves 212, 218, 219, 236, 238, 269 may be an electrical valve, a pneumatic valve, or other type of valve. The valves 212, 218, 219, 236, 238, 269 may be controlled via solenoids of the solenoid pack 262 or directly via the controller 260.

[0056] The downstream exhaust system 200 may further includes a chamber switch 274 indicative of whether the process chamber 201 is closed or open. The controller 260 receives a signal from the chamber switch 274 indicative of the closed state of the process chamber 201 . The closed state referring to whether the top plate 202 is on and locked down to the process chamber 201 .

[0057] FIG. 3 shows the downstream exhaust system 200 of FIG. 2 in an open state. The top plate 202 of the process chamber 201 of FIG. 2. has been removed. The downstream exhaust system 200 includes the primary exhaust path 203 and the maintenance exhaust path 204 and may include the pumps 210, 220, 240, valves 212, 218, 219, 236, 238, 269, sensors 263, 264, 265, 266, 268, the controller 260 and the solenoid bank 262. The blower and scrubber 250 may be used to draw gases from the maintenance exhaust path 204.

[0058] FIG. 4 shows an exhaust system 400 that includes the process chamber 200. The exhaust system 400 may be implemented as part of the substrate processing system 100 of FIG. 1 . The exhaust system 400 is configured for both downstream and upstream exhausting of gases. The exhaust system 400 includes both a downstream exhaust system 402 and an upstream exhaust system 404. The downstream exhaust system 402 includes the primary exhaust path 203 and the maintenance exhaust path 204 and may include the pumps 210, 220, 240, valves 212, 218, 219, 236, 238, 269, sensors 263, 264, 265, 266, 268, the controller 260 and the solenoid bank 262. The upstream exhaust system 404 includes a hood 410, a conduit 412, a valve 414, a conduit 416, and the blower and scrubber 250. The upstream exhaust system 404 may be used in addition to the downstream exhaust system 402 when drawing gases from the process chamber 200. This may occur prior to performing a wet cleaning process. The valve 414 may be an electrical valve, a pneumatic valve, or other type of valve.

[0059] FIG. 5 shows a timing diagram illustrating timing for performing a maintenance process including downstream and optionally upstream exhausting of gases from a process chamber (e.g., the process chamber 200 of FIGs. 2-4). The maintenanceprocess may be a wet cleaning process and include a pump out and purge mode, a maintenance exhaust mode, and a wet clean mode. The pump out and purge mode occurs during period 500, the maintenance exhaust mode occurs during period 502 and the wet clean mode occurs during period 504. The maintenance exhaust mode may continue during period 504, as represented by dashed line 508. The maintenance process may further include an auto venting mode during period 506.

[0060] The pump out and purge mode may include circulating one or more gases (e.g., nitrogen) and / or air through the process chamber and drawing gases and the air from the process chamber via, for example, a primary exhaust path (e.g., the primary exhaust path 203 of FIGs. 2-4 using the TMP 210 and the roughing pump 220. The process chamber is closed during the pump out and purge mode. The AVV 269 may be open during at least a portion of this mode.

[0061] The maintenance exhaust mode may include drawing gases and air from the process chamber when the process chamber is open. This may include use of the downstream exhaust system 402 and optionally the upstream exhaust system 404. During this mode, the downstream maintenance exhausting path 204 is opened. This includes opening one or more valves, such as valves 236, 238, and operating pump 240 if included. This may further optionally include opening the valve 414. The AVV 269 may be open during a portion of this mode. The AVV mode includes opening the AVV 269 to draw air into the process chamber. The AVV mode may overlap the pump out and purge mode and the exhausting mode, as shown. The wet clean mode includes a technician wet cleaning surfaces in the process chamber.

[0062] FIG. 6 shows a maintenance method including pump out, purge, and exhausting of gases. The following operations are applicable to the embodiments of FIGs. 1 -5.

[0063] At 600, the controller (e.g., the system controller 160 or controller 260 of FIGs. 1 -2) determines whether maintenance is to be done on the process chamber. For example, the controller may determine whether the interior of a process chamber is to be cleaned. If yes, operation 602 may be performed.

[0064] At 602, the controller determines whether an AVV (e.g., the AVV 269 of FIGs 2- 4) is to be opened during a pump out and purge mode. If yes, operation 604 may be performed, otherwise operation 606 may be performed.

[0065] At 604, the controller operates in the pump out and purge mode including opening the AVV, running the TMP 210, opening valve 212, maintaining the valves 218,219 in a closed state, and running the roughing pump 220. During the mode, the top plate (or lid) 202 of the process chamber 201 remains on the process chamber and is closed. While operating in the pump out and purge mode, gases within the process chamber, which may remain from previously processing one or more substrates are pumped out. During this stage, substances such as HCL and HF may be at least partially removed from the process chamber. In an embodiment and during this stage, one or more purge gases (e.g., nitrogen) may be supplied into the process chamber via the gas delivery system 130 and manifold 140.

[0066] At 606, the controller implements the pump out and purge mode without use of an AVV and / or refrains from opening the AVV. The controller runs the TMP 210, opens valve 212, maintains the valves 218, 219 in a closed state, and runs the roughing pump 220. One or more purge gases are supplied to the process chamber.

[0067] At 608, the controller may determine if the level(s) of certain substances (e.g., levels of HCL and HF) are less than one or more first predetermined thresholds and / or whether an amount of time operating in the pump out and purge mode is greater than a predetermined threshold (e.g., 30 minutes). This may be based on the outputs of one or more of the sensors 263, 264. If yes, operation 610 may be performed, otherwise operation 602 may be performed.

[0068] At 610, the controller may determine whether pressure within the process chamber is at atmospheric pressure. This may be referred to as an interlock condition. This may be based on a signal from sensor 266. If yes, operation 612 may be performed, otherwise operation 602 may be performed. At 610, the process chamber is in a closed state as indicated by the chamber switch 274.

[0069] At 612, the process chamber may be automatically or manually opened and a state of the chamber switch changes from 1 to 0. This may be implemented by and / or permitted by the controller, which may release one or more locks and / or open and move the top plate from a top of the process chamber.

[0070] At 614, the controller may enable a maintenance exhaust mode. The valves 236, 238 are maintained in a closed state. The valve 212 may be closed and the pumps 210 and 220 may be shut off. The valves 218, 219 remain in a closed state.

[0071] At 616, the controller may determine whether a user input has been received to activate the downstream maintenance exhaust mode. The user input may be receivedvia the user interface 170. If yes, operation 618 is performed. In an embodiment, the controller does not wait for a user input and automatically proceeds to operation 618.

[0072] At 618, the controller opens one or more valves of the downstream maintenance exhaust path, such as valves 236, 238, and may run the pump 240. Valves 218, 219 remain in a closed state. In an embodiment, the pump 240 is not included or is simply in an open state but is not running. In another embodiment, the pump 240 is running and is a booster pump. In another embodiment, the pump 240 is running and is a roughing pump. Gases are drawn from the process chamber via the pump 240 and / or via the blower and scrubber 250. In an embodiment, the controller allows the user to manually change states of the valves 236, 238 and the pump 240 such that the user can open and close the valves 236, 238 and turn on and off the pump 240 multiple times during this period.

[0073] At 620, the controller may determine whether a user input has been received to activate the upstream maintenance exhaust mode. This input may be received via the user interface 170. If yes, operation 622 may be performed. In an embodiment, the controller does not wait for a user input and automatically proceeds to operation 622.

[0074] At 622, the controller opens one or more valves of the upstream maintenance exhaust path, such as valve 414. The blower and scrubber 250 draws gases from the process chamber via the hood 410 through the valve 414.

[0075] At 624, the controller may determine if the level(s) of certain substances (e.g., levels of HOL and HF) are less than one or more second predetermined thresholds and / or whether an amount of time operating in the maintenance exhaust mode is greater than a predetermined threshold (e.g., 30 minutes). This may be based on the output of RGA 265. If yes, operation 626 may be performed, otherwise operation 602 may be performed. In an embodiment, the one or more second predetermined thresholds are respectively less than the one or more first predetermined thresholds. In another embodiment, the one or more second predetermined thresholds include a single threshold that is 1 ppb.

[0076] At 626, the controller may generate an indication that the maintenance operations (e.g., wet cleaning operations) on the process chamber may be performed. This indication may be provided to a user via the user interface. The user may then manually clean the interior of the process chamber. The valves 236, 238 are maintained in an open state and the pump 240 may be run during performance of the maintenance operations (e.g., wet cleaning operations) on the process chamber.

[0077] At 628, the controller determines whether an input has been received indicating that the maintenance operations on the process chamber have been completed. This indication may be received via the user interface 170. If yes, operation 630 may be performed.

[0078] At 630, the process chamber is automatically or manually closed. The controller may close the process chamber including returning the top plate to the process chamber and locking down the top plate to the process chamber. This may include receiving a signal from the user interface 170. The state of the chamber switch 274 may change from O to 1.

[0079] At 632, the controller may determine whether the process chamber is closed. This may be based on an output of the chamber switch 274 and be referred to as an interlock condition. If yes, operation 634 may be performed.

[0080] At 634, the controller may close the valves 236, 238, 414 and shuts off the pump 240. The method may end subsequent to operation 634.

[0081] The above-described operations are meant to be illustrative examples. The operations may be performed sequentially, synchronously, simultaneously, continuously, during overlapping time periods or in a different order depending upon the application. Also, any of the operations may not be performed or skipped depending on the implementation and / or sequence of events.

[0082] The examples set forth herein provide a downstream exhaust path dedicated for performing maintenance. The downstream exhaust path may continuously exhaust gases including hazardous gases from the process chamber prior to and during maintenance on an interior of the process chamber. An auto vent valve may be included to reduce pump out and purge time. A RGA sensor is included to provide feedback regarding levels of substances in the process chamber for enhanced reliability in testing air in the process chamber to determine whether it is safe to open and / or perform maintenance on the process chamber.

[0083] The examples disclosed herein: aid in maintaining stringent safe concentration levels below predetermined levels during maintenance; provide effective oxidation of polymer by products on chamber surfaces; enable faster removal of hazardous gases; and allow for uninterrupted wet cleaning using a downstream exhaust system. The time associated with performing wet cleaning the interior of a process chamber is reduced. Also, the need for a user to dedicate one hand for adjusting positioning of a hood of anupstream exhaust system during wet cleaning is eliminated. This results in increased ease and improved efficiency in cleaning the interior of a process chamber. The sensorbased feedback provided herein also enhances operational ease and ensures successful air sampling test compliance when testing air within the process chamber. The examples are scalable for various substrate processing tools.

[0084] The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and / or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with one another remain within the scope of this disclosure.

[0085] Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

[0086] In some implementations, a controller is part of a system, which may be part of the above-described examples. Such systems can include semiconductor processing equipment, including a processing tool or tools, chamber or chambers, a platform or platforms for processing, and / or specific processing components (a wafer pedestal, a gasflow system, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor wafer or substrate. The electronics may be referred to as the “controller,” which may control various components or subparts of the system or systems. The controller, depending on the processing requirements and / or the type of system, may be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, positional and operation settings, wafer transfers into and out of a tool and other transfer tools and / or load locks connected to or interfaced with a specific system.

[0087] Broadly speaking, the controller may be defined as electronics having various integrated circuits, logic, non-transitory memory, and / or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor wafer or to a system. The operational parameters may, in some embodiments, be part of a recipe defined by process engineers to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0088] The controller, in some implementations, may be a part of or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the “cloud” or all or a part of a fab host computer system, which can allow for remote access of the wafer processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to follow a current processing, or to start a new process. In some examples, a remote computer (e.g., a server) can provide process recipes to a system over a network, which mayinclude a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and / or settings, which are then communicated to the system from the remote computer. In some examples, the controller receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control. Thus, as described above, the controller may be distributed, such as by including one or more discrete controllers that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber.

[0089] Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing systems that may be associated or used in the fabrication and / or manufacturing of semiconductor wafers.

[0090] As noted above, depending on the process step or steps to be performed by the tool, the controller might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and / or load ports in a semiconductor manufacturing factory.

Claims

CLAIMSWhat is claimed is:1 . An exhaust system for a process chamber of a substrate processing system, the exhaust system comprising: a primary exhaust path connected to the process chamber and comprising a first one or more valves and a first pump, wherein the first pump is configured to pump gases from the process chamber; a secondary exhaust path connected to at least one of the process chamber and the primary exhaust path, wherein the secondary exhaust path comprises a second one or more valves; and at least one controller configured to open the first one or more valves and run the first pump to pump out and purge the process chamber during a pump out and purge mode and open the second one or more valves to remove gases from the process chamber during a maintenance exhaust mode.

2. The exhaust system of claim 1 , wherein the secondary exhaust path is dedicated for exhaust gases from the process chamber during the maintenance exhaust mode.

3. The exhaust system of claim 2, wherein the secondary exhaust path is in a closed state when the exhaust system is not operating in the maintenance exhaust mode.

4. The exhaust system of claim 1 , wherein the secondary exhaust path comprises a second pump, wherein the second pump is configured to remove gases from the process chamber during the maintenance exhaust mode.

5. The exhaust system of claim 4, wherein the second pump has at least one of a lower maximum capacity, a lower maximum flow strength, and a lower maximum power rating than the first pump.

6. The exhaust system of claim 4, wherein the at least one controller is configured to operate the first pump and the second pump independently.

7. The exhaust system of claim 4, wherein the at least one controller does not run the first pump when the second pump is running and does not run the second pump when the first pump is running.

8. The exhaust system of claim 4, wherein the at least one controller is configured to maintain the second one or more valves in an open state and the second pump in a running state during cleaning of an interior of the process chamber when the process chamber is open.

9. The exhaust system of claim 1 , wherein: the primary exhaust path comprises a first input receiving gases from the process chamber, and a first output supplying gases to a third pump; and the secondary exhaust path comprises a second input receiving gases from the process chamber or a conduit of the primary exhaust path, and a second output supplying gases to a facilities channel, which supplies gases to a blow and scrubber.

10. The exhaust system of claim 9, wherein the third pump is a roughing pump.1 1 . The exhaust system of claim 1 , further comprising: a first sensor configured to detect levels of one or more substances within the process chamber; and a second sensor configured to detect pressure within the process chamber, wherein the at least one controller is configured to change states of the first one or more valves, the first pump, and the second one or more valves based on outputs of the first sensor and the second sensor.

12. The exhaust system of claim 1 , further comprising a fume sensor, which is implemented as part of fab safety monitoring, and remains active during the maintenance exhaust mode as fumes are continuously exhausted by the secondary exhaust path to avoid triggering an alarm, wherein the at least one controller monitors the fume sensor during the maintenance exhaust mode.

13. The exhaust system of claim 1 , wherein the at least one controller is configured to maintain the second one or more valves in a closed state during the pump out and purge mode and close the first one or more valves and stop running the first pump during the maintenance exhaust mode.

14. The exhaust system of claim 1 , further comprising an upstream exhaust system comprising: a hood to draw gases from a top side of the process chamber; and a third one or more valves, wherein the at least one controller is configured to open the third one or more valves to draw gases from the process chamber via the hood during the maintenance exhaust mode.

15. The exhaust system of claim 14, wherein the at least one controller is configured to close the third one or more valves and maintain the second one or more valves in an open state during cleaning of the process chamber when the process chamber is open.

16. The exhaust system of claim 1 , further comprising a vent valve configured to vent air into the process chamber when the process chamber is closed, wherein the at least one controller is configured to open the vent valve for the pump out and purge mode.

17. The exhaust system of claim 16, wherein the at least one controller is configured to close the vent valve for the maintenance exhaust mode.

18. A method of performing maintenance on a process chamber of a substrate processing system, the method comprising: opening a first one or more valves and running a first pump to draw gases from the process chamber via a primary exhaust path during a pump out and purge mode; closing the first one or more valves and ceasing to run the first pump at an end of the pump out and purge mode; at the end of the pump out and purge mode, opening a second one or more valves to draw gases from the process chamber via a secondary exhaust path and during a maintenance exhaust mode; determining whether one or more conditions are satisfied;in response to the one or more conditions being satisfied, permitting opening of the process chamber for maintenance on an interior of the process chamber; and continuing to draw gases from the process chamber via the second one or more valves during the maintenance on the interior of the process chamber.

19. The method of claim 18, further comprising running a second pump during the maintenance exhaust mode.

20. The method of claim 19, further comprising running the second pump during the maintenance on the interior of the process chamber.21 . The method of claim 18, further comprising: determining at least one of whether a level of a substance is less than a predetermined level and an amount of time operating in the pump out and purge mode is greater than a predetermined threshold; and in response to at least one of the level being less than the predetermined level and the amount of time being greater than the predetermined threshold, transitioning from the pump out and purge mode to the maintenance exhaust mode.

22. The method of claim 18, further comprising: determining at least one of whether a level of a substance is less than a predetermined level and an amount of time operating in the maintenance exhaust mode is greater than a predetermined threshold; and in response to at least one of the level being less than the predetermined level and the amount of time being greater than the predetermined threshold, permitting performance of maintenance on the interior of the process chamber.

23. The method of claim 18, further comprising: determining whether pressure in the process chamber is at atmospheric pressure; and in response to the pressure in the process chamber being at atmospheric pressure, enabling the maintenance exhaust mode.

24. The method of claim 23, further comprising in response to the pressure in the process chamber being at atmospheric pressure, closing the first one or more valves and ceasing to run the first pump.

25. The method of claim 23, further comprising opening the second one or more valves based on whether the pressure in the process chamber is at atmospheric pressure.

26. The method of claim 18, further comprising, when the process chamber is closed, opening a vent valve to vent air into the process chamber during the pump out and purge mode.

27. The method of claim 18, further comprising: subsequent to opening the process chamber, receiving an input indicating that maintenance on the interior of the chamber is completed; subsequent to receiving the input, determining whether the process chamber is closed; and in response to the process chamber being closed, ceasing operation in the maintenance exhaust mode including closing the second one or more valves.

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