Cleaning system for removing deposits from a pump of an exhaust device of a substrate processing system

Abstract

An exhaust system for a substrate processing system includes: a radical generator configured to receive a gas mixture including a halogen species and generate halogen radicals; a first pump that draws exhaust gas from an exhaust outlet of a processing chamber; and a first valve configured to selectively fluidly connect the outlet of the radical generator to the first pump downstream of the outlet of the processing chamber.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Patent Application No. 62 / 685,532, filed on June 15, 2018. The entire disclosure of the above-referenced application is incorporated herein by reference. Technical Field

[0003] The present disclosure relates to substrate processing systems, and more particularly to a cleaning system for removing deposits from a pump in an exhaust of a substrate processing system. Background Art

[0004] The background description provided here is for the purpose of generally presenting the context of the present disclosure. No admission is made, either explicitly or implicitly, that the work of the presently designated inventors is prior art to the present disclosure to the extent that it is described in this background section and in aspects of the specification that were not determined to be prior art at the time the application was filed.

[0005] A substrate processing system can be used to perform etching, deposition, and / or other processing on a substrate, such as a semiconductor wafer. Example processes that can be performed on a substrate include, but are not limited to, etching, deposition, and cleaning processes. During processing, the substrate is placed on a substrate support, such as a pedestal, electrostatic chuck (ESC), or the like, in a processing chamber of the substrate processing system. A gas delivery system supplies a gas mixture into the processing chamber to process the substrate. A plasma may be excited to enhance chemical reactions within the processing chamber. An RF bias may also be provided to the substrate support to control ion energy.

[0006] Various types of reactive chemicals are used in processing. Turbomolecular pumps and roughing pumps are used to evacuate these chemicals from the process chamber. Some of these reactive chemicals may deposit on the internal components of the roughing pump. Deposits typically result from chemical reactions within the process chamber, in the gas lines between the process chamber and the pump, or within the pump itself. The accumulation of deposits in the pump can lead to reduced pumping efficiency or even pump seizure.

[0007] Efforts have been made to use reactive chemicals that do not deposit material in the pump. However, if this approach is not possible, pump failures require replacement, which is expensive. Alternatively, the backup pump is periodically replaced while another pump undergoes wet cleaning.

[0008] Another approach to reducing pump failures due to deposit formation involves using multiple pumps to handle different reactive chemistries. In other words, when the first reactive gas is flowing, the exhaust is output to the first pump. When the second reactive gas is flowing, the exhaust is diverted to the second pump. However, this approach increases system cost due to the additional pumps, valves, and piping. It also does not address situations where the first and second reactive gases need to flow simultaneously. Summary of the Invention

[0009] An exhaust system for a substrate processing system includes: a radical generator configured to receive a gas mixture containing a halogen species and generate halogen radicals; a first pump configured to draw exhaust gas from an exhaust outlet of a processing chamber; and a first valve configured to selectively fluidly connect the outlet of the radical generator to an inlet of the first pump downstream of the outlet of the processing chamber.

[0010] In other features, a mixing bowl is positioned upstream of the first pump and downstream of the outlet of the processing chamber, and a first valve is configured to selectively fluidly connect the outlet of the free radical generator to a first inlet of the mixing bowl. A second inlet of the mixing bowl is fluidly connected to the exhaust outlet. A second valve is configured to selectively fluidly connect the outlet of the free radical generator to the second inlet of the mixing bowl.

[0011] In other features, the exhaust system includes a second pump having an inlet fluidly connected to the outlet of the process chamber and an outlet fluidly connected to the inlet of the mixing bowl. The inlet of the first pump is fluidly connected to the outlet of the mixing bowl. The second pump comprises a turbomolecular pump, and the first pump is selected from the group consisting of a roughing pump and a dry pump. The mixing bowl includes a collector. The exhaust system also includes a purge gas source and a second valve configured to selectively fluidly connect the purge gas source to the first pump.

[0012] In other features, a gas detector is fluidly connected to an outlet of the first pump, a second valve is configured to selectively fluidly connect the outlet of the first pump to an inlet of the gas detector, a third pump is connected to the outlet of the gas detector, and a third valve is configured to selectively fluidly connect the outlet of the third pump to an abatement system.

[0013] In other features, a substrate processing system includes: the exhaust system; a processing chamber; a remote plasma source configured to generate a remote plasma and selectively deliver the remote plasma to the processing chamber; and a controller configured to selectively perform a chamber clean using the remote plasma source and a pump clean using the radical generator. The controller is configured to perform the chamber clean during a first time period and to perform the pump clean during a second time period. The second time period at least partially overlaps with the first time period. The second time period sequentially follows the first time period. The first time period sequentially follows the second time period.

[0014] In other features, the controller performs the chamber clean after processing X substrates after a previous chamber clean and performs the pump clean after processing Y substrates after a previous pump clean, where X and Y are integers greater than 1. X is not equal to Y.

[0015] In other features, a controller is configured to communicate with the gas detector and cause the pump cleaning to be performed until a gas concentration of a predetermined gas species is less than a predetermined threshold.

[0016] In other features, the substrate processing system includes: a purge gas source; and a second valve configured to selectively fluidly connect the purge gas source to the first pump. The controller performs chamber cleaning during a first period, performs pump cleaning during a second period, and performs substrate processing during a third period, the controller supplies the purge gas at a first flow rate during at least one of the first period and the second period and supplies the purge gas at a second flow rate during the third period, wherein the second flow rate is higher than the first flow rate.

[0017] A substrate processing tool includes: N process chambers, where N is an integer greater than 1; a radical generator configured to receive a gas mixture containing a halogen substance and generate halogen radicals; N pumps fluidly connected to exhaust outlets of the N process chambers, respectively; and N first valves configured to selectively connect the outlets of the radical generators downstream of the exhaust outlets of the N process chambers and upstream of the N pumps, respectively.

[0018] In other features, the substrate processing tool further includes: a purge gas source; and N second valves that selectively supply purge gas to the N pumps. N gas detectors are configured to sense gas concentrations of at least one gaseous species in exhaust gas at outlets of the N pumps, respectively. A controller is configured to control the N pumps, the N first valves, and the radical generator. The controller performs a chamber clean of one of the N process chambers during a first time period and performs a pump clean of the one of the N process chambers during a second time period. The second time period at least partially overlaps with the first time period. The second time period sequentially follows the first time period. The first time period sequentially follows the second time period.

[0019] In other features, the controller performs the chamber clean after processing X substrates after a previous chamber clean and performs the pump clean after processing Y substrates after a previous pump clean, where X and Y are integers greater than 1. X is not equal to Y.

[0020] In other features, the substrate processing tool further includes a controller configured to control the N pumps, the N first valves, and the radical generator. The controller communicates with one of the N gas detectors and performs pump cleaning until a gas concentration of a predetermined gas species sensed by the one of the N gas detectors is less than a predetermined threshold.

[0021] In other features, the substrate processing tool further includes: a purge gas source; and N second valves configured to selectively fluidly connect the purge gas source to the N pumps, respectively. The controller performs chamber cleaning during a first period, performs pump cleaning during a second period, and performs substrate processing during a third period, the controller supplies the purge gas at a first flow rate during at least one of the first period and the second period and supplies the purge gas at a second flow rate during the third period, wherein the second flow rate is higher than the first flow rate.

[0022] A substrate processing system includes: a processing chamber comprising a gas distribution apparatus and an exhaust outlet; a gas delivery system configured to selectively supply a gas mixture to the processing chamber; a remote plasma source configured to generate a remote plasma gas; a first valve configured to selectively supply the remote plasma gas to the gas distribution apparatus; a pump in fluid communication with the exhaust outlet; and a second valve configured to selectively supply the remote plasma gas downstream of the exhaust outlet and upstream of the pump.

[0023] In other features, a controller is configured to control the first valve, the second valve, the pump, and the remote plasma source. The substrate processing system further includes: a purge gas source; and a third valve configured to selectively supply purge gas to the pump. The controller is configured to control the first valve, the second valve, the third valve, the pump, and the remote plasma source. The controller performs a chamber clean of the processing chamber during a first time period and performs a pump clean of the processing chamber during a second time period. The second time period at least partially overlaps with the first time period. The second time period sequentially follows the first time period. The first time period sequentially follows the second time period.

[0024] In other features, the controller performs the chamber clean after processing X substrates after a previous chamber clean and performs the pump clean after processing Y substrates after a previous pump clean, where X and Y are integers greater than 1. X is not equal to Y.

[0025] In other features, the substrate processing system further comprises a gas detector in fluid communication with an output of the pump. The controller communicates with the gas detector and performs pump cleaning until a gas concentration of a predetermined gas species sensed by the gas detector is less than a predetermined threshold. The substrate processing system further comprises: a purge gas source; and a second valve configured to selectively fluidly connect the purge gas source to the pump, respectively. The controller performs chamber cleaning during a first period, performs pump cleaning during a second period, and performs substrate processing during a third period, and the controller is configured to control the second valve to supply purge gas at a first flow rate during at least one of the first period and the second period and to supply purge gas at a second flow rate during the third period, and the second flow rate is higher than the first flow rate.

[0026] Further scope of applicability of the present disclosure will become apparent from the detailed description, claims and 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

[0027] The present disclosure will be more fully understood from the detailed description and accompanying drawings, in which:

[0028] Figure 1 is a functional block diagram of an example of a substrate processing system according to the present disclosure, the substrate processing system including a cleaning system for a pump located in an exhaust;

[0029] Figure 2 is a flow chart of an example of a method for cleaning a process chamber and a pump in an exhaust device according to the present disclosure;

[0030] Figure 3 is a flow chart of another example of a method for cleaning a process chamber and a pump in an exhaust device according to the present disclosure;

[0031] Figure 4 is a flow chart of an example of a method for cleaning a pump in a discharge device according to the present disclosure;

[0032] Figure 5A and Figure 5B is a functional block diagram of an example of a substrate processing tool including a system for cleaning a process chamber and a pump in an exhaust system according to the present disclosure;

[0033] Figure 6 According to the present disclosure, Figure 5A and 5B A flow chart of an example of a method of discharging a pump in a system;

[0034] Figure 7 According to the present disclosure, Figure 5A and 5B A flow chart of another example of a method of discharging a pump in a system;

[0035] Figure 8A and Figure 8B is a functional block diagram of an example of a substrate processing tool including a system for cleaning a pump in an exhaust system according to the present disclosure;

[0036] Figure 9 According to the present disclosure, Figure 8A and 8B A flowchart of an example of a method of discharging a pump in a system; and

[0037] Figure 10 According to the present disclosure, Figure 8A and 8B A flow chart of an example of another method of discharging a pump in a system.

[0038] Among the drawings, reference numerals may be repeated to identify similar and / or identical elements. DETAILED DESCRIPTION

[0039] A remote plasma source (RPS) can be used to provide free radicals to clean components within a process chamber. In some examples, the free radicals include halogen species. The free radicals often recombine before reaching a pump located in an exhaust line connected to the process chamber's outlet. As a result, remote plasma sources used to clean process chamber components are not very effective at cleaning the pump, and deposits can accumulate over time.

[0040] The cleaning system according to the present disclosure uses a free radical generator to generate free radicals, which are introduced into the exhaust line between the processing chamber and the pump. In some examples, the free radical generator generates free radicals, which are introduced into the exhaust line between the turbomolecular pump and the roughing pump. In some examples, the free radical generator includes a plasma source or a microwave source. In some examples, a gas containing a halogen substance such as fluorine (F), chlorine (Cl), bromine (Br) and / or iodine (I) is supplied to the free radical generator to generate halogen free radicals.

[0041] In some examples, a gas containing a fluorine species is supplied to a free radical generator, which dissociates the gas to produce fluorine and fluorine radicals. The fluorine and fluorine radicals are used to clean the pump in situ without removing the pump. In some examples, the gas containing a fluorine species supplied to the free radical generator comprises nitrogen trifluoride (NF3) or another gas containing a fluorine species, such as molecular fluorine (F2), tetrafluoromethane (CF4), or hexafluoroethane (C2F6).

[0042] A gas detector such as an infrared gas detector, an infrared endpoint detector (IREPD), a residual gas analyzer (RGA), or a Fourier transform infrared spectrometer (FTIR) can be used to monitor the efficiency of pump cleaning using the systems and methods described herein. The gas detector also enables optimization of the cleaning time. In other words, cleaning is performed until the gas concentration of one or more substances drops below one or more predetermined concentrations. In other examples, the cleaning time can be estimated and the gas detector can be omitted.

[0043] Now refer to Figure 1 , an exemplary substrate processing system 120 is shown. Although an example of a process chamber for etching, chemical vapor deposition, or atomic layer deposition (ALD) is shown, which uses a capacitively coupled plasma (CCP) and a remote plasma source for chamber cleaning, the systems and methods described herein can also be used in other types of substrate processing systems. In some examples, the substrate processing system uses a mixed gas containing tungsten hexafluoride (WF6), diborane (B2H6), silane (SiH4), argon (Ar), and molecular hydrogen (H2) to deposit tungsten (W). In some examples, the process gas mixture can further contain ammonia (NH3). Cleaning the pump can prevent accumulation within the pump and / or pump failure.

[0044] exist Figure 1 , a substrate processing system 120 includes a processing chamber 122 that surrounds the other components of the substrate processing system 120 and contains an RF plasma (if used). The substrate processing system 120 includes an upper electrode 124 and a substrate support 126, such as an electrostatic chuck (ESC). During operation, a substrate 128 is disposed on the substrate support 126.

[0045] By way of example only, the upper electrode 124 may include a gas distribution device 129, such as a showerhead, that introduces and distributes the process gas. The gas distribution device 129 may include a stem portion including one end connected to the top surface of the processing chamber. The base portion is generally cylindrical and extends radially outward from the opposite end of the stem portion at a position spaced from the top surface of the processing chamber. The substrate-facing surface or faceplate of the base portion of the showerhead includes a plurality of holes for allowing precursors, reactants, etching gases, inert gases, carrier gases, other process gases, or purge gases to flow therethrough. Alternatively, the upper electrode 124 may include a conductive plate, and the process gas may be introduced in another manner.

[0046] The substrate support 126 includes a base plate 130 that serves as a lower electrode. The base plate 130 supports a heater plate 132, which may correspond to a ceramic multi-zone heater plate. A thermal resistance layer 134 may be disposed between the heater plate 132 and the base plate 130. The base plate 130 may include one or more channels 136 for flowing a coolant through the base plate 130.

[0047] If plasma is used, the RF generation system 140 generates an RF voltage and outputs the RF voltage to one of the upper electrode 124 and the lower electrode (e.g., the substrate 130 of the substrate support 126). The other of the upper electrode 124 and the substrate 130 can be DC grounded, AC grounded, or floating. By way of example only, the RF generation system 140 can include an RF source 142 that generates RF power that is fed to the upper electrode 124 or the substrate 130 by a matching and distribution network 144. In other examples, the plasma can be generated inductively or remotely.

[0048] A gas delivery system 150 includes one or more gas sources 152-1, 152-2, ..., and 152-N (collectively, gas sources 152), where N is an integer greater than zero. The gas sources 152 are connected to a manifold 160 via primary valves 154-1, 154-2, ..., and 154-N (collectively, primary valves 154), MFCs 156-1, 156-2, ..., and 156-N (collectively, MFCs 156), and secondary valves 158-1, 158-2, ..., and 158-N (collectively, secondary valves 158). Although a single gas delivery system 150 is shown, two or more gas delivery systems may be used.

[0049] The temperature controller 163 can be connected to a plurality of thermal control elements (TCEs) 164 disposed in the heating plate 132. The temperature controller 163 can be used to control the plurality of TCEs 164 to control the temperature of the substrate support 126 and the substrate 128. The temperature controller 163 can be in communication with a coolant assembly 166 to control the flow of coolant through the channels 136. For example, the coolant assembly 166 can include a coolant pump, a reservoir, and / or one or more temperature sensors. The temperature controller 163 operates the coolant assembly 166 to selectively flow coolant through the channels 136 to cool the substrate support 126.

[0050] The remote plasma source 165 receives one or more gases, such as a first gas and a second gas, from the gas delivery system 150. For example, the remote plasma source may receive a gas containing a halogen species, such as NF3, and an inert gas, such as argon.

[0051] A valve 170 and a pump 172 (e.g., a turbomolecular pump) can be used to exhaust reactants from the process chamber 122. A mixing bowl 174 receives the output of the turbomolecular pump 172. A pump 176 is connected to the output of the mixing bowl 174. In some cases, the turbomolecular pump 172 is not used, and the mixing bowl 174 receives the output directly from the process chamber 122. In some examples, the pump 176 is a dry pump or a roughing pump.

[0052] A free radical generator 184 is connected to another input of the mixing bowl 174 via a valve 186. The free radical generator 184 receives one or more gases from gas sources 188-1, ..., 188-G (collectively referred to as gas sources 188), where G is an integer greater than zero. In some examples, the gas source 188 can be supplied by the gas delivery system 150 or another gas delivery system. The free radical generator 184 can include a remote plasma source or a microwave. The free radicals generated by the free radical generator 184 are received by the mixing bowl 174 and flow to the inlet of the pump 176. In some examples, the valve 186 is omitted, and a purge gas flows through the free radical generator 184 to prevent backflow into the free radical generator 184 when no free radicals are generated.

[0053] In some examples, mixing bowl 174 is designed to function as a collector 175 to collect process deposits. For example, mixing bowl 174 may include a tube that provides additional volume and surface area to increase deposit formation on the inner surface of mixing bowl 174. As a result, mixing bowl 174 reduces deposit formation in pump 176 and increases the average time between pump cleanings. Free radical generator 184 can then be used to clean deposits from mixing bowl 174. For example, an additional valve 187 and gas line can be used to flow the output of free radical generator 184 to mixing bowl 174.

[0054] Most of the deposits from the mixing bowl 174 are converted to the gas phase and pumped out using pump 176. In some cases, powder, salt, or solid deposits are formed as part of the cleaning process. In some examples, the mixing bowl 174 includes a collector 175 to collect powder, salt, or solid deposits that are formed during the process gas deposition or as a byproduct of the halogen cleaning of the mixing bowl.

[0055] The inlet of gas detector 190 is connected to gas line 177 via valve 192, which is connected to the output of pump 176 to sample the gas output therefrom during cleaning. The output of pump 176 is also directly connected to abatement device 195 via gas line 177. The outlet of gas detector 190 is also selectively connected to gas line 177 connected to abatement device 195 via pump 193 and valve 194. Abatement device 195 is connected to the scrubber / exhaust system.

[0056] The gas detector 190 receives one or more gases from gas sources 196-1, ..., 196-D (collectively referred to as gas sources 196), where D is an integer greater than zero. For example, the gas detector 190 receives a calibration gas such as molecular nitrogen (N2), a process gas (such as tungsten hexafluoride (WF6), nitrogen trifluoride (NF3), or another gas containing a fluorine substance such as molecular fluorine (F2), tetrafluoromethane (CF4), or hexafluoroethane (C2F6)) and / or a purge gas (an inert gas such as argon). The pump 176 can also receive one or more gases from a gas source 197 via a valve 198. In some examples, the gas source 197 supplies a purge gas, such as molecular nitrogen (N2).

[0057] The controller 199 can be used to control the process by controlling the components of the substrate processing system 120. More specifically, the controller 199 communicates with the gas delivery system 150, valves (not all connections are shown for clarity), pumps 172 and 176, and the RF generation system 140 to control the operation of the process. The controller 199 also communicates with the temperature controller 163 to control the temperature of the substrate.

[0058] Now refer to Figure 2 , a method 200 for operating a cleaning system according to the present disclosure is shown. At 210, a substrate count is reset to zero. At 214, the method determines whether a substrate is to be processed. If 214 is true, the processing chamber processes the substrate. At 222, the method increments the substrate count.

[0059] At 226, the method compares the count to a predetermined threshold TH1. If the count is greater than or equal to the predetermined threshold TH1, the method performs a chamber clean using the remote plasma source at 230. At 234, the method performs a pump clean using a radical generator as described above.

[0060] In some examples, chamber cleaning and pump cleaning are performed simultaneously or partially overlapping. In other examples, chamber cleaning and pump cleaning are performed sequentially. In other examples, pump cleaning and chamber cleaning are performed sequentially. In other examples, chamber cleaning and pump cleaning are performed at different intervals and / or at different times.

[0061] Now refer to Figure 3 , shows another method for operating a cleaning system according to the present disclosure. At 310, a first count (Count1) and a second count (Count2) are reset. At 314, the method determines whether to process the substrate. At 318, substrate processing is performed on the substrate. At 322, the substrate counts (Count1 and Count2) are increased. At 324, the method compares the first count with a predetermined threshold (TH2). If the first count (Count1) is greater than or equal to the predetermined threshold TH2, then at 326, the method performs chamber cleaning using a remote plasma source. At 328, the first count is reset.

[0062] The method starts at 324 (if false) or 328 and continues to 340. At 340, the method compares the second count to a predetermined threshold value TH3. If the second count (Count2) is greater than or equal to the predetermined threshold value TH3, the method performs a pump cleaning using the free radical generator and the gas detector. At 344, the second count (Count2) is reset. It will be appreciated that Figure 3 The method in can be used to perform chamber cleaning and pump cleaning at different intervals set by thresholds TH2 and TH3, which can be the same or different.

[0063] Now refer to Figure 4, shows a method 400 for performing chamber cleaning. At 410, the method determines whether cleaning is required. At 414, the method supplies a gas mixture containing a halogen substance to a free radical generator and generates halogen free radicals. At 418, the output of the free radical generator is supplied to a gas line or mixing bowl connected near the inlet of the pump. At 422, the method optionally uses a gas detector to monitor the concentration of one or more gaseous substances flowing out of the outlet of the pump. At 426, the concentration of at least one gaseous substance is determined and compared with a predetermined concentration threshold TH4. If the concentration is less than the predetermined concentration threshold TH4, the cleaning is completed and the method ends. Alternatively, the cleaning can be performed for a predetermined time and the gas detector can be omitted. Otherwise, the method returns to 414.

[0064] The pump is regularly cleaned using free radicals supplied between the process chamber and the pump to remove deposits and extend pump life. This reduces pump failures, thereby increasing tool availability and uptime. The systems and methods described herein address the co-flow of reactive chemicals, which often leads to deposit accumulation in the pump. They also provide additional process input for process development. Using a gas detector to monitor cleaning efficiency or cleaning time is particularly useful in optimizing pump cleaning, considering free radical flow, the power required to dissociate the free radicals, and the time required for cleaning.

[0065] Now refer to Figure 5A and 5B The substrate processing tool 500 includes a plurality of process chambers 510-1, 510-2, ..., and 510-P (collectively referred to as process chambers 510), where P is an integer greater than 1. A plurality of gas sources 520-1, ..., and 520-G (collectively referred to as gas sources 520) supply one or more gases to a radical generator 524 through valves 522-1, ..., and 522-G (collectively referred to as valves 522), respectively.

[0066] The gas output by the radical generator 524 is selectively supplied by valves 530-1, 530-1, ..., and 530-P (collectively referred to as valves 530) to gas lines connecting the outlet of the process chamber to the inlets of pumps 542-1, 542-2, ..., 542-P (collectively referred to as pumps 542). Gas detectors 544-1, 544-2, ..., 544-P (collectively referred to as gas detectors 544) can be arranged to detect the gas composition of the gas mixture flowing from the outlet of the pump 542. The outlet of the pump 542 is connected to the abatement system 550.

[0067] exist Figure 5B , the controller 560 is connected to Figure 5A530 and 538, a gas detector 544 and a free radical generator 524. A controller 560 controls the operation of the pump 542 and the free radical generator 524. The controller 560 also controls the open or closed state of the valves 522, 530 and 538.

[0068] Now refer to Figure 6 , showing Figure 5A and 5B 6. A method 600 is provided for cleaning a pump 542 in an exhaust system of a substrate processing tool 500. At 620, the method determines whether the tool initiates a cleaning process for the pump and / or process chamber. In some examples, the pump cleaning process can be performed during, before, or after cleaning the process chamber, or at other times as previously described.

[0069] When 620 is true, the method continues at 624 and a gas or gas mixture containing a halogen or fluorine species is supplied to the free radical generator. In some examples, the gas mixture contains a gas mixture of nitrogen trifluoride (NF3) and argon (Ar), but other gas mixtures containing a halogen or fluorine species and / or another carrier gas may be used.

[0070] At 628, the method determines whether a valve that selectively provides a fluid connection between the free radical generator and the inlet of one of the plurality of pumps is open. If 628 is false, the method opens the selected valve between the free radical generator and the inlet of the one of the plurality of pumps at 632. The method continues from 628 and 632 to 634. At 634, the method determines whether a predetermined period of time for cleaning the pump has expired. If 634 is true, the valve between the free radical generator and the inlet of the one of the plurality of pumps is closed at 638, and the method returns to 620.

[0071] Now refer to Figure 7 , shows the cleaning Figure 5A Another method 700 is provided for cleaning a pump 542 in an exhaust system of a substrate processing tool 500 in a substrate processing tool 500. At 720, the method determines whether the substrate processing tool 500 initiates a cleaning process for the pump and / or the processing chamber. In some examples, the pump cleaning process can be performed during, before, or after cleaning the processing chamber, or at other times as previously described.

[0072] When 720 is true, the method continues at 724 and provides a gas or gas mixture containing a halogen or fluorine species to the free radical generator. In some examples, the gas mixture includes a gas mixture of nitrogen trifluoride (NF3) and argon (Ar), but other gases containing other halogen or fluorine species and / or another carrier gas may be used. At 728, the flow of the purge gas to the pump is reduced from a first flow rate to a second flow rate, the second flow rate being lower than the first flow rate. The reduced flow rate allows the gas mixture containing the halogen or fluorine species to reside in the pump for a longer time, which can improve the efficiency of the pump cleaning or reduce the time required to clean the selected pump.

[0073] At 732, the method determines whether a valve providing a fluid connection between the free radical generator and the inlet of one of the plurality of pumps is open. If 732 is false, the method opens a selected valve between the free radical generator and the inlet of the one of the plurality of pumps at 736. From 732 and 736, the method continues to 740. At 740, the method determines whether a predetermined period of time for cleaning the pump has expired. If 740 is true, the valve between the free radical generator and the inlet of the pump is closed at 742. At 746, the flow rate of the purge gas to the pump is increased to the first flow rate, and the method returns to 720.

[0074] Now refer to Figure 8A and 8B , a substrate processing system 800 for cleaning a pump in an exhaust system is shown. The substrate processing system 800 includes a gas box 810 that outputs one or more gases to a plasma source 816 and a gas distribution device 818, such as a gas injector or showerhead, of a processing chamber 830. In some examples, the gas box 810 includes T gas sources, which are connected to a manifold via T first valves, T mass flow controllers, and T second valves (where T is an integer greater than 1). The output of the plasma source 816 is selectively connected to the gas distribution device 818 via a valve 820. The output of the plasma source 816 is also selectively supplied to the outlet of the processing chamber 830 via a valve 824.

[0075] Valve 840 is located between the outlet of process chamber 830 and the inlet of pump 852. A purge gas source 844 supplies purge gas to pump 852 through valve 846. The outlet of pump 852 is fluidly connected to an abatement system 860. Figure 8B In the embodiment, the controller 870 controls the pump 852, the valve (in Figure 8A and the operation of the plasma source 816, collectively identified by reference numeral 874 in the accompanying drawings.

[0076] Now refer to Figure 9 , showing Figure 8A and 8B9. A method 900 is provided for cleaning the pump 852 in the exhaust system of the substrate processing system 800. At 910, the method determines whether the tool initiates a cleaning process for the pump and / or the process chamber. In some examples, the pump cleaning process can be performed during, before, or after cleaning the process chamber, or at other times as previously described.

[0077] When 910 is true, the method continues at 914 and a gas or gas mixture containing a fluorine species is supplied to the plasma source. In some examples, the gas mixture contains nitrogen trifluoride (NF3) and argon (Ar), but other halogen or fluorine species and / or another carrier gas may be used.

[0078] At 918, the method determines whether a valve providing a fluid connection between a remote plasma source (RPS) and the outlet of the processing chamber is open. If 918 is false, the method opens a valve between the plasma source and the outlet of the processing chamber at 922. The method continues from 918 and 922 to 928. At 928, the method determines whether a predetermined period for cleaning the pump has expired. If 928 is true, the valve between the plasma source and the outlet of the processing chamber is closed at 932, and the method returns to 910.

[0079] Now refer to Figure 10 , shows the cleaning Figure 8A and 8B Another method 1000 for cleaning a pump 852 in an exhaust system of a substrate processing system 800 in a substrate processing system 800. At 1020, the method determines whether the tool initiates a cleaning process for the pump and / or the processing chamber. In some examples, the cleaning process for the pump can be performed during, before, or after cleaning the processing chamber.

[0080] When 1020 is true, the method continues at 1024 and provides a gas or gas mixture containing a halogen or fluorine species to the plasma. In some examples, the gas mixture includes a gas mixture of nitrogen trifluoride (NF3) and argon (Ar), but other gases containing a fluorine species and / or another carrier gas may be used. At 1028, the flow of the sweep gas to the pump 852 is reduced from a first flow rate to a second flow rate that is lower than the first flow rate. The reduced flow rate allows the gas mixture containing the halogen or fluorine species to reside in the pump 852 for a longer time, which can improve the efficiency of the cleaning or reduce the time required to clean the selected pump.

[0081] At 1032, the method determines whether a valve providing a fluid connection between the plasma source and the outlet of the processing chamber is open. If 1032 is false, the method opens a selected valve between the plasma source and the outlet of the processing chamber at 1036. From 1032 and 1036, the method continues to 1040. At 1040, the method determines whether a predetermined period of time for cleaning the pump has expired. If 1040 is true, the valve between the plasma source and the outlet of the processing chamber is closed at 1042. At 1046, the flow rate of the purge gas to the pump is increased from the second flow rate to the first flow rate, and the method returns to 1020.

[0082] The foregoing description is merely illustrative in nature and is in no way intended to limit the present disclosure, its application or use. The broad teachings of the present disclosure can be implemented in various forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be so limited, because other modifications will become apparent when studying the drawings, description and appended claims. It should be understood that one or more steps in the method can be performed in a different order (or simultaneously) without changing the principles of the present disclosure. In addition, although each embodiment is described above as having certain features, any one or more of those features described with respect to any embodiment of the present disclosure can be implemented in the features of any other embodiment and / or combined with the features of any other embodiment, even if the combination is not explicitly described. In other words, the embodiments described are not mutually exclusive, and the replacement of one or more embodiments with each other remains within the scope of the present disclosure.

[0083] Various terms are used to describe the spatial and functional relationships between elements (e.g., between modules, between circuit elements, between semiconductor layers, etc.), including "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "above," "below," and "disposed." Unless the relationship between a first and a second element is explicitly described as "direct," when such a relationship is described in the above disclosure, the relationship can be a direct relationship, in which there are no other intervening elements between the first and second elements, but can also be an indirect relationship, in which there are one or more intervening elements (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."

[0084] In some implementations, the controller is part of a system that can be part of the examples above. Such a system can include semiconductor processing equipment that includes one or more processing tools, one or more chambers, one or more platforms for processing, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems can be integrated with electronic devices for controlling their operation before, during, and after processing of semiconductor wafers or substrates. The electronic device can be referred to as a "controller" that can control various components or subcomponents of one or more systems. Depending on the processing requirements and / or system type, the controller can be programmed to control any process disclosed herein, including the delivery of process 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, position and operation settings, wafer transfer in and out tools and other transfer tools and / or load locks connected to or interfaced with a specific system.

[0085] In general, a controller can be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits can include chips in the form of firmware that stores 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). The program instructions can be instructions sent to the controller in the form of various separate settings (or program files) that define operating parameters for performing a particular process on or for a semiconductor wafer or system. In some embodiments, the operating parameters can be part of a recipe defined by a process engineer to complete one or more processing steps during the manufacture of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or the die of the wafer.

[0086] In some implementations, the controller can be 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 can be in the "cloud" or all or part of a wafer fab host system that can allow remote access to wafer processing. The computer can enable remote access to the system to monitor the current progress of manufacturing operations, review the history of past manufacturing operations, review trends or performance metrics for multiple manufacturing operations, change parameters of the current process, set processing steps to follow the current process, or start a new process. In some examples, a remote computer (e.g., a server) can provide process recipes to the system via a network (which can include a local network or the Internet). The remote computer can include a user interface that enables the input or programming of parameters and / or settings, which are then sent from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specify parameters for each processing step to be performed during one or more operations. It should be understood that the parameters can be specific to the type of process to be performed and the type of tool the controller is configured to interface with or control. Thus, as described above, the controller can be distributed, for example, by including one or more discrete controllers networked together and working toward a common purpose (e.g., process and control as described herein). An example of a distributed controller for such a purpose is one or more integrated circuits on a chamber communicating with one or more integrated circuits remotely (e.g., at a platform level or as part of a remote computer), which combine to control the process on the chamber.

[0087] Example systems may include, but are not limited to, plasma etch chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel edge etch chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etch (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and any other semiconductor processing system that may be associated with or used in the manufacture and / or preparation of semiconductor wafers.

[0088] As described above, depending on one or more processing steps to be performed by the tool, the controller can communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the factory, a host computer, another controller, or tools used in the material transport of wafer containers to and from tool locations and / or load ports in a semiconductor manufacturing facility.

Claims

1. An exhaust system for a substrate processing system, comprising: a free radical generator configured to receive a gas mixture containing a halogen species and generate halogen free radicals; a first pump for pumping exhaust gas from an exhaust outlet of the processing chamber; a first valve configured to selectively fluidly connect an outlet of the free radical generator to an inlet of the first pump downstream of the outlet of the process chamber; as well as a mixing bowl arranged upstream of the first pump and downstream of the outlet of the treatment chamber, Wherein, the first valve is configured to selectively fluidly connect the outlet of the free radical generator to the first inlet of the mixing bowl.

2. The exhaust system according to claim 1, wherein: The second inlet of the mixing bowl is fluidly connected to the discharge outlet. 3 . The exhaust system of claim 2 , further comprising a second valve configured to selectively fluidly connect the outlet of the free radical generator to the second inlet of the mixing bowl.

4. The exhaust system according to claim 1, further comprising: a second pump having an inlet fluidly connected to the outlet of the processing chamber and an outlet fluidly connected to the inlet of the mixing bowl, wherein the inlet of the first pump is fluidly connected to the outlet of the mixing bowl.

5. The exhaust system according to claim 4, wherein: The second pump comprises a turbomolecular pump, and the first pump is selected from the group consisting of a rough pump and a dry pump.

6. The exhaust system according to claim 1, wherein: The mixing bowl includes a collector.

7. The exhaust system according to claim 4, further comprising: Purge gas source; and A second valve is configured to selectively fluidly connect the purge gas source to the first pump.

8. The exhaust system of claim 1, further comprising a gas detector fluidly connected to an outlet of the first pump. 9 . The exhaust system of claim 8 , further comprising a controller configured to communicate with the gas detector and cause the pump cleaning to be performed until a gas concentration of a predetermined gas species is less than a predetermined threshold.

10. The exhaust system of claim 4, further comprising: Gas detectors; a second valve configured to selectively fluidly connect the outlet of the first pump to an inlet of the gas detector; a third pump connected to an outlet of the gas detector; as well as A third valve is configured to selectively fluidly connect an outlet of the third pump to an abatement system.

11. A substrate processing system comprising: The exhaust system according to claim 1; processing room; a remote plasma source configured to generate a remote plasma and selectively deliver the remote plasma to the processing chamber; as well as A controller is configured to selectively perform a chamber clean using the remote plasma source and a pump clean using the radical generator.

12. The substrate processing system according to claim 11, wherein: The controller is configured to perform the chamber cleaning during a first period and to perform the pump cleaning during a second period.

13. The substrate processing system according to claim 12, wherein: The second time period at least partially overlaps with the first time period.

14. The substrate processing system according to claim 12, wherein: The second time period follows the first time period in sequence.

15. The substrate processing system according to claim 12, wherein: The first time period sequentially follows the second time period.

16. The substrate processing system according to claim 11, wherein: The controller performs the chamber clean after processing X substrates after a previous chamber clean and performs the pump clean after processing Y substrates after a previous pump clean, where X and Y are integers greater than one.

17. The substrate processing system according to claim 16, wherein: X does not equal Y.

18. The substrate processing system according to claim 11, further comprising: Purge gas source; and a second valve configured to selectively fluidly connect the purge gas source to the first pump, wherein the controller performs chamber cleaning during a first period, performs pump cleaning during a second period, and performs substrate processing during a third period, wherein the controller supplies the purge gas at a first flow rate during at least one of the first period and the second period and supplies the purge gas at a second flow rate during the third period, and The second flow rate is higher than the first flow rate.

19. A substrate processing tool comprising: N processing chambers, where N is an integer greater than 1; a free radical generator configured to receive a gas mixture containing a halogen species and generate halogen free radicals; N pumps fluidly connected to the exhaust outlets of the N process chambers, respectively; N first valves configured to selectively connect the outlet of the free radical generator downstream of the exhaust outlets of the N process chambers and upstream of the N pumps, respectively; Purge gas source; N second valves configured to selectively fluidly connect the sweep gas source to the N pumps, respectively, and a controller configured to control the N pumps, the N first valves, and the free radical generator, wherein the controller performs chamber cleaning of one of the N process chambers during a first period, performs pump cleaning for the one of the N process chambers during a second period, and performs substrate processing during a third period, wherein the controller supplies the purge gas at a first flow rate during at least one of the first period and the second period and supplies the purge gas at a second flow rate during the third period, and The second flow rate is higher than the first flow rate.

20. The substrate processing tool of claim 19, further comprising: N second valves selectively supply purge gas to the N pumps, respectively.

21. The substrate processing tool of claim 20, further comprising N gas detectors configured to respectively sense gas concentrations of at least one gaseous species in exhaust gas at outlets of the N pumps.

22. The substrate processing tool of claim 19, wherein: The second time period at least partially overlaps with the first time period.

23. The substrate processing tool of claim 19, wherein: The second time period follows the first time period in sequence.

24. The substrate processing tool of claim 19, wherein: The first time period sequentially follows the second time period.

25. The substrate processing tool of claim 19, wherein: The controller performs the chamber clean after processing X substrates after a previous chamber clean and performs the pump clean after processing Y substrates after a previous pump clean, where X and Y are integers greater than one.

26. The substrate processing tool of claim 25, wherein: X does not equal Y.

27. A substrate processing system comprising: a processing chamber including a gas distribution apparatus and an exhaust outlet; a gas delivery system configured to selectively supply a gas mixture to the processing chamber; a remote plasma source configured to generate a remote plasma gas; a first valve configured to selectively supply the remote plasma gas to the gas distribution apparatus; a pump in fluid communication with the discharge outlet; a second valve configured to selectively supply the remote plasma gas downstream of the exhaust outlet and upstream of the pump; and Purge gas source; a third valve configured to selectively supply purge gas to the pump; as well as a controller configured to control the first valve, the second valve, the pump, and the remote plasma source, wherein the controller performs chamber cleaning of the process chamber during a first period, performs pump cleaning for the process chamber during a second period, and performs substrate processing during a third period, wherein the controller is configured to control the second valve to supply the purge gas at a first flow rate during at least one of the first period and the second period and to supply the purge gas at a second flow rate during the third period, and The second flow rate is higher than the first flow rate.

28. The substrate processing system according to claim 27, wherein: The second time period at least partially overlaps with the first time period.

29. The substrate processing system according to claim 27, wherein: The second time period follows the first time period in sequence.

30. The substrate processing system according to claim 27, wherein The first time period sequentially follows the second time period.

31. The substrate processing system according to claim 27, wherein: The controller performs the chamber clean after processing X substrates after a previous chamber clean and performs the pump clean after processing Y substrates after a previous pump clean, where X and Y are integers greater than one.

32. The substrate processing system according to claim 31, wherein X does not equal Y.

33. The substrate processing system of claim 27, further comprising: a gas detector in fluid communication with an output of the pump, The controller communicates with the gas detector and performs pump cleaning until a gas concentration of a predetermined gas species sensed by the gas detector is less than a predetermined threshold.

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