Systems and techniques for semiconductor processing and foreline cleaning

Abstract

A semiconductor processing system is provided. The system may have: a processing chamber defining an interior volume; a foreline in fluid connection with the internal volume and configured to receive process gas from the internal volume, the foreline having a foreline network and a foreline outlet conduit downstream of the foreline network; a throttle valve within the foreline outlet conduit, including a movable gate having an orifice, and configured to control gas flow through the foreline; and a gas injector in the foreline network and configured to direct a buffer gas into a conduit of the foreline network. The system may have a remote plasma source interface fluidly connected to the foreline outlet conduit, downstream of the interior volume, and having a plasma channel configured to direct a remote plasma flow into the foreline outlet conduit.

Description

[0001] Incorporated by Reference The specification of the present application is hereby incorporated by reference in its entirety. Each of the applications identified in the concurrently filed Application Data Sheet as having a claim to priority or benefit under 35 U.S.C. § 119(e) is hereby incorporated by reference in its entirety and for all purposes. BACKGROUND

[0002] The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently designated inventors, to the extent the work is described in this background section, as well as aspects of the description that can not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

[0003] Chemical deposition systems can be used to deposit films on substrates, such as semiconductor wafers and the like. Examples of chemical deposition systems can include plasma enhanced chemical vapor deposition (PECVD) systems, chemical vapor deposition (CVD) systems, and atomic layer deposition (ALD) systems. Such systems can include one or more showerheads positioned within a processing chamber having a substrate processing region. The substrate processing region can be defined between a bottom side of the showerhead and a wafer support (i.e., susceptor, substrate support, etc.) that can be positioned beneath the respective showerhead and configured to support a substrate within the substrate processing region. The bottom side of the showerhead can include ports facing the wafer support that are configured to provide one or more precursor gases to facilitate deposition of a material layer onto the substrate. The chemical deposition system can also include a foreline having various conduits, including a foreline network and a common foreline outlet conduit that is fluidly coupled to the processing chamber to evacuate process gases and materials from the processing chamber. SUMMARY

[0004] The details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims. The following non-limiting implementations are considered part of this disclosure; other implementations will become readily apparent to those of ordinary skill in the art following the

[0005] In some implementations, a semiconductor processing system can be provided. The system can have a processing chamber defining an interior volume, a foreline fluidly coupled to the interior volume and configured to receive process gases from the interior volume, the foreline having a foreline network and a foreline outlet conduit downstream of the foreline network, a throttle valve within the foreline outlet conduit including a movable gate having an orifice and configured to control gas flow through the foreline, and a gas injector in the foreline network and configured to direct a buffer gas into a conduit of the foreline network.

[0006] In some embodiments, the gas injector can have an outlet located at a center of the conduit.

[0007] In some embodiments, the gas injector can have an outlet having a circular cross-sectional area.

[0008] In some embodiments, the conduit can have an internal bore diameter between about two times and about six times a diameter of the outlet.

[0009] In some embodiments, the gas injector can have an outlet having a pneumatic exhaust muffler.

[0010] In any of the above embodiments, the foreline network can have a first section spanning between a first exhaust port of the processing chamber and a junction, a second section spanning between a second exhaust port of the processing chamber and the junction, and a third section spanning and fluidically interposed between the junction and the foreline, and the conduit can be a portion of the third section, such that the gas injector is disposed along the third section and configured to direct the buffer gas into the third section.

[0011] In any of the above embodiments, the system can further include a trap included within the foreline outlet conduit and downstream of the movable gate, and gas flowing through the foreline is configured to contact the trap.

[0012] In some such embodiments, the trap can include an accumulation surface configured to be impacted by the gas flowing through the foreline.

[0013] In some such embodiments, when the throttle valve is in a closed position, gas can be configured to flow through the orifice and into the trap.

[0014] In some such embodiments, the trap can further have an inlet configured to receive the gas and a plurality of outlets.

[0015] In any of the above embodiments, the throttle valve can be a swing valve.

[0016] In any of the above embodiments, a surface of the movable gate can have aluminum.

[0017] In some embodiments, the movable gate includes stainless steel and an aluminum coating.

[0018] In any of the foregoing embodiments, the system can further include a remote plasma source interface (RPS interface) fluidically connected with the foreline outlet conduit, downstream of the interior volume and having a plasma passage configured to direct a flow of remote plasma into the foreline outlet conduit.

[0019] In some such embodiments, the RPS interface can be fluidically interposed between the foreline network and the throttle valve.

[0020] In some such embodiments, the plasma passage can be configured to direct a flow of plasma along a direction having a component parallel to a central axis of the foreline outlet conduit.

[0021] In some such embodiments, the plasma passage can be configured to direct a flow of plasma along a direction between 30 degrees and 60 degrees relative to the central axis of the foreline outlet conduit.

[0022] In some such embodiments, the plasma passage can be configured to direct a flow of plasma along a direction having a component perpendicular to a central axis of the foreline outlet conduit.

[0023] In some such embodiments, the RPS interface can further have a nozzle that defines the plasma passage and extends into an interior of the foreline outlet conduit.

[0024] In some such embodiments, the plasma passage can have a first end portion and a second end portion configured to direct a flow of plasma into the foreline outlet conduit, the first end portion can have a first diameter, and the second end portion can have a second diameter smaller than the first diameter.

[0025] In some such embodiments, the RPS interface can further have a nozzle that defines the plasma passage and has one or more internal coolant channels configured to flow a coolant.

[0026] In some such embodiments, the RPS interface can further have a nozzle that defines the plasma passage and one or more heat sinks thermally coupled to an exterior surface of the nozzle and each having one or more coolant channels configured to flow a coolant.

[0027] In any of the above embodiments, the system can also have: a buffer gas source fluidly connected to the gas injector; and one or more controllers having one or more processors and one or more memories storing instructions for controlling the system, the instructions configured to cause the one or more processors to cause a flow of buffer gas through the gas injector and into the frontline network during one or more processing operations.

[0028] In some such embodiments, the system can also have a pressure sensor configured to detect a pressure upstream of the gas injector, and the instructions can also be configured to cause the one or more processors to cause: one controller to receive a signal from the pressure sensor, and the buffer gas to flow through the gas injector based on the detected pressure, and thereby maintain a portion of the frontline network within a pressure range.

[0029] In some such embodiments, one of the controllers is an upstream pressure controller.

[0030] In some such embodiments, the buffer gas can be caused to flow to maintain the portion of the frontline network within the pressure range using proportional-integral-derivative (PID) control.

[0031] In some such embodiments, the pressure sensor can be configured to measure a pressure in the internal volume.

[0032] In some such embodiments, the pressure range can be from about 7 Torr to about 11 Torr, from about 14 Torr to about 18 Torr, or from about 16 Torr to about 20 Torr.

[0033] In some such embodiments, the instructions can also be configured to cause the one or more processors to cause the throttle valve to be in a closed position while the buffer gas is flowing through the gas injector.

[0034] In some such embodiments, the one or more processing operations can be depositing one or more materials on a substrate.

[0035] In some such embodiments, the instructions can also be configured to cause the one or more processors to cause the throttle valve to control a pressure within the internal volume during one or more other operations other than the one or more processing operations.

[0036] In some such embodiments, one other operation can be a cleaning operation.

[0037] In some such embodiments, the system may further include: a remote plasma source (RPS) configured to generate remote plasma; and a remote plasma source interface (RPS interface) fluidly connected to the foreline and the RPS, downstream of the internal volume and having a plasma channel configured to guide the remote plasma from the RPS into the foreline outlet conduit, wherein the instructions may further be configured to cause the one or more processors to cause: the RPS to generate the remote plasma, and the remote plasma to flow into the foreline outlet conduit during a cleaning operation.

[0038] In some such implementations, the instructions may also be configured to cause the one or more processors to prevent the buffer gas from flowing through the gas injector during the cleaning operation.

[0039] In some embodiments, a method may be provided. This method may include: depositing one or more materials onto a substrate in a processing chamber, wherein the processing chamber defines an internal volume and is fluidly connected to a foreline, and wherein the foreline has a foreline network fluidly connected to the internal volume and is configured to receive process gas from the internal volume; maintaining a throttle valve in a closed position during the deposition, wherein the throttle valve includes a movable gate with an orifice located in a foreline outlet conduit of the foreline and is configured to control gas flow through the foreline, and wherein the foreline outlet conduit is downstream of the foreline network and fluidly connected to the foreline network and is configured to be fluidly connected to an exhaust system; and during the deposition, allowing buffer gas to flow through a gas injector into a conduit of the foreline network.

[0040] In some implementations, the buffer gas flow may include maintaining the pressure within a pressure range in a portion of the upstream pipeline network.

[0041] In some implementations, the flow of the buffer gas may include controlling the pressure within the internal volume.

[0042] In some embodiments, the method may further include detecting pressure upstream of the gas injector, wherein the flow of the buffer gas is based at least in part on the detected pressure.

[0043] In some such implementations, detecting the pressure may include detecting the pressure within the internal volume of the processing chamber.

[0044] In some embodiments, the method can further include performing one or more other operations other than the depositing, and the one or more other operations are performed while the throttle valve is not in the closed position and the buffer gas is not flowing into the conduit.

[0045] In some such embodiments, flowing the buffer gas can include maintaining a pressure within a portion of the precursor line network within a pressure range, and during the one or more other operations, the precursor line can be at a second pressure range that is less than the pressure range.

[0046] In some such embodiments, one other operation can be a cleaning operation. In some further such embodiments, the method can further include, during the cleaning operation, flowing a remote plasma from a remote plasma source (RPS) to a remote plasma source interface (RPS interface), the RPS interface being fluidly connected with the precursor line outlet conduit and the RPS, downstream of the internal volume and having a plasma passage configured to direct the remote plasma from the RPS into the precursor line outlet conduit.

[0047] Additional aspects will be set forth in the detailed description which follows, and in part will be apparent from the disclosure, or can be learned by the practice of the disclosed embodiments and / or claims thereof.

[0048] The foregoing general description and the following detailed description are explanatory and are intended to provide further explanation of the claimed subject matter. BRIEF DESCRIPTION OF DRAWINGS

[0049] The various embodiments disclosed herein are illustrated in the figures of the accompanying drawings, which are presented for the purpose of example and not limitation, wherein like reference numerals refer to like elements in the various figures.

[0050] FIG. 1A depicts a semiconductor processing system, according to various implementations.

[0051] FIG. 1B depicts an enlarged cross-section of a portion of the system of FIG. 1A.

[0052] FIG. 1C depicts the semiconductor processing system 100 of FIG. 1A, according to various implementations.

[0053] FIG. 2 depicts an enlarged cross-sectional view of an example portion of the semiconductor processing system of FIG. 1C taken from region 1.

[0054] FIG. 3 depicts an enlarged cross-sectional view of region 1 of the semiconductor processing system of FIG. 1C.

[0055] Figure 4 depicts an enlarged cross-sectional view of an exemplary portion of the semiconductor processing system of Figure 1C, taken from region 2.

[0056] Figure 5 depicts an enlarged view of the swing valve of Figure 4.

[0057] Figure 6 depicts an enlarged view of the swing valve of Figure 5.

[0058] Figure 7A depicts a schematic view of another exemplary semiconductor processing system in one configuration.

[0059] Figure 7B depicts the exemplary semiconductor processing system of Figure 7A in a second configuration.

[0060] Figure 8A depicts a simplified enlarged schematic view of the system of Figure 7A.

[0061] Figure 8B depicts a simplified enlarged schematic view of the system of Figure 7B.

[0062] Figure 9 depicts a cross-sectional view of an exemplary front end line anti- contamination assembly of the front end line of Figure 1C, taken along the longitudinal axis of the trap.

[0063] Figure 10 depicts another implementation of the trap of Figure 9.

[0064] Figure 11 depicts another implementation of the trap of Figure 9.

[0065] Figure 12 depicts a bottom perspective view of the faceplate of Figure 11.

[0066] Figure 13 depicts a side view of another implementation of the front end line anti- contamination assembly of Figure 9.

[0067] Figure 14 depicts a perspective end view of the trap of Figure 13.

[0068] Figure 15 depicts an enlarged cross-sectional view of region 1 of the semiconductor processing system of Figure 1C.

[0069] Figure 16 depicts a cross-sectional side view of a portion of a front end line with a gas injector.

[0070] Figure 17 depicts a cross-sectional side view of a portion of a front end line with another gas injector.

[0071] Figure 18 depicts an exemplary technique in accordance with various embodiments.

[0072] Figure 19 depicts a cross-sectional view of a process tool in accordance with some implementations.

[0073] Figure 20 depicts a cross-sectional view of a vacuum pump system in accordance with some implementations.

[0074] Figure 21 depicts a plan view of a front end line network in accordance with some implementations.

[0075] Figure 22 depicts a cross-sectional view of a process tool system.

[0076] Figure 23 depicts a cross-sectional view of the process tool system of Figure 22 undergoing a deposition operation.

[0077] Figure 24 depicts a cross-sectional view of the process tool system of Figure 22 undergoing a cleaning operation.

[0078] Figure 25 depicts a flowchart of a technique for performing a deposition operation in a vacuum processing chamber, according to some implementations.

[0079] Figure 26 depicts a flowchart of a technique for performing a cleaning operation in a vacuum processing chamber, according to some implementations. DETAILED DESCRIPTION

[0080] Semiconductor processing tools have one or more processing chambers in which various processing operations are performed, such as deposition, etching, or both deposition and etching. Some processing chambers can be considered single-chamber, such that they have a single station in which only one substrate is processed at a time. Other processing chambers can be considered multi-station chambers, such that they have two or more stations in which two or more substrates can be processed simultaneously. This can include two, three, four, five, six, or eight stations in a single chamber. During processing operations in the processing chamber, deposition precursors, reactants, gases, contaminants, particles, byproducts, and the like flow through the processing chamber and can be exhausted from the processing chamber to an exhaust system via a foreline. The foreline can have multiple conduits or branches that are configured to flow gases from multiple exhaust ports of the processing chamber to a single outlet of the foreline. The multiple conduits or branches can be referred to as a foreline network, and the single outlet of the foreline can be referred to as a common foreline outlet conduit. The various foreline conduits in the foreline network can be connected to one another until they reach the single common foreline outlet conduit that is fluidly connected to the exhaust system.

[0081] Many tools use adjustable valves downstream of the processing chamber as part of the foreline to assist in regulating the chamber pressure to a working level as process gas effluent leaks into the vacuum pump system. In some cases, the adjustable valve can be slightly opened to create a small orifice through which the effluent gas flows into the foreline. The small valve opening can act as a flow restriction, allowing a working pressure to exist in the chamber upstream of the adjustable valve, while allowing the gas to exit the chamber and flow into the large diameter conduit presented by the foreline downstream of the valve. As used herein, such adjustable valves can be referred to as throttling valves.

[0082] Unwanted deposition of these particles and byproducts often occurs within the foreline as the precursors, reactants, gases, contaminants, particles, byproducts, and so on exit the process chamber and flow through the foreline network. This can include unwanted deposition on the conduits in the foreline as well as on the flow control elements, such as control valves. In some cases, the geometry of the foreline and its components can further contribute to such deposition. For example, based on the particular conditions associated with each of the focus regions, material can be deposited at different respective rates in the multiple focus regions of the foreline. These conditions can include the foreline geometry of that focus region (e.g., structures that can change the direction of process gas flow and / or converge two or more gas streams into a common passage), the distance between the process chamber and the focus region, and so on. In another example where a control valve is located in the foreline, the geometry of the valve and the region around the valve can cause material to accumulate at a much higher rate near the valve than in other sections of the foreline. Gas flowing through a small opening in an adjustable valve can suddenly expand into the foreline, rapidly decreasing in temperature due to adiabatic or near-adiabatic expansion (Joule-Thomson effect). The sudden temperature drop can cause unused deposition precursors in the effluent gas to condense on the interior walls of the foreline and other components of the vacuum pump system. This unwanted deposition can have a number of undesirable effects, such as clogging conduits, clogging flow control elements, preventing them from functioning properly or at all, and adversely affecting the flow and pressure within the foreline and process chamber.

[0083] Many techniques to remove unwanted deposits in the foreline do not adequately remove the deposits. For example, some semiconductor processing tools perform cleaning operations that flow plasma through the process chamber and into the foreline. These cleaning operations can clean the process chamber and components or features in the foreline, but such operations can not effectively clean the foreline and can adversely affect the process chamber. For example, the efficacy of plasma to remove material in the foreline can be based on the plasma flow rate (volume or mass units / unit time), the duration of the plasma flow, the amount of free radicals in the plasma that have recombined before reaching the material in the focus regions of the foreline, and so on. Since the rate of material deposition in certain regions of the foreline can be higher than in other regions, adequately cleaning these regions can use a higher flow rate and / or a longer duration of plasma flow from the chamber than would be needed to clean just the chamber. These flow conditions can unnecessarily expose the chamber surfaces to plasma for too long or too strongly, which can damage them. Alternatively, these focus regions can not be fully cleaned during each cleaning cycle and can develop clogs or other defects due to the material that builds up over time.

[0084] Provided herein are new techniques for reducing and removing deposits in a foreline. Some implementations have a foreline flow control valve that uses a gate with an orifice (e.g., a through hole) that provides a flow path through the valve that has few obstructions and causes less deposition compared to flow around the exterior of the valve. In some cases, when the valve with the orifice is in a closed position, the valve acts as a flow restrictor that creates back pressure in the foreline. The back pressure can gradually reduce the pressure of the gas, which can prevent sudden expansion of the gas and thereby prevent or reduce unwanted condensation and deposition of material in the foreline. Some implementations can also have a trap downstream of the foreline flow control valve that is configured to provide an accumulation surface for unwanted deposits. The accumulation surface is located within the foreline so that gas in the foreline flows onto the accumulation surface and deposits there instead of in other areas of the foreline. The trap can be more easily cleaned and / or replaced.

[0085] In some implementations, a ballast gas flows into the foreline network to provide flow conditions in the foreline network that reduce and prevent unwanted deposition. The ballast gas can be injected using a gas diffuser or a gas muffler, both of which can reduce unwanted shearing and turbulent gas flow that causes material deposition. Some implementations also provide favorable pressure control inside the processing chamber by at least partially using the ballast gas flow into the foreline. The ballast gas flow into the foreline can also create back pressure, or increase the pressure in the foreline, which can control the pressure inside the processing chamber and allow the processing chamber pressure to be maintained within a desired pressure range.

[0086] FIG. 1A depicts a semiconductor processing system, according to various implementations. The semiconductor processing system 100 can be a chemical deposition system, a chemical vapor deposition (CVD) system, a plasma-enhanced chemical vapor deposition (PECVD) system, an atomic layer deposition (ALD) system, an etching system, an atomic layer etching (ALE) system, or a system configured to perform both deposition and etching. The system 100 has a processing chamber 106 with an interior volume 108 and one or more exhaust ports 109. The system 100 also includes two processing stations 119a and 119b, each having one or more wafer supports 110 located within the interior volume 108 and configured to support a respective substrate 112 during one or more semiconductor processing operations (e.g., a deposition process, a preparation process, a thermal treatment process, etc.) performed in the interior volume 108. In this implementation, the semiconductor processing system 100 also includes one or more showerheads 114 (e.g., a recessed inlay showerhead, a chandelier showerhead, etc.) located above the wafer supports 110; and the showerheads 114 can be used to flow one or more process gases toward the substrates 112 during the processing operations.

[0087] The system 100 also includes a foreline 102 configured to receive process gas and material from the exhaust ports 109 of the processing chambers 106. The foreline 102 has a foreline network 103 having a plurality of conduits fluidly connected to a single common outlet conduit, i.e., the foreline outlet conduit 105. As shown, the foreline network 103 has a first section 196a circumscribed by a dashed line figure that defines a flow path from one exhaust port 109 to a junction 111 of two or more sections. The first section has a first non-linear segment 197b and a linear segment 197a. The foreline network 103 has a second section 196b that defines a flow path from another exhaust port 109 to the junction 111. The second section 196b has a first non-linear segment 197d and a linear segment 197c. Gas flow from the processing chambers enters the foreline 102 in the exhaust ports and flows through the interior 118 of the foreline 102 to the common outlet 105 and to the exhaust system 122 as shown by the arrows.

[0088] The foreline 102 includes a foreline wall that defines an interior 118 that is fluidly connected to the interior volume 108 of the processing chambers 106. In this implementation, the foreline 102 is made of stainless steel and / or aluminum alloy components; the interior of the foreline 102 can also have an aluminum or aluminum alloy (allow) coating that can prevent or reduce undesirable deposition. The foreline 102 also includes an exhaust interface 120 configured to be fluidly connected to an exhaust system 122 (e.g., a vacuum device, a pump device, etc.). The interior 118 provides a conduit configured to flow one or more process gases from the interior volume 108 of the processing chambers 106 to the exhaust system 122 during one or more semiconductor processing operations.

[0089] The system 100 also includes adjustable or control valves in the foreline configured to control the flow of gas through the foreline. Many plasma assisted deposition and etching processes can be conducted at various pressures, and adjustable valves can be employed between the chamber and the foreline outlet conduit. The adjustable valves can help to regulate the chamber pressure to a working level while leaking process gas outflow into the vacuum pump system or exhaust system. For example, the adjustable valves can be throttle valves, swing valves, butterfly valves, or gate valves. These terms can be used synonymously herein.

[0090] In FIG. 1A, the control valve is a throttle valve, which can be a swing valve 162 having a movable gate 166 with an orifice 174. The orifice 174 can be configured to reduce fouling, e.g., caused by material buildup associated with tortuous flow paths and higher flow rates. The orifice 174 is located in a central region of the gate 166 so as to generally maintain the flow direction and flow rate of a portion of the process gas flowing along an inner core space radially inward from and spaced apart from the pre-pipeline wall 116. The swing valve 162 can support a large flow conduct range without the orifice 174. When operated to control the pressure and / or flow upstream of the valve 162, the gate 166 is in one or more open positions. In some such open positions, flow around an outer region of the gate 166 can cause turbulent flow of the gas and result in undesirable deposits on the gate 166 and structures surrounding the gate 166. In some embodiments, as discussed in more detail below, the gate 166 can be in a closed position during certain processing operations, e.g., deposition, etching, or both, and thereby cause the gas flowing through the pre-pipeline 102 to flow through the orifice 174. By having the gate 166 in a closed position, undesirable deposits on the gate, e.g., an outer region thereof, and surrounding structures are reduced or eliminated. FIG. 1A depicts the gate 166 in a closed position such that the gas passing through the pre-pipeline outlet conduit 105 flows through the orifice 174. Various implementations of the valve 162 are discussed below.

[0091] In some embodiments, the gate 166 can have a surface containing aluminum that is configured to reduce recombination of radicals flowing through the pre-pipeline. In some cases, the gate can have an aluminum coating on other materials, e.g., stainless steel, while in other cases the entire gate can be made of a hard anodized aluminum alloy that is also configured to reduce recombination of radicals flowing through the pre-pipeline.

[0092] Some embodiments have a remote plasma source interface (RPS interface) that is fluidically connected to the foreline. In FIG. 1A, the RPS interface 126 is fluidically connected to the foreline 102 and fluidically connected to the foreline outlet conduit 105. As shown in FIG. 1A, the RPS interface 126 is positioned on the foreline outlet conduit 105 such that remote plasma from a remote plasma source flows into the foreline 102 through the RPS interface 126 in the foreline outlet conduit 105. The remote plasma flowing into the foreline 102 can clean components downstream of the RPS interface 126. As shown, a valve 162 is interposed between the RPS interface 126 and the exhaust interface 120 such that remote plasma flowing through the RPS interface 126 into the foreline 102 can contact and clean the shutter 166 and valve 162 structures. In some implementations, the RPS interface 126 is positioned proximate to a focus region having a first threshold deposition rate and / or having an outlet vector directed toward the focus region, which first threshold deposition rate is higher than a deposition rate. Various implementations of the RPS interface 126 are discussed below.

[0093] As noted above, certain implementations can have one or more gas injectors in the foreline for injecting a buffer gas into the foreline. Such gas injection into the foreline can help prevent and reduce material deposition in the foreline, control pressure in the foreline and internal volume, or both. As explained in more detail below, the buffer gas flow into the foreline is such that the valve 162 with the orifice 174 remains closed during processing operations and reduces undesirable deposition on the valve 162. Having the valve in a closed position during processing operations also advantageously provides a back pressure upstream of the valve 162 in the foreline outlet conduit 105 and the foreline network 103. By acting as a flow restrictor or orifice plate, the valve 162 causes a flow resistance that creates the back pressure. The back pressure can provide a gradual decrease in gas pressure flowing from the chamber interior 108 through the foreline 102, thereby preventing a sudden expansion of the gas and thus preventing or reducing unwanted condensation and reactions of components in the gas and deposition of material in the foreline. The back pressure can be at least 5 Torr or higher.

[0094] By having the valve 162 in a closed position, it does not actively control or maintain the upstream pressure in the foreline 102 and internal volume 108. Rather, the valve 162 with the orifice 174 acts as an orifice plate or flow restrictor. The buffer gas flow into the foreline 102 advantageously increases the pressure in the foreline network 103 and allows for active pressure control of the foreline and chamber interior 108 while the valve 162 is closed. The buffer gas flow also provides the active pressure control function while reducing and removing some undesirable deposits in the foreline 102. In FIG. 1A, the gas injector 115 is positioned in a linear section 197c of the foreline network 103.

[0095] Figure IB depicts an enlarged cross-section of a portion of the system of Figure 1A. Here, a bottom portion 113 of the processing chamber 106, the interior volume 108, and the exhaust port 109 are shown along with a portion of the foreline network 103 and the foreline outlet conduit 105. In the depicted embodiment, the system 100 also has a gas injector 115 located in the foreline 102, which here is in the foreline network 103. For ease of illustration, the gas injector 115 is shown in the linear section 197c of the second section. The gas injector 115 is fluidly connected to a buffer gas source 117, which can be an inert gas such as, for example, nitrogen, argon, or helium. Flow of the buffer gas is represented by the dashed arrow out of the gas injector 115, which can cause a back pressure in the foreline 102 upstream of the gas injector 115 that can be used to control the pressure in the interior volume 108. Various implementations of the gas injector are provided below.

[0096] Figure 1C depicts the semiconductor processing system 100 of Figure 1A, according to various implementations. Here, additional or alternative features are depicted with respect to Figure 1A. The system 100 has a foreline 102 configured to clean one or more focus areas 104 of the foreline 102 during a foreline cleaning operation. The foreline 102 includes a foreline wall 116 that defines an interior 118 that is fluidly connected to the interior volume 108 of the processing chamber 106. In such implementations, the foreline 102 is made of stainless steel and / or aluminum alloy components. The foreline 102 also includes an exhaust interface 120 configured to be fluidly connected to an exhaust system 122 (e.g., a vacuum device, a pump device, etc.). The interior 118 provides a conduit configured to flow one or more process gases from the interior volume 108 of the processing chamber 106 to the exhaust system 122 during one or more semiconductor processing operations.

[0097] Flow of process gas through the foreline 102 can cause material 113 from the process gas stream to be deposited in the plurality of focus regions 104 of the foreline 102 at different respective rates based on particular conditions associated with each focus region. These conditions can include the geometry of the foreline at that focus region (e.g., structures that can change the direction of process gas flow and / or converge two or more gas streams into a common passage), the distance between the process chamber 106 and the focus region, and so on. For example, the foreline 102 can branch into a plurality of segments 196 that include a plurality of linear sections 197a each defining a linear portion of a respective flow path through the foreline 102, and a plurality of non-linear sections 197b (e.g., arcuate elbow sections) each defining a non-linear portion of a respective flow path through the foreline 102. The non-linear sections 197b are configured to redirect the respective flow paths, and thus can cause radicals in the plasma to interact with these non-linear sections 197b at a higher rate than the radicals can interact with the linear sections 197a. As another example, one of the linear sections 197a can define a common linear portion CLP of two or more flow paths that are redirected from two other respective linear sections 197a. Independent flows from different exhaust ports 109 of the process chamber 106 can merge in this common linear portion CLP, thereby depositing material in the common linear portion CLP. Other conditions that can affect the rate of material deposition can include process gas flow rate (volume or mass units per unit time), duration of process gas flow, composition of the process gas, composition of the foreline, and so on.

[0098] In some cases, a foreline flow regulating valve, such as a throttle or flapper valve 162, can be disposed downstream of the non-linear section 197b, for example, in a portion of the foreline 102 that receives process gas from all of the exhaust ports 109, such that the gas flow from all upstream sections of the foreline can be regulated by this foreline flow regulating valve. Due to the geometry of such a valve, material can accumulate around the valve at a much higher rate than in both the linear section 197a and the non-linear section 197b of the foreline 102. The area around the valve can be associated with conditions such as a bottleneck of all process gas, a flow-disrupting foreline geometry, and a valve geometry, among others, that collectively disrupt flow and thus can contribute more to material deposition than other areas of the foreline 102. Furthermore, in a multi-station chamber foreline, the valve can effectively be subjected to a potentially higher deposition rate than upstream sections of the foreline can be subjected to. For example, in a four-station chamber, where each station has an independent exhaust port connected to a corresponding foreline section, whenever gas flow from two independent sections of the foreline converges into a downstream foreline section, the downstream section can see a deposition gas exposure that is potentially twice as high as any of the upstream sections of the foreline. Thus, at the location in the system where the flow regulating valve can be located, the exposure rate of deposition forming gas can be several times higher than in upstream sections of the foreline.

[0099] The semiconductor processing system 100 can also include a chamber cleaning plasma source 199 fluidly connected to the processing chamber 106 and configured to flow plasma into the processing chamber 106 to clean components or features in the processing chamber 106. The foreline 102 can be configured to evacuate plasma from the processing chamber 106. While the plasma from the chamber cleaning plasma source 199 primarily cleans components or features in the processing chamber 106, the plasma can also remove material 113 deposited within the foreline 102. The efficacy of the plasma to remove material in the foreline 102 can be based on the plasma flow rate (volume or mass units per unit time), the duration of the plasma flow, the amount of free radicals in the plasma that have recombined before reaching material in the focus regions of the foreline 102, and the like. As described above, some focus regions can have a higher material deposition rate than other regions, and thus can experience deposition of a thicker layer of material than other regions over a given time interval. To completely remove material from these focus regions with higher material deposition rates, the semiconductor processing system 100 can flow plasma from the chamber cleaning plasma source 199 at a higher flow rate and / or for a longer duration than is necessary to clean the processing chamber 106. These flow conditions can unnecessarily expose chamber surfaces to plasma for a longer time or more intensely than is necessary to clean these surfaces, which can damage them. Alternatively, these focus regions can not be completely cleaned during each cleaning cycle, and can develop a clog or other defect as material builds up over time.

[0100] By using a second plasma source that is independent of the chamber cleaning plasma source 199 and configured to flow cleaning plasma directly into the foreline 102, material buildup in the foreline 102 can be removed without damaging chamber surfaces. As described in detail below, the foreline 102 includes a remote plasma source interface 126 (RPS interface) positioned proximate to and / or having an outlet vector directed toward a focus region 104 having a first threshold deposition rate that can be higher than the deposition rate in one or more other regions of the foreline 102. In one implementation, the first threshold deposition rate can be greater than the deposition rate in all other regions of the foreline. In other implementations, the first threshold deposition rate can be less than the deposition rate in one or more other focus regions of the foreline when the system has other features for cleaning or preventing buildup in these focus regions.

[0101] The RPS interface 126 is configured to be fluidly connected with the remote plasma source 128 such that plasma from the remote plasma source 128 is configured to flow into the foreline 102 via the RPS interface 126 without first flowing through the interior volume 108 of the processing chamber 106. The RPS interface 126 is fluidly interposed between the interior volume 108 of the processing chamber 106 and the exhaust interface 120, and more particularly, between the interior volume 108 of the processing chamber 106 and the one or more focus regions 104 of the foreline 102 (on which the material 113 is deposited in high concentration). In such implementations, the remote plasma source 128 is configured to generate plasma having oxygen and / or fluorine (i.e., generate oxygen and / or fluorine radicals, etc.), although other suitable gases can be used instead. The RPS interface 126 is located within a predetermined distance of the one or more focus regions 104 and / or is configured to direct the plasma to these focus regions 104 to reduce or eliminate the amount of plasma lost to recombination (e.g., associated with the plasma interacting with the processing chamber 106 and foreline wall 116) and maintain the efficacy of the plasma to remove the material 113 from the one or more focus regions 104 having the highest accumulation of material 113. Plasma from the chamber cleaning plasma source 199 can be introduced to the processing chamber 106 to remove deposited material from surfaces in the processing chamber 106, while a second plasma from the remote plasma source 128 is introduced to the foreline 102 via the RPS interface 126 to remove deposited material in the foreline 102. If the chamber plasma cleaning is completed before the foreline plasma cleaning is completed, the flow of plasma into the processing chamber 106 can be stopped, and the flow of plasma via the RPS interface 126 can continue to complete cleaning of the foreline 102 without unnecessarily subjecting the chamber surfaces to additional plasma exposure.

[0102] Figure 2 depicts an enlarged cross-sectional view of an example portion of the semiconductor processing system of Figure 1C taken from region 1. In this implementation, the RPS interface 126 includes a nozzle 130 having a first surface facing radially inward toward the central axis and defining a plasma passageway 132 in which fluid is interposed between the remote plasma source 128 and the foreline 102. The plasma passageway 132 is configured to direct plasma along a direction D1 during a foreline cleaning operation, the direction D1 having a component D1'parallel to a downstream direction D2 of the foreline 102 and another component D" perpendicular to the direction D2. In some embodiments, the downstream direction D2 can be parallel or substantially parallel to a central axis of the foreline conduit or the foreline wall 116. One or more focal regions 104 of the foreline 102 on which material 113 is deposited can be positioned along the direction D1 from the RPS interface 126 such that plasma from the RPS interface 126 can reach the material 113 in a more direct manner, thereby reducing the chance that free radicals in the plasma will recombine before reaching the material 125. The cleaning efficacy of the plasma (e.g., oxygen and fluorine radicals, among others) can thus be maintained to remove the material 113.

[0103] The plasma channel 132 can be configured to direct plasma during a foreline cleaning operation in a direction at a predetermined angle relative to the foreline wall 116 between (including at) the first endpoint and the second endpoint. In such implementations, the plasma channel 132 can be configured to direct plasma during a foreline cleaning operation in a direction at a predetermined angle relative to the foreline wall 116 in a range between 30 degrees and 60 degrees (including at 30 degrees relative to the foreline wall 116 and at 60 degrees relative to the foreline wall 116). In other implementations, the plasma channel 132 can be configured to direct plasma in any angle relative to the foreline wall 116 during a foreline cleaning operation or other process. In some instances where the plasma channel 132 is configured to direct plasma in a direction less than 30 degrees relative to the foreline wall 116 (e.g., parallel or nearly parallel to the downstream direction D2), the plasma will flow through the area to be cleaned and thus remove less material from that area than would be removed by plasma directed in a direction more than 30 degrees relative to the foreline wall 116. However, such a configuration can be more suitable for removing material buildup on the same side of the foreline 102 as the RPS interface 126. In other instances where the plasma channel 132 is configured to direct plasma in a direction more than 60 degrees relative to the foreline wall 116 (e.g., perpendicular or nearly perpendicular to the downstream direction D2), radicals in the plasma can be closer to the RPS interface 126 to recombine and thus the plasma efficacy downstream of the RPS interface 126 can be less than for plasma directed in a direction less than 60 degrees relative to the foreline wall 116. However, such an implementation can be more useful in instances where the area of maximum material buildup is directly opposite the RPS interface.

[0104] In such implementations, the nozzle 130 has a tip end 134 that protrudes into the interior 118 of the foreline 102 such that the nozzle 130 can introduce plasma into the interior 118 of the foreline 102 radially inward from the foreline wall 116 and at a location spaced apart from the foreline wall 116, and the nozzle 130 can direct the plasma to flow in a direction at least approximately parallel to the foreline wall 116, thereby reducing interaction between the foreline wall 116 and the plasma. In such implementations, the RPS interface 126 can be made of a hard anodized aluminum alloy configured to reduce recombination of oxygen and fluorine radicals flowing through the plasma channel 132.

[0105] The RPS interface 126 (e.g., the nozzle 130) has a first end portion 136 that connects with the remote plasma source 128 and a second end portion 138 that connects with the RPS interface 126 of the front-end line 102. In this implementation, the first end portion 136 can include a lip or collar 137 that extends radially outward from a central axis of the plasma channel 132 and / or circumferentially outward from an outer surface 131 of the RPS interface 126. The plasma channel 132 of the nozzle 130 can taper from the first end portion 136 toward the second end portion 138 (e.g., along the first end portion 136, up to a portion of the nozzle 130 spaced from the second end portion 138, up to a portion of the nozzle 130 adjacent to the second end portion 138, up to and terminating at an upstream side of the second end portion 138, through the second end portion 138 and terminating at a downstream side of the second end portion 138, etc.). The plasma channel 132 can have a first segment with a first diameter DIA1 in the first end portion 136 and a second segment with a second diameter DIA2 in the second end portion 138, and the first diameter DIA1 of the first segment can be greater than the second diameter DIA2 of the second segment. The plasma channel 132 can be linear through the first end portion 136 and curved at least partially along the second end portion 138 and through the tip 134. The curvature of the plasma channel 132 along the second end portion 138 and through the tip 134 can be configured to direct plasma along the direction D1 described above. In some implementations, the diameter of the outer surface 131 of the nozzle 130 can taper from the first end portion 136 toward the second end portion 138 (e.g., along the first end portion 136, up to a portion of the nozzle 130 spaced from the second end portion 138, up to a portion of the nozzle 130 adjacent to the second end portion 138, up to and terminating at an upstream side of the second end portion 138, through the second end portion 138 and terminating at a downstream side of the second end portion 138, etc.).

[0106] As further shown in FIG. 2, the nozzle 130 includes an inlet port 140 and an outlet port 142, both of which are located in the first end portion 136 of the nozzle wall 144. In other implementations, the inlet port 140 and the outlet port 142 can be located within other portions of the RPS interface 126 (e.g., in the second end portion 138, between the first end portion 136 and the second end portion 138, etc.). The inlet port 140 and the outlet port 142 can extend radially outward from the plasma channel 132 and / or the outer surface 131 of the RPS interface 126. The inlet port 140 and the outlet port 142 can be positioned proximate to each other and / or circumferentially spaced apart.

[0107] The nozzle 130 also includes one or more coolant channels 146 positioned along the outer surface 131 and in the nozzle wall 144. As shown in FIG. 2, the one or more coolant channels 146 define one or more coolant flow paths from the inlet port 140 to the outlet port 142 and through the second end portion 138.

[0108] The one or more coolant channels 146 in the nozzle wall 144 are disposed around the plasma channel 132 and are configured to flow a coolant (e.g., water, air, etc.). The coolant maintains the temperature of the plasma flowing from the remote plasma source 128 below a predetermined temperature threshold (e.g., 200 degrees Fahrenheit) to reduce or prevent thermal damage to the nozzle 130 and / or the foreline 102. The coolant also maintains the temperature of the plasma below the predetermined temperature threshold to preserve oxygen in the plasma and reduce recombination of free radicals in the plasma before the plasma reaches the focus region 104 to be cleaned. In such implementations, the one or more coolant channels 146 can include a first plenum 150 within the first end portion 136 and fluidly connected to the inlet port 140. The one or more coolant channels 146 can also include a second plenum 152 within the second end portion 138. The one or more coolant channels 146 can also include a third plenum 154 within the first end portion 136 and fluidly connected to the outlet port 142. The one or more coolant channels 146 can also include a set of one or more first channels or passages 156 fluidly interposed between the first plenum 150 and the second plenum 152, and a set of one or more second channels or passages 158 fluidly interposed between the second plenum 152 and the third plenum 154.

[0109] FIG. 3 depicts another example RPS interface 226 that is somewhat similar to the RPS interface 126 of FIG. 2. To avoid unnecessary repetition, elements in the FIG. 3 implementation that are similar to elements shown in FIG. 2 are labeled with a number that shares the same last two digits as the similar element in FIG. 2. Thus, unless otherwise noted, the discussion provided above regarding the elements of the FIG. 2 implementation will be understood to apply equally to the similar elements in FIG. 3. To be brief and to the point, discussion of elements that would be redundant of the earlier discussion of such elements herein is not provided where it is understood that the prior discussion of such elements applies to the similar elements in FIG. 3. This applies to any of the figures illustrated herein, e.g., including FIGS. 1A-1C and 7A-8B.

[0110] Figure 3 depicts an enlarged cross-sectional view of region 1 of the semiconductor processing system of Figure 1C. While the RPS interface 126 of Figure 2 includes a nozzle 130 that protrudes through an opening 160 defined in the foreline wall 116 and into the interior 118 of the foreline 102, the RPS interface 226 of Figure 3 terminates at an opening 260 within the foreline wall 216 without protruding into the interior 218 of the foreline 202. The valve 262 in Figure 3 is in an open position, with material 213 deposited thereon. Omitting the RPS interface 226 from the interior 218 of the foreline 202 causes less resistance to the flow of process gas through the foreline 202, and can prevent (or at least reduce the rate of) deposition of material from the process gas flow on the RPS interface 226.

[0111] A further difference between the plasma channel 232 of Figure 3 and the plasma channel 132 of Figure 2 is that the plasma channel 232 is configured to direct plasma in a direction D3 that has no component parallel to the downstream direction D2 of the foreline 204; as described above, this direction D2 can be parallel or substantially parallel to a central axis of the foreline 202. In such implementations, the plasma channel 232 can be configured to direct plasma toward a portion of the foreline wall 216 opposite the opening 260 and within a predetermined distance PD from the first of the focusing regions 104, such that the introduced plasma is able to reach the focusing regions 104 quickly, thereby avoiding a substantial reduction in the plasma cleaning effect.

[0112] The RPS interface 126 of FIG. 2 includes a plurality of first passages 156 fluidically interposed in a parallel connection between the first plenum 150 and the second plenum 152, and a plurality of second passages 158 fluidically interposed in a parallel connection between the second plenum 152 and the third plenum 154. The RPS interface 226 of FIG. 3 includes a single serpentine coolant passage 246 that alternately traverses a plurality of segments of the first end portion 236 and a plurality of segments of the second end portion 238. The single serpentine coolant passage 246 has one end that is fluidically connected to the inlet port 240, and another end that is fluidically connected to the outlet port 242. The coolant passage 246 includes linear segments that extend parallel and adjacent to the plasma passage, and U-shaped segments that extend circumferentially around and adjacent to the plasma passage 232. The linear segments and U-shaped segments are fluidically connected to one another. In other implementations, the RPS interface 226 can include a plurality of serpentine coolant passages (e.g., extending parallel to one another, nested within one another, etc.) that are fluidically connected to a common inlet port (e.g., the inlet port 240) and a common outlet port (e.g., the outlet port 242). In yet other implementations, the RPS interface 226 can include coolant passages arranged in alternative configurations that are fluidically connected to independent inlet ports and / or independent outlet ports, and / or one or more segments that are concentric and / or coaxial with the plasma passage 232.

[0113] The RPS interface 226 can have a cylindrical shape, and the plasma passage 232 includes a tapered segment 233 that is located within the first end portion 236 of the RPS interface 226. The plasma passage 232 can also include a linear segment 235 that is fluidically connected to the tapered segment 233. The linear segment 235 can extend at least partially along the first end portion 236 and through the second end portion 238.

[0114] Properties of a throttle valve within a foreline according to various implementations will now be discussed. FIG. 4 depicts an enlarged cross-sectional view of an example portion of the semiconductor processing system 100 of FIG. 1C, taken from region 2. As described above, the valve 162 can be the same valve depicted in the simplified system 100 of FIG. 1A. FIG. 4 depicts a foreline 102 having a swing valve 162 with a gate 166 that includes an orifice 174 configured to reduce fouling, e.g., caused by material buildup associated with a tortuous flow path and higher flow rates. The orifice 174 is located in a central region 176 of the gate 166 to generally maintain a flow direction and flow rate of a portion of process gas flowing along an inner core space of the foreline interior 118 radially inward from and spaced apart from the foreline wall 116. The swing valve 162 can support a large conductance range without the orifice 174.

[0115] When certain chemical deposition processes are run in certain implementations, the gate 166 can move to one or more small valve angles below a predetermined angle threshold, and can thus require process gas to flow along a tortuous path (i.e., between the outer edge region 168 of the gate 166 and the inner perimeter of the seal ring 164, which has features configured to couple to the foreline 102). The tortuous flow path can increase the likelihood of entrained polymer particles detaching from the flow stream and adhering to surfaces and fouling the swing valve 162 when set at small angles, in addition, in certain cases, the chemical deposition process can require process gas to flow at high velocity along the tortuous path. This can cause material 113 to deposit within or near the interface between the outer edge region 168 of the gate 166 and the inner perimeter 178 of the seal ring 164 and to build up until the gate 166 becomes stuck. In some implementations, such issues are reduced or minimized by including the aperture 174, which causes a majority of the process gas to flow through the inner core space of the foreline interior 118 radially inward from and spaced apart from the foreline wall 116, and by maintaining the flow direction and flow rate within the inner core space. The flow of process gas through the aperture 174 significantly reduces the amount of gas flowing along the tortuous path around the outer edge region 168 of the gate 166, and thus reduces fouling at or near the outer edge region 168. Reduced fouling at or near the outer edge region 168 can further prevent the gate 166 from becoming stuck, reduce preventative maintenance of the foreline 102, and maintain the uptime and corresponding productivity of the semiconductor processing system 100. In such implementations, the thickness of the central region 176 of the gate 166 can be greater than the thickness of the outer edge region 168 of the gate 166. In other implementations, the thickness of the central region 176 of the gate 166 can be less than or equal to the thickness of the outer edge region 168 of the gate 166.

[0116] In this implementation, the swing valve 162 is fluidly interposed between the RPS interface 126 and the exhaust interface 120. As best shown in FIGS. 4-6, the seal ring 164 is positioned coaxially with the foreline 102. The shutter 166 is movable between a first position (i.e., the closed position of FIGS. 4 and 5) in which the outer edge region 168 is sealingly engaged with at least a portion of the seal ring 164 and a second position (i.e., the open position shown in FIG. 6) in which the portion of the outer edge region 168 is radially displaced inward from the inner perimeter 178 of the seal ring 164 relative to the valve seat 172 and the seal ring 164. The shutter 166 is movable in a plurality of open positions, one of which is shown in FIG. 6, as described herein. The valve 162 is configured to limit the flow through the foreline 102 by positioning the shutter in various open positions to control the pressure in the foreline 102 and the interior volume 108. As discussed herein, at this time the shutter 166 is positioned in the closed position shown in FIGS. 4 and 5, the shutter 166 and the orifice 174 act as an orifice plate providing a constant flow restriction. The foreline includes the valve seat 172 configured to accommodate the portion of the outer edge region 168 when the shutter 166 is in the first position (FIGS. 4 and 5) such that at least a portion of the seal ring 164 is sealingly engaged with the portion of the outer edge region 168 and directs all process gas through the orifice 174. The foreline 102 is not limited to a swing valve for flow control or adjustment and other valves having a shutter with an orifice (e.g., a linear gate valve) can be used in place of the swing valve 162.

[0117] FIG. 5 depicts an enlarged view of the swing valve of FIG. 4 and FIG. 6 depicts an enlarged view of the swing valve of FIG. 5. As shown, in some embodiments, the swing valve 162 can have a notch 170 at the outer edge region 168 of the shutter 166 to flow a portion of the process gas when the shutter 166 is moved by a small angular movement from the first position (FIG. 5) to the second position (FIG. 6) and allow the swing valve 162 to precisely control and gradually adjust the flow rate. When the shutter 166 is in the second position, the flow of process gas through the swing valve 162 can be distributed between the orifice 174 and the notch 170 such that the swing valve 162 experiences less fouling at the outer edge region 168 of the shutter 166 compared to a shutter without an orifice and requiring all process gas to flow along a tortuous path around the outer edge region 168 of the shutter 166. The plasma channel 232 (FIG. 3) of the RPS interface 226 can be configured to direct plasma generally toward the location of the outer edge region 168 of the shutter 166 when the shutter 166 is in the second position.

[0118] The semiconductor processing system is configured to set or adjust a chamber pressure of the processing chamber 106 when the gate 166 is in the first position that causes at least a portion of the seal ring 164 to sealingly engage at least a portion of the outer edge region 168, thereby preventing process gas from flowing through the interface between the outer edge region 168 and the inner perimeter 178 of the seal ring 164 and requiring all process gas to flow through the aperture 174. In this implementation, the semiconductor processing system further includes a gas distribution system 180 having a plurality of valves 182 that can be controlled to selectively cause one or more process gases from a plurality of different gas sources 184 that can be connected to the gas distribution system 180 to flow into the processing chamber 106 and then through the aperture 174 of the shutter valve 162. The systems of FIGS. 1A and IB can have these features and they are not shown for the sake of clarity.

[0119] The semiconductor processing system 100 further includes a controller 186 that is configured to control the valves 182 of the gas distribution system 180 to cause one or more process gases to flow into the processing chamber 106 to adjust the chamber pressure associated with all process gas flowing through the aperture when the gate 166 is in the first position. The controller 186 is further configured to control the valves 182 of the gas distribution system 180 so as to not cause one or more process gases to flow into the processing chamber 106 during a pre-pipeline cleaning operation. In this implementation, the semiconductor processing system 100 further includes the remote plasma source 128 and a pre-pipeline plasma valve 188 that is fluidly interposed between the remote plasma source 128 and the RPS interface 126 of the pre-pipeline 102. The controller 186 is configured to control the remote plasma source 128 and the pre-pipeline plasma valve 188 to cause plasma from the remote plasma source 128 to flow into the pre-pipeline 102 during a pre-pipeline cleaning operation.

[0120] The controller 186 is also configured to control the pre-pipeline plasma valve 188 to prevent one or more process gases from flowing through the RPS interface 126 and into the remote plasma source 128, thereby preventing material from the process gases from depositing in the RPS interface 126. The semiconductor processing system 100 can also include a chamber cleaning plasma source 199 (which is separate from the pre-pipeline cleaning plasma source 192) and a chamber plasma valve 198 fluidically interposed between the chamber cleaning plasma source 199 and the interior 108 of the processing chamber 106. The controller 186 is configured to control the chamber cleaning plasma source 199 and the chamber plasma valve 198 to cause plasma from the chamber cleaning plasma source 199 to flow into the interior 108 of the processing chamber 106 during a chamber cleaning process. The controller 186 is also configured to control the chamber plasma valve 198 to stop the flow of plasma into the interior 108 of the processing chamber 106, thereby avoiding unnecessarily exposing chamber surfaces to additional plasma (e.g., when the chamber surfaces have already been cleaned and the pre-pipeline plasma valve 188 continues to cause plasma to flow into the pre-pipeline 102 and downstream to the exhaust interface).

[0121] The semiconductor processing system 100 also includes a gate valve 190 fluidically interposed between the RPS interface 126 and the swing valve 162, where the gate valve 190 is configured to switch between an open position, in which the gate valve allows fluid to flow through the pre-pipeline 102, and a closed position, in which the gate valve 190 completely prevents all fluid from flowing through the pre-pipeline 102. In such implementations, the gate valve (rather than the swing valve 162) can be used to completely block all fluid flow through the pre-pipeline 102, as even with the gate 166 in the first position, the apertures 174 in the gate 166 of the swing valve 162 allow for some flow. However, in other implementations, the gate valve 190 can be located downstream of the swing valve 162 or upstream of the RPS interface 126. In other implementations, the pre-pipeline 102 can not include the gate valve 190.

[0122] In some embodiments, the systems provided herein can have more branches of the foreline than shown in FIGS. 1A-1C. For example, additional branches can be used when a processing chamber has more than two processing stations and / or more than two exhaust ports. FIG. 7A depicts a schematic diagram of another exemplary semiconductor processing system in one configuration, and FIG. 7B depicts the exemplary semiconductor processing system of FIG. 7A in a second configuration. The system 300 shown in FIGS. 7A and 7B is somewhat similar to the semiconductor processing system 100 of FIGS. 1A-1C. To avoid undue repetition, elements in the implementation of FIGS. 7A and 7B that are similar to elements shown in FIGS. 1A-1C are labeled with the same last two digits of numbers as the similar elements in FIGS. 1A-1C. Thus, unless otherwise noted, the above discussion of elements of the implementation of FIGS. 1A-1C is understood to apply equally to similar elements in FIGS. 7A and 7B. To be brief and to the point, discussion of elements herein that would be redundant of the earlier discussion of similar elements is not provided where it is understood that the earlier discussion of such elements applies to the similar elements in FIGS. 7A and 7B. For example, valve 362 corresponds to valve 162, and gas injectors 315a and 315b correspond to gas injectors 115.

[0123] The semiconductor processing system 300 of FIGS. 7A and 7B is a multi-station processing chamber having four processing stations in the chamber interior volume 308. As described herein, multi-station chambers are not limited to four stations and can include fewer or more stations, such as 3, 5, 6, 7, 8, 9, or 10 stations in one chamber. In FIG. 7A, the processing chamber 306 has four processing stations in the chamber interior volume 308, and for clarity, the processing stations are not labeled. Four showerheads 314a-314d and four exhaust ports 398 for each of the four stations are identified. The foreline 302 branches into more segments 396 that define flow paths fluidly connecting to and leading to different exhaust ports 398. The segments 396 include a plurality of linear segments 397a each defining a linear portion of a respective flow path through the foreline 302, and a plurality of non-linear segments 397b (e.g., arcuate elbow segments) each defining a non-linear portion of a respective flow path through the foreline 302. An RPS interface 326 is fluidly interposed between at least one non-linear portion of a respective flow path and the exhaust interface 320. More specifically, in this implementation, the RPS interface 326 is fluidly interposed between all non-linear portions of the flow paths and the exhaust interface 320. The RPS interface is positioned along the foreline outlet conduit 305. Also as can be seen, the system 300 includes two gas injectors 315a and 315b disposed in the foreline 302, such as within the foreline network 303 and upstream of the foreline outlet conduit 305.

[0124] In FIG. 7A, one or more processing operations are being performed in four stations within interior volume 308. For example, the one or more processing operations can be deposition of material onto a substrate by CVD, PECVD, ALD, or etching of material from a substrate, for example by ALE. During these deposition and / or etching operations, a buffer gas can be flowed into foreline 302 via gas injectors 315a and 315b to prevent undesirable deposition in the foreline and to control pressure in interior volume 308. As further shown in FIG. 7A, during these operations, valve 362 is positioned in a closed position, thereby acting as a flow restrictor or orifice plate and providing a constant restriction to flow from chamber interior 308. Gas flowing through foreline 302 flows through the orifice of valve 362. Positioning valve 362 in the closed position during processing operations advantageously reduces and prevents undesirable deposition on the face of valve 362, which cannot be moved and provides active pressure control to foreline 302 and chamber interior 308. Valve 362 in the closed position also creates back pressure upstream of the valve, which can also provide a gradual decrease in pressure within foreline 102 and thereby reduce undesirable material condensation and deposition in foreline 102. As discussed in more detail herein, injection of a buffer gas via gas injectors 315a and 315b when valve 362 is in the closed position during processing operations advantageously provides active pressure control of foreline 302 and chamber interior 308, as well as preventing and reducing undesirable deposition in foreline 302.

[0125] In FIG. 7B, one or more other operations are being performed in chamber 306. This can include cleaning, pre-treatment operations, or post-treatment operations. Cleaning operations can include flowing plasma in the stations, interior volume 308, and flowing plasma into foreline 302 via RPS interface 328. During these other operations, valve 362 can be operated to actively control flow and pressure in foreline 302 and chamber interior 308 by moving the shutter in one or more open positions. During such cleaning, plasma removes material deposited near the orifice of valve 362.

[0126] Figure 8A depicts a simplified, enlarged schematic of the system of Figure 7A. Here, this portion of system 300 includes chamber interior 308, four exhaust ports 398a-398d, and four processing stations represented by blocks 319a-319d. Figure 8A depicts system 300 during one or more processing operations, such as deposition or etching, and with valve 362 in a closed position and buffer gas flowing through gas injectors 315a and 315b. Gas from chamber interior volume 308 is represented by white arrows, and it can be seen that this gas passes through exhaust ports 398a-398d into a foreline; these exhaust ports can be the same as exhaust ports 109 in Figures 1A-1C. Foreline network 303 of foreline 302 has multiple branches that define various flow paths, such as a first segment 396a across between exhaust port 398a and junction 311a, and a second segment 396b across between exhaust port 398b and junction 311a. Downstream of junction 311a is another segment 396c that is across between junction 311a and another junction 311b, and downstream of junction 311b is common foreline outlet conduit 305. Gas injector 315a is positioned in a third segment of conduit downstream of junction 311a and before common foreline outlet conduit 305, which conduit is identified as linear segment 397c. Positioning gas injector 315a in this location can advantageously provide uniform pressure along upstream segments 396c, 396a, and 396b, as well as exhaust ports 398a and 398b. This positioning enables a single injector to provide uniform back pressure and flow for the foreline network, as well as for half of processing chamber 306 and interior 308. Another portion of foreline network 303 is similarly configured, but is not labeled for clarity.

[0127] As previously described, valve 362 in the closed position can create back pressure upstream of valve 362, which can also provide a gradual drop in pressure within foreline 102 compared to chamber pressure. This back pressure can create a high pressure environment in foreline 102 that is close to but less than chamber pressure, and can also reduce undesirable condensation and deposition of materials in foreline 102.

[0128] Figure 8B depicts a simplified, enlarged schematic of the system of Figure 7B. Here, this portion of system 300 includes chamber interior 308, four exhaust ports 398a-398d, and four processing stations represented by blocks 319a-319d. Figure 8B depicts system 300 during one or more other operations, such as a cleaning operation, with valve 362 in an open position and buffer gas not flowing through gas injectors 315a and 315b. It is seen that a cleaning plasma (represented by dashed arrows) flows through chamber interior and into foreline 302, and through RPS interface 326 into foreline outlet conduit 305.

[0129] In some embodiments, the system can include features configured to detect pressure within the chamber interior and / or in the foreline, and to control the flow of buffer gas into the foreline to control (including adjust and maintain) the pressure within the chamber interior. This can include one or more pressure sensors connected to the controller and positioned within the chamber interior, the foreline, or both, upstream of the gas injectors. The controller can be configured to receive signals from the one or more pressure sensors, and to cause gas to flow into the foreline through the gas injectors to affect the pressure within the foreline and upstream of the foreline to the chamber interior. For example, the system 300 of FIG. 8A has a pressure sensor 321 positioned in the interior volume 308 of the chamber 306 in communication with the controller 386. The pressure sensor 321 detects the pressure in the chamber interior 308 and transmits these signals to the controller 386, which receives the signals. The controller 386 is configured to control the flow of buffer gas from the buffer gas source 317 and to the gas injectors 315a and 315b based on the received pressure signals to control the pressure within the foreline 302 and upstream of the chamber interior 308. In some embodiments, the controller 386 can use proportional-integral-derivative (PID) control to control the buffer gas flow based at least in part on the detected pressure from the pressure sensor 321. In some cases, the controller can determine a buffer gas flow rate through the gas injectors to achieve a desired pressure result at or near the pressure sensor. In some embodiments, this type of control can be considered upstream pressure control. In some implementations, the controller can be an upstream pressure controller.

[0130] In some implementations, the system 300 can have a flow controller 333 fluidically connected to the gas injectors 315a and 315b and to the pressure sensor 321. The flow controller 333 is configured to control the flow of buffer gas to the gas injectors 315a and 315b based at least in part on the pressure detected by the pressure sensor 321. The flow controller 333 can include some of the functionality of the controller 386 described above. For example, the flow controller 333 can use PID control to control the buffer gas flow based at least in part on the detected pressure from the pressure sensor 321. In some cases, the flow controller 333 can determine a buffer gas flow rate through the gas injectors to achieve a desired pressure result at or near the pressure sensor. In some implementations, this type of control can be considered upstream pressure control. In some implementations, the flow controller 333 can be an upstream pressure controller.

[0131] In some embodiments, the orifice size in the valve can be configured to produce a pressure in the foreline that is less than but close to the pressure inside the chamber during one or more processing operations. For example, this closeness can be 5%, 10%, or 20% of the desired pressure inside the chamber during operation. Without any buffer gas flow and when the valve is in the closed position, the orifice can thus cause the foreline to have a first pressure that is less than the pressure in the chamber interior during processing operations. Additional buffer gas into the foreline thereby increases the pressure in the foreline, and thus can increase its pressure above the first pressure and close to or equal to the pressure of the chamber interior. In one example, the chamber interior can have a desired pressure of about 10 Torr during deposition in the chamber, and to achieve the same pressure, the gas flow through the foreline can be 30 SLM. The orifice can be sized to allow less than but close to this flow rate, for example 25 SLM. By allowing a flow rate of about 25 SLM through the orifice, the pressure in the foreline is less than but close to the chamber pressure of 10 Torr. To produce the desired flow rate through the foreline and thereby produce the desired pressure in the foreline, buffer gas can be flowed into the foreline at about 5 SLM to achieve a total of 30 SLM and the desired pressure in the foreline. If pressure fluctuations occur in the chamber during processing operations, the pressure sensor can detect these changes, and the buffer gas flow into the foreline can be adjusted so that the desired pressure in the chamber interior can be maintained. For example, if the chamber pressure drops, the buffer gas flow can be increased to increase the foreline pressure and the chamber pressure.

[0132] As described herein, some embodiments of the gas injector are configured to reduce or prevent deposition of material in the foreline. The gas injector can be located within the internal bore of the foreline conduit, such as the linear section depicted in FIGS. 1A-1C and 7A-8B. In some implementations, the gas injector acts as an outlet, which can be centered or substantially centered within the conduit. This centered placement can reduce undesirable disturbances to the gas flow around the gas injector and provide more uniform conditions around the gas injector. Disturbances around and downstream of the gas injector can be undesirable because these disturbances can increase the shear forces and turbulence of the gas flow, which can cause reactions, such as nucleation reactions, of the constituents and gases, and form unwanted materials and byproducts, which can deposit on the foreline and valves therein, such as valves 162 and 362. These disturbances caused by the gas injector can be reduced in various ways, such as configuring the diameter of the injector to be large enough to diffuse the buffer gas flow, or having a muffler at the end of the injector, which can also diffuse the gas flow.

[0133] FIG. 16 depicts a cross-sectional side view of a portion of a foreline with a gas injector. The gas injector 2415 is located within the interior of a conduit 2497c of a foreline, which can be any conduit of the foreline network of FIGS. 1A-1C and 7A-8B. The gas injector 2415 has an outlet 2423 that is located within the interior 2418 of the conduit 2497c. The buffer gas flowing through the gas injector 2415 and into the conduit 2497c is indicated by dashed arrows. In some cases, the center of the outlet 2423 is located within the central region of the conduit 2497c, and in some such instances, the center of the outlet 2423 is colinear, or substantially colinear (e.g., within 1%, 5%, or 10% of colinear), with the central axis 2425 of the conduit 2497c as shown. The outlet 2423 can also have a circular cross-sectional area, which in certain implementations can advantageously cause the buffer gas flowing into the conduit 2497c to flow uniformly.

[0134] Making the diameter of the gas injector and its outlet outer diameter OD too small relative to the bore diameter BD of the conduit 2497c can result in unwanted turbulence in the conduit 2497c. In some implementations, the outer diameter of the gas injector outlet 2123 is made 1 / 2-5 / 6, 1 / 2-4 / 5, 2 / 3-4 / 5, and / or 2 / 3-5 / 6 times smaller than the bore diameter BD of the conduit 2497c, thereby advantageously reducing unwanted gas turbulence. In addition, the gas injector 2415 can act as a gas expander, which allows the gas to expand from a delivery line having a smaller diameter. In FIG. 16, the delivery line 2427 from a buffer gas source (not shown) has a second outer diameter OD2 that is smaller than the outer diameter OD of the gas injector 2415. This difference in size allows the buffer gas to expand and diffuse so that it can enter the interior 2418 of the conduit 2497c with less turbulence.

[0135] FIG. 17 depicts a cross-sectional side view of a portion of a front-end line with another gas injector. As with the gas injector of FIG. 16, the gas injector 2515 is located inside a conduit 2597c of a front-end line, which can be any conduit of the front-end line network of FIGS. 1A-1C and 7A-8B. The gas injector 2515 has an outlet with a muffler 2529 located inside the conduit 2597c interior 2518. The buffer gas flowing through the gas injector 2515 and into the conduit 2597c is indicated with dashed arrows. In some cases, the center of the muffler 2529 is located in a central region of the conduit 2597c, and in some such instances, the center of the muffler 2529 is colinear, or substantially colinear (e.g., within 1%, 5%, or 10% of colinear), with the central axis of the conduit 2597c. As shown, the muffler 2529 causes the buffer gas to flow radially outward in various directions to disperse the buffer gas in the conduit interior 2518, which can reduce and prevent unwanted turbulence and deposition therein. The muffler 2529 can be a type of structure that acts to block and spread the flow of buffer gas entering the conduit. This can include a structure with a porous outer shell, such as a muffler made of sintered metal. In certain implementations, the muffler can be considered a pneumatic exhaust muffler.

[0136] As previously mentioned, the flow of buffer gas through a gas injector into a front-end line can control the pressure inside a chamber. In some embodiments, flowing such buffer gas through a gas injector with an orifice during one or more processing operations (e.g., depositing material on a substrate in a multi-station chamber) when the valve with the orifice is in a closed position can result in maintaining the pressure inside the chamber within a particular pressure range. This range can be from about 7 Torr to about 11 Torr, from about 14 Torr to about 18 Torr, or from about 16 Torr to about 20 Torr.

[0137] Additional or alternative features of the system will now be discussed. In some implementations, a foreline anti-contamination assembly can be implemented in the foreline to assist in trapping potential undesirable byproducts, e.g., that can pass through the swing valve 162. Referring to FIGS. 9-15, an implementation of a foreline anti-contamination assembly 400 (“assembly”) is provided for the foreline 102 of the semiconductor processing system 100 of FIG. 1C. FIG. 9 depicts a cross-sectional view of an example foreline anti-contamination assembly of the foreline of FIG. 1C taken along the longitudinal axis of the trap. The assembly 400 is configured to initiate deposition of material from one or more process gases flowing through the foreline 102 during one or more semiconductor processing operations, and is further configured to retain the deposited material and prevent the deposited material from traveling through the foreline 102 downstream of the assembly 400 during the one or more semiconductor processing operations and / or a foreline cleaning operation. As described in detail above in connection with the description of FIGS. 4-6, the apertures 174 in the gate 166 of the valve 162 can cause a majority of the process gas to flow through an inner core space of the foreline interior 118 radially inward from and spaced apart from the foreline wall 116, and to minimize flow disruptions by maintaining the flow direction and flow rate within the inner core space.

[0138] The reduced flow of process gas through the orifice 174 significantly reduces the amount of gas flowing along the tortuous path around the outer edge region 168 of the shutter 166 and, thus, reduces fouling at or near the outer edge region 168. The reduced fouling at or near the outer edge region 168, in turn, can prevent the shutter 166 from sticking, reduce the frequency of preventative maintenance of the foreline 102, and maintain uptime and corresponding productivity of the semiconductor processing system 100. However, because the orifice 174 maintains a flow direction and flow rate within the inner core space of the foreline interior 118 radially inward from and spaced apart from the foreline wall 116, process gas can directly impinge the foreline wall 116 at a region of the shutter 166 more downstream. This region can be difficult to access and / or clean, and in such a region, material can contaminate and / or damage other components (e.g., a pump of the exhaust system 122) and, thus, degrade performance of these components and / or the entire semiconductor processing system 100. As detailed below, the semiconductor processing system 100 can include an assembly 400 having a trap 402 (e.g., a well, a filter, etc.) configured to deposit material from one or more process gases on one or more accumulation surfaces 404 and retain the material (e.g., material that flakes off the surfaces of the trap 402) so that the material does not pass through the foreline 102 during one or more semiconductor processing operations and / or foreline cleaning operations. During a foreline cleaning operation (e.g., after a predetermined number of batches of semiconductors have been produced, such as 30 batches), a plasma source (e.g., the RPS 128 of FIG. 1) can be activated to flow plasma into the foreline 102 and through the assembly 400, thereby volatilizing material deposited and stored within the trap 402. The trap 402 is also configured to provide a flow conductance through the foreline 102 within a predetermined performance loss range (e.g., within about 20% of an original flow conductance of the foreline 102 without the trap 402 and before any material from the process gases is deposited on the trap 402). As material gradually accumulates on the trap 402 during one or more semiconductor processing operations, the flow conductance through the trap 402 can decrease by a corresponding amount. The trap 402 is configured to be cleaned within a maximum cleaning time (e.g., 20-30 minutes) to remove an amount of material associated with an amount of process gas used to produce a predetermined number of batches (e.g., 30 batches) of semiconductors. The foreline cleaning operation (during which the trap can be cleaned) can be performed in sequence before or after a chamber cleaning operation during scheduled maintenance downtime. However, in other implementations, the foreline cleaning operation and the chamber cleaning operation can be performed concurrently (e.g., when the semiconductor processing system 100 has sufficient plasma resources and corresponding hardware to concurrently supply the required amount of plasma to the processing chamber 106 and the assembly 400).In yet other implementations (e.g., where reducing planned downtime and increasing output relative to the above implementations), a foreline cleaning operation can be performed concurrently during one or more semiconductor processing operations. In yet other implementations, the trap 402 can deflect a flow of one or more process gases onto a foreline wall (e.g., foreline section 408, as discussed below) that can be cleaned during the foreline cleaning operation.

[0139] In such implementations, the assembly 400 includes a foreline section 408 (e.g., a flanged pipe or short pipe section separate from the foreline 102) configured to integrate the trap 402 in the foreline 102 and receive a flow of one or more process gases from the interior volume 108 of the processing chamber 106. The foreline section 408 has an inlet end 410 configured to fluidly connect a first portion of the foreline 102 that is fluidly connected to the interior volume 108 of the processing chamber 106. The foreline section 408 also includes an outlet end 412 configured to fluidly connect a second portion of the foreline 102 that is fluidly connected to the exhaust system 122. The foreline section 408 has a section wall 414 that defines a flow path 416 fluidly interposed between the inlet end 410 and the outlet end 412. The flow path 416 extends along a longitudinal axis 418 and has a section cross-sectional area A coaxial with the longitudinal axis 418. The assembly 400 also includes one or more support structures 420 configured to attach the trap 402 to the foreline section 408 (e.g., before the inlet end 410 and the outlet end 412 of the foreline section 408 fluidly connect to the first portion and the second portion of the foreline 102, respectively). Alternatively, the foreline section 408 can be an indivisible portion of the foreline 102, and the trap 402 can be inserted into the foreline 102 via a removable access plate of the foreline 102 and directly coupled to the foreline wall 116.

[0140] In this implementation, the assembly 400 also includes a valve 162 (e.g., the swing valve 162 of FIGS. 4-6). To avoid unnecessary repetition, elements in the FIG. 13-15 implementation that are similar to elements shown in FIGS. 4-6 are labeled with a number that shares the same last two digits as the similar element in FIGS. 4-6. Thus, unless otherwise noted, the discussion provided above regarding the elements of the FIG. 4-6 implementation will be understood to apply equally to the similar elements in FIG. 9. For the sake of brevity, discussion of elements that would be redundant of the earlier discussion of such elements herein is not provided where it is understood that the prior discussion of such elements applies to the similar elements in FIG. 9. In this implementation, the valve 162 includes a shutter 166 having an orifice 174 configured to flow a majority of the process gas through an inner core space of the foreline interior 118 radially inward from and spaced apart from the foreline wall 116 and to minimize flow disruption by maintaining a flow direction and flow rate within the inner core space. The orifice 174 in the shutter 166 has a circular shape with a first diameter Dl. In other implementations, the orifice 174 can have a non-circular shape (e.g., polygonal, oblong, etc.) with a corresponding maximum width. Additional axial features (e.g., ramps or steps) can also be designed into this apparatus to achieve a desired flow profile and minimize disturbances that lead to deposition.

[0141] The assembly 400 also includes a device 422 having a trap 402 configured to be coupled to the foreline section 408 and further configured to be fluidly interposed between the orifice 174 of the valve 162 and the exhaust system 122 and to remove depositable material from the process gas. The trap 402 includes one or more accumulation surfaces 404 configured to be impacted by one or more process gases flowing through the foreline section 408 during one or more semiconductor processing operations and when the trap 402 is coupled to the foreline section 408 and the foreline section 408 is fluidly connected to the foreline 102 and to cause material from the one or more process gases to be deposited on the one or more accumulation surfaces 404. The one or more accumulation surfaces 404 are further configured to be impacted by, for example, plasma from the RPS 128 that can be directly upstream of the valve 162 or from another plasma source to remove material from the one or more accumulation surfaces 404 during a foreline cleaning operation and when the trap 402 is coupled to the foreline section 408 and the foreline section 408 is fluidly connected to the foreline 102.

[0142] In this implementation, the trap is a conduit 424 having a first end portion 426, where the first end portion 426 is an open end 428 having an edge 430 defining an inlet 432. The inlet 432 is configured to receive at least a portion of the flow of one or more process gases from the orifice 174 in the valve 162 during one or more semiconductor processing operations. The inlet 432 is also configured to receive a flow of plasma (e.g., from the RPS 128 and / or chamber plasma source 199, etc.) during a pre-pipeline clean operation.

[0143] Referring to FIG. 9, the inlet 432 in the trap 402 is offset a maximum distance (e.g., in a range between 0.001 inches to 0.500 inches, etc.) along the longitudinal axis 418 from the orifice 174 to allow process gas to flow from the orifice 174 into the inlet 432. The inlet 432 in the trap 402 and the orifice 174 in the shutter 166 are coaxially positioned when the shutter 166 is in the closed position. The inlet 432 of the trap 402 has a second diameter D2 that is greater than a first diameter Dl of the shutter 166, and the ratio of the second diameter of the inlet 432 to the first diameter of the orifice 174 is greater than a minimum ratio (e.g., at least 1.5: 1) to further allow process gas to flow from the orifice 174 into the inlet 432.

[0144] The conduit 424 also includes a second end portion 434 opposite the first end portion 426. The one or more accumulation surfaces 404 include a first accumulation surface 406a spaced apart from the second end portion 434 and a second accumulation surface 406b on the second end portion 434. The second end portion 434 can be configured to trap material that can dislodge (e.g., due to flaking) from the first accumulation surface 406a. In one implementation, the second end portion 434 of the conduit 424 is a closed end 435. In other implementations, the second end portion 434 can have one or more openings (e.g., the end wall / second accumulation surface 406b has one or more holes, mesh, grating, etc. therethrough). The conduit 424 can be made of a steel alloy (e.g., SAE 304 stainless steel), an aluminum alloy, a ceramic material, or other suitable material.

[0145] Assembly 400 can include one or more support structures 420 configured to attach a first end portion 426 of conduit 424 to foreline section 408 (e.g., to hold inlet 432 of conduit 424 in a precise position relative to orifice 174 in gate 166 at which conduit 424 is coaxially positioned with orifice 174), while a second end portion 434 of conduit 424 can be free of support structures 420 (e.g., to avoid such support structures 420 obstructing the flow path and to avoid a corresponding reduction in flow conductance, to improve ease of installation, and so forth). Other implementations can configure these support structures to attach second end portion 434 to foreline section 408, and first end portion 426 free of support structures 420, although this can result in a more challenging to hold first end portion 426 in a position coaxial with orifice 174. Support structures 420 can include an outer collar 436 configured to be supported by section wall 414 in a lateral direction perpendicular to longitudinal axis 418. Support structures 420 can also include an annular flange 438 extending radially outward from outer collar 436 and configured to support trap 402 in a longitudinal direction. Annular flange 438 can be held between inlet end 410 of foreline section 408 and the first portion of foreline 102 when inlet end 410 and the first portion of foreline 102 are connected to one another. Support structures 420 can also include an inner collar 440 configured to hold trap 402. Support structures 420 can also include one or more radial arms 452 connecting outer collar 436 and inner collar 440 and positioning trap 402 radially inward from outer collar 436 (e.g., at a position at which inlet 432 of trap 402 is coaxially positioned with orifice 174 in gate 166). First end portion 426 of conduit 424 can have a first outer diameter, and the remainder of the conduit (e.g., at least second end portion 434) can have a second diameter that is less than the first outer diameter of first end portion 426 of conduit 424. An inner diameter of inner collar 440 can be less than the first diameter and greater than the second diameter. An upstream side of inner collar 440 can be configured to engage with first end portion 426 of conduit 424 and support trap 402 in an upstream direction. The inner diameter of inner collar 440 can be configured to support trap 402 in a lateral direction perpendicular to longitudinal axis 418. In other implementations, assembly 400 can include any suitable support structures configured to attach any one or more portions of trap 402 to foreline section 408, or directly to foreline 102 in implementations that omit foreline section 408.

[0146] The conduit 424 includes one or more struts 442 (e.g., three struts) extending between a first end portion 426 and a second end portion 434, which are configured to retain material within the trap 402 (e.g., material that is deposited on the one or more accumulation surfaces 404 and then dislodged therefrom). The conduit 424 also includes one or more outlets 444 configured to provide a relatively high flow conductance of the trap 402 (e.g., much higher than that provided by a porous or mesh filter). In this implementation, the conduit 424 includes three radially outward outlets 444 each defined by the first end portion 426, the second end portion 434, and a respective strut 442. For one or more angular positions on the conduit 424, a single outlet 444 exists and extends from the first end portion 426 to the second end portion 434. The middle portions of the struts 442 (i.e., the segments spaced apart from the first end portion 426 and the second end portion 434) are not connected to one another (e.g., by cross-beams to prevent these cross-beams from blocking flow through the trap 402 and to avoid a corresponding reduction in the flow conductance through these outlets 444). The second end portion 434 can include an annular flange 438 connected to the struts 442 and configured to retain material within the trap 402. The conduit 424 also includes a channel 446 fluidly interposed between the inlet 432 and the one or more outlets 444. The struts 442 and the annular wall 448 are configured to prevent dislodged material from exiting the channel of the trap 402 and traveling down the foreline 102.

[0147] The trap 402, without material deposited thereon, has a lateral obscuration profile configured to obscure a portion of the flow path 416 in the foreline section 408. The lateral obscuration profile can correspond to all locations on one or more direct impingement sections 450 of the accumulation surface 404 of the trap 402 that are within one or more direct line-of-sight views from the location to one or more locations that extend from the location and through the orifice 174 in the valve 162 to a point upstream of the valve 162. The one or more direct impingement sections 450 are configured to be directly impinged by one or more process gases to cause material from the process gases to deposit onto the direct impingement sections 450. More particularly, the one or more direct impingement sections 450 extend in a direction having a lateral component that is perpendicular to the longitudinal axis 418 of the trap 402. For each location in a first set of locations, there are a plurality of direct line-of-sight views from the location to a respective point of view that is outside of the trap 402 and positioned in an upstream direction along the foreline 102 relative to the trap 402 and / or the valve 162. Each of the locations in the first set of locations is on the one or more direct impingement sections 450. When the trap 402 (i.e., without material from the process gases deposited on the trap 402) is installed within the flow path of the foreline section 408, the lateral obscuration profile of the trap is configured to obscure between 10% and 50% of a section cross-sectional area of the foreline section 408. This range can depend on the flow profile created by the orifice 174 and the distance from the orifice 174 that creates the angle of view. The lateral obscuration profile is the total cross-sectional area of the lateral component of all of the one or more direct impingement sections 450. In this implementation, each of the struts 442 extends between the first end portion 426 and the second end portion 434 and in a direction that does not have a lateral component that is perpendicular to the longitudinal axis 418, and thus the struts 442 do not contribute to the lateral obscuration profile. In other words, the total cross-sectional area can be the cross-sectional flow area of the foreline 102 without the trap 402 in the foreline 102 minus the cross-sectional flow area of the foreline 102 with the trap 402 in the foreline 102.

[0148] FIG. 10 depicts another implementation of the trap of FIG. 9. The example trap 502 of FIG. 10 is somewhat similar to the trap 402 of FIG. 9. To avoid undue repetition, elements in the implementation of FIG. 10 that are similar to elements shown in FIG. 9 are identified with numbers that share the same last two digits as the similar elements in FIG. 9. Thus, unless otherwise noted, the above discussion of elements with respect to the implementation of FIG. 9 is to be understood to apply equally to similar elements in FIG. 10. To be brief and to the point, discussion of elements that would be redundant of earlier discussion of such elements herein is not provided where it is understood that the prior discussion of such elements applies to the similar elements in FIG. 10.

[0149] While the trap 402 of FIG. 9 includes a single outlet 444 at respective one or more angular positions of the conduit 424, the trap 502 can be a cage or filter including a plurality of outlets 544 in groups at respective angular positions on the wall of the conduit 424. Unlike the conduit 424 of FIG. 9 having a plurality of independent struts 442 and an intermediate portion (i.e., a section spaced apart from the first end portion 426 and the second end portion 434) that are not connected to one another, the conduit 524 includes a transverse wall extending between the first end portion 526 and the second end portion 534. At one or more angular positions on the wall of the conduit 524, the transverse wall 542 includes a respective plurality of outlets 544 in groups. The transverse wall 542 bounds a channel 546 along the longitudinal axis 518, where the channel 546 is interposed between the inlet 532 and the one or more outlets 544 by fluid. In some embodiments, the trap 502 can be oriented similar to the trap of FIG. 9, with the open end of the first end portion 526 adjacent to the gate 166. In other embodiments, the second end portion 534 of the trap 534 can be open and positioned closer to the gate 162 than the first end portion 526, which can be closed.

[0150] FIGS. 11 and 12 depict another example front-end line section 708 and trap 702, which are similar to the front-end line section 408 and trap 402 of FIG. 9. FIG. 11 depicts another implementation of the trap of FIG. 9. FIG. 12 depicts a bottom perspective view of the panel of FIG. 12. To avoid undue repetition, elements of the implementation of FIGS. 11 and 12 that are similar to elements shown in FIG. 9 are labeled with numbers that share the same last two digits as the similar elements in FIG. 9. Thus, unless otherwise noted, the above discussion of elements of the implementation of FIG. 9 is understood to apply equally to similar elements in FIGS. 11 and 12. To be brief and to the point, where it is understood that the prior discussion of such elements applies to these similar elements in FIGS. 11 and 12, no discussion of these elements is provided that would be redundant of the earlier discussion of similar elements herein.

[0151] While the trap 402 of Figure 9 is a conduit 424 having an inlet 432 and one or more outlets 444, the trap 702 of Figures 11 and 12 includes a plurality of panels 754 having accumulation surfaces 704 with direct impingement segments 750. There are a plurality of direct line-of-sight lines from a first position of a set of positions on the various direct impingement segments 750 to an external viewpoint located at a position upstream of the foreline 102 (Figure 1). The accumulation surfaces 704 can include one or more convex surface portions 756 and / or one or more concave surface portions 758. In other implementations, the accumulation surfaces can have one or more planar surface portions, as shown in Figure 13, and the support structure 720 can be an outer collar 736 connected between the various panels 754 and the foreline segment 408 (Figure 9).

[0152] Figures 13 and 14 depict another example foreline segment 808 and trap 802, which are similar to the foreline segment 408 and trap 402 of Figure 9. Figure 13 depicts a side view of another implementation of the foreline anti-pollution assembly of Figure 9, and Figure 14 depicts a perspective end view of the trap of Figure 13. To avoid undue repetition, elements in the implementation of Figures 13 and 14 that are similar to elements shown in Figure 9 are identified with numbers that share the same last two digits as the similar elements in Figure 9. Thus, unless otherwise noted, the above discussion of elements of the implementation of Figure 9 is to be understood as equally applicable to similar elements in Figures 13 and 14. To be brief and to the point, no discussion of elements is provided herein that is redundant to the earlier discussion of such elements to the extent that the earlier discussion of such elements is understood to apply to these similar elements in Figures 13 and 14.

[0153] While the trap 402 of Figure 9 is a conduit 424 having an inlet 432 and one or more outlets 444, the trap 802 of Figures 13 and 14 is a post 860 having a shaft 862 that terminates in a tip 864 (e.g., a tapered tip, such as a conical tip), and one or both of the shaft 862 and the tip 864 have one or more accumulation surfaces 804 that cause material from the process gas to deposit on these accumulation surfaces 804. Unlike the support structure 420 of Figure 9 having an outer collar 436 (e.g., a ring-shaped band), an inner collar 440, and one or more radial arms 452, the support structure 820 of Figures 13 and 14 has an outer collar 836 (e.g., a tube), a support platform 840 configured to support the post 860, and one or more radial arms 852 that connect the outer collar 836 with the support platform 840 and position the post 860 radially inward from the outer collar 436 (e.g., at a position where the shaft 862 of the post 860 is coaxial with the orifice 174 in the gate 166 of Figure 9).

[0154] FIG. 15 depicts another example RPS interface 926 that is somewhat similar to the RPS interface 126 of FIGS. 2 and 3. FIG. 15 depicts an enlarged cross-sectional view of region 1 of the semiconductor processing system of FIG. 1C. To avoid undue repetition, elements in the implementation of FIG. 15 that are similar to elements shown in FIGS. 2 and 3 are identified with the same last two digits of the number as the similar elements in FIGS. 2 and 3. Thus, unless otherwise noted, the above discussion of the elements of the implementation of FIGS. 2 and 3 is understood to apply equally to the similar elements in FIG. 15. To be brief and to the point, discussion of elements herein that is not provided for similar elements in FIG. 15 is not provided for those elements where it is understood that the prior discussion of such elements applies to the similar elements in FIG. 15.

[0155] While the RPS interface 126 of FIG. 2 includes a nozzle 130 having one or more coolant channels 146 located in the nozzle wall 144, the RPS interface 926 of FIG. 15 includes one or more coolant channels 946 located outside of the nozzle 930 and / or the foreline 102. The RPS interface 926 includes one or more heat sinks 945 located outside of the nozzle wall 944 and attached to a second surface of the nozzle wall 944 that is radially outward relative to a central axis of the plasma channel 932.

[0156] As shown in FIG. 15, one or more coolant channels 946a, 946b are located in the heat sinks 945 and define one or more coolant flow paths that lead from an inlet port 940a, 940b in a respective heat sink 945 to an outlet port 942a, 942b in that respective heat sink 945. In this implementation, the one or more heat sinks 945 are attached to the first end portion 936 of the nozzle wall 944 (e.g., adjacent to the remote plasma source 128, etc.). In other implementations, the one or more heat sinks 945 can be attached at other portions of the nozzle wall 944 (e.g., the second end portion 938 adjacent to the foreline 102).

[0157] In this implementation, the one or more heat sinks 945 can include a first heat sink 949 (e.g., a first block) and a second heat sink 951 (e.g., a second block), each made of a material (e.g., aluminum, copper, nickel, etc.) having a thermal conductivity within a predetermined range (e.g., between 100 and 500 W / m*K). The first heat sink 949 and the second heat sink 951 can each have one or more interfacing surfaces (e.g., concave surfaces 953, 955) configured to contact and receive heat from a corresponding one of two portions (e.g., convex surfaces 957, 959) of the nozzle wall 944. The first heat sink 949 and the second heat sink 951 can be clamped to the nozzle 930 by one or more fasteners 961 (e.g., threaded fasteners, etc.). The first heat sink 949 can have a first plurality of coolant channels 946a (e.g., seven coolant channels 946a) arranged in parallel with one another and fluidly interposed between a first inlet port 940a and a first outlet port 942a. The first inlet port 940a of the first heat sink 949 can be fluidly connected to a coolant supply line (not shown). The second heat sink 951 can have a second plurality of coolant channels 946b (e.g., seven coolant channels 946b) arranged in parallel with one another and fluidly interposed between a second inlet port 940b and a second outlet port 942b. The second outlet port 942b of the second heat sink 951 can be fluidly connected to a coolant return line (not shown). A connector line 963 can be fluidly interposed between the first outlet port of the first heat sink 949 and the second inlet port 940b of the second heat sink 951. In other implementations, the first heat sink 949 and / or the second heat sink 951 can have more or less than seven coolant channels (e.g., a single serpentine coolant channel in one or more respective heat sinks, etc.), and the RPS interface 926 can include more or less than two heat sinks 949, 951.

[0158] In some implementations, the controller 186 is part of a semiconductor processing system 100, which can be part of or include the above-described examples. As described above, the controller 186 can be configured to control the valves 182 of the gas distribution system 180 to flow one or more process gases into the processing chamber 106 to adjust the chamber pressure associated with all process gases flowing through the orifices 174 when the shutter 166 is in the first position. The controller 186 can also be configured to control the valves 182 of the gas distribution system 180 to not cause the one or more process gases to flow into the processing chamber 106 during the pre-pipeline cleaning operation. In implementations where the semiconductor processing system 100 also includes the remote plasma source 128 and a pre-pipeline plasma valve 188 fluidically interposed between the remote plasma source 128 and the RPS interface 126 of the pre-pipeline 102, the controller 186 can be further configured to control the remote plasma source 128 and the pre-pipeline plasma valve 188 to flow plasma from the remote plasma source 128 into the pre-pipeline 102 and / or through the trap 402 during the pre-pipeline cleaning operation.

[0159] The controller 186 can also be configured to control the pre-pipeline plasma valve 188 to block the one or more process gases from flowing through the RPS interface 126 and into the remote plasma source 128 to prevent material from the process gases from depositing in the RPS interface 126. The semiconductor processing system 100 can also include a chamber cleaning plasma source 199 (separate from the pre-pipeline cleaning plasma source 192) and a chamber plasma valve 198 fluidically interposed between the chamber cleaning plasma source 199 and the interior volume 108 of the processing chamber 106. The controller 186 can also be configured to control the chamber cleaning plasma source 199 and the chamber plasma valve 198 to flow plasma from the chamber cleaning plasma source 199 into the interior volume 108 of the processing chamber 106 during a chamber cleaning process.

[0160] The controller 186 can also be configured to control the chamber plasma valve 198 to stop the flow of plasma into the interior volume 108 of the processing chamber 106 to avoid unnecessarily exposing the chamber surfaces to additional plasma (e.g., when the chamber surfaces have been cleaned and the pre- chamber line plasma valve 188 continues to flow plasma into the pre-chamber line 102 and downstream to the exhaust interface). Such systems having these example controllers can include semiconductor processing equipment including 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 electronics for controlling the various processes and sub-processes during semiconductor manufacturing such as the deposition of materials, the etching of materials, thermal processes, sputtering, chemical vapor deposition (CVD), atomic layer deposition (ALD), physical vapor deposition (PVD), plasma processes, etc. The electronics can be referred to as controllers, which can control various components in the one or more systems. The controllers, depending on the processing requirements and / or type of system, can be programmed to control any of the processes disclosed herein that can result in the fouling of the pre-chamber line 102 and / or valve 162, 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, transfer into and out of tool and other transfer tools, and / or load locks connected or interfaced with the particular system.

[0161] Various techniques can be used with the systems provided herein. FIG. 18 depicts one example technique in accordance with various embodiments. In block 2651, one or more processing operations are performed on at least one substrate in a processing chamber, such as depositing a material. This can include performing one or more processing operations on a substrate in a multi-station chamber, such as the chambers 106 and 306 provided herein. During the processing operations of block 2651, a valve in a pre-chamber line, such as the throttle or swing valve 162 and 362 provided herein, can be in a closed position, such as shown in FIGS. 4, 7A, and 8A, in block 2653. During the processing operations of block 2651, gases flow through the pre-chamber line and throttle or swing valve 162 and 362, which can only flow around the orifice and other gate other features. Also during the processing operations of block 2651, in certain implementations, a buffer gas flows into the pre-chamber line through a buffer gas injector, such as the gas injectors 115, 315a, and 315b, as indicated in block 2655.

[0162] In some embodiments, during such buffer gas flow, the pressure of a portion of the precursor line network, such as the region upstream of the injector, can be maintained within a desired pressure range. For example, referring to FIG. 8A, flowing buffer gas through gas injector 315a can result in a pressure upstream of gas injector 315a (e.g., segments 396c, 396b, and 396a, and interior of chamber 308) that can be maintained at a pressure within a certain pressure range. In some cases, the pressure range can be within a certain threshold of the desired pressure of the interior chamber volume 308 during a processing operation. For example, the pressure range can be within 0.1%, 0.5%, 1%, 5%, 10%, or 25% of the desired pressure in the chamber. As provided herein, some techniques can detect the pressure upstream of the gas injector, and the flow of buffer gas can be based at least in part on the detected pressure. This can include using pressure sensor 321 in FIG. 8A to detect the pressure, and using upstream flow control and / or PID control to flow buffer gas into the precursor line 302 and maintain the desired pressure in the precursor line 302 and / or interior of the chamber 308. Such maintaining of the chamber interior pressure and detection of the pressure is represented by optional block 2657 in FIG. 18.

[0163] In some embodiments, a remote plasma can be flowed through the RPS interface provided herein into the precursor line to clean aspects of the precursor line. This is represented by optional block 2659 of FIG. 18. During this flow of the remote plasma, no buffer gas is flowed into the precursor line, and the throttle valve is not in the closed position. The throttle valve is operated to control the flow and / or pressure in the precursor line and interior of the chamber. This block 2659 can allow for one or more other operations to be performed in the chamber, which can be cleaning operations. Further, in certain implementations, such remote plasma flow can occur during a cleaning operation of the processing chamber, where a cleaning plasma is flowed within the interior of the chamber.

[0164] The controller can be configured to cause performance of various techniques, including causing various functions to occur in the systems provided herein. In some implementations, this can include causing one or more processors to cause a flow of buffer gas through a gas injector and into a front-end line network during one or more processing operations, as described herein. This can also include receiving a signal from a pressure sensor inside the chamber and causing the gas to flow based at least in part on a pressure detected by the pressure sensor. This flow can maintain a portion of the front-end line (e.g., the front-end line network) within a pressure range. The instructions can further cause a throttle valve to be in a closed position while the gas flows through the gas injector and while one or more processing operations are performed in the chamber. During other operations, such as pre- and post-treatment steps (such as cleaning), the instructions can cause the throttle valve to control the pressure within the internal volume during these other operations. The controller can also cause a remote plasma generation and flow to the RPS interface and into the front-end line.

[0165] Some other embodiments are provided herein that utilize a bypass conduit. In some other embodiments, to mitigate a sudden expansion of effluent within the front-end line, the front-end line can include a bypass conduit of a small diameter (e.g., lower flow conductance) that branches off from a larger diameter (e.g., larger flow conductance) front-end line outlet conduit. The bypass conduit can extend from a branching point and rejoin the front-end line outlet conduit at a reentry point on the front-end line outlet conduit downstream of the branching point. The bypass conduit can have a first diameter that is smaller than a second diameter of the front-end line outlet conduit. For example, the first diameter is half or less than the second diameter. The bypass conduit can have a first length that is at least the same as a second length of the front-end line.

[0166] In some implementations, the bypass conduit mitigates or eliminates clogging of the front-end line by directing the flow of effluent through a higher pressure flow path rather than through a lower pressure flow path provided by the larger diameter front-end line outlet conduit. In certain implementations, during a typical deposition process, a first valve in the front-end line can be closed and a second valve in the bypass conduit can be opened to direct the effluent into the bypass conduit. Since many deposition processes are performed at relatively high pressures within a deposition chamber, the gradual pressure reduction of the effluent gas through the bypass conduit can prevent a sudden expansion of the effluent gas. In at least one implementation, by mitigating the sudden gas expansion, the deposition of solid or semi-solid material on the surfaces of the conduit is also mitigated or prevented. In at least one implementation, the first diameter and length of the bypass conduit can be adjusted to tune the pressure drop of the effluent gas to match the design criteria of a particular vacuum pump system.

[0167] Figure 19 depicts a cross-sectional view of a process tool 2700, according to some implementations. The process tool 2700 includes a vacuum chamber 2702, also referred to as a process chamber provided above, such as the chambers 106 and 306, operable to maintain a high vacuum level (e.g., 20 Torr or less). The vacuum process chamber can include a showerhead 2704 and a susceptor 2708 above a base 2710, respectively. In some implementations, the vacuum chamber 2702 includes multiple processing stations disposed within the vacuum chamber 2702. The showerhead 2704 and the susceptor 2708 can be assigned to a first processing station, while the showerhead 2706 and the susceptor 2710 can be assigned to a second processing station. In some examples similar to the above, the vacuum chamber 2702 includes four processing stations, each station including one showerhead (e.g., similar or identical to the showerhead 2704) and one susceptor (e.g., similar or identical to the susceptor 2708). In some embodiments, the vacuum chamber 2702 can be a plasma deposition chamber operable to generate and sustain a plasma (e.g., a plasma sustained between a showerhead and a susceptor pair) at one or more processing stations. The plasma can be ignited by a large radio frequency (RF) voltage applied at the showerheads 2704 and 2706.

[0168] Process gas can be introduced into the vacuum chamber 2702 through the showerheads 2704 and 2706. Outlet ports 2712 and 2714, which are the same as the exhaust ports described above, are located on a bottom wall 2716 (or a side wall) of the vacuum chamber 2702. The outlet ports 2712 and 2714 provide an exhaust path to remove process gas effluent from the vacuum chamber 2702. The outlet ports 2712 and 2714 are coupled to a foreline having a foreline network 2718. Here, the foreline network 2718 includes a conduit 2719 coupled to the outlet ports 2712 and 2714. In some implementations, the foreline network 2718 includes multiple conduits (see Figure 21).

[0169] The foreline further includes a foreline outlet conduit 2722 coupled to the foreline network 2718. The foreline outlet conduit 2722 includes an expansion section 2724, and a metering valve 2726 is shown between the foreline network 2718 and the foreline outlet conduit 2722. The metering valve 2726 is operable to be adjustable between full open to minimum open. The metering valve 2726 can provide a leak path for process gas effluent to escape into the expansion section 2724. The metering valve 2726 can be adjusted to limit the effluent flow to maintain a minimum operating pressure within the vacuum chamber 2702. In at least one implementation, the metering valve 2726 is a throttle valve, a swing valve, a butterfly valve, or a gate valve.

[0170] In some embodiments, the vacuum chamber 2702 can be maintained at a pressure that is substantially lower than the operating pressure employed during deposition operations. To maintain a low pressure within the vacuum chamber 2702, the flow rate of the purge gas effluent (e.g., nitrogen, argon) can be substantially higher than the effluent flow rate during deposition operations. The higher flow rate of the purge gas can allow for a rapid chamber purge and maintain a lower pressure in the vacuum chamber 2702. The metering valve 2726 can be adjusted to be fully open during chamber purge operations to support the high effluent flow rate.

[0171] As shown in FIG. 19, a bypass conduit 2728 is coupled to the foreline outlet conduit 2722 at two locations. The bypass conduit 2728 diverges from the foreline outlet conduit 2722 at a branch point 2730. In at least one implementation, the branch point 2730 is located on the expansion section 2724 and proximate to or within the metering valve 2726. The bypass conduit 2728 rejoins the foreline outlet conduit 2722 at a reentry point 2732 downstream of the branch point 2730.

[0172] The bypass conduit 2728 provides a region of controlled expansion of the effluent gas flowing from the metering valve 2726. The volume of the bypass conduit 2728 is substantially smaller than the expansion section 2724. In at least one implementation, the effluent gas can be directed to flow into the bypass conduit 2728 by opening a valve 2734 proximate to or within the inlet of the bypass conduit 2728 and closing a valve 2736 on the foreline outlet conduit 2722. The effluent gas flowing in the bypass conduit 2728 experiences a controlled pressure drop after flowing through the metering valve 2726 from the foreline network 2718, thereby slowing the Joule-Thomson cooling of the effluent gas.

[0173] In at least one implementation, the process gas effluent through the narrow opening in the metering valve 2726 can rapidly expand upon entering the expansion section 2724. The sudden drop in gas pressure can cause an adiabatic expansion of the effluent gas, resulting in a rapid drop in the temperature of the gas (Joule-Thomson effect). When the effluent gas temperature drops below the condensation temperature of the deposition precursor, solid and semi-solid material can condense on the interior surface of the foreline outlet conduit 2722. The solid and semi-solid material can build up on the interior surface of the foreline outlet conduit 2722 over several process operations, which is formed from the condensed (and polymerized) deposition compounds (e.g., deposition precursor) entrained in the effluent. This contamination can clog the foreline outlet conduit 2722, requiring the vacuum pump system to be disassembled to remove the clog and clean the foreline outlet conduit 2722.

[0174] In some embodiments, bypass conduit 2728 provides an alternative flow path to front stage line outlet conduit 2722. In FIG. 19, bypass conduit 2728 branches from front stage line outlet conduit 2722 at branch point 2730 and rejoins front stage line outlet conduit 2722 at reentry point 2732. Due to the smaller expansion volume compared to expansion section 2724, bypass conduit 2728 can mitigate the sudden pressure drop of effluent gas flowing through metering valve 2726. In at least one implementation, the flow resistance of bypass conduit 2728 can be designed to provide sufficient back pressure upstream of metering valve 2726 to allow the deposition process to proceed in vacuum chamber 2702 without limiting the flow through metering valve 2726, as described above. In at least one implementation, the pressure drop of effluent gas flowing within bypass conduit 2728 can be gradual. In at least one implementation, the effluent gas pressure can monotonically decrease over the length of bypass conduit 2728. In at least one implementation, the temperature of the effluent gas can be maintained above the condensation temperature, mitigating condensation of effluent constituents. Effluent gas can be directed to flow into bypass conduit 2728 by opening of valve 2734 on bypass conduit 2728 and closing of valve 2736 on front stage line outlet conduit 2722.

[0175] In at least one implementation, a filter or filters 2738 can be disposed in series with front stage line outlet conduit 2722 proximate reentry point 2732 to capture condensed particles that can be entrained within the effluent flow through bypass conduit 2728. Front stage line outlet conduit 2722 can terminate at valve 2740. Valve 2740 can isolate front stage line outlet conduit 2722 from a vacuum pump (indicated by downward arrow) that can be coupled to front stage line outlet conduit 2722 via valve 2740.

[0176] FIG. 20 depicts a cross-sectional view of vacuum pump system 2720, according to some implementations. While many of the components of vacuum pump system 2720 have already been introduced in FIG. 19, further details will be introduced below. Branch point 2730 can be located a distance LI downstream of metering valve 2726, and reentry point 2732 can be located a distance L2 downstream of branch point 2730. In some cases, distance L2 can also approximate the length of bypass conduit 2728. Bypass conduit 2728 has a diameter Dl, and in some implementations, diameter Dl can be smaller than diameter D2 of expansion section 2724 to support a low conductance flow path for process effluent. Bypass conduit can be a low conductance conduit to achieve low effluent flow rates and higher operating pressures within vacuum chamber 2702.

[0177] In at least one implementation, the diameter D2 of the expansion section 2724 can be about 4 inches (about 10 cm). The diameter D2 can be selected to establish a high conductance, high flow path to allow the cleaning gas and effluent to be swept quickly through the process chamber 2702. In some implementations, the diameter D1 of the bypass conduit 2728 can be about 2 inches (about 5 cm) or less. In at least one implementation, the bypass conduit 2728 can be designed to allow a gradual pressure drop of the effluent gas to avoid a rapid pressure drop of the effluent gas to mitigate condensation of the precursor on the inner walls of the foreline outlet conduit 2722. The diameter D1 and length L2 of the bypass conduit 2728 can be adjusted to form a low conductance flow path suitable for generating a small pressure gradient along the bypass conduit 2728, which can significantly limit the pressure drop of the effluent gas flowing through the bypass conduit 2728 before re-entering the foreline outlet conduit 2722. In at least one implementation, a buffer gas can be introduced near the branch point 2730 to maintain the operating pressure in the vacuum chamber 2702 at a pre-set level. This can be the same or similar to the buffer gas injection provided above.

[0178] In at least one implementation, the pressure gradient within the bypass conduit 2728 can also be designed to maintain a relatively high operating pressure within the vacuum chamber 2702 without substantially closing the metering valve 2726 to limit the effluent flow into the vacuum pump system 2720. In certain implementations, the operating pressure within the vacuum chamber 2702 can be 5 Torr or higher during a plasma or non-plasma deposition process. The bypass conduit 2728 can include an expansion section 2742 upstream of the re-entry point 2732. In at least one implementation, the expansion section 2742 can allow a gradual expansion and pressure drop of the effluent gas re-entering the foreline outlet conduit 2722 at the re-entry point 2732. In at least one implementation, the foreline outlet conduit 2722 is a high conductance flow path.

[0179] As shown in FIG. 20, the re-entry point 2732 opens into a lower section 2744 of the foreline outlet conduit 2722. The lower section 2744 can have a diameter D3 that is similar to the diameter D2 of the expansion section 2724. In at least one implementation, within the lower section 2744, the effluent can expand more quickly than in the bypass conduit 2728, but can occur less abruptly than in the expansion section 2724. A filter 2738 can be included within the lower section 2744 to capture condensed particles that can be entrained within the effluent flow. In some implementations, the filter 2738 includes a throat 2746, as shown in the inset. The throat 2746 can have a characteristic diameter of 3 mm or less, while in other implementations, the characteristic diameter can be a geometric diameter (e.g., a circular throat 2746) or a hydraulic diameter (e.g., a rectangular throat 2746).

[0180] Figure 21 depicts a plan view of a foreline network 2718, according to at least one implementation. This can be similar to the foreline networks of Figures 8A and 8B. Here, the bottom wall 2716 of a vacuum chamber 2702 can be seen, and the vacuum chamber 2702 includes four process stations. The foreline network 2718 extends across the bottom wall 2716 of the vacuum chamber 2702, and the foreline network 2718 includes conduits 2748 and 2750. In at least one implementation, the conduits 2748 and 2750 are interconnected by a conduit 2719. In at least one implementation, the conduits 2748 and 2750 include vertical interconnections (e.g., extending in the z-dimension of the figure), coupling the conduits 2748 and 2750 to outlet ports (e.g., outlet ports 2712 and 2714, shown as hidden lines).

[0181] In at least one implementation, a flange 2752 extends across the conduit 2719. In at least one implementation, the flange 2752 has a diameter greater than the conduit 2719. In at least one implementation, the flange 2752 can provide a junction to couple the extension section 2724 of the foreline outlet conduit 2722, or the metering valve 2726, to the foreline network 2718.

[0182] Figure 22 depicts a cross-sectional view of a process tool system 3000, according to at least one implementation, including a process tool 2700 (enclosed in a dashed box) coupled to a mass flow controller 3010 and a vacuum pump 3020. The flow controller 3010 is coupled to the foreline network 2718 by a conduit 3012, and can be coupled to a supply of supplemental or buffer gas (e.g., nitrogen, argon) that is introduced to the foreline network 2718. The flow controller 3010 can operate to control the flow of the supplemental or buffer gas to maintain a working pressure in the vacuum chamber 2702 during a deposition process. In at least one implementation, while the pressure drop of the effluent gas can be controlled as described above, the bypass conduit 2728 can not be able to maintain the working pressure within the vacuum chamber 2702. In at least one implementation, the flow controller 3010 can be adjusted to flow supplemental gas from an external gas supply (not shown) into the foreline network 2718 to pressurize the conduit 2719 (and the conduits 2748 and 2750, Figure 21), increasing the working pressure within the vacuum chamber 2702.

[0183] A vacuum pump 3020 is shown coupled to the foreline outlet conduit 2722 below the valve 2740. In at least one implementation, the vacuum pump 3020 includes a diffusion pump or a turbomolecular pump to create a high vacuum followed by a roughing pump (not shown). The valve 2740 is operable to isolate the process tool 2700 from the vacuum pump 3020. In at least one implementation, the valve 2740 is a gate valve and is configured to be closed to isolate the vacuum chamber 2702 and the vacuum pump system 2720 when performing tool maintenance. In at least one implementation, the vacuum chamber 2702 can be brought to atmospheric pressure and opened to access the processing stations. By isolating the process tool 2700 and the vacuum pump 3020 through the valve 2740, the pumps of the pump system can be allowed to continue pumping during tool maintenance, thereby saving start-up time (e.g., pre-conditioning of diffusion pumps) when the process tool system 3000 is brought back into use.

[0184] Figure 24 depicts a cross-sectional view of the process tool system of Figure 22 performing a deposition operation, according to at least one implementation. As shown, the chamber 2702 is a multi-station chamber and the deposition operation is performed on two substrates in the chamber 2702. As described herein, in some embodiments, this operation can be an etching operation on the substrates in the chamber 2702, while in other embodiments, this operation can perform etching on at least one substrate while performing deposition on another substrate. Process gas is introduced into the vacuum chamber 2702 of the process tool system 3000 through the showerheads 2704 and 2706. The downward arrows below the showerheads 2704 and 2706 indicate the introduction of process gas into the vacuum chamber 2702.

[0185] In certain implementations, the process gas can include a gas phase precursor compound diluted in a carrier gas, such as nitrogen or argon. The precursor compound can be sublimed or vaporized from a solid or liquid source at an elevated temperature. The process gas can be pre-heated to the elevated temperature before entering the showerheads 2704 and 2706. In certain implementations, the vaporized precursor can not condense as it exits the showerheads 2704 and 2706 because the process gas can not be subjected to a large pressure change as it enters the vacuum chamber 2702. A plasma (not shown) can be ignited and maintained between the showerheads 2704 and the susceptor 2708 and between the showerheads 2706 and the susceptor 2710. The temperature within the plasma can be significantly elevated above room temperature, thereby also maintaining the gas phase existence of the deposition precursor.

[0186] In some implementations, the susceptor 2708 and 2710 support a semiconductor or insulating wafer or substrate on which a film is grown by impinging precursor molecules. The wafer or substrate can be heated to an elevated temperature to allow surface reactions, such as decomposition or polymerization of the precursors to grow a solid film on the wafer surface. Waste process gas can flow through the susceptor 2708 and 2710 and can be substantially free of precursor molecules. Some precursor molecules can be entrained in the waste process gas flow that bypasses the susceptor 2708 and 2710.

[0187] The waste process gas can be collected as process gas effluent at the outlet ports 2712 and 2714, indicated by converging arrows at the openings of the outlet ports 2712 and 2714. The process gas effluent can be exhausted from the vacuum processing chamber into interconnected conduits (e.g., conduits 2719, 2748, and 2750) of a foreline network 2718. The arrow in the conduit 2719 shows the flow of process gas effluent toward a metering valve 2726. The process gas effluent passes through the metering valve 127 into an expansion section 2724 of a foreline outlet conduit 2722. In at least one implementation, a valve 2736 in the foreline outlet conduit 2722 is closed, directing the effluent flow at a branch point 2730 into a bypass conduit 2728. A valve 2734 can be opened to allow the flow to enter the bypass conduit 2728. In some implementations, the valves 2734 and 2736 are butterfly valves or gate valves. In at least one implementation, the valves 2734 and 2736 can be coupled to actuators (not shown) that receive signals (not shown) from a controller.

[0188] In at least one implementation, the bypass conduit 2728 can be designed to prevent sudden expansion of the effluent gas flowing therein to mitigate condensation of entrained precursor vapor. The gradual reduction in pressure is achieved by the effluent flow within the bypass conduit 2728, thereby optimizing the size of the bypass conduit 2728 for a range of flow rates, as described above. The effluent gas can expand more gradually within a portion 2742 of the bypass conduit 2728 before expanding into a lower section 2744. In at least one implementation, any entrained condensate (e.g., particulates) can be captured by a filter 2738 as the effluent flow passes out of the vacuum pump system 2720.

[0189] Bypass conduit 2728 can generate sufficient back pressure to maintain at least a minimum operating pressure within vacuum chamber 2702. In at least one implementation, the operating pressure can be 5 Torr or greater. In at least one implementation, metering valve 2726 can be fully open during a deposition process because bypass conduit 2728 is operable to maintain the operating pressure in vacuum chamber 2702. Similar to that described above, in at least one implementation, a supplemental or buffer gas (e.g., nitrogen, argon) can be introduced into the foreline, including foreline network 2718, to raise the pressure level. The rate of flow of the supplemental gas can be adjusted by flow controller 3010. The supplemental gas can be coupled into foreline network 2718 via conduit 3012, as described herein, for example, by a gas injector not shown here but shown in Figures 1A-1C and Figures 7A-8B. The operating pressure within vacuum chamber 2702 can be different depending on the particular process.

[0190] Figure 24 depicts a cross-sectional view of process tool system 3000 performing a cleaning operation, according to at least one implementation. A cleaning gas can be introduced into vacuum chamber 2702 of process tool system 3000 through cleaning gas inlet port 3030. The downward arrows below cleaning gas inlet port 3030 indicate the introduction of cleaning gas into vacuum chamber 2702. The cleaning gas can include a fluorinated compound diluted in a carrier gas such as nitrogen or argon, and the cleaning gas can be pre-heated to an elevated temperature before entering cleaning gas inlet port 3030.

[0191] The cleaning gas can be collected as a cleaning gas effluent at outlet ports 2712 and 2714, indicated by converging arrows at the openings of outlet ports 2712 and 2714. In at least one implementation, the cleaning gas effluent is exhausted from the vacuum processing chamber into interconnected conduits (e.g., conduits 2719, 2748, and 2750) of foreline network 2718. The arrows in conduit 2719 show the flow of cleaning gas effluent toward metering valve 2726. The cleaning gas effluent passes through metering valve 127 into the expanded section 2724 of foreline outlet conduit 2722. As shown, valve 2736 in foreline outlet conduit 2722 is open, directing the effluent flow to continue along foreline outlet conduit 2722, as indicated by the arrows. Valve 2734 can be closed to block flow into bypass conduit 2728.

[0192] During the cleaning operation, the pressure within the vacuum chamber 2702 can be reduced relative to the working pressure of the deposition process. The pressure within the vacuum chamber 2702 can be 1 Torr or less, and the cleaning gas can be swept rapidly through the vacuum chamber 2702. The cleaning operation can employ a higher flow rate at a lower pressure than the deposition operation. In some implementations, the diameter of the foreline outlet conduit 2722 (e.g., Dl, FIG. 20) is greater than the diameter of the bypass conduit 2728 (e.g., D2, FIG. 20). The higher flow rate of the cleaning gas can be supported by flowing the cleaning gas through the foreline outlet conduit 2722. The valve 2726 can be fully open during the cleaning operation to achieve the large flow rate. In certain implementations, the valve 2726 can be omitted.

[0193] FIG. 25 depicts a flowchart of a technique for performing a deposition operation in a vacuum processing chamber, according to some implementations. Prior to or during the deposition process, a foreline valve, such as the valve 2736, can be closed at operation 3302, and a bypass line can be opened at operation 3304. With the foreline valve closed and the bypass line open, a deposition can be performed at operation 3306. During this deposition, a buffer gas can be flowed into the foreline at operation 3308, similar to that described above.

[0194] At operation 3302, a valve in the foreline (e.g., valve 2736) can be closed to direct effluent flow to the bypass conduit 2728. For example, referring to FIG. 19, spent process gas flowing through one or more processing stations can flow into the outlet ports 2712 and 2714, and into the foreline network 2718. With the valve 2736 closed, the gas flows to the bypass conduit 2728, which can provide a lower flow resistance path than the foreline outlet conduit 2722 to allow the pressure of the effluent gas flowing to the vacuum pump to gradually decrease (e.g., along the length of the bypass conduit). The gradual decrease in pressure of the effluent gas can mitigate rapid expansion of the effluent, prevent sudden condensation of the precursor material, and deposition on the interior surfaces of the vacuum lines in the vacuum system.

[0195] At operation 3304, the bypass conduit valve 2734 can be opened to enable the effluent to flow through the bypass conduit and rejoin the foreline downstream of the closed foreline valve 2736. Because the volume of the lower section of the foreline can be large relative to the internal volume of the bypass conduit, the effluent reentering the foreline can be subject to several rapid expansions. In at least one implementation, some condensate can be entrained by the effluent reentering the foreline. A screen or filter 2738 can be present in the lower section of the foreline to capture and filter out the condensate and particulates entrained in the effluent flow. The effluent can continue to flow to the vacuum pump at the terminal end of the vacuum system.

[0196] At operation 3306, at least one deposition process is performed in a vacuum chamber of a process tool (e.g., vacuum chamber 2702 of process tool 2700). As described above, a process tool can include multiple processing stations. During deposition, one or more layers of film can be grown on a substrate. For example, a deposition process can be CVD, PECVD, or ALD.

[0197] At operation 3308, a buffer gas can be introduced into the foreline network to provide back pressure within the foreline network, allowing the operating pressure in the vacuum chamber to be maintained at a setpoint value. In at least one implementation, the bypass conduit (bypass conduit 2728), while a low flow conductance conduit, can not be able to maintain the operating pressure within the vacuum chamber at the desired precursor flow rate. The buffer gas can be introduced via a flow controller (e.g., flow controller 3010). The flow controller can dynamically control the flow rate of the buffer gas in response to pressure fluctuations within the chamber. The buffer gas can include an inert gas, such as argon or nitrogen. The flow controller can be adjusted to flow make-up gas from an external gas supply into the foreline network, increasing the operating pressure within the vacuum chamber.

[0198] FIG. 26 depicts a flowchart of a technique to perform a cleaning operation in a vacuum processing chamber, according to some implementations. At operation 3402, the bypass line can be closed, and at operation 3404, the foreline outlet conduit can be opened. When the bypass line is closed and the foreline outlet conduit is opened, a cleaning operation can be performed at operation 3406. At operation 3402, referring to FIG. 19, the bypass conduit valve 2734 is closed to direct the flow of cleaning gas outflow into the higher flow conductance foreline outlet conduit 2722. At operation 3406, the foreline valve 2736 can be opened to direct the flow into the foreline outlet conduit 2722. In at least one implementation, the foreline outlet conduit 2722 has a larger diameter than the bypass conduit and provides a flow path of higher flow conductance than the bypass conduit. In some cases, the rapid expansion of the cleaning gas outflow can not be an issue, and the foreline outlet conduit 2722 can be preferred to direct the cleaning gas outflow because higher flow rates and lower chamber pressures can be supported.

[0199] At operation 3402, a cleaning process is performed in a vacuum chamber of a process tool (e.g., vacuum chamber 2702 of process tool 2700). The cleaning gas can include fluorine radicals and / or oxygen radicals. In at least one implementation, the cleaning gas can be introduced into the vacuum chamber through an inlet port (e.g., cleaning gas inlet port 3030). In at least one implementation, the cleaning operation can be performed at a relatively lower chamber pressure and at a higher flow rate than employed during a deposition process.

[0200] The following additional implementations are provided for the above implementations. One or more features of an implementation, whether alone or in combination, can be combined with one or more features of one or more other implementations to form further implementations that also fall within the scope of the disclosure. Thus, various implementations can be combined with other implementations without changing the scope of the disclosure.

[0201] Implementation 1 : An apparatus for a front-of-line anti-pollution component of a semiconductor processing system, the apparatus comprising: a trap configured to be coupled to a front-of-line section configured to be fluidically connected to a front-of-line of the semiconductor processing system; wherein the trap comprises an accumulation surface configured to be impacted by a gas flow of a process gas through the front-of-line section and to cause material from the process gas to be deposited on the accumulation surface during a semiconductor processing operation when the trap is coupled to the front-of-line section and the front-of-line section is fluidically connected to the front-of-line; and wherein the accumulation surface is further configured to be subjected to plasma impact to remove the material from the accumulation surface during a front-of-line cleaning operation when the trap is coupled to the front-of-line section and the front-of-line section is fluidically connected to the front-of-line.

[0202] Implementation 2: The apparatus of implementation 1, wherein the trap comprises a conduit including a first end portion, wherein the first end portion is an open end having an edge defining an inlet; the inlet is configured to receive the gas flow of the process gas during the semiconductor processing operation; the inlet is further configured to receive a plasma flow during the front-of-line cleaning operation.

[0203] Implementation 3: The apparatus of implementation 2, wherein the conduit further includes a second end portion opposite the first end portion; the accumulation surface comprises a first accumulation surface spaced apart from the second end portion and a second accumulation surface on the second end portion; and the second end portion is configured to trap the material dislodged from the first accumulation surface.

[0204] Implementation 4: The apparatus of implementation 3, wherein the conduit is made of a steel alloy, an aluminum alloy, or a ceramic material.

[0205] Implementation 5: The apparatus of implementation 3, wherein the second end portion of the conduit is a closed end.

[0206] Implementation 6: The apparatus of implementation 5, further comprising a support structure configured to attach the first end portion of the conduit to the front-of-line section.

[0207] Implementation 7: The apparatus of implementation 6, wherein the second end portion of the conduit is free of the support structure.

[0208] Implementation 8: The apparatus of implementation 3, wherein the conduit includes a transverse wall extending between the first end portion and the second end portion and bounding a channel along a longitudinal axis, the transverse wall configured to retain the material deposited by the process gas within the channel of the trap.

[0209] Implementation 9: The apparatus of implementation 8, wherein the transverse wall includes an outlet, and the channel is fluidically interposed between the inlet and the outlet.

[0210] Implementation 10: The apparatus of implementation 9, wherein the outlet in the transverse wall is spaced apart from the second accumulation surface, and the transverse wall includes an annular flange configured to retain the material within the channel of the trap.

[0211] Implementation 11: The apparatus of implementation 3, wherein the conduit includes a strut extending between the first end portion and the second end portion, the strut configured to retain the material within a channel of the trap.

[0212] Implementation 12: The apparatus of implementation 1, wherein the accumulation surface includes a direct-impingement section extending along a direction having a transverse component that is normal to a longitudinal axis of the trap; for each position in a first set of positions, there are a plurality of direct lines of sight from the position to a respective viewpoint that is external to the trap and positioned with respect to the trap in an upstream direction along the foreline; each position in the first set of positions is located on the direct-impingement section; the direct-impingement section includes a transverse obscuration profile in the foreline; and the transverse obscuration profile is configured to obscure a range between 10% and 90% of a segment cross-sectional area of the segment of the foreline.

[0213] Implementation 13: The apparatus of implementation 1, wherein the trap includes a plurality of panels having the accumulation surface.

[0214] Implementation 14: The apparatus of implementation 1, wherein the accumulation surface includes a planar surface portion, a convex surface portion, or a concave surface portion.

[0215] Implementation 15: The apparatus of implementation 1, wherein the trap includes a post having a shaft terminating in a tip, one or both of the shaft and the tip including the accumulation surface.

[0216] Implementation 16: A semiconductor processing system comprising a processing chamber defining an internal volume; a front-end pipeline fluidly connected to the internal volume of the processing chamber and configured to receive a flow of process gas from the processing chamber, the front-end pipeline having a discharge port configured to be connected to a discharge system; a valve within the front-end pipeline and including an orifice; and a trap within the front-end pipeline and configured to be fluidly inserted between the valve and the discharge port of the front-end pipeline; wherein the trap includes an accumulation surface configured to be impinged by a flow of process gas through the front-end pipeline and to deposit material from the process gas during semiconductor processing operations when the trap is coupled to the front-end pipeline; and wherein the accumulation surface is further configured to be impinged by plasma to remove the material from the accumulation surface during a front-end pipeline cleaning operation when the trap is coupled to the front-end pipeline segment and the front-end pipeline is fluidly connected to the front-end pipeline.

[0217] Implementation 17: The semiconductor processing system according to Implementation 16, wherein the valve includes a sealing ring coaxially positioned with the pre-line; and a gate having an outer edge region, wherein the gate is movable between a first position and a second position, in which the outer edge region is sealingly engaged with at least a portion of the sealing ring, and in the second position, a portion of the outer edge region is radially displaced inward from the inner periphery of the sealing ring.

[0218] Implementation Scheme 18: The semiconductor processing system according to Implementation Scheme 17, wherein the orifice is positioned within a certain area of ​​the gate, and the area is located within the central area of ​​the sealing ring when the gate is in the first position.

[0219] Implementation 19: The semiconductor processing system according to Implementation 18, wherein the trap includes a post having a rod shaft terminating at a tip, one or both of the rod shaft and the tip including the accumulation surface and the rod shaft being coaxially positioned with respect to the orifice in the gate.

[0220] Implementation 20: The semiconductor processing system according to Implementation 17, wherein: the trap includes a conduit including a first end portion, the first end portion being an open end having an edge defining an inlet; the inlet is configured to receive a flow of process gas during the semiconductor processing operation; and the inlet is further configured to receive a plasma flow during the front-end pipeline cleaning operation.

[0221] Implementation scheme 21: According to the semiconductor processing system of implementation scheme 20, when the gate is in the first position, the inlet in the trap and the orifice in the gate are coaxially positioned.

[0222] Implementation 22: The semiconductor processing system of implementation 20, wherein the orifice in the gate has a first diameter, and the inlet of the trap has a second diameter that is greater than the first diameter of the orifice in the gate.

[0223] Implementation 23: The semiconductor processing system of implementation 22, wherein a ratio of the second diameter of the inlet to the first diameter of the orifice is at least 1.5: 1.

[0224] Implementation 24: The semiconductor processing system of implementation 20, wherein: the conduit further comprises a second end portion opposite the first end portion; the accumulation surface includes a first accumulation surface spaced apart from the second end portion and a second accumulation surface on the second end portion; and the second end portion is configured to trap the material dislodged from the first accumulation surface.

[0225] Implementation 25: The semiconductor processing system of implementation 24, wherein the conduit is made of a steel alloy, an aluminum alloy, or a ceramic material.

[0226] Implementation 26: The semiconductor processing system of implementation 24, wherein the second end portion of the conduit is a closed end.

[0227] Implementation 27: The semiconductor processing system of implementation 26, further comprising a support structure configured to attach the first end portion of the conduit to the front-end line.

[0228] Implementation 28: The semiconductor processing system of implementation 27, wherein the second end portion of the conduit is free of the support structure.

[0229] Implementation 29: The semiconductor processing system of implementation 24, wherein the conduit includes a lateral wall extending between the first end portion and the second end portion and defining a channel along a longitudinal axis, and the lateral wall is configured to retain the material deposited by the process gas within the channel of the trap.

[0230] Implementation 30: The semiconductor processing system of implementation 29, wherein the lateral wall includes an outlet, and the channel is fluidically interposed between the inlet and the outlet.

[0231] Implementation 31: The semiconductor processing system of implementation 30, wherein the outlet includes a single outlet or a set of outlets at one or more angular positions of the lateral wall.

[0232] Implementation 32: The semiconductor processing system of implementation 16, wherein the accumulation surface includes a direct-impingement section that extends along a direction having a transverse component that is perpendicular to a longitudinal axis of the trap; for each position in a first set of positions, there are a plurality of direct lines of sight from the position to a respective viewpoint that is located outside the trap and positioned in an upstream direction along the front-end line with respect to the trap; each position in the first set of positions is located on the direct-impingement section; and the direct-impingement section includes a transverse blocking profile in the front-end line, wherein the transverse blocking profile is configured to block between 10% and 50% of a segment cross-sectional area of the front-end line.

[0233] Implementation 33: The semiconductor processing system of implementation 16, wherein the trap is coupled to a front-end line segment of the front-end line; and the front-end line segment is an inseparable part of the front-end line or a standalone flange tube fluidically interposed between a first portion of the front-end line and a second portion of the front-end line.

[0234] Implementation 34: The semiconductor processing system of implementation 33, wherein the standalone flange tube includes: an inlet end configured to fluidically connect the first portion of the front-end line that is fluidically connected to the interior volume of the processing chamber; an outlet end configured to fluidically connect the second portion of the front-end line that is fluidically connected to the exhaust system; and a flow path fluidically interposed between the inlet end and the outlet end.

[0235] Implementation 35: The semiconductor processing system of implementation 34, wherein the flow path of the front-end line segment has a segment cross-sectional area in the front-end line segment without the trap; and the trap includes a transverse blocking profile configured to block between 10% and 50% of the segment cross-sectional area of the front-end line segment when the trap (without the material deposited on the trap) is installed within the flow path of the front-end line segment.

[0236] Implementation 36: The semiconductor processing system of implementation 35, wherein the accumulation surface includes a direct-impingement section that extends along a second direction having a transverse component that is perpendicular to a longitudinal axis of the trap; and the transverse blocking profile includes a total cross-sectional area of the transverse component of the direct-impingement section as a whole.

[0237] Implementation 37: A semiconductor processing system comprising a process chamber defining an interior volume; a foreline fluidically connected with the interior volume of the process chamber and configured to receive a gas flow of process gas from the process chamber, the foreline having a drain interface configured to connect with a drain system; wherein the foreline further comprises a remote plasma source interface (RPS interface) fluidically interposed between the interior volume of the process chamber and the drain interface; and wherein the RPS interface is configured to fluidically connect a remote plasma source and to direct a plasma flow from the remote plasma source into the foreline without first flowing through the interior volume of the process chamber.

[0238] Implementation 38: The semiconductor processing system of implementation 37, wherein the RPS interface is fluidically interposed between the interior volume of the process chamber and a focus region of the foreline, wherein material is deposited at a higher rate on the focus region than a first threshold rate of material deposited on another region of the foreline during a semiconductor processing operation performed in the interior volume.

[0239] Implementation 39: The semiconductor processing system of implementation 37 or 38, wherein the foreline branches into multiple segments defining multiple flow paths, each flow path leading to a different drain port of the process chamber, the segments including non-linear sections each defining a non-linear portion of the corresponding flow path through the foreline; and the RPS interface is fluidically interposed between at least one of the non-linear portions of the corresponding flow paths and the drain interface.

[0240] Implementation 40: The semiconductor processing system of implementation 39, wherein the RPS interface is fluidically interposed between all of the non-linear portions of the flow paths and the drain interface.

[0241] Implementation 41 : The semiconductor processing system of any of implementations 37-40, wherein the RPS interface defines a plasma channel configured to direct plasma flow during a foreline cleaning process along a direction having a component parallel to a downstream direction of the foreline.

[0242] Implementation 42: The semiconductor processing system of implementation 41, wherein the foreline includes a foreline wall, and the plasma channel is configured to direct plasma flow during the foreline cleaning process along a direction that is between 30 degrees and 60 degrees relative to the foreline wall.

[0243] Implementation 43: The semiconductor processing system of implementation 37, wherein the RPS interface comprises a nozzle having a plasma passage fluidically interposed between the remote plasma source and the RPS interface of the precursor line.

[0244] Implementation 44: The semiconductor processing system of implementation 43, wherein the RPS interface comprises a nozzle having a first end portion connected with the remote plasma source and a second end portion connected with the RPS interface of the precursor line; and the plasma passage includes a first segment having a first diameter within the first end portion of the nozzle and a second segment having a second diameter within the second end portion of the nozzle, and the first diameter of the first segment is greater than the second diameter of the second segment.

[0245] Implementation 45: The semiconductor processing system of implementation 43, wherein the nozzle has a nozzle wall comprising a surface defining the plasma passage; the nozzle wall has a first end portion connected with the remote plasma source and a second end portion connected with the RPS interface of the precursor line; and the nozzle includes an inlet port and an outlet port, both located within the first end portion of the nozzle wall; and a coolant passage is located within the nozzle wall, the coolant passage defining a flow path extending from the inlet port to the outlet port and through the second end portion.

[0246] Implementation 46: The semiconductor processing system of implementation 45, wherein the coolant passage comprises a serpentine coolant passage alternating through a plurality of sections of the first end portion and a plurality of sections of the second end portion, the serpentine coolant passage having one end fluidically connected with the inlet port and having another end fluidically connected with the outlet port.

[0247] Implementation 47: The semiconductor processing system of implementation 43, wherein the RPS interface comprises a nozzle having a first end portion connected with the remote plasma source and a second end portion connected with the RPS interface of the precursor line; and the nozzle has a nozzle wall comprising a first surface facing radially inward toward a central axis and defining the plasma passage along the central axis, the nozzle wall further comprising a second surface facing radially outward relative to the central axis; and one or more heat sinks are attached to the second surface, wherein the one or more heat sinks each have one or more coolant passages fluidically interposed between an inlet port and an outlet port.

[0248] Implementation 48: The semiconductor processing system of implementation 47, wherein the one or more heat sinks comprise first and second blocks clamped to the nozzle by one or more fasteners.

[0249] Implementation 49: The semiconductor processing system of implementation 48, wherein the first block and the second block are made of aluminum, copper, or nickel.

[0250] Implementation 50: The semiconductor processing system of implementation 48, wherein a connector line is fluidically interposed between the one or more coolant channels of the first block and the one or more coolant channels of the second block.

[0251] Implementation 51: The semiconductor processing system of implementation 47, wherein the one or more coolant channels are external to at least one of the foreline and the nozzle.

[0252] Implementation 52: The semiconductor processing system of implementation 51, wherein the one or more heat sinks are attached to the first end portion of the nozzle adjacent to the remote plasma source.

[0253] Implementation 53: The semiconductor processing system of implementation 43, wherein the nozzle extends into an interior of the foreline.

[0254] Implementation 54: The semiconductor processing system of implementation 37, wherein the RPS interface terminates within an opening defined in a foreline wall of the foreline.

[0255] Implementation 55: The semiconductor processing system of implementation 37, wherein the foreline includes a swing valve fluidically interposed between the RPS interface and the exhaust interface.

[0256] Implementation 56: The semiconductor processing system of implementation 55, wherein the swing valve includes a seal ring positioned coaxially with the foreline and a gate having an outer edge region, wherein the gate is movable between a first position in which the outer edge region is sealingly engaged with at least a portion of the seal ring and a second position in which a portion of the outer edge region is radially displaced inward from an inner perimeter of the seal ring.

[0257] Implementation 57: The semiconductor processing system of implementation 56, wherein the RPS interface defines a plasma channel configured to direct plasma flow to a location at which the outer edge region of the gate is located when the gate is in the second position.

[0258] Implementation 58: The semiconductor processing system of implementation 57, wherein the gate includes an aperture positioned within an area of the gate that is within a central region of the seal ring when the gate is in the first position.

[0259] Implementation 59: The semiconductor processing system of implementation 58, further comprising: a gas distribution system including a plurality of valves controllable to selectively connect process gas from a plurality of different gas sources to the gas distribution system for flow into the processing chamber; and a controller, wherein the controller is configured to control the valves of the gas distribution system to flow process gas into the processing chamber during a semiconductor processing operation to adjust chamber pressure when the gate is in the first position, wherein in the first position the outer edge region of the gate is sealingly engaged with at least a portion of the seal ring and prevents process gas flow between the interface between the outer edge region and the seal ring.

[0260] Implementation 60: The semiconductor processing system of implementation 59, wherein the controller is configured to control the valves of the gas distribution system to not flow process gas into the processing chamber during a front line clean process.

[0261] Implementation 61: The semiconductor processing system of implementation 60, wherein the remote plasma source is configured to generate a plasma having at least one of oxygen and fluorine.

[0262] Implementation 62: The semiconductor processing system of implementation 60, further comprising the remote plasma source and a front line plasma valve fluidically interposed between the remote plasma source and the RPS interface of the front line, wherein the controller is configured to control the remote plasma source and the front line plasma valve to flow plasma from the remote plasma source into the front line during a front line clean process.

[0263] Implementation 63: The semiconductor processing system of implementation 62, wherein the controller is configured to control the front line plasma valve to prevent process gas flow through the RPS interface and to prevent material deposition within the RPS interface during a semiconductor processing operation.

[0264] Implementation 64: The semiconductor processing system of implementation 58, wherein the portion of the outer edge region comprises a notch configured to allow a portion of process gas flow when the gate is moved from the first position to the second position by a small angle movement below a predetermined angle, and to allow the swing valve to precisely control and gradually adjust a flow rate of the process gas; and to distribute a gas flow of the process gas between the orifice and the notch when the gate is in the second position, wherein in the second position the gate is positioned radially inward from an inner perimeter of the seal ring.

[0265] Implementation 65: The semiconductor processing system of implementation 64, further comprising a gate valve fluidly interposed between the RPS interface and the swing valve, wherein the gate valve is configured to move between an open position and a closed position, in which the gate valve is configured to completely prevent all process gas from flowing through the foreline.

[0266] Implementation 66: The semiconductor processing system of implementation 37, wherein the RPS interface is made of anodized aluminum alloy.

[0267] Implementation 67: The semiconductor processing system of implementation 37, wherein the remote plasma source is separate from a chamber cleaning plasma source and is configured to supply plasma to the processing chamber.

[0268] Implementation 68 is a process tool comprising a vacuum chamber; a first conduit having a first diameter, wherein the first conduit is coupled to the vacuum chamber via a foreline network, and wherein the foreline network is coupled to an outlet on the vacuum chamber; and a second conduit coupled to the first conduit, wherein the second conduit has a second diameter that is less than the first diameter.

[0269] Implementation 69 is the process tool of any implementation herein, particularly implementation 68, wherein the second conduit branches from the first conduit at a branch point located a first distance from a junction of the first conduit and the foreline network, and rejoins the first conduit at a reentry point located a second distance from the junction of the first conduit and the foreline network, wherein the second distance is greater than the first distance.

[0270] Implementation 70 is the process tool of any implementation herein, particularly implementation 69, wherein a first valve is seated on the first conduit between the branch point and the reentry point, and wherein a second valve is seated between the foreline network and the first conduit.

[0271] Implementation 71 is the process tool of any implementation herein, particularly implementation 70, wherein the first valve and the second valve are any of a ball valve, a butterfly valve, or a gate valve.

[0272] Implementation 72 is the process tool of any implementation herein, particularly implementation 70, wherein a third valve is seated between the foreline network and the first conduit.

[0273] Implementation 73 is the process tool of any implementation herein, particularly implementation 69, wherein the third valve is a swing valve, a butterfly valve, or a gate valve.

[0274] Implementation 74 is the process tool of any one of the implementations herein, particularly implementation 73, wherein the filter is positioned within the first conduit adjacent to the reentry point.

[0275] Implementation 75 is the process tool of any one of the implementations herein, particularly implementation 74, wherein the filter comprises a plurality of openings, wherein the plurality of openings have at least one characteristic diameter.

[0276] Implementation 76 is the process tool of any one of the implementations herein, particularly implementation 75, wherein the at least one characteristic diameter is 3 mm or less.

[0277] Implementation 77 is the process tool of any one of the implementations herein, particularly any one of implementations 68-76, wherein the foreline network comprises a third conduit coupled to the outlet of the vacuum chamber and the first conduit.

[0278] Implementation 78 is the process tool of any one of the implementations herein, particularly implementation 77, further comprising at least one fourth conduit coupled to the foreline network.

[0279] Implementation 79 is a process tool system comprising: a process chamber; a first conduit having a first diameter coupled to the process chamber via a foreline network, wherein the first conduit is coupled to the foreline network, and wherein the foreline network is coupled to one or more outlets on the process chamber; a second conduit coupled to the first conduit, wherein the second conduit has a second diameter that is less than the first diameter, wherein the process tool system comprises a vacuum pump coupled to the first conduit; and a flow controller coupled to the foreline network.

[0280] Implementation 80 is the process tool system of any one of the implementations herein, particularly implementation 79, wherein the foreline network comprises a plurality of interconnected third conduits, wherein the plurality of interconnected third conduits are coupled to the one or more outlets on the process chamber and the first conduit.

[0281] Implementation 81 is the process tool system of any one of the implementations herein, particularly implementation 79, further comprising a fourth conduit coupled to the foreline network, wherein the flow controller is coupled to the fourth conduit.

[0282] Implementation 82 is the process tool system of any one of the implementations herein, particularly implementation 81, wherein a gas supply is coupled to the flow controller.

[0283] Implementation 83 is all of the process tool systems of any one of the implementations herein, particularly implementation 79, wherein a first valve is positioned on the first conduit, and wherein a second valve is positioned on the second conduit.

[0284] Implementation 84 is all of the process tool systems of any one of the implementations herein, particularly implementation 83, wherein the first valve is coupled to a first valve actuator, and the second valve is coupled to a second valve actuator.

[0285] Implementation 85 is a method comprising performing a deposition process in a deposition process tool, wherein the deposition process tool comprises: a process chamber; a first conduit having a first diameter, wherein the first conduit is coupled to the process chamber via a foreline network, and wherein the foreline network is coupled to an outlet on the process chamber; and a second conduit coupled to the first conduit, wherein the second conduit has a second diameter that is less than the first diameter, wherein the second conduit has a lower flow conductance for a process gas relative to the first conduit; closing a first valve on the first conduit to stop the process gas from flowing through the first conduit; and opening a second valve on the second conduit, wherein the process gas flows through the second conduit; and wherein the flow of the process gas through the second conduit is limited by the second diameter.

[0286] Implementation 86 is all of the methods of any one of the implementations herein, particularly implementation 85, further comprising flowing a buffer gas into the foreline network.

[0287] Implementation 87 is all of the methods of any one of the implementations herein, particularly implementation 86, wherein flowing a buffer gas into the foreline network comprises: adjusting a flow rate of the buffer gas to maintain a minimum pressure within the process chamber.

[0288] Implementation 88 is a method comprising flowing a cleaning gas into a process tool, wherein the process tool comprises: a process chamber; and a process gas exhaust system coupled to the process chamber, wherein the process gas exhaust system comprises: a first conduit coupled to the process chamber via a foreline network, and wherein the foreline network is coupled to an outlet on the process chamber; and a second conduit coupled to the first conduit; and opening a first valve on the first conduit, wherein a flow of the cleaning gas exits the foreline network and flows through the first conduit.

[0289] Implementation 89 is all of the methods of any one of the implementations herein, particularly implementation 88, further comprising closing a second valve in the second conduit, wherein the flow of the cleaning gas bypasses the second conduit.

[0290] Broadly speaking, the controller can be defined as electronics having various circuitry, logic, memory, and / or software that receives instructions, issues instructions, controls operations, enables cleaning operations, enables endpoint measurements, and the like. The circuitry can include chips, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors, or microcontrollers in firmware form that store program instructions such as software. The program instructions can be in the form of routines that are executed in various sets (or program files) that are sent to the controller in various sequences, defining the operational parameters of a process to be performed on or for a semiconductor wafer or system, where process gases flow from the process chamber 106 through the foreline 102, and material from the process gas flow deposits on the foreline 102. In some examples, the operational parameters can 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 wafers.

[0291] For purposes of this disclosure, the term "fluidly connected" is used in connection with volumes, plenums, holes, and the like, that are connected to each other, either directly or through one or more intervening components or volumes, so as to form a fluid connection, similar to the use of the term "electrically connected" in connection with components that are connected together to form an electrical connection. The term "fluidly interposed" (if used) can be used to refer to a component, volume, plenum, or hole that is fluidly connected to at least two other components, volumes, plenums, or holes, such that fluid flowing from one of those other components, volumes, plenums, or holes to the other or another of those components, volumes, plenums, or holes will first flow through the "fluidly interposed" component, and then reach the other or another of those components, volumes, plenums, or holes. For example, if a pump is fluidly interposed between a reservoir and an outlet, fluid flowing from the reservoir to the outlet will first flow through the pump, and then reach the outlet. The term "fluidly adjacent" (if used) refers to the placement of one fluid element relative to another fluid element such that no intervening structure is possible between the two elements that could interrupt fluid flow between the two fluid elements. For example, in a flow path having a first valve, a second valve, and a third valve placed sequentially along the flow path, the first valve will be fluidly adjacent to the second valve, the second valve will be fluidly adjacent to both the first and third valves, and the third valve will be fluidly adjacent to the second valve.

[0292] Unless otherwise indicated herein, the term "between" as used herein in connection with a range of values is understood to include the start and end values of the range. For example, between 1 and 5 is understood to include the numbers 1, 2, 3, 4, and 5, not just 2, 3, and 4.

[0293] 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 appended claims. For clarity, identical numbers can refer to similar elements throughout the figures. 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 the non-exclusive logical OR. It will be understood that one or more steps within a method, or methods, can be executed in differing order (or concurrently) without altering the principles of the disclosure.

Claims

1. A semiconductor processing system comprising: a process chamber defining an interior volume; a foreline fluidly connected with the interior volume and configured to receive process gas from the interior volume, wherein the foreline has a foreline network and a foreline outlet conduit downstream of the foreline network; a throttle valve within the foreline outlet conduit comprising a movable gate having an orifice and configured to control gas flow through the foreline; and a gas injector in the foreline network and configured to direct a buffer gas into a conduit of the foreline network.

2. The system of claim 1, wherein the gas injector has an outlet that is centered in the conduit.

3. The system of claim 1 or 2, wherein the gas injector has an outlet that has a circular cross-sectional area.

4. The system of claim 3, wherein the conduit has an internal bore diameter that is between about two times and about six times a diameter of the outlet.

5. The system of claim 1 or 2, wherein the gas injector has an outlet that has a pneumatic exhaust muffler.

6. The system of any of claims 1-5, wherein: the foreline network comprises: a first segment spanning between a first exhaust port of the process chamber and a junction point, a second segment spanning between a second exhaust port of the process chamber and the junction point, and a third segment spanning and fluidly interposed between the junction point and the foreline, and the conduit is part of the third segment such that the gas injector is disposed along the third segment and configured to direct the buffer gas into the third segment.

7. The system of any of claims 1-6, further comprising a trap within the foreline outlet conduit and downstream of the movable gate, wherein gas flowing through the foreline is configured to contact the trap.

8. The system of claim 7, wherein the trap comprises an accumulation surface configured to be impacted by the gas flowing through the foreline.

9. The system of claim 7, wherein when the throttle valve is in a closed position, gas is configured to flow through the orifice and into the trap.

10. The system of claim 7, wherein the trap further comprises: an inlet configured to receive the gas; and a plurality of outlets.

11. The system of any of claims 1-10, wherein the throttle valve is a swing valve.

12. The system of any of claims 1-11, wherein a surface of the movable gate comprises aluminum.

13. The system of claim 1, wherein the movable gate comprises stainless steel and an aluminum coating. ​ 14. The system of any of claims 1-13, further comprising a remote plasma source interface (RPS interface) fluidically connected with the foreline outlet conduit, downstream of the interior volume and having a plasma passage configured to direct a flow of remote plasma into the foreline outlet conduit.

15. The system of claim 14, wherein the RPS interface is fluidically interposed between the foreline network and the throttle valve.

16. The system of claim 14, wherein the plasma passage is configured to direct a flow of plasma along a direction having a component parallel to a central axis of the foreline outlet conduit.

17. The system of claim 16, wherein the plasma passage is configured to direct a flow of plasma along a direction between 30 and 60 degrees relative to the central axis of the foreline outlet conduit.

18. The system of claim 14, wherein the plasma passage is configured to direct a flow of plasma along a direction having a component perpendicular to a central axis of the foreline outlet conduit.

19. The system of claim 14, wherein the RPS interface further comprises a nozzle that defines the plasma passage and extends into an interior of the foreline outlet conduit.

20. The system of claim 14, wherein: the plasma passage has a first end portion and a second end portion, the first end portion and the second end portion are configured to direct a flow of plasma into the foreline outlet conduit, the first end portion has a first diameter, and the second end portion has a second diameter that is less than the first diameter.

21. The system of claim 14, wherein the RPS interface further comprises a nozzle that defines the plasma passage and has one or more internal coolant channels configured to flow a coolant.

22. The system of claim 14, wherein the RPS interface further comprises: a nozzle that defines the plasma passage, and one or more heat sinks that are thermally coupled to an exterior surface of the nozzle and each have one or more coolant channels configured to flow a coolant.

23. The system of any of claims 1-22, further comprising: a buffer gas source fluidically connected to the gas injector; and one or more controllers having one or more processors and one or more memories storing instructions for controlling the system, the instructions configured to cause the one or more processors to cause a flow of buffer gas through the gas injector and into the foreline network during one or more processing operations.

24. The system of claim 23, further comprising a pressure sensor configured to detect a pressure upstream of the gas injector, wherein the instructions are further configured to cause the one or more processors to cause: one controller to receive a signal from the pressure sensor, and the other controller to cause a flow of buffer gas through the gas injector in response to the signal. The buffer gas flows through the gas injector based on a detected pressure, and thereby maintains a portion of the front-end line network within a pressure range.

25. The system of claim 24, wherein one of the controllers is an upstream pressure controller.

26. The system of claim 24, wherein the buffer gas is caused to flow to maintain the portion of the front-end line network within the pressure range using proportional-integral-derivative (PID) control.

27. The system of any of claims 24-26, wherein the pressure sensor is configured to measure a pressure in the internal volume.

28. The system of any of claims 24-26, wherein the pressure range is from about 7 Torr to about 11 Torr, from about 14 Torr to about 18 Torr, or from about 16 Torr to about 20 Torr.

29. The system of any of claims 24-26, wherein the instructions are further configured to cause the one or more processors to cause the throttle valve to be in a closed position while the buffer gas flows through the gas injector.

30. The system of any of claims 24-26, wherein the one or more processing operations include depositing one or more materials on a substrate.

31. The system of any of claims 24-26, wherein the instructions are further configured to cause the one or more processors to cause the throttle valve to control a pressure within the internal volume during one or more other operations that are not the one or more processing operations.

32. The system of claim 31, wherein one other operation is a cleaning operation.

33. The system of claim 32, further comprising: a remote plasma source (RPS) configured to generate a remote plasma; and a remote plasma source interface (RPS interface) fluidically connected to the front-end line and the RPS, downstream of the internal volume and having a plasma passageway configured to direct the remote plasma from the RPS into the front-end line outlet conduit, wherein the instructions are further configured to cause the one or more processors to cause: the RPS to generate the remote plasma, and the remote plasma to flow into the front-end line outlet conduit during a cleaning operation.

34. The system of claim 32 or 33, wherein the instructions are further configured to cause the one or more processors to cause the buffer gas to not flow through the gas injector during the cleaning operation.

35. A method for semiconductor processing, comprising: depositing one or more materials on a substrate in a processing chamber, wherein the processing chamber defines an internal volume and is fluidically connected to a front-end line, wherein the front-end line has a front-end line network fluidically connected to the internal volume and is configured to receive a process gas from the internal volume; maintaining a throttle valve in a closed position during the deposition, wherein the throttle valve includes a movable gate having an aperture located in a foreline outlet conduit of a foreline, and is configured to control gas flow through the foreline, and wherein the foreline outlet conduit is downstream of and fluidically connected to the foreline network, and is configured to be fluidically connected to an exhaust system; and flowing a buffer gas through a gas injector into a conduit of the foreline network during the deposition.

36. The method of claim 35, wherein flowing the buffer gas includes: maintaining a pressure in a portion of the foreline network within a pressure range.

37. The method of claim 35, wherein flowing the buffer gas includes: controlling a pressure within the internal volume.

38. The method of any of claims 35-37, further comprising detecting a pressure upstream of the gas injector, wherein flowing the buffer gas is based at least in part on the detected pressure.

39. The method of claim 38, wherein detecting the pressure includes detecting a pressure within the internal volume of the processing chamber.

40. The method of any of claims 35-39, further comprising performing one or more other operations other than the deposition, wherein the one or more other operations are performed while the throttle valve is not in the closed position and the buffer gas is not flowing into the conduit.

41. The method of claim 40, wherein: flowing the buffer gas includes: maintaining a pressure within a portion of the foreline network within a pressure range, and during the one or more other operations, the foreline is at a second pressure range that is less than the pressure range.

42. The method of claim 40, wherein one other operation is a cleaning operation.

43. The method of claim 42, further comprising flowing a remote plasma from a remote plasma source (RPS) to a remote plasma source interface (RPS interface) during the cleaning operation, the RPS interface being fluidically connected to the foreline outlet conduit and the RPS, downstream of the internal volume, and having a plasma passage configured to direct the remote plasma from the RPS into the foreline outlet conduit.

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