Airflow control in treatment tool

Abstract

One example provides a processing tool including a processing chamber and a remote plasma generator (RPG) fluidly connected to the processing chamber. The processing tool also includes an RPG gas supply system for mixing and delivering gas to the RPG. The RPG gas supply system includes a first RPG gas line for delivering a first gas to the RPG at a first lower flow rate, a second RPG gas line for delivering a second gas to the RPG at a second higher flow rate, a joint connecting the first RPG gas line and the second RPG gas line, an orifice in the first RPG gas line, a diverter valve on the second RPG gas line, a diverter valve to divert flow from the RPG, and a shared RPG gas line connecting the joint and the RPG.

Description

Background Art

[0001] Semiconductor device manufacturing processes can involve multiple steps such as material deposition, patterning, and removal to form integrated circuits on a substrate. One such deposition method is atomic layer deposition (ALD). Atomic layer deposition is a process of forming a film in the form of one or more individual layers on a substrate. The formation of each thin film layer includes sequentially adsorbing precursors onto the substrate and then chemically converting the adsorbed precursors with reactants. Summary of the Invention

[0002] The present invention content is provided to introduce a selection of concepts in a simplified form, which will be further described in the following detailed description. The present invention content is not intended to identify the key features or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. Additionally, the claimed subject matter is not limited to implementations that solve any or all of the disadvantages mentioned in any part of the present disclosure.

[0003] Examples related to controlling the flow rate of process gases in a processing tool are disclosed. One example provides a processing tool that includes a processing chamber and a remote plasma generator (RPG) fluidly connected to the processing chamber. The processing tool further includes an RPG gas supply system for mixing and delivering gases to the RPG. The RPG gas supply system includes a first RPG gas line for delivering a first gas to the RPG at a first flow rate and a second RPG gas line for delivering a second gas to the RPG at a second flow rate, the second flow rate being higher than the first flow rate. The RPG gas supply system further includes a joint connecting the first RPG gas line and the second RPG gas line. The RPG gas supply system further includes an orifice in the first RPG gas line and a diverter valve in the second RPG gas line for diverting flow from the RPG. The RPG gas supply system further includes a shared RPG gas line connecting the joint and the RPG.

[0004] In some such examples, the second RPG gas line alternatively or additionally includes a mass flow controller located upstream of the joint connecting the first RPG gas line and the second RPG gas line.

[0005] In some such examples, the first RPG gas line alternatively or additionally is connected to a hydrogen source and a nitrogen source.

[0006] In some such examples, the second RPG gas line alternatively or additionally is connected to a nitrogen source.

[0007] In some such examples, the processing chamber includes a showerhead and a pedestal, and the showerhead includes a showerhead purge gas outlet disposed adjacent to the periphery of the showerhead.

[0008] In some such examples, the processing tool alternatively or additionally includes a controller configured to control an inert gas flow through the showerhead purge gas outlet during a deposition process.

[0009] In some such examples, the processing tool alternatively or additionally includes a susceptor and a below-susceptor purge system. The below-susceptor purge system includes one or more openings to allow purge gas to flow into the space below the susceptor in the processing chamber.

[0010] In some such examples, the processing tool alternatively or additionally includes a controller configured to control an inert gas flow through the below-susceptor purge system during a deposition process.

[0011] In some such examples, the processing tool alternatively or additionally includes a flowing-over-vapor (FOV) chemical supply system for delivering a processing chemical to the processing chamber. The FOV chemical supply system includes a processing chemical delivery gas line having an inner diameter in the range of 0.110 - 0.430 inches.

[0012] Another example provides a processing tool including a processing chamber. The processing chamber includes a susceptor well. The processing tool further includes a susceptor at least partially located within the susceptor well and a below-susceptor purge system configured to introduce a flow of purge gas into the susceptor well below the susceptor.

[0013] In some such examples, the below-susceptor purge system alternatively or additionally includes a below-susceptor plenum at least partially disposed around a susceptor support of the susceptor. The below-susceptor plenum includes one or more openings to allow purge gas to flow from below the susceptor into the processing chamber.

[0014] In some such examples, the below-susceptor plenum alternatively or additionally is annular.

[0015] In some such examples, the below-susceptor plenum alternatively or additionally includes a plurality of openings.

[0016] In some such examples, the below-susceptor plenum alternatively or additionally is additively manufactured.

[0017] In some such examples, the processing tool alternatively or additionally includes a showerhead. The showerhead includes a showerhead purge gas outlet.

[0018] Another example provides a method of modifying a processing tool. The processing tool includes a processing chamber and a flowing over vapor (FOV) chemical supply system for delivering a processing chemical to the processing chamber. The FOV chemical supply system includes a gas line for delivering the processing chemical to the processing chamber. The method includes replacing an initial gas line with a replacement gas line. The replacement gas line includes an inner diameter smaller than that of the initial gas line. The replacement gas line reduces the time elapsed between opening a valve of the FOV chemical supply system and the FOV chemical reaching the processing chamber. The method further includes replacing at least one other FOV chemical supply system component to reduce the dead volume in the FOV chemical supply system.

[0019] In some such examples, the initial gas line includes an inner diameter greater than or equal to 0.305 inches, and the replacement gas line includes an inner diameter in the range of 0.110 - 0.430 inches.

[0020] In some such examples, replacing at least one other FOV chemical supply system component alternatively or additionally includes shortening a valve connection.

[0021] In some such examples, replacing at least one other FOV chemical supply system component alternatively or additionally includes removing plenum volume hardware.

[0022] In some such examples, replacing at least one other FOV chemical supply system component alternatively or additionally includes replacing a first valve manifold with a second valve manifold having a reduced dead volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A block diagram of an exemplary processing tool is shown.

[0024] Figure 2 An example remote plasma generator (RPG) gas manifold for selectively diverting a purge gas to an exhaust system is schematically shown.

[0025] Figures 3A - 3B A diverter valve in the RPG gas manifold is schematically shown.

[0026] Figures 4A - 4B An exemplary effect of the diverter valve of FIG. 3 on the flow rates of the inflow and outflow of an exemplary processing chamber is schematically shown.

[0027] Figure 5A An exemplary initial flowing over vapor (FOV) gas line is schematically shown.

[0028] Figure 5B An exemplary replacement FOV gas line is schematically shown.

[0029] Figure 6 Shows an illustration Figures 5A - 5B of the exemplary effect of the modification on the precursor flow rate into an exemplary processing chamber.

[0030] Figure 7 Schematically shows an exemplary showerhead including a purge gas outlet.

[0031] Figure 8 Schematically shows an exemplary below-pedestal purge system.

[0032] Figure 9 Schematically shows another exemplary below-pedestal purge system.

[0033] Figure 10 Shows a flowchart illustrating an exemplary process for modifying a processing tool to reduce dead volume in a FOV chemical supply system. Detailed Description

[0034] The term "atomic layer deposition" (ALD) generally refers to a process in which one or more thin films in the form of discrete layers are formed on a substrate by sequentially adsorbing precursors onto the substrate and then chemically transforming the adsorbed precursors to form a film layer. Examples of ALD processes include plasma-enhanced ALD (PEALD) and thermal ALD (TALD). PEALD and TALD utilize a plasma of a reactive gas and heat, respectively, to facilitate the chemical transformation of the precursors adsorbed on the substrate, thereby forming a film on the substrate.

[0035] The term "below-pedestal purge system" generally refers to a system that introduces a controlled purge gas flow into the chamber at a location below the pedestal in a processing chamber.

[0036] The term "inflatable volume hardware" generally refers to an open volume in a gas pipeline that is used to increase the internal volume of a processing gas distribution system. For example, the inflatable volume hardware may include a pipe section for collecting and subsequently releasing a gas volume during pressure variations in a processing cycle.

[0037] The term "dead volume" generally refers to a volume in a fluid pipeline that has no inlet and outlet and only a single opening. The dead volume can exist temporarily. For example, a valve may include a valve stem that defines a dead volume when the valve is closed, but does not define a dead volume when the valve is open.

[0038] The term "divert valve" generally refers to a valve that can switch between introducing a fluid into a processing chamber and introducing the fluid into a discharge system.

[0039] The term "flow over vapor" (FOV) generally refers to the delivery of a liquid precursor to a processing chamber by flowing a carrier gas over the surface of the liquid precursor, thereby entraining precursor vapor as the carrier gas flows.

[0040] The term "gas supply system" generally refers to a system consisting of pipes, fittings, connectors, valves, mass flow controllers, and / or other components for delivering gas from a starting point to a destination point in a controlled manner.

[0041] The term "mass flow controller" (MFC) generally refers to a device for controlling the mass flow of a fluid. The mass flow controller compensates for density to maintain a constant mass flow at a given set point.

[0042] The term "pedestal" generally refers to a structure upon which a substrate is placed in a processing chamber during processing.

[0043] The term "pedestal rod" generally refers to a support structure that secures the pedestal in a position above the base of the processing chamber within the processing chamber.

[0044] The term "pedestal well" generally refers to a volume of space within the processing chamber that is located below the pedestal and is recessed compared to an adjacent bottom surface in the processing chamber. The pedestal rod may be located within the pedestal well.

[0045] The term "plasma" generally refers to a gaseous component that includes cations and free electrons.

[0046] The term "processing chamber" generally refers to an enclosure in which a substrate is subjected to chemical and / or physical processing. The pressure, temperature, and atmospheric composition within the processing chamber can be controlled to perform chemical and / or physical processing.

[0047] The term "processing tool" generally refers to a machine that includes a processing chamber and other hardware configured to be capable of performing ALD on a substrate located within the processing chamber.

[0048] The term "purging" and its variants generally refer to a process of removing unwanted substances from the processing chamber.

[0049] The term "remote plasma" generally refers to a plasma used to generate a chemical species at a location remote from the substrate being treated with the chemical species.

[0050] The term "remote plasma generator" (RPG) generally refers to a combination of components that can be used to form a remote plasma.

[0051] The term "showerhead" generally refers to an outlet for a processing chemical that includes a plurality of holes distributed over an area.

[0052] The term "substrate" generally refers to any object on which a film can be deposited.

[0053] The term "manifold" generally refers to a structure that can distribute process gas from one pipeline to multiple pipelines, or collect process gas from multiple pipelines into one pipeline.

[0054] As described above, ALD refers to forming a film in the form of one or more individual thin film layers on a substrate in a processing chamber: adsorbing a first precursor onto the substrate in sequence, and then chemically converting the adsorbed precursor to form a film layer. Reactants can be used in the chemical conversion step. In some examples, the reactants for chemical conversion can be introduced into a remote plasma generator (RPG). The RPG can convert the reactants into reactive species. The reactive species are introduced into the processing chamber. The reactive species in the processing chamber react with the precursor adsorbed on the substrate, thereby causing chemical conversion.

[0055] ALD processing includes alternately introducing a precursor and a reactant into the processing chamber. A purge step is used between introducing the precursor into the processing chamber and introducing the reactant from the RPG into the processing chamber. However, it takes some time for the flow rates of the first precursor and the reactive species from the RPG to stabilize and reach their respective set values. In the case of using a mass flow controller to control the gas flow rate, the ramp-up and ramp-down times of the mass flow controller may account for a large part of the ALD cycle time.

[0056] Reducing the switching time between the flow rates of the first precursor and the reactant from the RPG can shorten the ALD cycle time. This helps to increase the throughput. Accordingly, the present invention discloses a processing tool configured to switch gas flows in an efficient manner. One example provides a processing tool. The processing tool includes a processing chamber. The processing tool further includes a remote plasma generator (RPG) fluidly connected to the processing chamber. The processing tool further includes an RPG gas supply system for mixing gases and delivering the gases to the RPG. The RPG gas supply system includes a first RPG gas pipeline for delivering a first gas to the RPG at a first flow rate; and a second RPG gas pipeline for delivering a second gas to the RPG at a second flow rate, the second flow rate being higher than the first flow rate. In some examples, the first RPG gas pipeline can deliver a low flow rate of nitrogen and a high concentration of hydrogen as a precursor gas mixture for forming nitrogen-containing radical species in the RPG. The second RPG gas pipeline can deliver a higher flow rate of nitrogen for purging the processing chamber. The RPG gas supply system further includes a junction at the intersection of the first RPG gas pipeline and the second RPG gas pipeline. The RPG gas supply system further includes an orifice in the first RPG gas pipeline, a diverter valve of the second RPG gas pipeline for selectively diverting the flow rate in the second RPG gas pipeline from the RPG, and a shared RPG gas pipeline connecting the junction to the RPG.

[0057] If the ramp-up and ramp-down of the purge gas flow rate in the second RPG gas line are achieved by controlling a mass flow controller, the ramp-up and ramp-down processes in each cycle may take a significant amount of time. However, a diverter valve in the second gas supply line can quickly introduce the purge gas flow rate in the second RPG gas line into the RPG for the purge process and then quickly divert it to the exhaust system for the reactant deposition cycle. The gas flow rate in the first RPG gas line can be maintained at a set low level. When the diverter value in the second RPG line switches to supply the purge gas to the RPG, the orifice in the first RPG gas line can prevent backflow. For example, this helps prevent an interruption in the hydrogen gas flow rate that may occur when the diverter valve is switched back to the operating diverter valve to direct the purge gas to the exhaust system. Therefore, this helps to more quickly stabilize the gas flow rate between ALD cycles.

[0058] Another example provides a processing tool including a processing chamber that includes a susceptor well, a susceptor at least partially located within the susceptor well, and a susceptor-under purge system configured to introduce a purge gas flow rate beneath the susceptor into the susceptor well. During precursor adsorption and during the chemical conversion process, the purge gas flow rate from the susceptor well can help reduce the migration of the process gas into the susceptor well. When switching the gas flow rate, the purge gas flow rate from beneath the susceptor can help shorten the purge time. The susceptor-under purge system also helps increase the residence time of the precursor gas and / or reactant species on the substrate surface, which will be described in more detail below. These effects can help increase the throughput.

[0059] In addition, an ALD tool can be modified to reduce the time required for the precursor feed to reach the processing chamber. For example, the inner diameter of one or more gas lines in the ALD tool can be reduced to increase the flow rate within one or more gas lines. Therefore, another example disclosed provides a method of modifying a processing tool. The processing tool includes a processing chamber and a flowing vapor stream (FOV) chemical supply system for delivering a processing chemical to the processing chamber. The FOV chemical supply system includes a gas line for delivering the processing chemical to the processing chamber. The method includes replacing an initial gas line with a replacement gas line, the initial gas line having an inner diameter greater than or equal to 0.305 inches, and the replacement gas line having an inner diameter in the range of 0.110 - 0.430 inches. Replacing the initial gas line with the replacement gas line can shorten the time between opening the valve of the FOV chemical supply system and the FOV chemical reaching the processing chamber. The method also includes replacing at least one other FOV chemical supply system component to reduce the amount of dead volume in the FOV chemical supply system.

[0060] Figure 1FIG. 0 shows a block diagram of an exemplary processing tool 100 for performing material deposition. The processing tool 100 includes a processing chamber 102. The processing chamber 102 includes a processing station 104. The processing station 104 includes a pedestal 106 for supporting a substrate 108. The pedestal 106 is at least partially located within a pedestal well 107 that is recessed from a surrounding area of the processing chamber base 109. The pedestal 106 may further include a substrate heater 110 configured to heat the substrate 108.

[0061] The processing station 104 further includes a processing gas outlet 112. In some examples, the processing gas outlet 112 may include a nozzle, a showerhead, or other means for introducing a processing gas into the processing station 104. The pedestal 106 can be raised and lowered to adjust the spacing between the substrate 108 and the processing gas outlet 112. In some examples, the processing gas outlet 112 may include a heater.

[0062] The processing gas outlet 112 is in fluid connection with a remote plasma generator (RPG) 114. The RPG 114 is configured to generate radical species from a gas-phase precursor. The radical species formed by the RPG 114 can react with the precursor adsorbed on the substrate surface to form a film layer in an ALD process. The RPG 114 will be discussed in more detail below.

[0063] In some examples, the processing chamber 102 may include multiple processing stations. The multiple processing stations are shown as processing station 2 116 to processing station N 118 in Figure 1 In this example, N is an integer equal to or greater than zero. In this schematic, both processing station 2 116 and processing station N 118 are located outside the processing chamber 102, but may also be located within the processing chamber 102. Each of processing station 2 116 and processing station N 118 includes a substrate holder, a substrate heater, a processing gas outlet, an RPG, and other hardware for processing a substrate within the processing chamber 102. In other examples, the processing chamber may include a single processing station.

[0064] The processing tool 100 further includes an ampoule 120 configured to hold a liquid-phase precursor having a vapor pressure. The ampoule 120 includes a flowing-over-vapor (FOV) gas inlet 122 for flowing a carrier gas from a carrier gas source 124 into the ampoule 120. Exemplary carrier gases include nitrogen and argon. Other exemplary carrier gases include helium, neon, krypton, and xenon. The FOV gas inlet 122 may include a mass flow controller (not shown) for controlling the flow rate of the carrier gas.

[0065] The ampoule 120 further includes a FOV gas outlet 126 for allowing gas to flow out of the ampoule 120. When the carrier gas flows through the ampoule 120, the carrier gas will flow over the surface of the precursor and draw in the precursor vapor via the FOV gas outlet 126. The valve 128 can be controlled to direct the gas flowing out of the ampoule 120 into the FOV distribution system 130 or the exhaust system 131. The exhaust system 131 is configured to exhaust gas from the processing chamber 102. The exhaust system 131 can include any suitable components, including one or more pumps.

[0066] The FOV distribution system 130 is configured to distribute the precursor from the ampoule 120 to the processing stations 104, 116, and 118. A portion of the gas from the FOV distribution system 130 flows to the processing station 104 and to the substrate via the process gas outlet 112. Similar portions of the gas from the FOV distribution system 130 also flow into the processing station 2 116 and the processing station N 118, respectively.

[0067] The processing tool 100 further includes an RPG gas manifold 132 and an RPG gas distribution system 134. The RPG gas manifold 132 is in fluid connection with one or more gas sources A 136 and one or more gas sources B 138. The gas source A 136 can include a reactive gas or a reactive gas mixture. The gas source B 138 can include a purge gas or a purge gas mixture. Thus, the gas source A can be configured to allow the process gas to flow into the RPG gas manifold 132 at a first flow rate. Additionally, the gas source B can be configured to allow the purge gas to flow into the RPG gas manifold 132 at a second flow rate, which is higher than the first flow rate. In the depicted example, the gas source A 136 includes a mixture of hydrogen and nitrogen at 140. Additionally, the gas source B 138 includes nitrogen at 142. In other examples, the gas source A 136 and / or the gas source B 138 can use any suitable gas or gas mixture.

[0068] When the RPG 114 generates reactants for ALD processing, the gas source A 136 rather than the gas source B 138 can supply gas to the RPG 114. During purging, the gas source A 136 and the gas source B 138 can supply gas to the RPG 114. Thus, as described in more detail below, an RPG gas manifold 132 valve can be provided to selectively direct gas from the gas source B to the RPG gas manifold 132 or to the exhaust system 131.

[0069] As described in more detail below, the RPG gas manifold 132 includes an orifice 133. When the gas source B 138 switches from supplying gas to the exhaust system 131 to supplying gas to the RPG gas manifold 132, the orifice 133 is configured to prevent the gas flow from the gas source B 138 from causing hydrogen to flow backward into the gas source A 136. Exemplary orifices will be described in more detail in conjunction with Figure 2 Exemplary orifices will be described in more detail.

[0070] The gas from the RPG gas manifold 132 is directed to the RPG gas distribution system 134. The RPG gas distribution system 134 is configured to distribute gas among the RPGs (such as the RPG 114, the RPG of process station 2 116, and the RPG of process station N 118) at different process stations. During ALD processing, the RPG 114 generates reactants from the gas introduced by the gas source A 136. The reactants from the RPG 114 enter the process station 104 through the process gas outlet 112.

[0071] The processing tool 100 further includes a radio frequency power supply 144 electrically connected to the RPG 114. The processing tool 100 further includes a matching network 146 for impedance matching of the radio frequency power supply 144. The RPG 114 may include a capacitively coupled plasma generator or an inductively coupled plasma generator. In other examples, the RPG may include a microwave plasma generator.

[0072] The radio frequency power supply 144 can be configured for any suitable frequency and power. Examples of suitable frequencies include 400 kHz, 13.56 MHz, 27 MHz, 60 MHz, and 90 MHz. Examples of suitable power include power between 50 W (watts) and 50 kW. In some examples, the radio frequency power supply 144 can be configured to operate at multiple different frequencies and / or powers.

[0073] The controller 148 is operably coupled to the controllable components of the processing tool 100. For example, the controller 148 is operably coupled to the substrate heater 110, the RPG 114, the ampoule 120, the exhaust system 131, the RPG gas manifold 132, the radio frequency power supply 144, and the matching network 146. The controller 148 is also capable of being operably coupled to any other appropriate components of the processing tool 100. The controller 148 is configured to control the various functions of the processing tool 100 to perform ALD processing.

[0074] For example, the controller 148 is configured to operate the substrate heater 110 to heat the substrate. The controller 148 is also configured to control the valve 128 to allow gas to flow from the ampoule 120 to the FOV distribution system 130 or direct the gas to the exhaust system 131.

[0075] As a further example, the controller 148 is also configured to control a diverter valve in the RPG gas manifold 132. The controller 148 can direct the gas flow from the RPG gas manifold 132 to the RPG gas distribution system 134 by switching the diverter valve to flow to the RPG gas distribution system 134. Similarly, the controller 148 can direct the gas flow to the exhaust system 131 by switching the diverter valve to flow to the exhaust system 131. The controller 148 is also configured to operate the exhaust system 131 to exhaust the gas in the processing chamber 102.

[0076] Figure 2 Schematically shows an exemplary RPG gas manifold 200. The RPG gas manifold is an Figure 1 example of the RPG gas manifold 132. The RPG gas manifold 200 receives gas flows from gas source A and gas source B. The gas from gas source A is conveyed via the first RPG gas pipeline 201. The gas from gas source B is conveyed via the second RPG gas pipeline 203. Each of gas source A and gas source B can include a single gas from a single gas source, or a gas mixture from one or more sources. As described above, in some examples, gas source A can include a mixture of hydrogen and nitrogen, and gas source B can include nitrogen.

[0077] The gas flow rate from gas source A is controlled by one or more mass flow controllers, which are represented herein as mass flow controller 202. In some examples, a single mass flow controller 202 can be calibrated to allow the mixture of hydrogen and nitrogen to flow. In other examples, nitrogen and hydrogen can use separate mass flow controllers. In addition, the flow from gas source B is controlled by one or more mass flow controllers, which are represented herein as mass flow controller 204. Gas source B can be configured to provide nitrogen. Accordingly, the mass flow controller 204 is calibrated to allow nitrogen to flow. In other examples, one or more purge gases other than nitrogen can be used as an alternative or supplement.

[0078] The diverter valve 206 is located downstream of the mass flow controller 204. The diverter valve 206 includes an inlet 208, a first outlet 210, and a second outlet 212. When the diverter valve 206 is in the first state, the gas from gas source B is diverted to the exhaust system 213. Downstream of the diverter valve 206, the second RPG gas pipeline 203 is connected to a tee 214. The first RPG gas pipeline 201 is also connected to the tee 214. There is a shared RPG gas pipeline 216 between the tee 214 and the RPG gas distribution system 218. The RPG gas distribution system 218 is an Figure 1 example of the RPG gas distribution system 134 in

[0079] When the diverter valve 206 is switched to the second state, the gas from the gas source B is introduced into the tee 214. As previously described, the flow rate of the process gas mixture that the gas source A can provide is relatively lower than the flow rate of the purge gas from the gas source B. The difference in flow rates has the potential to cause the gas from the gas source B to flow back into the first RPG gas pipeline 201. This can cause a concentration transient, thereby delaying the gas stabilization in the ALD process. Therefore, the first RPG gas pipeline 201 includes an orifice 220 that prevents such backflow by blocking the higher flow rate flowing into the first RPG gas pipeline 201 from the gas source B. The orifice 220 can have any suitable configuration. In some examples, the orifice 220 can be formed in the gas pipeline gasket. In other examples, the orifice 220 can include a structure separate from the gasket. The orifice 220 can be located at any appropriate distance upstream of the tee 214 in the path of the first RPG gas pipeline 201. In some examples, the diameter of the orifice 220 can be in the range of 0.015 to 0.080 inches. In some examples, the diameter of the orifice 220 can be in the range of 0.015 to 0.025 inches. In other such examples, the diameter of the orifice 220 can be in the range of 0.050 to 0.080 inches. In various implementations, an orifice with a diameter in these ranges helps prevent the backflow of hydrogen. In other examples, the size of the orifice can be outside these ranges.

[0080] Compared with using a mass flow controller to control the purge gas flow rate, using the diverter valve 206 to control the purge gas flow rate from the gas source B enables the purge gas flow rate flowing to the RPG to stabilize more quickly.

[0081] Figure 3A An RPG gas system 300A including an RPG gas manifold 302A without a diverter valve is schematically shown. The term "RPG gas system" refers to the components that provide an air flow to the RPG and control the gas flow rate. Figure 3B An RPG gas system 300B including an RPG gas manifold 302B having a diverter valve 303 is schematically shown. In Figure 3A , S1, S2, S3, and S4 represent four processing stations in the processing chamber 304A. In Figure 3B , 3A , S1, S2, S3, and S4 represent four processing stations in the processing chamber 304B.

[0082] Figure 3AThe RPG gas system 300A includes a first RPG gas pipeline 306A and a second RPG gas pipeline 308A. The first RPG gas pipeline 306A is configured to provide a flow rate of reaction gas 310A. The reaction gas may include a gas mixture, such as a hydrogen / nitrogen mixture. The second RPG gas pipeline 308A is configured to provide a flow rate of purge gas 312A. Nitrogen is an exemplary purge gas. During ALD processing, the flow rate of the purge gas is controlled by a mass flow controller 314A. The flow rate of the reaction gas may also be controlled by a mass flow controller (not shown) along the first RPG gas pipeline 306A.

[0083] Figure 3B The RPG gas system 300B includes a first RPG gas pipeline 306B and a second RPG gas pipeline 308B. The first RPG gas pipeline 306B is configured to provide a flow rate of reaction gas 310B. The reaction gas may be a gas mixture, such as a hydrogen / nitrogen mixture. The second RPG gas pipeline 308B is configured to provide a flow rate of purge gas 312B. The RPG gas system 300B further includes a diverter valve 303 in the second RPG gas pipeline 308B. During ALD processing, the flow rate of the purge gas is controlled by the diverter valve 303 instead of by a mass flow controller 314B. The flow rate of the reaction gas may also be controlled by a mass flow controller (not shown) along the first RPG gas pipeline 306B.

[0084] Figure 4A Shows a graph of the flow rate of reactant gas flowing into the processing chamber over time for the RPG gas system 300A and the RPG gas system 300B. Curve 402 is for the RPG gas system 300A, where the mass flow controller 314A is used to control the flow rate of the purge gas flowing into the processing chamber 304A. Curve 404 is for the RPG gas system 300B, where the diverter valve 303 is used to control the flow rate of the purge gas flowing into the processing chamber 304B, while the mass flow controller 314B maintains a set flow rate. Figure 4A The graph 402 in shows a relatively large time lag. This time lag represents Figure 3A the time required for the purge gas to reach the processing chamber after the mass flow controller 314A in is opened. If the mass flow controller 314A is moved further upstream of the processing chamber 304A, the time lag may increase. In contrast, referring to graph 404, when the diverter valve 303 is used in the RPG gas system 300B, the time lag is relatively low. Placing the diverter valve 303 and the RPG gas manifold 302B physically closer to the processing chamber 304B to shorten the gas pipeline between these components (as compared to using a longer gas pipeline between these components) can help further reduce the time lag.

[0085] Next, Figure 4BShows a graph of the purge gas flow rate in the effluent processing chamber of RPG gas system 300A and RPG gas system 300B over time. Curve 406 is for RPG gas system 300A, where mass flow controller 314A is used to control the purge gas flow rate to processing chamber 304A. Curve 408 is for RPG gas system 300B, where diverter valve 303 is used to control the purge gas flow rate to processing chamber 304B, while mass flow controller 314B maintains a set flow rate. As shown, compared to the mass flow controller, using diverter valve 303 to control the gas flow rate into the processing chamber can empty the processing chamber faster after purging, because the response speed of diverter valve 303 is faster.

[0086] In ALD processing, the purge gas flow rate can be turned on and off multiple times. If only a mass flow controller is used to control the purge gas flow rate, then as shown by curves 402 and 406, the ramp-up and ramp-down times can comprise a large proportion of the ALD cycle time. In contrast, as shown by curves 404 and 408, additionally using a diverter valve to control the purge gas flow rate can speed up the ramp-up and ramp-down times. This can reduce the overall time of the ALD process and help increase the tool throughput.

[0087] Switching the precursor flow to the chamber also affects the overall time of the ALD process. As described above, in ALD processing, the precursor is adsorbed onto the substrate surface. Then the excess precursor is purged from the processing chamber. After purging, the precursor adsorbed on the substrate surface is chemically converted to a film on the substrate surface by the reactant. In some examples, the precursor can include a liquid-phase chemical having a vapor pressure. In these examples, the precursor vapor can be delivered to the processing chamber using a FOV delivery system. Briefly referring back Figure 1 The liquid-phase precursor is stored in ampoule 120. The precursor in ampoule 120 includes a vapor pressure. Thus, the precursor vapor can be carried to the FOV distribution system 130 using the carrier gas of carrier gas source 124.

[0088] However, during ALD processing, cycling the FOV precursor delivery on and off can cause delays. Some delays may be due to the diameter of the gas lines used in the FOV precursor delivery system. The dead volume within the FOV precursor delivery system can also cause other delays. For example, compared to a gas line with a smaller inner diameter, a gas line with a larger inner diameter delivers the feed of the precursor vapor to the processing chamber more slowly. Similarly, the dead volume in the FOV precursor delivery system slows down the delivery of the precursor.

[0089] Therefore, to reduce the lag time associated with turning the FOV precursor delivery system on and off between ALD cycles, the inner diameter of the gas lines can be reduced. Additionally, the FOV gas lines can be modified to reduce the dead volume. Figure 5ASchematically shows an exemplary initial gas line 502 from an ampoule to a FOV distribution system. Figure 5A Also shown is an inflation volume hardware 504 and a diverter valve 506. The inflation volume hardware 504 represents the hardware in the FOV distribution system that increases the internal volume of the system. In some examples, the inner diameter of the initial gas line 502 is 0.305 inches or greater.

[0090] Figure 5B Schematically shows an exemplary modification of replacing the initial gas line 502 with a replacement gas line 508. The inner diameter of the replacement gas line 508 is less than the inner diameter of the initial gas line 502. In some examples, the inner diameter of the replacement gas line 508 is in the range of 0.110 - 0.430 inches. The replacement gas line 508 also removes the inflation volume hardware 504. Figure 5B Also shown is a replacement diverter valve 510. In some examples, the replacement gas line 508 and / or the replacement diverter valve 510 can be used with Figure 2 the RPG gas manifold 200 of Figure 1 the processing tool 100.

[0091] Figure 6 Shows an exemplary graph of the FOV precursor flow rate over time for the initial gas line 502 and the replacement gas line 508. Curve 602 corresponds to the initial gas line 502. Curve 604 corresponds to the replacement gas line 508. The time when the ampoule is opened is marked at 606, and the time when the ampoule is closed is marked at 608. The time from 606 to 608 can be referred to as the dosing time.

[0092] Compared with the replacement gas line 508, the relatively large inner diameter of the initial gas line 502 results in a relatively long delay before the precursor flow rate starts to ramp up in the processing chamber after the ampoule is set to open at 606, as shown at 602. Additionally, due to the inflation volume hardware 504 as Figure 5A shown, the early part of the dosing step may be diluted by the gas accumulated in this volume during the next step, which may result in a longer ramp-up time. In contrast, compared with the initial gas line 502, the replacement gas line 508 has a relatively small inner diameter, so there is a relatively short delay time before the flow rate starts to rise in the processing chamber after the ampoule is set to open at 606, as shown at 604.

[0093] Similarly, the relatively small inner diameter of the replacement gas line 508 results in a relatively short pump downtime, as Figure 6 shown at 610 in Figure 6As shown at 612 in [reference]. Thus, replacing the initial gas line 502 with a replacement gas line 508 having a smaller inner diameter and a smaller dead volume can result in less delay during ALD processing. This helps to increase the throughput.

[0094] The above examples relate to shortening the ALD cycle time by reducing the delay caused by the stable gas flow. Additionally, the ALD cycle time can be shortened by increasing the residence time of the precursor molecules and / or reactant species on the substrate. In some examples, the showerhead can include a purge gas outlet that generates a purge gas flow in the form of a shroud that at least partially surrounds the substrate on the pedestal. This purge gas flow impedes the flow of the precursor from above the substrate to the exhaust system. This can increase the residence time of the precursor and / or radical species on the substrate. The increase in residence time helps to improve the efficiency of the conversion of the precursor to the deposited film.

[0095] Figure 7 Schematically shows an exemplary process tool component 700. For example, the process tool component 700 can be installed in Figure 1 the process tool 100. In some examples, the process tool component 700 can be used in the same tool as Figure 2 the RPG gas manifold 200. Additionally, in some examples, the process tool component 700 can be used in the same process tool as Figure 5B the replacement gas line 508 and the replacement diverter valve 510.

[0096] The process tool component 700 includes a showerhead 702. The process tool component 700 also includes a pedestal support 704 that extends upward from the process chamber base 706, and a pedestal 708 that supports the substrate 710.

[0097] The process tool component 700 also includes a showerhead purge gas source 712. The flow rate of the purge gas from the showerhead purge gas source 712 can be controlled by a controller 714. The controller 714 is an example of Figure 1 the controller 148.

[0098] The process tool component 700 also includes a process gas source, which is illustrated as a remote plasma generator (RPG) 716 and a flow-over vapor (FOV) distribution system 718. The RPG 716 and the FOV distribution system 718 are fluidly connected to the showerhead 702 to provide process gas to the showerhead 702. The flow of the process gas from the showerhead 702 to the substrate 710 is indicated by the arrow 720. For clarity, the internal gas flow channels of the showerhead 702 for delivering the process gas from the RPG 716 and the FOV distribution system 718 are omitted. In some examples, the RPG 716 can receive a gas flow from the RPG gas manifold 200.

[0099] During a portion of the ALD cycle, precursors from the FOV distribution system 718 are adsorbed onto the substrate 710. During another portion of the ALD cycle, reactants from the RPG 716 react with the precursors adsorbed on the substrate 710. Unreacted precursors, radical species, and reaction products flow through the opening 722 to the exhaust system. A purge cycle can be performed between exposing the substrate 710 to the precursors and reactants.

[0100] To help increase the residence time of the precursors and / or reactants on the substrate 710, purge gas from the showerhead purge gas source 712 flows out through showerhead purge gas outlets 726 disposed adjacent to the periphery of the showerhead 702. In the depicted example, the showerhead purge gas flows through the inlet 724 and then through the showerhead purge gas outlets 726. Arrow 727 indicates the flow direction of the showerhead purge gas. The plenum 728 distributes the showerhead purge gas flow such that the showerhead purge gas flows through different locations of the showerhead purge gas outlets 726 at an appropriate and uniform flow rate. In other examples, the showerhead purge gas outlets can be located at different positions from the showerhead purge gas outlets 726. Exemplary purge gases can include inert gases such as helium and argon.

[0101] The purge gas can create a backpressure on the gas flow through the opening 722. This can slow down the gas flow rate through the opening 722, thereby increasing the residence time of the processing chemicals on the substrate 710. The residence time of the precursors and reactive species on the substrate 710 can be changed by controlling the relative flow rates of the purge gas and the flow of precursors and / or the flow of reactive species-containing flow from the RPG.

[0102] In some examples, the showerhead purge gas outlets 726 can be annular and continuous. In other examples, multiple showerhead purge gas outlets can be distributed around the showerhead. In the depicted example, the showerhead purge gas outlets 726 are directed vertically downward. In other examples, one or more showerhead purge gas outlets can direct the purge gas towards the pedestal support 704. In other examples, one or more showerhead purge gas outlets can direct the purge gas away from the pedestal support 704.

[0103] By using a below-pedestal purge system, a similar backpressure effect can be created on the gas flow through the opening 722. Figure 8 Such a below-pedestal purge system is shown. More specifically, Figure 8 an exemplary process tool component 800 of a process tool is shown. For example, the process tool component 800 can be incorporated into Figure 1 the process tool 100. In some examples, the process tool component 800 can be used in the same tool as Figure 2 the RPG gas manifold 200. Additionally, in some examples, the process tool component 800 can be used in the same tool as Figure 5BThe replacement gas line 508 and the replacement diverter valve 510 are used in the same processing tool. Additionally, in some examples, the processing tool component 800 and Figure 7 the showerhead purge gas outlet 726 are used in the same processing tool.

[0104] The processing tool component 800 includes a pedestal 802 and a pedestal support 806 located within a pedestal well 804 formed by a chamber base 805. The processing tool 800 component also includes an under-pedestal plenum 814 within the pedestal well 804. The under-pedestal plenum 814 includes an interior for containing purge gas and a purge gas outlet disposed in a lower portion of the under-pedestal plenum 814. The arrow indicates the flow of purge gas out of the under-pedestal plenum 814. An under-pedestal purge gas source 810 supplies purge gas to the under-pedestal plenum 814. A controller 812 controls the purge gas flow rate. For example, the controller 812 can control a mass flow controller or other flow controller of the under-pedestal purge gas source 810.

[0105] The purge gas flow rate from the under-pedestal plenum 814 can help create a backpressure effect to increase the residence time of precursors and / or reactants on the substrate. This can help reduce the time required to perform ALD cycles. Additionally, the pedestal well 804 includes the volume of the space below the pedestal 802. Unreacted precursors and reaction products diffuse into the pedestal well 804 during deposition. Thus, the purge gas flow rate from the under-pedestal plenum 814 helps sweep these materials out of the pedestal well 804. The under-pedestal plenum 814 also helps fill the volume of the pedestal well 804. This reduces the volume of space that needs to be purged. This can further help reduce the time required to purge the processing chamber between ALD steps. The under-pedestal purge gas can include any suitable gas that does not react with the materials or surfaces exposed to the purge gas. Exemplary purge gases include argon.

[0106] In the depicted example, the under-pedestal plenum 814 includes an annular structure having one or more openings in a lower portion of the under-pedestal plenum 814. The purge gas flows toward the pedestal support 806 and into the pedestal well 804. In different examples, the height of the under-pedestal plenum 814 can vary. Using a higher under-pedestal plenum 814 can reduce the open volume within the pedestal well 804. This can help shorten the duration of the purge step in the ALD cycle. The height of the under-pedestal plenum 814 can be selected to accommodate the desired range of pedestal height adjustment.

[0107] The opening of the plenum chamber 814 below the base can take various different forms. In some examples, the plenum chamber 814 below the base may include a single opening extending around the plenum chamber below the base. In other examples, the plenum chamber below the base may include multiple horizontal openings of the same or different sizes. In other examples, the plenum chamber below the base may include multiple vertical openings of the same or different sizes. In more examples, the plenum chamber below the base may include an array of holes. The size and shape of the holes can vary.

[0108] In Figure 8 the example, the plenum chamber 814 below the base has a vertical inner wall with an opening in the bottom region of the inner wall through which the purge gas flows. In other examples, the plenum chamber below the base may have any other suitable configuration. For example, the plenum chamber below the base may have diagonal walls and / or curved walls. Similarly, the plenum chamber below the base may have an opening of any suitable shape.

[0109] Figure 9 Another example of a purge system below the base is shown. More specifically, Figure 9 a process tool component 900 of an exemplary process tool is shown. For example, the process tool component 900 can be mounted in Figure 1 the process tool 100. In some examples, the process tool component 900 can be used in the same tool as Figure 2 the RPG gas manifold 200. Additionally, in some examples, the process tool component 900 can be used in the same process tool as Figure 5B the replacement gas line 508 and the replacement diverter valve 510. Additionally, in some examples, the process tool component 900 can be used in the same process tool as Figure 7 the showerhead purge gas outlet 726 in

[0110] The process tool component 900 includes a base 902, a base support 906 located within a base well 904, and a process chamber base 908 that defines the base well 904. The process tool component 900 also includes a plenum chamber 914 below the base within the base well 904. The plenum chamber 914 below the base includes an interior for containing purge gas and a plurality of purge gas outlets represented by dashed lines and gas flow arrows. A purge gas source 910 below the base supplies purge gas to the plenum chamber 914 below the base. A controller 912 controls the purge gas flow. For example, the controller 912 can control a mass flow controller or other flow controller of the purge gas source 910 below the base.

[0111] The plenum chamber 914 below the susceptor includes an opening 916 that faces the susceptor 902 rather than the inner side of the susceptor support 906. As described above, the flow rate of the purge gas can generate a backpressure effect to increase the residence time of the precursor on the substrate. This can improve the utilization efficiency of the precursor and also shorten the exposure time of the precursor.

[0112] As above Figure 5A , 5B As described in 6 above, by modifying the gas flow line for delivering the precursor, the ramp-up and ramp-down times for the precursor to flow into and out of the processing chamber can be shortened. Figure 10 A flowchart depicting an example method 1000 for modifying a FOV chemical supply system is shown. Method 1000 includes replacing an initial gas line with a replacement gas line in step 1002. The inner diameter of the replacement gas line is smaller than that of the initial gas line. In some examples, as shown at 1004, the inner diameter of the initial gas line is greater than or equal to 0.305 inches, while the inner diameter of the replacement gas line is in the range of 0.110 - 0.430 inches. Using a gas line with a smaller inner diameter can shorten the time between opening the FOV chemical supply system valve and the FOV chemical reaching the processing chamber. This can shorten the ALD cycle time and increase the throughput.

[0113] Modifying the FOV chemical supply system in step 1002 can also include replacing at least one other FOV chemical supply system component in step 1006 to reduce the dead volume in the FOV chemical supply system. Reducing the dead volume can shorten the time required for the FOV chemical to reach the processing chamber. This is because the time required to fill the dead volume is eliminated. Reducing the dead volume can also help avoid the transient dilution of the FOV chemical, which can be a precursor in the ALD process.

[0114] The valve connection may include a dead volume. Thus, in some examples, method 1000 can include shortening the valve connection in step 1008. For example, this can include replacing a first valve with a second valve having a smaller dead volume.

[0115] Method 1000 can also include removing the plenum volume hardware in step 1010. Removing the plenum volume hardware reduces the total volume of the gas line. This reduces the time required for the FOV chemical to reach the processing chamber. In addition, removing the plenum volume hardware can also help avoid dilution caused by the gas in the plenum volume hardware early in the FOV chemical introduction step.

[0116] In addition, in some examples, modifying the FOV chemical supply system can include replacing the first valve manifold with a second valve manifold having a reduced dead volume in step 1012. As previously described, the valve manifold can include one or more valves, one or more three-ways, and associated fittings. In some examples, valves and associated fittings for maintainability of the processing tool can be reduced or removed. In other examples, valves and associated fittings for sampling or measuring the FOV chemical in the FOV chemical supply system can be reduced or removed. In other examples, three-ways, elbows, and other fittings can be reduced or removed to reduce the dead volume. In other examples, one or more valves can be replaced with valves that reduce the dead volume inside the valve assembly.

[0117] Method 1000 can be used to install the modified gas line 508 and / or the replacement diverter valve 510 into a processing tool, such as Figure 1 processing tool 100. In addition, method 1000 can be performed on a processing tool including the RPG gas manifold 200, a replacement gas line, and / or the replacement diverter valve 510. Additionally, in some examples, method 1000 can be performed on a processing tool including a showerhead purge gas outlet as shown in Figure 7 . Further, in some examples, method 1000 can be performed on the same processing tool including an under pedestal purge system as shown in Figure 8 and Figure 9 .

[0118] It should be understood that the configurations and / or methods described herein are exemplary in nature and that these specific one or more embodiments or examples should not be considered limiting as many variations are possible. The specific routines or methods described herein can represent one or more of any number of processing strategies. Accordingly, the various acts shown and / or described can be performed in the order shown and / or described, in other orders, in parallel, or omitted. Similarly, the order of the above processes can be changed.

[0119] The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of various processes, systems, and configurations, as well as other features, functions, acts, and / or properties disclosed herein, and any and all equivalents thereof.

Claims

1. A processing tool, comprising: A processing chamber; A remote plasma generator (RPG) fluidly connected to the processing chamber; And An RPG gas supply system for mixing and delivering gases to the RPG, the RPG gas supply system comprising: A first RPG gas line for delivering a first gas to the RPG at a first flow rate; A second RPG gas line for delivering a second gas to the RPG at a second flow rate, the second flow rate being higher than the first flow rate; A joint connecting the first RPG gas line and the second RPG gas line; An orifice in the first RPG gas line; A diverter valve on the second RPG gas line for diverting flow from the RPG; And A shared RPG gas line for connecting the joint to the RPG.

2. The processing tool according to claim 1, wherein the second RPG gas line includes a mass flow controller upstream of the joint connecting the first RPG gas line and the second RPG gas line.

3. The processing tool according to claim 1, wherein the first RPG gas line is connected to a hydrogen source and a nitrogen source.

4. The processing tool according to claim 1, wherein the second RPG gas line is connected to a nitrogen source.

5. The processing tool according to claim 1, wherein the processing chamber includes a showerhead and a susceptor, and the showerhead includes a showerhead purge gas outlet disposed adjacent to the periphery of the showerhead.

6. The processing tool according to claim 5, further comprising a controller configured to control the flow rate of an inert gas through the showerhead purge gas outlet during a deposition process.

7. The processing tool according to claim 6, further comprising: A susceptor, and A susceptor under purge system including one or more openings to allow a purge gas to flow into the processing chamber under the susceptor.

8. The processing tool according to claim 7, further comprising a controller configured to control the flow rate of an inert gas through the susceptor under purge system during a deposition process.

9. The processing tool according to claim 1, wherein the processing tool includes a flowing over vapor (FOV) chemical supply system for delivering a processing chemical to the processing chamber, the FOV chemical supply system including a processing chemical delivery gas line having an inner diameter in the range of 0.110 - 0.430 inches.

10. A processing tool, comprising: A processing chamber including a susceptor well; A susceptor at least partially located within the susceptor well; And A susceptor under purge system configured to introduce a flow rate of a purge gas into the susceptor well under the susceptor.

11. The processing tool according to claim 10, wherein the susceptor under purge system includes a susceptor under inflation chamber disposed at least partially around a susceptor support of the susceptor, the susceptor under inflation chamber including one or more openings to allow the purge gas to flow from under the susceptor into the processing chamber.

12. The processing tool according to claim 11, wherein the plenum chamber below the base is annular.

13. The processing tool according to claim 11, wherein the plenum chamber below the base includes a plurality of openings.

14. The processing tool according to claim 11, wherein the plenum chamber below the base is formed by additive manufacturing.

15. The processing tool according to claim 10, further comprising a showerhead that includes a showerhead purge gas outlet.

16. A method of modifying a processing tool, the processing tool including a processing chamber and a flow-over vapor (FOV) chemical supply system for delivering a processing chemical to the processing chamber, the FOV chemical supply system including a gas line for delivering the processing chemical to the processing chamber, the method comprising: replacing an initial gas line with a replacement gas line, the replacement gas line having an inner diameter smaller than the initial gas line, thereby reducing the time elapsed between opening a valve of the FOV chemical supply system and the FOV chemical reaching the processing chamber, and replacing at least one other FOV chemical supply system component to reduce the dead volume in the FOV chemical supply system.

17. The method according to claim 16, wherein the initial gas line has an inner diameter greater than or equal to 0.305 inches, and the replacement gas line has an inner diameter in the range of 0.110 inches - 0.430 inches.

18. The method according to claim 16, wherein replacing at least one other FOV chemical supply system component includes shortening a valve connection.

19. The method according to claim 16, wherein replacing at least one other FOV chemical supply system component includes removing plenum volume hardware.

20. The method according to claim 16, wherein replacing at least one other FOV chemical supply system component includes replacing a first valve manifold with a second valve manifold having a reduced dead volume.

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