WO2025034455A1

WO2025034455A1 - Chemical deposition system and method for deposition

Info

Publication number: WO2025034455A1
Application number: PCT/US2024/040161
Authority: WO
Inventors: Brian Lewis RATLIFF; Kevin Gerber; Amir KOOLIVAND; Prasad Prakash PATEL; Damien Long; Ramesh Chandrasekharan; Jon Henri; Antonio Xavier; Hu Kang; Pramod Subramonium; Changhe GUO
Original assignee: Lam Research Corporation
Priority date: 2023-08-04
Filing date: 2024-07-30
Publication date: 2025-02-13

Abstract

A chemical deposition system includes a backside purge system having ports configured to direct gas into a backside region between a top side of a showerhead and a top wall of a processing chamber. A gas distribution system includes multiple valves controllable to selectively cause one or more gases from multiple different gas sources connectable to the gas distribution system to be flowed to the showerhead and/or the backside purge system. A controller is configured to control the valves to cause a first gas to flow through the showerhead during a first deposition process, a second gas to flow through the showerhead during a second deposition process, a non-reactive gas to flow through the showerhead during a first preparation process, and the non-reactive gas to flow through the backside purge ports during the first deposition process, the first preparation process, and the second deposition process.

Description

CHEMICAL DEPOSITION SYSTEM AND METHOD FOR DEPOSITION

INCORPORATION BY REFERENCE

[0000] A PCT Request Form is filed concurrently with this specification as part of the present application. Each application that the present application claims benefit of or priority to as identified in the concurrently filed PCT Request Form is incorporated by reference herein in its entirety and for all purposes.

FIELD

[0001] The present disclosure relates to chemical deposition systems, and more specifically to chemical deposition systems that suppress precursor flow away from a substrate region of a processing chamber thereby shortening deposition cycle times and decreasing parasitic deposition.

BACKGROUND

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

[0003] Chemical deposition systems may be used to deposit films on substrates (e.g., semiconductor wafers, etc.). Examples of chemical deposition systems may include plasma-enhanced chemical vapor deposition systems (PECVD systems). Some PECVD systems include chandelier-type showerheads that are positioned within a processing chamber to define a substrate region. The substrate region may be defined between a bottom side of the showerhead and a bottom surface of the processing chamber. A wafer support (i.e., a pedestal, a substrate support, etc.) may be positioned within the substrate region and be configured to support a substrate within the substrate region. The bottom side of the showerhead may include ports facing the wafer support and configured to supply precursor gas to facilitate with depositing layers of material onto the substrates. The showerhead may be positioned within the processing chamber to further define a backside region between a top side of the showerhead and a top surface of the processing chamber. The pedestal may be spaced away from the backside region, such that the backside region may be dead volume in the processing chamber. SUMMARY

[0004] A chemical deposition system may include a processing chamber defining an interior volume. The chemical deposition system may further include a wafer support positioned within the interior volume and configured to support a substrate during a chemical deposition process. The chemical deposition system may further include a showerhead positioned above the wafer support and supported by a stem, and a backside region exists between a top side of the showerhead and a top wall of the processing chamber. The showerhead may include multiple gas distribution ports that are distributed across a bottom surface of the showerhead facing the wafer support. The chemical deposition system may further include a backside purge system having one or more backside purge ports configured to direct gas into the backside region. The chemical deposition system may further include a gas distribution system having multiple valves controllable to selectively cause one or more gases from a plurality of different gas sources connectable to the gas distribution system to be flowed the showerhead and/or the backside purge system. The different gas sources may include one or more gas sources for providing a first gas containing at least a first precursor for use in generating a silane film, one or more gas sources for providing a second gas containing at least a second precursor for use in generating an oxide film, and one or more gas sources for providing a non-reactive gas. The chemical deposition system may further include a controller. The controller may be configured to control the valves of the gas distribution system to cause at least the first gas to flow through the showerhead and towards the wafer support during a first deposition process. The controller may be configured to control the valves of the gas distribution system to cause at least the second gas to flow through the showerhead and towards the wafer support during a second deposition process. The controller may be configured to control the valves of the gas distribution system to cause at least the non-reactive gas to flow through the showerhead and towards the wafer support during a first preparation process between the first and second deposition processes. The controller may be configured to control the valves of the gas distribution system to cause at least the non-reactive gas to flow through the backside purge ports and into the backside region during the first deposition process, the first preparation process, and the second deposition process.

[0005] In other implementations, the controller may be further configured to control the valves of the gas distribution system to cause at least the non-reactive gas to flow through the showerhead and towards the wafer support during a second preparation process after the second deposition process.

[0006] In other implementations, the first precursor of the first gas may include a first combination of silane and ammonia (NH3) or silane alone.

[0007] In other implementations, the second precursor of the second gas may include a first combination including at least tetraethyl orthosilicate (TEOS), a second combination including at least silane, and an oxidizer.

[0008] In other implementations, the controller may be further configured to control the valves of the gas distribution system to cause at least the non-reactive gas to flow through the backside purge ports and into the backside region during the second preparation process.

[0009] In other implementations, the controller may be further configured to control the valves of the gas distribution system to cause the non-reactive gas to flow through the backside purge ports at a backside flow rate that is at least 100% of a total flow rate of the first gas flowing through the showerhead and towards the wafer support during the first deposition process.

[0010] In other implementations, the gas distribution system may further include a first gas divert flow path configured to flow the first gas to a location other than the showerhead and the interior volume of the processing chamber. The controller may be further configured to control the valves of the gas distribution system to cause the first gas to flow at a divert flow rate into the first gas divert flow path during the second preparation process. The controller may be further configured to control the valves of the gas distribution system to cause the first gas to flow through the showerhead and into the processing chamber at the total flow rate during the first deposition process. The total flow rate of the first gas through the showerhead during the first deposition process may be at least a predetermined percentage above the divert flow rate of the first gas through the first gas divert flow path during the second preparation process.

[0011] In other implementations, the controller may be further configured to control the valves of the gas distribution system to cause the non-reactive gas to flow through the backside purge ports at a backside flow rate that is at least 100% of a total flow rate of the second gas flowing through the showerhead and towards the wafer support during the second deposition process. [0012] In other implementations, the chemical deposition system may further include a second gas divert flow path configured to flow the second gas to a location other than the showerhead and the interior volume of the processing chamber. The controller may be further configured to control the valves of the gas distribution system to cause the second gas to flow at a divert flow rate into the second gas divert flow path during the first preparation process. The controller may be further configured to control the valves of the gas distribution system to cause the second gas to flow through the showerhead and into the processing chamber at the total flow rate during the second deposition process. The total flow rate of the second gas through the showerhead during the second deposition process may be at least a predetermined percentage above the divert flow rate of the second gas through the second gas divert flow path during the first preparation process.

[0013] In other implementations, the chemical deposition system may further include one or more sensors configured to generate, during the first preparation process, an input signal associated with data indicative of one or more parameters of the first preparation process. The controller may be further configured to compare the parameters to one or more corresponding predetermined set points. The controller may be further configured to determine that the internal environment of the processing chamber reached a predetermined condition responsive, at least in part to, the parameter being within a predetermined range of the corresponding predetermined set points. The controller may be further configured to cause the valves of the gas distribution system to actuate to cause the second gas to flow through the showerhead and towards the wafer support responsive, at least in part to, the controller determining that the internal environment of the processing chamber has reached the predetermined condition during the first preparation process.

[0014] In other implementations, the chemical deposition system may further include one or more sensors configured to generate, during the second preparation process, an input signal associated with data indicative of one or more parameters of the second preparation process. The controller may be further configured to compare the parameters to one or more corresponding predetermined set points. The controller may be further configured to determine that the internal environment of the processing chamber reached a predetermined condition responsive, at least in part to, the parameter being within a predetermined range of the corresponding predetermined set points. The controller may be further configured to cause the valves of the gas distribution system to actuate to cause the first gas to flow through the showerhead and towards the wafer support responsive, at least in part to, the controller determining that the internal environment of the processing chamber has reached the predetermined condition during the second preparation process.

[0015] In other implementations, the controller may be further configured to define a deposition cycle as a sequential order including the first deposition process, the first preparation process, the second deposition process, and the second preparation process. The controller is further configured to control the valves of the gas distribution system to perform two or more sequential instances of the deposition cycle.

[0016] In other implementations, the controller may be further configured to control the valves of the gas distribution system to cause the non-reactive gas to continuously flow through the backside purge ports and into the backside region during each deposition cycle.

[0017] In other implementations, the non-reactive gas may be nitrogen.

[0018] In other implementations, the different gas sources may include another gas source further providing an ammonia-containing gas. The controller may be further configured to control the valves of the gas distribution system to cause at least the ammonia-containing gas to flow through the showerhead and towards the wafer support during the second preparation process.

[0019] In other implementations, the controller may be further configured to control the valves of the gas distribution system to cause at least the ammonia-containing gas to flow through the showerhead and towards the wafer support during the first deposition process.

[0020] In other implementations, the controller may be further configured to control the valves of the gas distribution system to prevent the second gas from flowing through the showerhead and into the processing chamber when the first gas flows through the showerhead and into the processing chamber.

[0021] In other implementations, the controller may be further configured to control the valves of the gas distribution system to prevent the first gas from flowing through the showerhead and into the processing chamber when the second gas flows through the showerhead and into the processing chamber.

[0022] A controller may be provided for a chemical deposition system including a processing chamber that defines an interior volume. The chemical deposition system may further include a wafer support positioned within the interior volume and configured to support a substrate during a chemical deposition process. The chemical deposition system may further include a showerhead positioned above the wafer support and supported by a stem, and a backside region exists between a top side of the showerhead and a top wall of the processing chamber. The showerhead may include multiple gas distribution ports that are distributed across a bottom surface of the showerhead facing the wafer support. The chemical deposition system may further include a backside purge system having one or more backside purge ports configured to direct gas into the backside region. The controller may include one or more processors configured to communicate with a gas distribution system including multiple valves controllable to selectively cause one or more gases from multiple different gas sources connectable to the gas distribution system to be flowed to the showerhead and/or the backside purge system. The gas sources may include one or more gas sources for providing a first gas containing at least a first precursor for use in generating a silane film, a second gas containing at least a second precursor for use in generating an oxide film, and a non- reactive gas. The controller may further include one or more non-transitory computer readable media (CRM) storing instructions which, when executed by the processor, cause the processor to control the valves of the gas distribution system to cause at least the first gas to flow through the showerhead and towards the wafer support during a first deposition process. The CRM may store additional instructions which, when executed by the processor, cause the processor to control the valves of the gas distribution system to cause at least the second gas to flow through the showerhead and towards the wafer support during a second deposition process. The CRM may store additional instructions which, when executed by the processor, cause the processor to control the valves of the gas distribution system to cause at least the non-reactive gas to flow through the showerhead and towards the wafer support during a first preparation process between the first and second deposition processes. The CRM may store additional instructions which, when executed by the processor, cause the processor to control the valves of the gas distribution system to cause at least the non-reactive gas to flow through the backside purge ports and into the backside region during the first deposition process, the first preparation process, and the second deposition process.

[0023] In other implementations, the CRM may store additional instructions which, when executed by the processor, further cause the processor to control the valves of the gas distribution system to cause at least the non-reactive gas to flow through the showerhead and towards the wafer support during a second preparation process after the second deposition process.

[0024] In other implementations, the CRM may store additional instructions which, when executed by the processor, further cause the processor to control the valves of the gas distribution system to cause at least the non-reactive gas to flow through the backside purge ports and into the backside region during the second deposition process.

[0025] In other implementations, the CRM may store additional instructions which, when executed by the processor, further cause the processor to control the valves of the gas distribution system to cause the non-reactive gas to flow through the backside purge ports at a backside flow rate that is at least 100% of a total flow rate of the first gas flowing through the showerhead and towards the wafer support during the first deposition process.

[0026] In other implementations, the gas distribution system may further include a first gas divert flow path configured to flow the first gas to a location other than the showerhead and the interior volume of the processing chamber. The CRM may store additional instructions which, when executed by the processor, further cause the processor to control the valves of the gas distribution system to cause the first gas to flow at a divert flow rate into the first gas divert flow path during the second preparation process. The CRM may store additional instructions which, when executed by the processor, further cause the processor to control the valves of the gas distribution system to cause the first gas to flow through the showerhead and into the processing chamber at the total flow rate during the first deposition process. The total flow rate may be at least a predetermined percentage above the divert flow rate.

[0027] In other implementations, the CRM may store additional instructions which, when executed by the processor, further cause the processor to control the valves of the gas distribution system to cause the non-reactive gas to flow through the backside purge ports at a backside flow rate that is at least 100% of a total flow rate of the second gas flowing through the showerhead and towards the wafer support during the second deposition process.

[0028] In other implementations, the controller may further include a second gas divert flow path configured to flow gas to a location other than the showerhead and the interior volume of the processing chamber. The CRM may store additional instructions which, when executed by the processor, further cause the processor to control the valves of the gas distribution system to cause the second gas to flow at a divert flow rate into the second gas divert flow path during the first preparation process. The CRM may store additional instructions which, when executed by the processor, further cause the processor to control the valves of the gas distribution system to cause the second gas to flow through the showerhead and into the processing chamber at the total flow rate during the second deposition process. The total flow rate may be at least a predetermined percentage above the divert flow rate.

[0029] In other implementations, the CRM may store additional instructions which, when executed by the processor, further cause the processor to compare, during the first preparation process, one or more parameters of the first preparation process to one or more corresponding predetermined set points. The CRM may store additional instructions which, when executed by the processor, further cause the processor to determine that the internal environment of the processing chamber has reached a predetermined condition responsive, at least in part, to the processor determining that the parameters are within a predetermined range of the corresponding predetermined set points. The CRM may store additional instructions which, when executed by the processor, further cause the processor to control the valves of the gas distribution system to actuate to cause the second gas to flow through the showerhead and towards the wafer support responsive, at least in part to, the processor determining that the internal environment of the processing chamber has reached the predetermined condition during the first preparation process.

[0030] In other implementations, the CRM may store additional instructions which, when executed by the processor, further cause the processor to compare, during the second preparation process, one or more parameters of the second preparation process to one or more corresponding predetermined set points. The CRM may store additional instructions which, when executed by the processor, further cause the processor to determine that the internal environment of the processing chamber has reached a predetermined condition responsive, at least in part, to the parameters being within a predetermined range of corresponding predetermined set points. The CRM may store additional instructions which, when executed by the processor, further cause the processor to control the valves of the gas distribution system to actuate to cause the first gas to flow through the showerhead and towards the wafer support responsive, at least in part to, the processor determining that the internal environment of the processing chamber has reached the predetermined condition during the second preparation process.

[0031] A method may be provided for operating a controller of a chemical deposition system that includes a backside purge system. The backside purge system may include one or more backside purge ports configured to direct gas into a backside region between a top side of a showerhead and a top wall of a processing chamber. The chemical deposition system may further include a gas distribution system having multiple valves controllable to selectively cause one or more gases from multiple different gas sources connectable to the gas distribution system to be flowed to the showerhead and/or the backside purge system. The method may include supporting, using a wafer support positioned within an interior volume defined by the processing chamber, a substrate. The method may further include controlling, using the controller, the valves of the gas distribution system to cause at least a first gas to flow through the showerhead and towards the wafer support during a first deposition process. The first gas may contain at least a first precursor for use in generating a silane film. The method may further include controlling, using the controller, the valves of the gas distribution system to cause at least a second gas to flow through the showerhead and towards the wafer support during a second deposition process. The second gas may contain at least a second precursor for use in generating an oxide film. The method may further include controlling, using the controller, the valves of the gas distribution system to cause at least a non-reactive gas to flow through the showerhead and towards the wafer support during a first preparation process between the first and second deposition processes. The method may further include controlling, using the controller, the valves of the gas distribution system to cause at least the non-reactive gas to flow through the backside purge ports and into a backside region between the top side of the showerhead and the top wall of the processing chamber during the first deposition process, the first preparation process, and the second deposition process.

[0032] In other implementations, the method may further include controlling, using the controller, the valves of the gas distribution system to cause at least the non-reactive gas to flow through the showerhead and towards the wafer support during a second preparation process after the second deposition process.

[0033] In other implementations, the method may further include controlling, using the controller, the valves of the gas distribution system to cause at least the non-reactive gas to flow through the backside purge ports and into the backside region during the second preparation process.

[0034] In other implementations, the method may further include controlling, using the controller, the valves of the gas distribution system to cause the non-reactive gas to flow through the backside purge ports at a backside flow rate that is at least 100% of a total flow rate of the first gas flowing through the showerhead and towards the wafer support during the first deposition process.

[0035] In other implementations, the method may further include controlling, using the controller, the valves of the gas distribution system to cause the first gas to flow at a divert flow rate into a first gas divert flow path during the second preparation process. The method may further include controlling, using the controller, the valves of the gas distribution system to cause the first gas to flow through the showerhead and into the processing chamber at the total flow rate during the first deposition process. The total flow rate may be at least a predetermined percentage above the divert flow rate.

[0036] In other implementations, the method may further include controlling, using the controller, the valves of the gas distribution system to cause the non-reactive gas to flow through the backside purge ports at a backside flow rate that is at least 100% of a total flow rate of the second gas flowing through the showerhead and towards the wafer support during the second deposition process.

[0037] In other implementations, the method may further include controlling, using the controller, the valves of the gas distribution system to cause the second gas to flow at a divert flow rate into a second divert flow path during the first preparation process. The method may further include controlling, using the controller, the valves of the gas distribution system to cause the second gas to flow through the showerhead and into the processing chamber at the total flow rate during the second deposition process. The total flow rate may be at least a predetermined percentage above the divert flow rate.

[0038] Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0040] FIG. 1 is a schematic diagram of an example of a chemical deposition system having a backside purge system for decreasing transition time of a chemical deposition process and minimizing parasitic deposition.

[0041] FIG. 2 is a flowchart of an example of a method for operating the chemical deposition system of FIG. 1 .

DETAILED DESCRIPTION

[0042] Referring to FIG. 1 , a chemical deposition system 100 includes a backside purge system 102 and multiple divert flow paths (e.g., a first gas divert flow path 104, a second gas divert flow path 106, etc.) that are configured to shorten deposition cycle times and minimize parasitic deposition away from a substrate 108. The specific hardware shown in FIG. 1 is just one example of the backside purge system 102. The chemical deposition system 100 includes a processing chamber 110 defining an interior volume 1 12. The chemical deposition system 100 further includes a wafer support 1 14 that is positioned within the interior volume 1 12 and configured to support the substrate 108 during a chemical deposition process. The chemical deposition system 100 further includes a showerhead 1 16 (e.g., a chandelier-type showerhead) positioned within the interior volume 112 and above the wafer support 114. The showerhead 1 16 includes multiple gas distribution ports 118 distributed across a bottom surface 120 of the showerhead 116 facing the wafer support 114. The showerhead 116 is supported by a stem 122 , and a backside region 124 exists between a top side 126 of the showerhead 1 16 and a top wall 128 of the processing chamber 1 10. The interior volume 112 further includes a substrate region 130 that is separate from the backside region 124 and defined between the bottom surface 120 of the showerhead 1 16 and the wafer support 1 14. As described in detail below, the backside purge system 102 includes a plurality of backside purge ports 132a configured to direct gas into the backside region 124 to provide an air curtain that prevents a precursor gas from flowing into the backside region 124 and forming unwanted deposition on surfaces defining the backside region 124. Furthermore, as also described in detail below, the chemical deposition system 100 alternates flow paths to which stable fluid flows may be diverted with little to no transient effects when not being routed to the processing chamber, thereby avoiding the need to ramp fluid flows up or down. [0043] In this example, the backside purge ports 132a may be a plurality of slots 132b formed in a collar 134 to allow a non-reactive or inert gas (e.g., nitrogen, argon, etc.) to flow from a bore 136 of the collar 134 into the backside region 124. More specifically, the collar 134 may connect the stem 122 of the showerhead 116 to the top wall 128 of the processing chamber 1 10. The collar 134 may include an annular flange 138 and a tubular portion 140 extending from the annular flange 138. The bore 136 may be cylinder-shaped and receives the stem 122 of the showerhead 1 16. A fluid connector 142 may be connected to an edge of the annular flange 138 and may be used to supply the non- reactive gas from the backside purge system 102 to the collar 134. The fluid connector 142 includes one or more conduits and/or connectors that are generally identified at 144. The annular flange 138 of the collar 134 likewise includes conduits and/or connectors that are generally identified at 146 to direct the flow of the non-reactive gas to the bore 136 of the collar 134. When connected, the conduit 146 of the collar 134 is aligned with the conduit 144 of the fluid connector 142. In other examples, the backside purge ports 132a may be defined in the top wall 128 of the processing chamber 1 10 or other suitable portions of the chemical deposition system 100 that are fluidly connected to the backside region 124 of the processing chamber 1 10.

[0044] In some implementations, the chemical deposition system 100 may perform a process, such as a PECVD process. As described in detail below, the chemical deposition system 100 may alternately flow a precursor gas through the showerhead 116 and towards the wafer support 114 and then flow a non-reactive gas through the showerhead 1 16 and towards the wafer support 1 14 to purge the precursor gas from the substrate region 130 of the processing chamber. The non-reactive gases remove the excess precursor gas in the processing chamber 110 and the shared portions of the precursor flow paths (e.g., the showerhead 116) before introduction of the next precursor, thereby preventing parasitic deposition, e.g., within the showerhead.

[0045] The chemical deposition system 100 further includes a gas distribution system 148 having multiple valves 150 controllable to selectively cause one or more gases from multiple different gas sources 152a connectable to the gas distribution system 148 to be flowed to the showerhead 1 16 and/or the backside purge system 102. The different gas sources 152a include one or more gas sources (e.g., a first gas source 152b, etc.) for providing a first gas containing at least a first precursor for use in generating a silane film. The first precursor may include a first combination of TEOS and oxygen, a second combination of silane and N2O, a third combination of silane and CO2, TEOS alone, or other suitable individual gases or combinations of gases. The different gas sources 152a further include one or more gas sources (e.g., a second gas source 152c, etc.) for providing a second gas containing at least a second precursor for use in generating an oxide film. The second precursor may include a first combination of silane and NH3, silane alone, or other suitable individual gases or combinations of gases. The different gas sources 152a further include one or more gas sources (e.g., a third gas source 152d, etc.) for providing an ammonia-containing gas. The different gas sources 152a further include one or more gas sources (e.g., a fourth gas source 152e, etc.) for providing a non-reactive gas (e.g., nitrogen, etc.).

[0046] The gas distribution system 148 further includes the divert flow paths for some gas flows to decrease or avoid ramp times needed to reach a stable or steady-state flow condition for corresponding deposition processes. More specifically, the gas distribution system 148 further includes a first gas divert flow path 104 configured to flow the first gas to a location other than the showerhead and the interior volume 1 12 of the processing chamber 110. The gas distribution system 148 further includes a second gas divert flow path 106 configured to flow the second to a location other than the showerhead 1 16 and the interior volume 1 12 of the processing chamber 1 10. The gas distribution system 148 further includes a third gas divert flow path 154 configured to flow the third gas to a location other than the showerhead 116 and the interior volume 1 12 of the processing chamber 110. In one implementation, the third gas divert flow path 154 may flow the third gas to a waste outlet or abatement system (i.e., a system that inactivates or neutralizes at least a portion of the harmful chemicals in a waste stream before releasing the third gas to the atmosphere).

[0047] The chemical deposition system 100 further includes one or more sensors 156 configured to generate, during a first preparation process, an input signal associated with data indicative of one or more parameters of the first preparation process. In a similar manner, the chemical deposition system 100 further includes one or more sensors 156 configured to generate, during the second preparation process, an input signal associated with data indicative of one or more parameters of the processing chamber 1 10. In some implementations, the same sensor or sensors may be used during both the first and second preparation processes. In other implementations, different sensors may be used during the first and second preparation processes.

[0048] The chemical deposition system 100 further includes a controller 158 configured to control the valves 150 of the gas distribution system 148. The controller 158 includes one or more processors 160 configured to communicate with the gas distribution system 148. The controller 158 further includes one or more non-transitory computer readable media 162 (CRM) storing instructions which, when executed by the processor 160, cause the processor 160 to control the valves 150 of the gas distribution system 148 to cause at least the first gas to flow through the showerhead 116 and towards the wafer support 114 during a first deposition process. The controller 158 is configured to control the valves 150 of the gas distribution system 148 to prevent the second gas from flowing through the showerhead 1 16 and into the internal environment of the processing chamber 110 when the first gas flows through the showerhead 1 16 and into the internal environment of the processing chamber 110.

[0049] The CRM 162 further stores instructions which, when executed by the processor 160, cause the processor 160 to control the valves 150 of the gas distribution system 148 to cause at least the second gas to flow through the showerhead 116 and towards the wafer support 114 during a second deposition process. The controller is configured to control the valves 150 of the gas distribution system 148 to prevent the first gas from flowing through the showerhead 1 16 and into the internal environment of the processing chamber 1 10 when the second gas flows through the showerhead 116 and into the internal environment of the processing chamber 1 10.

[0050] The CRM 162 further stores instructions which, when executed by the processor 160, cause the processor 160 to control the valves 150 of the gas distribution system 148 to cause at least the non-reactive gas to flow through the showerhead 1 16 and towards the wafer support 1 14 during a first preparation process between the first and second deposition processes. The non-reactive gas flushes the first gas from the showerhead 1 16 and the processing chamber 110 and out through one or more exit ports 164. In an analogous manner, the CRM 162 further stores instructions which, when executed by the processor 160, cause the processor 160 to control the valves 150 of the gas distribution system 148 to cause at least the non-reactive gas to flow through the showerhead 1 16 and towards the wafer support 1 14 during a second preparation process after the second deposition process. The non-reactive gas flushes the second gas from the showerhead 1 16 and the processing chamber 1 10 and out through the exit ports 164. The controller 158 is configured to define a deposition cycle as a sequential order including the first deposition process, the first preparation process, the second deposition process, and the second preparation process. The controller 158 is further configured to control the valves

deposition cycle.

[0051] The controller 158 is further configured to control the valves of the gas distribution system to cause the non-reactive gas to continuously flow through the backside purge ports 132a and into the backside region 124 during each deposition cycle. The CRM 162 further stores instructions which, when executed by the processor 160, cause the processor 160 to control the valves 150 of the gas distribution system 148 to cause at least the non-reactive gas to flow through the backside purge ports 132a and into the backside region 124 during the first deposition process, the first preparation process, the second deposition process, and the second preparation process.

[0052] In some implementations, the CRM 162 stores additional instructions which, when executed by the processor 160, cause the processor 160 to control the valves 150 of the gas distribution system 148 to cause the non-reactive gas to flow through the backside purge ports 132a at a backside flow rate that is at least 100% of a total flow rate of the first gas flowing through the showerhead 1 16 and towards the wafer support 114. The CRM 162 further stores instructions which, when executed by the processor 160, cause the processor 160 to control the valves 150 of the gas distribution system 148 to cause the first gas to flow at a divert flow rate into the first gas divert flow path 104 during the second preparation process. The CRM 162 further stores instructions which, when executed by the processor 160, cause the processor 160 to control the valves 150 of the gas distribution system 148 to cause the first gas to flow through the showerhead 1 16 and into the internal environment of the processing chamber 1 10 at the total flow rate during the first deposition process. In some implementations, the total flow rate is at least a predetermined percentage above the divert flow rate of the first gas through the first gas divert flow path 104.

[0053] In a similar manner that the backside flow rate is at least 100% of the total flow rate of the first gas, other implementations include a backside flow rate based on the total flow rate of the second gas. More specifically, the CRM 162 stores additional instructions which, when executed by the processor 160, cause the processor 160 to control the valves 150 of the gas distribution system 148 to cause the non-reactive gas to flow through the backside purge ports 132a at a backside flow rate that is at least 100% of a total flow rate of the second gas flowing through the showerhead 1 16 and towards the wafer support 114. The CRM 162 further stores instructions which, when executed by the processor 160, cause the processor 160 to control the valves 150 of the gas distribution system 148 to cause the second gas to flow at a divert flow rate into the second gas divert flow path 106 during the first preparation process. The CRM 162 further stores instructions which, when executed by the processor 160, cause the processor 160 to control the valves 150 of the gas distribution system 148 to cause the second gas to flow through the showerhead 1 16 and into the internal environment of the processing chamber 110 at the total flow rate during the second deposition process. The total flow rate is at least a predetermined percentage above the divert flow rate of the second gas through the second gas divert flow path 106. In this implementation, the first gas and the second gas have a respective total flow rates that are different and/or independent from one another. In other implementations, the first gas and the second gas have a common total flow rate.

[0054] The CRM 162 stores additional instructions which, when executed by the processor 160, further cause the processor 160 to compare during the first preparation process one or more parameters of the first preparation process to one or more corresponding predetermined set points. The CRM 162 stores additional instructions which, when executed by the processor 160, further cause the processor 160 to determine that the internal environment of the processing chamber 1 10 has reached a predetermined condition responsive, at least in part, to the parameters being within a predetermined range of the corresponding predetermined set points. The CRM 162 stores additional instructions which, when executed by the processor 160, further cause the processor 160 to cause the valves 150 of the gas distribution system 148 to actuate to cause the second gas to flow through the showerhead 1 16 and towards the wafer support 1 14 responsive, at least in part to, the processor 160 determining that the internal environment of the processing chamber 1 10 has reached the predetermined condition.

[0055] In an analogous manner, the CRM 162 stores similar instructions which, when executed by the processor 160, cause the processor 160 to perform similar functions during the second preparation process. In particular, the CRM 162 stores additional instructions which, when executed by the processor 160, further cause the processor 160 to compare, during the second preparation process, one or more parameters of the second preparation process to one or more corresponding predetermined set points. The CRM 162 also stores additional instructions which, when executed by the processor 160, further cause the processor 160 to determine that the internal environment of the processing chamber 1 10 has reached a predetermined condition during the second preparation process responsive, at least in part, to the parameters being within a predetermined range of the corresponding predetermined set points. The CRM 162 stores additional instructions which, when executed by the processor 160, further cause the processor 160 to cause the valves 150 of the gas distribution system 148 to actuate to cause the second gas to flow through the showerhead 116 and towards the wafer support 114 responsive, at least in part to, the processor 160 determining that the internal environment of the processing chamber 1 10 has reached the predetermined condition. The CRM 162 stores additional instructions which, when executed by the processor 160, further cause the processor 160 to control the valves 150 of the gas distribution system 148 to cause at least the ammonia-containing gas to flow through the showerhead 1 16 and towards the wafer support 1 14 during at least part of the second preparation process and the first deposition process.

[0056] Referring to FIG. 2, an example of a method 200 is provided for operating the chemical deposition system 100 of FIG. 1. The method 200 begins at block 202 with supporting, using the wafer support 1 14, the substrate 108 during the chemical deposition process. The method 200 then proceeds to block 204.

[0057] At block 204, the method 200 includes controlling, using the controller 158, the valves 150 of the gas distribution system 148 during the first deposition process to cause at least the first gas to flow at the total flow rate through the showerhead 1 16 and towards the wafer support 1 14 in the processing chamber 110. The total flow rate is at least a predetermined percentage above the divert flow rate of the first gas through the first gas divert flow path (as described below in connection with block 212). The first precursor of the first gas is used for generating a silane film and may include a first combination of silane and NH3, silane alone, or other suitable individual gases or combinations of gases. The method 200 further includes controlling, using the controller 158, the valves 150 of the gas distribution system 148 to prevent the second gas from flowing through the showerhead 116 and into the processing chamber 1 10 when the first gas flows through the showerhead 1 16 and into the processing chamber 1 10. The method 200 further includes controlling, using the controller 158, the valves 150 of the gas distribution system 148 to cause at least the non-reactive gas to flow through the backside purge ports 132a and into the backside region 124 during the first deposition process. The method 200 then proceeds to block 206.

[0058] At block 206, the method 200 includes controlling, using the controller 158, the valves 150 of the gas distribution system 148 during the first preparation process to cause the second gas to flow at the divert flow rate into the second gas divert flow path 106. The method 200 further includes controlling, using the controller 158, the valves 150 of the gas distribution system 148 to cause at least the non-reactive gas to flow through the showerhead 116 and towards the wafer support 1 14 during the first preparation process. The non-reactive gases force the first gas out of the showerhead 1 16 and the processing chamber 110 and through the exit ports 164. The method 200 further includes controlling, using the controller 158, the valves 150 of the gas distribution system 148 to cause at least the non-reactive gas to flow through the backside purge ports 132a and into the backside region 124 during the first preparation process. The method 200 then proceeds to block 208.

[0059] At block 208, the method 200 includes generating, using one or more sensors 156 during the first preparation process, the input signal associated with data indicative of one or more parameters of the first preparation process. The method 200 further includes comparing, using the processor 160, the parameters to corresponding predetermined set points. The method 200 further includes determining, using the processor 160, that the parameters of the first preparation process have reached a predetermined condition responsive, at least in part to, the processor 160 determining that the parameter is outside of the predetermined range of the corresponding predetermined set points. If the processor 160 determines that the parameters of the first preparation process have reached the predetermined condition, the method 200 proceeds to block 210. If the processor 160 determines that the parameters of the first preparation process have not reached the predetermined condition, the method 200 returns to block 206.

[0060] At block 210, the method 200 further includes controlling, using the processor 160, the valves 150 of the gas distribution system 148 during the second deposition process to cause the second gas to flow at the total flow rate through the showerhead 116 and towards the wafer support 114. The total flow rate is at least a predetermined percentage above the divert flow rate of the second gas through the second gas divert flow path (as described above in connection with block 206). The second precursor of the second gas is used for generating an oxide film and may include a first combination of TEOS and oxygen, a second combination of silane and N2O, a third combination of silane and CO2, TEOS alone, or other suitable individual gases or combinations of gases. The method 200 further includes controlling, using the controller 158, the valves 150 of the gas distribution system 148 to prevent the first gas from flowing through the showerhead 1 16 and into the processing chamber 1 10 when the second gas flows through the showerhead 1 16 and into the processing chamber 1 10. The method 200 further includes controlling, using the controller 158, the valves 150 of the gas distribution system 148 to cause at least the non-reactive gas to flow through the backside purge ports 132a and into the backside region 124 during the second deposition process. The method 200 then proceeds to block 212.

[0061] At block 212, the method 200 includes controlling, using the controller 158, the valves 150 of the gas distribution system 148 during the second preparation process to cause the first gas to flow at the divert flow rate into the first gas divert flow path 104. The method 200 further includes controlling, using the controller 158, the valves 150 of the gas distribution system 148 to cause at least the non-reactive gas to flow through the showerhead 1 16 and towards the wafer support 1 14 during the second preparation process. The non-reactive gases force the second gas out of the processing chamber 110 and through the exit ports 164. The method 200 further includes controlling, using the controller 158, the valves 150 of the gas distribution system 148 to cause at least the non-reactive gas to flow through the backside purge ports 132a and into the backside region 124 during the second preparation process. The method 200 then proceeds to block 214.

[0062] At block 214, the method 200 includes generating, using one or more sensors 156 during the second preparation process, the input signal associated with data indicative of one or more parameters of the second preparation process. The method 200 further includes comparing, using the processor 160, the parameters to corresponding predetermined set points. The method 200 further includes determining, using the processor 160, that the parameters of the second preparation process have reached a predetermined condition responsive, at least in part to, the processor 160 determining that the parameter is outside of the predetermined range of the corresponding predetermined set points. If the processor 160 determines that parameters of the second preparation process have reached the predetermined condition, the method 200 returns to block 204. If the processor 160 determines that the parameters of the second preparation process have not reached the predetermined condition, the method 200 returns to block 212.

[0063] In this implementation, the method 200 may include controlling, using the controller 158, the valves 150 of the gas distribution system 148 to cause the non-reactive gas to flow through the backside purge ports 132a at a backside flow rate that is at least 100% of a total flow rate of the first gas flowing through the showerhead 1 16 and towards the wafer support 1 14 during the first deposition process. The method 200 may further include controlling, using the controller 158, the valves 150 of the gas distribution system 148 to cause the non-reactive gas to flow through the backside purge ports 132a at a backside flow rate that is at least 100% of a total flow rate of the second gas flowing through the showerhead 1 16 and towards the wafer support 1 14 during the second deposition process.

[0064] In some implementations, a controller is part of a system, which may be part of the above-described examples. Such systems can comprise semiconductor processing equipment, including a processing tool or tools, chamber or chambers, a platform or platforms for processing, and/or specific processing components (a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor wafer or substrate. The electronics may be referred to as the “controller,” which may control various components or subparts of the system or systems (e.g., the valves 150 discussed above in accord with the method of FIG. 2). The controller, depending on the processing requirements and/or the type of system, may be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., heating and/or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, positional and operation settings, wafer transfers into and out of a tool and other transfer tools and/or load locks connected to or interfaced with a specific system.

[0065] Broadly speaking, the controller may be defined as electronics having various integrated circuits, logic, memory, and/or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and/or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor wafer or to a system. The operational parameters may, in some examples, be part of a recipe defined by process engineers to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and/or dies of a wafer. [0066] The controller, in some implementations, may be a part of or coupled to a computer that is integrated with, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the “cloud” or all or a part of a fab host computer system, which can allow for remote access of the wafer processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to follow a current processing, or to start a new process. In some examples, a remote computer (e.g., a server) can provide process recipes to a system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and/or settings, which are then communicated to the system from the remote computer. In some examples, the controller receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control. Thus, as described above, the controller may be distributed, such as by comprising one or more discrete controllers that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber.

[0067] As noted above, depending on the process step or steps to be performed by the tool, the controller might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and/or load ports in a semiconductor manufacturing factory.

[0068] In view of this description embodiments may include different combinations of features. Implementation examples are described in the following numbered clauses:

[0069] Implementation 1 : A chemical deposition system comprising: a processing chamber defining an interior volume; a wafer support positioned within the interior volume and configured to support a substrate during a chemical deposition process; a showerhead positioned above the wafer support and supported by a stem, and a backside region exists between a top side of the showerhead and a top wall of the processing chamber, the showerhead having a plurality of gas distribution ports distributed across a bottom surface of the showerhead facing the wafer support; a backside purge system including one or more backside purge ports configured to direct gas into the backside region between the top side of the showerhead and the top wall of the processing chamber; a gas distribution system including a plurality of valves controllable to selectively cause one or more gases from a plurality of different gas sources connectable to the gas distribution system to be flowed to one or both of the showerhead and the backside purge system, wherein the plurality of different gas sources includes a gas source for providing a first gas containing at least a first precursor for use in generating a silane film, a gas source for providing a second gas containing at least a second precursor for use in generating an oxide film, and a gas source for providing a non-reactive gas; and a controller. The controller is configured to control the valves of the gas distribution system to cause: at least the first gas to flow through the showerhead and towards the wafer support during a first deposition process, at least the second gas to flow through the showerhead and towards the wafer support during a second deposition process, at least the non-reactive gas to flow through the showerhead and towards the wafer support during a first preparation process between the first and second deposition processes, and at least the non-reactive gas to flow through the one or more backside purge ports and into the backside region between the top side of the showerhead and the top wall of the processing chamber during the first deposition process, the first preparation process, and the second deposition process.

[0070] Implementation 2: The chemical deposition system of implementation 1 , wherein the controller is further configured to control the valves of the gas distribution system to cause at least the non-reactive gas to flow through the showerhead and towards the wafer support during a second preparation process after the second deposition process.

[0071] Implementation 3: The chemical deposition system of implementation 1 , wherein the first precursor of the first gas includes at least one of: a first combination of silane and ammonia (NH3), and silane alone.

[0072] Implementation 4: The chemical deposition system of implementation 1 , wherein the second precursor of the second gas includes at least one of: a first combination including at least tetraethyl orthosilicate (TEOS), a second combination including at least silane, and an oxidizer. [0073] Implementation 5: The chemical deposition system of implementation 1 , wherein the controller is further configured to control the valves of the gas distribution system to cause at least the non-reactive gas to flow through the one or more backside purge ports and into the backside region between the top side of the showerhead and the top wall of the processing chamber during the second preparation process.

[0074] Implementation 6: The chemical deposition system of implementation 1 , wherein the controller is further configured to control the valves of the gas distribution system to cause the non-reactive gas to flow through the one or more backside purge ports at a backside flow rate that is at least 100% of a total flow rate of the first gas flowing through the showerhead and towards the wafer support.

[0075] Implementation 7: The chemical deposition system of implementation 1 , wherein the gas distribution system further includes a first gas divert flow path configured to flow the first gas to a location other than the showerhead and the interior volume of the processing chamber; and the controller is further configured to control the valves of the gas distribution system to cause: the first gas to flow at a divert flow rate into the first gas divert flow path during the second preparation process, and the first gas to flow through the showerhead and into the processing chamber at a total flow rate during the first deposition process, with the total flow rate being at least a predetermined percentage above the divert flow rate.

[0076] Implementation 8: The chemical deposition system of implementation 5, wherein the controller is further configured to control the valves of the gas distribution system to cause the non-reactive gas to flow through the one or more backside purge ports at a backside flow rate that is at least 100% of a total flow rate of the second gas flowing through the showerhead and towards the wafer support.

[0077] Implementation 9: The chemical deposition system of implementation 8, further comprising a second gas divert flow path configured to flow the second gas to a location other than the showerhead and the interior volume of the processing chamber; wherein the controller is further configured to control the valves of the gas distribution system to cause: the second gas to flow at a divert flow rate into the second gas divert flow path during the first preparation process, and the second gas to flow through the showerhead and into the processing chamber at the total flow rate during the second deposition process, with the total flow rate being at least a predetermined percentage above the divert flow rate. [0078] Implementation 10: The chemical deposition system of implementation 2, further comprising one or more sensors configured to generate, during the first preparation process, an input signal associated with data indicative of one or more parameters of the first preparation process, wherein the controller is further configured to: compare the one or more parameters to one or more corresponding predetermined set points, determine that that the one or more parameters have reached a predetermined condition responsive, at least in part to, the one or more parameters is outside of a predetermined range of the one or more corresponding predetermined set points, and cause the valves of the gas distribution system to actuate to cause the second gas to flow through the showerhead and towards the wafer support responsive, at least in part to, the controller determining that the one or more parameters of the first preparation process have reached the predetermined condition.

[0079] Implementation 1 1 : The chemical deposition system of implementation 2, further comprising one or more sensors configured to generate, during the second preparation process, an input signal associated with data indicative of one or more parameters of the second preparation process, wherein the controller is further configured to: compare the one or more parameters to one or more corresponding predetermined set points, determine that the one or more parameters have reached a predetermined condition responsive, at least in part to, the at least one parameter being outside of a predetermined range of the one or more corresponding predetermined set points, and cause the valves of the gas distribution system to actuate to cause the first gas to flow through the showerhead and towards the wafer support responsive, at least in part to, the controller determining that the one or more parameters of the second preparation process have reached the predetermined condition.

[0080] Implementation 12: The chemical deposition system of implementation 2, wherein the controller is further configured to: define a deposition cycle as a sequential order including the first deposition process, the first preparation process, the second deposition process, and the second preparation process, and control the valves of the gas distribution system to perform two or more sequential instances of the deposition cycle.

[0081] Implementation 13: The chemical deposition system of implementation 12, wherein the controller is further configured to control the valves of the gas distribution system to cause the non-reactive gas to continuously flow through the one or more backside purge ports and into the backside region between the top side of the showerhead and the top wall of the processing chamber during each deposition cycle. [0082] Implementation 14: The chemical deposition system of implementation 12, wherein the non-reactive gas comprises nitrogen.

[0083] Implementation 15: The chemical deposition system of implementation 12, wherein the plurality of different gas sources includes another gas source further providing an ammonia-containing gas, and the controller is further configured to control the valves of the gas distribution system to cause at least the ammonia-containing gas to flow through the showerhead and towards the wafer support during the second preparation process.

[0084] Implementation 16: The chemical deposition system of implementation 15, wherein the controller is further configured to control the valves of the gas distribution system to cause at least the ammonia-containing gas to flow through the showerhead and towards the wafer support during the first deposition process.

[0085] Implementation 17: The chemical deposition system of implementation 16, wherein the controller is further configured to control the valves of the gas distribution system to prevent the second gas from flowing through the showerhead and into the processing chamber when the first gas flows through the showerhead and into the processing chamber.

[0086] Implementation 18: The chemical deposition system of implementation 12, wherein the controller is further configured to control the valves of the gas distribution system to prevent the first gas from flowing through the showerhead and into the processing chamber when the second gas flows through the showerhead and into the processing chamber.

[0087] Implementation 19: A controller for a chemical deposition system including a processing chamber that defines an interior volume, the chemical deposition system further including a wafer support positioned within the interior volume and configured to support a substrate during a chemical deposition process, the chemical deposition system further including a showerhead positioned above the wafer support and supported by a stem, with a backside region existing between a top side of the showerhead and a top wall of the processing chamber, the showerhead having a plurality of gas distribution ports distributed across a bottom surface of the showerhead facing the wafer support, the chemical deposition system further including a backside purge system including one or more backside purge ports configured to direct gas into a backside region between the top side of the showerhead and the top wall of the processing chamber, the controller comprising: one or more processors configured to communicate with a gas distribution system including a plurality of valves controllable to selectively cause one or more gases from a plurality of different gas sources connectable to the gas distribution system to be flowed to one or both of the showerhead and the backside purge system, wherein the plurality of different gas sources include a gas source for providing a first gas containing at least a first precursor for use in generating a silane film, a gas source for providing a second gas containing at least a second precursor for use in generating an oxide film, and a gas source for providing a non-reactive gas; and one or more non-transitory computer readable media storing instructions which, when executed by the one or more processors, cause the one or more processors to control the valves of the gas distribution system to cause: at least the first gas to flow through the showerhead and towards the wafer support during a first deposition process, at least the second gas to flow through the showerhead and towards the wafer support during a second deposition process, at least the non-reactive gas to flow through the showerhead and towards the wafer support during a first preparation process between the first and second deposition processes; and at least the non-reactive gas to flow through the one or more backside purge ports and into the backside region between the top side of the showerhead and the top wall of the processing chamber during the first deposition process, the first preparation process, and the second deposition process.

[0088] Implementation 20: The controller of implementation 19, wherein the one or more non-transitory computer-readable media store additional instructions which, when executed by the one or more processors, further cause the one or more processors to control the valves of the gas distribution system to cause at least the non-reactive gas to flow through the showerhead and towards the wafer support during a second preparation process after the second deposition process.

[0089] Implementation 21 : The controller of implementation 20, wherein the one or more non-transitory computer-readable media store additional instructions which, when executed by the one or more processors, further cause the one or more processors to control the valves of the gas distribution system to cause at least the non-reactive gas to flow through the one or more backside purge ports and into the backside region between the top side of the showerhead and the top wall of the processing chamber during the second deposition process.

[0090] Implementation 22: The controller of implementation 21 , wherein the one or more non-transitory computer-readable media store additional instructions which, when executed by the one or more processors, further cause the one or more processors to control the valves of the gas distribution system to cause the non-reactive gas to flow through the one or more backside purge ports at a backside flow rate that is at least 100% of a total flow rate of the first gas flowing through the showerhead and towards the wafer support.

[0091] Implementation 23: The controller of implementation 22, wherein the gas distribution system further includes a first gas divert flow path configured to flow the first gas to a location other than the showerhead and the interior volume of the processing chamber; and the one or more non-transitory computer-readable media store additional instructions which, when executed by the one or more processors, further cause the one or more processors to control the valves of the gas distribution system to cause: the first gas to flow at a divert flow rate into the first gas divert flow path during the second preparation process, and the first gas to flow through the showerhead and into the processing chamber at the total flow rate during the first deposition process, with the total flow rate being at least a predetermined percentage above the divert flow rate.

[0092] Implementation 24: The controller of implementation 23, wherein the one or more non-transitory computer-readable media store additional instructions which, when executed by the one or more processors, further cause the one or more processors to control the valves of the gas distribution system to cause the non-reactive gas to flow through the one or more backside purge ports at a backside flow rate that is at least 100% of a total flow rate of the second gas flowing through the showerhead and towards the wafer support.

[0093] Implementation 25: The controller of implementation 24, further comprising a second gas divert flow path configured to flow gas to a location other than the showerhead and the interior volume of the processing chamber; wherein the one or more non- transitory computer-readable media store additional instructions which, when executed by the one or more processors, further cause the one or more processors to control the valves of the gas distribution system to cause: the second gas to flow at a divert flow rate into the second gas divert flow path during the first preparation process, and the second gas to flow through the showerhead and into the processing chamber at the total flow rate during the second deposition process, with the total flow rate being at least a predetermined percentage above the divert flow rate.

[0094] Implementation 26: The controller of implementation 21 , wherein the one or more non-transitory computer-readable media store additional instructions which, when executed by the one or more processors, further cause the one or more processors to: compare, during the first preparation process, one or more parameters of the first preparation process to one or more corresponding predetermined set points; determine that the one or more parameters have reached a predetermined condition responsive, at least in part, to the one or more parameters being outside of a predetermined range of the one or more corresponding predetermined set points; and cause the valves of the gas distribution system to actuate to cause the second gas to flow through the showerhead and towards the wafer support responsive, at least in part to, the one or more processors determining that the one or more parameters have reached the predetermined condition.

[0095] Implementation 27: The controller of implementation 21 , wherein the one or more non-transitory computer-readable media store additional instructions which, when executed by the one or more processors, further cause the one or more processors to: compare, during the second preparation process, one or more parameters of the second preparation process to one or more corresponding predetermined set points; determine that the one or more parameters have reached a predetermined condition responsive, at least in part, to the one or more parameters being outside of a predetermined range of the one or more corresponding predetermined set points; and cause the valves of the gas distribution system to actuate to cause the first gas to flow through the showerhead and towards the wafer support responsive, at least in part to, the one or more processors determining that the one or more parameters have reached the predetermined condition.

[0096] Implementation 28: A method of operating a controller for a chemical deposition system including a backside purge system having one or more backside purge ports configured to direct gas into a backside region between a top side of a showerhead and a top wall of a processing chamber, the chemical deposition system further including a gas distribution system having a plurality of valves controllable to selectively cause one or more gases from a plurality of different gas sources connectable to the gas distribution system to be flowed to one or both of the showerhead and the backside purge system, the method comprising: supporting, using a wafer support positioned within an interior volume defined by the processing chamber, a substrate during a chemical deposition process; and controlling, using the controller, the valves of the gas distribution system to cause: at least a first gas containing at least a first precursor for use in generating a silane film to flow through the showerhead and towards the wafer support during a first deposition process, at least a second gas containing at least a second precursor for use in generating an oxide film to flow through the showerhead and towards the wafer support during a second deposition process, at least a non-reactive gas to flow through the showerhead and towards the wafer support during a first preparation process between the first and second deposition processes, and at least the non-reactive gas to flow through the one or more backside purge ports and into the backside region between the top side of the showerhead and the top wall of the processing chamber during the first deposition process, the first preparation process, and the second deposition process.

[0097] Implementation 29: The method of implementation 28, further comprising controlling, using the controller, the valves of the gas distribution system to cause at least the non-reactive gas to flow through the showerhead and towards the wafer support during a second preparation process after the second deposition process.

[0098] Implementation 30: The method of implementation 29, further comprising controlling, using the controller, the valves of the gas distribution system to cause at least the non-reactive gas to flow through the one or more backside purge ports and into the backside region between the top side of the showerhead and the top wall of the processing chamber during the second preparation process.

[0099] Implementation 31 : The method of implementation 30, further comprising controlling, using the controller, the valves of the gas distribution system to cause the non-reactive gas to flow through the one or more backside purge ports at a backside flow rate that is at least 100% of a total flow rate of the first gas flowing through the showerhead and towards the wafer support.

[0100] Implementation 32: The method of implementation 31 , further comprising controlling, using the controller, the valves of the gas distribution system to cause: the first gas to flow at a divert flow rate into a first gas divert flow path during the second preparation process, and the first gas to flow through the showerhead and into the processing chamber at the total flow rate during the first deposition process, with the total flow rate being at least a predetermined percentage above the divert flow rate.

[0101] Implementation 33: The method of implementation 30, further comprising controlling, using the controller, the valves of the gas distribution system to cause the non-reactive gas to flow through the one or more backside purge ports at a backside flow rate that is at least 100% of a total flow rate of the second gas flowing through the showerhead and towards the wafer support.

[0102] Implementation 34: The method of implementation 33, further comprising controlling, using the controller, the valves of the gas distribution system to cause: the second gas to flow at a divert flow rate into a second divert flow path during the first preparation process, and the second gas to flow through the showerhead and into the processing chamber at the total flow rate during the second deposition process, with the total flow rate being at least a predetermined percentage above the divert flow rate.

[0103] Systems and methods according to the present disclosure use a controller configured to control one or more valves of a gas distribution system to cause a first gas having at least a first precursor to flow through a showerhead and into a processing chamber during a first deposition process, with the first gas being used for generating a silane film. The controller is further configured to control the valves to cause a second gas having at least a second precursor to flow through the showerhead and into the processing chamber during a second deposition process, with the second gas being used for generating an oxide film. The controller is further configured to control the valves to cause a non-reactive gas to flow through the showerhead and into the processing chamber during a first preparation process between the first and second deposition processes, with the reactive gas flushing any remaining first gas from the showerhead and the processing chamber through exit ports thereby decreasing unwanted deposition in the showerhead and/or processing chamber. The controller is further configured to control the valves to cause a non-reactive gas to flow through the showerhead and into the processing chamber during a second preparation after the second deposition process, with the reactive gas flushing any remaining second gas from the showerhead and the processing chamber through exit ports thereby decreasing unwanted deposition in the showerhead and/or processing chamber. Furthermore, systems and methods according to the present disclosure use a backside purge system to direct gas and into a backside region between a top side of a showerhead and a top wall of a processing chamber to provide an air curtain that prevents a precursor gas from flowing into the backside region and forming unwanted deposition on surfaces defining the backside region. Systems and methods according to the present disclosure reduce the effective chamber volume, which provides substantial reduction in precursor consumption, shortens deposition cycle times, and reduces operating costs. Systems and methods according to the present disclosure also alternates flow paths to which stable fluid flows may be diverted with little to no transient effects when not being routed to the processing chamber, thereby avoiding the need to ramp fluid flows up or down.

[0104] The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A, B, or C), using a non-exclusive logical OR. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure.

Claims

CLAIMS What is claimed is:

1 . A chemical deposition system comprising: a processing chamber defining an interior volume; a wafer support positioned within the interior volume and configured to support a substrate during a chemical deposition process; a showerhead positioned above the wafer support and supported by a stem, and a backside region exists between a top side of the showerhead and a top wall of the processing chamber, the showerhead having a plurality of gas distribution ports distributed across a bottom surface of the showerhead facing the wafer support; a backside purge system including one or more backside purge ports configured to direct gas into the backside region between the top side of the showerhead and the top wall of the processing chamber; a gas distribution system including a plurality of valves controllable to selectively cause one or more gases from a plurality of different gas sources connectable to the gas distribution system to be flowed to one or both of the showerhead and the backside purge system, wherein the plurality of different gas sources includes a gas source for providing a first gas containing at least a first precursor for use in generating a silane film, a gas source for providing a second gas containing at least a second precursor for use in generating an oxide film, and a gas source for providing a non-reactive gas; and a controller, wherein the controller is configured to control the valves of the gas distribution system to cause: at least the first gas to flow through the showerhead and towards the wafer support during a first deposition process, at least the second gas to flow through the showerhead and towards the wafer support during a second deposition process, at least the non-reactive gas to flow through the showerhead and towards the wafer support during a first preparation process between the first and second deposition processes, and at least the non-reactive gas to flow through the one or more backside purge ports and into the backside region between the top side of the showerhead and the top wall of the processing chamber during the first deposition process, the first preparation process, and the second deposition process.

2. The chemical deposition system of claim 1 , wherein the controller is further configured to control the valves of the gas distribution system to cause at least the non- reactive gas to flow through the showerhead and towards the wafer support during a second preparation process after the second deposition process.

3. The chemical deposition system of claim 2, further comprising: one or more sensors configured to generate, during the first preparation process, an input signal associated with data indicative of one or more parameters of the first preparation process, wherein the controller is further configured to: compare the one or more parameters to one or more corresponding predetermined set points, determine that that the one or more parameters have reached a predetermined condition responsive, at least in part to, the one or more parameters is outside of a predetermined range of the one or more corresponding predetermined set points, and cause the valves of the gas distribution system to actuate to cause the second gas to flow through the showerhead and towards the wafer support responsive, at least in part to, the controller determining that the one or more parameters of the first preparation process have reached the predetermined condition.

4. The chemical deposition system of claim 2, further comprising: one or more sensors configured to generate, during the second preparation process, an input signal associated with data indicative of one or more parameters of the second preparation process, wherein the controller is further configured to: compare the one or more parameters to one or more corresponding predetermined set points, determine that the one or more parameters have reached a predetermined condition responsive, at least in part to, the at least one parameter being outside of a predetermined range of the one or more corresponding predetermined set points, and cause the valves of the gas distribution system to actuate to cause the first gas to flow through the showerhead and towards the wafer support responsive, at least in part to, the controller determining that the one or more parameters of the second preparation process have reached the predetermined condition.

5. The chemical deposition system of claim 2, wherein the controller is further configured to: define a deposition cycle as a sequential order including the first deposition process, the first preparation process, the second deposition process, and the second preparation process, and control the valves of the gas distribution system to perform two or more sequential instances of the deposition cycle.

6. The chemical deposition system of claim 5, wherein the controller is further configured to control the valves of the gas distribution system to cause the non-reactive gas to continuously flow through the one or more backside purge ports and into the backside region between the top side of the showerhead and the top wall of the processing chamber during each deposition cycle.

7. The chemical deposition system of claim 5, wherein the non-reactive gas comprises nitrogen.

8. The chemical deposition system of claim 5, wherein the plurality of different gas sources includes another gas source further providing an ammonia-containing gas, and the controller is further configured to control the valves of the gas distribution system to cause at least the ammonia-containing gas to flow through the showerhead and towards the wafer support during the second preparation process.

9. The chemical deposition system of claim 8, wherein the controller is further configured to control the valves of the gas distribution system to cause at least the ammonia-containing gas to flow through the showerhead and towards the wafer support during the first deposition process.

10. The chemical deposition system of claim 9, wherein the controller is further configured to control the valves of the gas distribution system to prevent the second gas from flowing through the showerhead and into the processing chamber when the first gas flows through the showerhead and into the processing chamber.

11 . The chemical deposition system of claim 5, wherein the controller is further configured to control the valves of the gas distribution system to prevent the first gas from flowing through the showerhead and into the processing chamber when the second gas flows through the showerhead and into the processing chamber.

12. The chemical deposition system of any one of claims 1 to 1 1 , wherein the first precursor of the first gas includes at least one of: a first combination of silane and ammonia (NH3), and silane alone.

13. The chemical deposition system of any one of claims 1 to 1 1 , wherein the second precursor of the second gas includes at least one of: a first combination including at least tetraethyl orthosilicate (TEOS), a second combination including at least silane, and an oxidizer.

14. The chemical deposition system of any one of claims 1 to 11 , wherein the controller is further configured to control the valves of the gas distribution system to cause at least the non-reactive gas to flow through the one or more backside purge ports and into the backside region between the top side of the showerhead and the top wall of the processing chamber during the second preparation process.

15. The chemical deposition system of claim 14, wherein the controller is further configured to control the valves of the gas distribution system to cause the non-reactive gas to flow through the one or more backside purge ports at a backside flow rate that is at least 100% of a total flow rate of the second gas flowing through the showerhead and towards the wafer support.

16. The chemical deposition system of claim 15, further comprising: a second gas divert flow path configured to flow the second gas to a location other than the showerhead and the interior volume of the processing chamber; wherein the controller is further configured to control the valves of the gas distribution system to cause: the second gas to flow at a divert flow rate into the second gas divert flow path during the first preparation process, and the second gas to flow through the showerhead and into the processing chamber at the total flow rate during the second deposition process, with the total flow rate being at least a predetermined percentage above the divert flow rate.

17. The chemical deposition system of any one of claims 1 to 11 , wherein the controller is further configured to control the valves of the gas distribution system to cause the non- reactive gas to flow through the one or more backside purge ports at a backside flow rate that is at least 100% of a total flow rate of the first gas flowing through the showerhead and towards the wafer support.

18. The chemical deposition system of any one of claims 1 to 1 1 , wherein: the gas distribution system further includes a first gas divert flow path configured to flow the first gas to a location other than the showerhead and the interior volume of the processing chamber; and the controller is further configured to control the valves of the gas distribution system to cause: the first gas to flow at a divert flow rate into the first gas divert flow path during the second preparation process, and the first gas to flow through the showerhead and into the processing chamber at a total flow rate during the first deposition process, with the total flow rate being at least a predetermined percentage above the divert flow rate.

19. A controller for a chemical deposition system including a processing chamber that defines an interior volume, the chemical deposition system further including a wafer support positioned within the interior volume and configured to support a substrate during a chemical deposition process, the chemical deposition system further including a showerhead positioned above the wafer support and supported by a stem, with a backside region existing between a top side of the showerhead and a top wall of the processing chamber, the showerhead having a plurality of gas distribution ports distributed across a bottom surface of the showerhead facing the wafer support, the chemical deposition system further including a backside purge system including one or more backside purge ports configured to direct gas into a backside region between the top side of the showerhead and the top wall of the processing chamber, the controller comprising: one or more processors configured to communicate with a gas distribution system including a plurality of valves controllable to selectively cause one or more gases from a plurality of different gas sources connectable to the gas distribution system to be flowed to one or both of the showerhead and the backside purge system, wherein the plurality of different gas sources include a gas source for providing a first gas containing at least a first precursor for use in generating a silane film, a gas source for providing a second gas containing at least a second precursor for use in generating an oxide film, and a gas source for providing a non-reactive gas; and one or more non-transitory computer readable media storing instructions which, when executed by the one or more processors, cause the one or more processors to control the valves of the gas distribution system to cause: at least the first gas to flow through the showerhead and towards the wafer support during a first deposition process, at least the second gas to flow through the showerhead and towards the wafer support during a second deposition process, at least the non-reactive gas to flow through the showerhead and towards the wafer support during a first preparation process between the first and second deposition processes; and at least the non-reactive gas to flow through the one or more backside purge ports and into the backside region between the top side of the showerhead and the top wall of the processing chamber during the first deposition process, the first preparation process, and the second deposition process.

20. A method of operating a controller for a chemical deposition system including a backside purge system having one or more backside purge ports configured to direct gas into a backside region between a top side of a showerhead and a top wall of a processing chamber, the chemical deposition system further including a gas distribution system having a plurality of valves controllable to selectively cause one or more gases from a plurality of different gas sources connectable to the gas distribution system to be flowed to one or both of the showerhead and the backside purge system, the method comprising: supporting, using a wafer support positioned within an interior volume defined by the processing chamber, a substrate during a chemical deposition process; and controlling, using the controller, the valves of the gas distribution system to cause: at least a first gas containing at least a first precursor for use in generating a silane film to flow through the showerhead and towards the wafer support during a first deposition process, at least a second gas containing at least a second precursor for use in generating an oxide film to flow through the showerhead and towards the wafer support during a second deposition process, at least a non-reactive gas to flow through the showerhead and towards the wafer support during a first preparation process between the first and second deposition processes, and at least the non-reactive gas to flow through the one or more backside purge ports and into the backside region between the top side of the showerhead and the top wall of the processing chamber during the first deposition process, the first preparation process, and the second deposition process.