Methods and systems for mitigating CVD foreline growth

Abstract

Various embodiments of the present technology may provide a system having a bypass line to a foreline of a reaction chamber. The system may include a pump coupled to the foreline. The system may include a pressure flow controller upstream of the bypass line. The bypass line may be coupled to the foreline at the pump inlet. The bypass line may include a low flow path with a conductivity of between 1% and 10% relative to unlimited flow. The bypass line may include a decomposition device configured to decompose a fluid (e.g., a gas) in the bypass line.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is a non-provisional application of U.S. Provisional Patent Application No. 63 / 538,762, filed on September 15, 2023, entitled “METHODS AND SYSTEM FOR MITIGATINGCVD FORELINE GROWTH”, and claims priority and benefits thereof, which application is incorporated herein by reference. Technical Field

[0003] The present disclosure generally relates to methods and systems for mitigating CVD foreline growth. More specifically, the present disclosure relates to utilizing a pressure controller to meter dosage, relocating a bypass terminal near a pump inlet, and / or decomposing gases prior to or within a foreline. Background Art

[0004] Semiconductor processing equipment performing deposition may suffer from CVD growth in undesirable areas of the processing equipment. In particular, in ALD processes where a precursor is pulsed with a co-reactant, excessive CVD growth may be observed in the foreline due to the co-reactant coexisting with the precursor. This CVD growth forms a low-density powder that is not firmly adhered to the inner walls of the foreline and can periodically break away from the wall and be transported into the pump, causing pump failure. Summary of the invention

[0005] Various embodiments of the present technology may provide a system having a bypass line to a foreline leading to a reaction chamber. The system may include a pump coupled to the foreline. The system may include a pressure flow controller upstream of the bypass line. The bypass line may be coupled to the foreline at a pump inlet. The bypass line may include a low flow path wherein the conductivity is between 1% and 10%.

[0006] According to one aspect, a system includes: a reaction chamber; a first container configured to hold a precursor, wherein the first container is connected to the reaction chamber via a first gas pipeline; a second container configured to hold a co-reactant, wherein the second container is connected to the reaction chamber; a foreline, which includes a first end directly connected to the reaction chamber and an opposite second end; a pump, which is connected to the second end of the foreline at a first junction; a second gas line, which includes a first portion connected to an inlet of the reaction chamber and a second portion connected to the foreline; wherein the first portion and the second portion are connected to each other at a second junction; and a mass flow controller, which is connected between the second container and the second junction.

[0007] In one embodiment, the co-reactant is one of ozone, ammonia, silane or disilane.

[0008] In one embodiment, the first portion of the second gas line has a first conductance and the second portion has a second conductance, wherein the first conductance is the same as the second conductance.

[0009] In one embodiment, the co-reactant has a high pressure gas state.

[0010] In one embodiment, the system further comprises a first valve within the first portion of the second gas line and a second valve within the second portion of the second gas line.

[0011] In an embodiment, the system further comprises a control unit configured to transmit a control signal to the first and second valves.

[0012] In an embodiment, the pump is a dry vacuum pump.

[0013] In one embodiment, the system further comprises a decomposition device coupled to the second portion of the second gas line and configured to decompose the co-reactant. The decomposition device may comprise a catalyst and / or a heater.

[0014] On the other hand, a system includes: a reaction chamber; a foreline comprising a first end directly connected to the reaction chamber and an opposite second end; a pump connected to the second end of the foreline; a first container configured to hold a precursor, wherein the first container is connected to the reaction chamber via a first gas line; a second container configured to hold a co-reactant, wherein the second container is connected to the reaction chamber; a second gas line comprising a first portion connected to an inlet of the reaction chamber, a second portion connected to the foreline, and a third portion connected to the foreline; wherein the first portion and the second portion are connected to each other at a junction; and wherein the second and third portions are parallel to each other; and a pressure flow controller connected between the second container and the second junction.

[0015] In one embodiment, the system further includes a first valve within the first portion of the second gas line, a second valve within the second portion of the second gas line, and a third valve within the third portion of the second gas line.

[0016] In one embodiment, the system further includes a flow restrictor coupled between the junction and the third valve.

[0017] In an embodiment, the system further comprises a control unit configured to transmit control signals to the first, second and third valves.

[0018] In one embodiment, the co-reactant is one of ozone, ammonia, silane or disilane.

[0019] In one embodiment, the first portion has a first conductivity, the second portion has a second conductivity, and the third portion has a third conductivity, wherein the third conductivity is less than 95% of the first conductivity and / or the second conductivity.

[0020] In one embodiment, the pump may be a dry vacuum pump.

[0021] On the other hand, a system includes: a reaction chamber; a foreline comprising a first end directly connected to the reaction chamber and an opposite second end; a pump coupled to the second end of the foreline at a first junction; a first container configured to hold a precursor, wherein the first container is coupled to the reaction chamber via a first gas line; a second container configured to hold a co-reactant, wherein the second container is coupled to the reaction chamber; and a second gas line comprising a first portion coupled to an inlet of the reaction chamber and a second portion coupled to the first junction; wherein the first portion and the second portion are connected to each other at the second junction.

[0022] In one embodiment, the system further comprises a pressure flow controller connected between the second container and the second junction. The second gas pipeline further comprises a third portion connected between the second junction and the foreline. The second portion and the third portion may be parallel to each other.

[0023] In one embodiment, the pump may be a dry vacuum pump.

[0024] In one embodiment, the first portion has a first conductivity, the second portion has a second conductivity, and the third portion has a third conductivity, wherein the third conductivity is less than 95% of the first conductivity and / or the second conductivity.

[0025] In one embodiment, the system further includes a first valve within the first portion of the second gas line, a second valve within the second portion of the second gas line, and a third valve within the third portion of the second gas line.

[0026] In one embodiment, the system further includes a flow restrictor coupled to the third portion between the second junction and the third valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] A more complete understanding of the present technology may be obtained by referring to the detailed description when considered in conjunction with the following illustrative drawings.In the following drawings, like reference numerals refer to like elements and steps throughout the drawings.

[0028] Figure 1 A system according to an embodiment of the present technology is representatively shown.

[0029] Figure 2 Representatively, systems according to alternative embodiments of the present technology are shown.

[0030] Figure 3 Representatively, systems according to alternative embodiments of the present technology are shown.

[0031] Figure 4Representatively, systems according to alternative embodiments of the present technology are shown. DETAILED DESCRIPTION

[0032] The present technology can be described in terms of functional block components and various processing steps. Such functional blocks can be implemented by any number of components configured to perform specified functions and achieve various results. For example, the present technology can use various reaction chambers, valves and valve manifolds, gas pipeline connectors and containers. The components of any of the embodiments depicted in the drawings can be combined and / or arranged in any suitable combination of components within the system (i.e., according to the present disclosure, components depicted in one embodiment in the first drawing but not depicted in the second drawing can also be implemented in the second drawing).

[0033] refer to Figure 1-4 , exemplary system 100 may include reaction chamber 105 , first vessel 115 , second vessel 110 , foreline 130 , and pump 120 .

[0034] In various embodiments, reaction chamber 105 may be configured to deposit a film on a substrate such as a wafer.Reaction chamber 105 may be configured for any desired deposition process.

[0035] In various embodiments, the first container 115 can be configured to contain or otherwise store a first chemical substance (e.g., a precursor). The first chemical substance can be in the form of a solid, a liquid, or a gas. In some cases, the first container 115 can be configured to sublime the first chemical substance into a gas. For example, the first container 115 can include a heating element and / or a sublimator.

[0036] In various embodiments, the second container 110 can be configured to contain or otherwise store a second chemical substance (e.g., a co-reactant). The second chemical substance can include a chemical substance having a high-pressure gas state, such as ozone, ammonia, silane, or disilane. The second container 110 can be configured to sublimate the second chemical substance into a gas. For example, the second container 110 can include a heating element and / or a sublimator.

[0037] In various embodiments, foreline 130 may be coupled to reaction chamber 105 and may be configured to exhaust excess chemicals from reaction chamber 105. For example, foreline 130 may include a first end coupled to an opening in a bottom surface of reaction chamber 105 and an opposing second end. Foreline 130 may be formed of any suitable material, such as a metallic material, e.g., stainless steel.

[0038] In various embodiments, pump 120 can be configured to facilitate evacuation of reaction chamber 105. For example, the inlet of pump 120 can be coupled to the second end of foreline 130. The connection point of the inlet of pump 120 and foreline 130 can be referred to as a first junction. Pump 120 can include a vacuum pump. The outlet of pump 120 can output gas to a waste line (not shown).

[0039] In various embodiments, the system 100 may also include a first gas line 135 configured to couple the first container 115 to an inlet of the reaction chamber 105. The first gas line 135 may be formed of any suitable material, such as stainless steel. The first gas line may include any number of couplers, connectors, gas line portions, etc.

[0040] In various embodiments, the system 100 may further include a second gas line. The second gas line may be formed of any suitable material, such as stainless steel. In an exemplary embodiment, the second gas line includes a first portion 140 (i.e., a main delivery line) configured to deliver gas to the reaction chamber 105. For example, a first end of the first portion 140 may be coupled or otherwise connected to the second container 110, and a second end of the first portion 140 may be coupled or otherwise connected to an inlet of the reaction chamber 105.

[0041] In an exemplary embodiment, the second gas line may also include a second portion (e.g., a first bypass line), such as second portion 145A or 145B. The second portion may include a first end and an opposite second end. The first end of second portion 145A may be connected to first portion 140 at second junction 165 (or any other suitable location), and the second end of second portion 145A may be connected to the first junction. The first end of second portion 145B may be connected to first portion 140 at second junction 165 (or any other suitable location), and the second end of second portion 145B may be connected to foreline 130.

[0042] In an exemplary embodiment, referring to Figure 2 The second gas line may further include a third portion 200 (eg, a second bypass line). The third portion 200 may include a first end coupled to the portion junction 165 (or any other suitable location) and a second end coupled to the foreline 130.

[0043] In various embodiments, the system 100 may include various valves to restrict or allow gas to flow through the gas line. For example, the system 100 may include a first valve 160 in the first gas line 135, a second valve 150 in the first portion 140, and a third valve 155 in the second portion (e.g., the second portion 145A or 145B).

[0044] The first valve 160 can be disposed between the inlet of the reaction chamber 105 and the outlet of the first container 115. The first valve 160 can include any suitable valve type. In an exemplary embodiment, the first valve 160 can include a diaphragm valve that responds to a control signal. The control signal can open or close the valve.

[0045] The second valve 150 can be disposed between the second junction 165 and the inlet of the reaction chamber 105. The second valve 150 can include any suitable valve type. In an exemplary embodiment, the second valve 150 can include a diaphragm valve that responds to a control signal. The control signal can open or close the valve.

[0046] The third valve 155 may be disposed between the first junction and the partial junction 165, or between the second junction and the foreline 130. The second valve 150 may include any suitable valve type. In an exemplary embodiment, the third valve 155 may include a diaphragm valve responsive to a control signal. The control signal may open or close the valve.

[0047] In addition, in the exemplary embodiment, the third portion 200 may include a fourth valve 205 and / or a flow restrictor 210. The fourth valve 205 and the flow restrictor 210 may be disposed between the second junction 165 and the foreline 130. The flow restrictor 210 may be disposed upstream of the fourth valve 205. The fourth valve 205 may include any suitable valve type. In the exemplary embodiment, the fourth valve 205 may include a diaphragm valve responsive to a control signal. The control signal may open or close the valve.

[0048] In various embodiments including the third portion 200, the second portion 145B may be absent. In various embodiments, the third portion 200 may be absent, but a flow restrictor may be coupled to the second portion 145B.

[0049] In one embodiment, referring to Figure 1 , 3 4, the system 100 may further include a mass flow controller 125. The mass flow controller 125 may be coupled to the second gas line between the outlet of the second container 110 and the second junction 165. In particular, the mass flow controller 125 may be disposed upstream of the second junction 165. In various embodiments, in addition to the mass flow controller 125, or in place of the mass flow controller 125, there may be a pressure flow controller (e.g., similar to the pressure flow controller 215).

[0050] In another embodiment, reference Figure 2, the system 100 may further include a pressure flow controller (PFC) 215 configured to adjust the flow rate and conductivity of the second gas pipeline. PFC215 can be connected to the second gas pipeline between the outlet of the second container 110 and the second junction 165. In particular, PFC215 can be arranged upstream of the second junction 165. PFC215 can be configurable, for example, set to a desired pressure set point (for example, a relatively high set point pressure can result in a larger flow rate, while a relatively low set point pressure can result in a smaller flow rate). PFC215 can be any suitable type of PFC that regulates the gas flow according to the pressure. In various embodiments, in addition to PFC215, or instead of PFC215, there can be a mass flow controller (for example, similar to mass flow controller 125).

[0051] In various embodiments, the system 100 may further include a control unit 170. The control unit 170 may be in electronic communication with any other suitable components of the system 100 (e.g., generating and transmitting valve control signals and / or controlling mass flow controllers and / or PFCs). The control unit may also be used to set a set point for the PFC 215.

[0052] In operation, the system 100 can perform an atomic layer deposition (ALD) process. For example, the system 100 can perform a series of pulses with precursors and co-reactants and perform a purge step with an inert gas, such as argon, between pulses.

[0053] In conventional systems, full flow of co-reactant into the foreline (e.g., during a purge of the second gas line, and / or during a pulse or purge of the precursor) can result in CVD reactions with the precursor occurring within the foreline (e.g., on the sidewalls of the foreline.) This is undesirable because such accumulation can break away from the sidewalls and enter the pump, which can cause the pump to fail.

[0054] Embodiments of the present technology can reduce CVD front-end pipeline accumulation. For example, in operation and with reference to Figure 1 , during the pulse of the co-reactant, the second valve 150 is open and the third valve 155 is closed. During the purge of the co-reactant and / or the pulse and purge of the precursor, the second valve 150 is closed and the third valve 155 is opened. During the purge, the gas flows through the second portion 145A and directly to the inlet of the pump 120 (e.g., to the first junction), thereby bypassing most or all of the foreline 130 and thereby mitigating or preventing CVD buildup along most of the entire length of the foreline 130. The second portion 145A can be coupled to the foreline 130 at or near the inlet of the pump 120, and / or the second portion 145A can be coupled to the pump 120 at an inlet different from the pump inlet coupled to the foreline 130.

[0055] As another example, refer to Figure 3 and Figure 4 , the second portion of the second gas line and / or at least a portion of the foreline 130 may include a decomposition device configured to decompose the co-reactant. For example, the second portion 145B of the second gas line may include a decomposition device 183 disposed along at least a portion of the second portion 145B (e.g., between the second junction 165 and the foreline 130). The decomposition device may be configured to decompose the co-reactant before the co-reactant reaches the foreline 130. As another example, the foreline 130 may include a decomposition device 186 disposed along at least a portion of the foreline 130 (e.g., to decompose the co-reactant and / or any other gas therein, such as a precursor). The decomposition device may also be disposed along the second portion of the second gas line and at least a portion of the foreline 130. Therefore, by decomposing the co-reactant in the decomposition device, the reaction between the co-reactant and the precursor is reduced or prevented, and the film formation and / or accumulation within the foreline 130 is mitigated or prevented.

[0056] In various embodiments, the decomposition device can be any suitable structure or device to decompose the gas (e.g., co-reactant and / or precursor) flowing through the corresponding gas pipeline. For example, the decomposition device can include a heater device (e.g., a heater connected to the second portion of the second gas pipeline and / or the foreline 130 and / or disposed around it). The heater device can be configured to heat the gas (e.g., co-reactant) in the corresponding gas path (e.g., the second portion of the second gas pipeline and / or the foreline 130) to decompose the gas flowing therethrough by thermal decomposition. The heater device can be configured to heat the gas to a temperature that can cause the gas (e.g., co-reactant) to be at least partially or substantially or completely decomposed. For example, in order to decompose the gas, the heating temperature can be selected so that the half-life of the corresponding gas is less than 10 seconds, less than 5 seconds, less than 2 seconds, less than 1 second, and / or less than 0.5 seconds. For example, for a gas containing ozone, the temperature to which the gas is heated can be about or at least 200°C, above 200°C, 200-400°C, 200-300°C, etc. For example, for a gas containing silane and / or disilane, the temperature to which the gas is heated may be about or at least 200° C. or 300° C., 200-400° C., 200-300° C., 300-400° C., etc. For example, for a gas containing ammonia, the temperature to which the gas is heated may be about or at least 400° C., 400-700° C., 400-600° C., 400-500° C., etc. (“about” herein means ±50° C.).

[0057] As another example, the decomposition device may include a catalyst device (e.g., a catalytic bed) configured to receive and decompose the gas in the corresponding gas path (e.g., the second portion of the second gas pipeline and / or the front stage pipeline 130) via catalytic decomposition. The catalyst device may include a body that contains the catalyst. The catalyst can be any suitable material or compound configured to at least partially decompose the gas, and can be selected based on the co-reactant or other gas to be decomposed. For example, in order to decompose the gas, the catalyst can be selected so that the half-life of the corresponding gas is less than 10 seconds, less than 5 seconds, less than 2 seconds, less than 1 second, and / or less than 0.5 seconds.

[0058] For example, for a co-reactant comprising ozone, the catalyst may comprise a metal and / or a metal oxide. The metal may be any suitable metal (e.g., transition metal), such as platinum, palladium, ruthenium, copper, tungsten, copper, silver, tin, nickel, iron, gold, iridium, rhodium, cerium, manganese, cobalt, titanium, zinc, vanadium, chromium, molybdenum and / or any combination thereof. The metal oxide may comprise any of the aforementioned oxides (e.g., manganese oxide). The catalyst may comprise other oxide materials (e.g., ceramic materials), such as silicon oxide, aluminum oxide, zirconium oxide, etc. The catalyst may comprise a metal or metal oxide supported by another material (e.g., ceramic material), such as manganese oxide supported by silicon oxide, aluminum oxide, zirconium oxide, and / or titanium oxide. The catalyst may comprise carbon or a carbon material (e.g., activated carbon, carbon black, graphite, carbon fiber, etc.). The catalyst for a co-reactant comprising ozone may decompose ozone (e.g., decompose into oxygen (O2)), and ozone will not react with the precursor in the foreline 130, thereby alleviating or preventing the accumulation in the foreline 130.

[0059] In various embodiments, the decomposition device may include multiple components to decompose the corresponding gas (eg, a catalyst and a heater).

[0060] As another example, refer to Figure 2, PFC215 can be set to a desired pressure set point to achieve a desired flow rate of the co-reactant to the reaction chamber 105. In an exemplary embodiment, the third portion 200 can be set to have a conductivity of between 1% and 10% or about 5% relative to the conductivity through the first portion 140 (e.g., the reduced conductivity of the third portion 200 can be relative to the unrestricted flow through the flow path) (in this context, "about" means ±3%). The conductivity through the third portion 200 can be set (e.g., limited) by the restrictor 210 and / or the fourth valve 205. Therefore, the third portion can have a conductivity that is 95% less than the conductivity of the first portion and / or the second portion of the second gas pipeline. In this case, in response to the second valve 150 and / or the third valve 155 being closed and the fourth valve 205 being opened (e.g., during the time when the co-reactant is not provided to the reaction chamber 105), this relatively restricted and / or low co-reactant flow through the third portion 200 reduces the amount of co-reactant to the foreline 130. Thus, reactions between the co-reactant and the precursor are reduced or prevented, mitigating or preventing film formation and / or buildup within the foreline 130 .

[0061] In various embodiments, the third portion 200 may include a disassembly device disposed along at least a portion of the third portion 200 (similar to the disassembly device described with respect to Figure 3 and 4 decomposition device as described).

[0062] In the foregoing description, the technology has been described with reference to specific exemplary embodiments. The specific embodiments shown and described are illustrations of the technology and its best mode and are not intended to limit the scope of the technology in any way. In fact, for the sake of brevity, the conventional manufacturing, connection, preparation and other functional aspects of the method and system may not be described in detail. In addition, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and / or steps between the various elements. In actual systems, there may be many alternative or additional functional relationships or physical connections.

[0063] The technology has been described with reference to specific exemplary embodiments. However, various modifications and changes may be made without departing from the scope of the technology. The description and drawings are to be regarded as illustrative rather than restrictive, and all such modifications are intended to be included within the scope of the technology. Therefore, the scope of the technology should be determined by the general embodiments described and their legal equivalents, rather than solely by the specific examples described above. For example, the steps described in any method or process embodiment may be performed in any order unless otherwise expressly specified, and are not limited to the explicit order presented in the specific examples. In addition, the components and / or elements described in any device embodiment may be assembled or otherwise operably configured in various arrangements to produce substantially the same results as the technology, and are therefore not limited to the specific configurations described in the specific examples.

[0064] Benefits, other advantages, and solutions to problems have been described above with respect to specific embodiments. However, any benefit, advantage, solution to a problem, or any element that may cause any particular benefit, advantage, or solution to occur or become more significant should not be construed as a critical, required, or essential feature or component.

[0065] The terms "comprises," "comprising," or any variations thereof, are intended to refer to non-exclusive inclusion, such that a process, method, article, composition, or apparatus that includes a list of elements includes not only those elements listed, but may also include other elements not expressly listed or inherent to such process, method, article, composition, or apparatus. Other combinations and / or modifications of the above-described structures, arrangements, applications, proportions, elements, materials, or components used in the practice of the present technology, except those not specifically recited, may be changed or otherwise specially adapted to a particular environment, manufacturing specifications, design parameters, or other operating requirements without departing from the general principles thereof.

[0066] The present technology has been described above with reference to exemplary embodiments. However, changes and modifications may be made to the exemplary embodiments without departing from the scope of the present technology. These and other changes or modifications are intended to be included within the scope of the present technology, as expressed in the following claims.

Claims

1. A system comprising: Reaction chamber; a first container configured to contain a precursor, wherein the first container is coupled to the reaction chamber via a first gas line; a second container configured to contain a co-reactant, wherein the second container is coupled to the reaction chamber; a foreline including a first end directly coupled to the reaction chamber and an opposite second end; a pump coupled to the second end of the foreline at the first junction; a second gas line comprising a first portion coupled to the inlet of the reaction chamber and a second portion coupled to the foreline; wherein the first portion and the second portion are connected to each other at a second junction; as well as A mass flow controller is coupled between the second container and the second junction.

2. The system according to claim 1, wherein: The co-reactant is one of ozone, ammonia, silane or disilane.

3. The system according to claim 1, wherein: The first portion of the second gas line has a first conductance and the second portion has a second conductance, wherein the first conductance is the same as the second conductance. 4 . The system of claim 1 , further comprising a first valve within the first portion of the second gas line and a second valve within the second portion of the second gas line. 5 . The system of claim 4 , further comprising a control unit configured to transmit control signals to the first and second valves.

6. The system of claim 1, further comprising a decomposition device coupled to the second portion of the second gas line and configured to decompose the co-reactant.

7. The system according to claim 6, wherein: The decomposition device includes at least one of a catalyst or a heater.

8. A system comprising: Reaction chamber; a foreline including a first end directly coupled to the reaction chamber and an opposite second end; a pump coupled to the second end of the foreline; a first container configured to contain a precursor, wherein the first container is coupled to the reaction chamber via a first gas line; a second container configured to contain a co-reactant, wherein the second container is coupled to the reaction chamber; a second gas line comprising a first portion coupled to the inlet of the reaction chamber, a second portion coupled to the foreline, and a third portion coupled to the foreline; wherein the first portion and the second portion are connected to each other at a junction; and wherein the second and third portions are parallel to each other; as well as A pressure flow controller is coupled between the second container and the second junction.

9. The system of claim 8, further comprising a first valve within the first portion of the second gas line, a second valve within the second portion of the second gas line, and a third valve within the third portion of the second gas line.

10. The system of claim 9, further comprising a flow restrictor coupled to the third portion between the junction and the third valve.

11. The system of claim 9, further comprising a control unit configured to transmit control signals to the first, second, and third valves.

12. The system according to claim 8, wherein: The co-reactant is one of ozone, ammonia, silane or disilane.

13. The system according to claim 8, wherein: The first portion has a first conductivity, the second portion has a second conductivity, and the third portion has a third conductivity, wherein the third conductivity is 95% less than the first conductivity.

14. The system according to claim 8, wherein: The pump is a dry vacuum pump.

15. A system comprising: Reaction chamber; a foreline including a first end directly coupled to the reaction chamber and an opposite second end; a pump coupled to the second end of the foreline at the first junction; a first container configured to contain a precursor, wherein the first container is coupled to the reaction chamber via a first gas line; a second container configured to contain a co-reactant, wherein the second container is coupled to the reaction chamber; as well as A second gas line includes a first portion coupled to the inlet of the reaction chamber and a second portion coupled to the first junction; wherein the first portion and the second portion are connected to each other at the second junction.

16. The system of claim 15, further comprising a pressure flow controller coupled between the second container and the second junction, in, The second gas line also includes a third portion coupled between the second junction and the foreline, and wherein the second and third portions are parallel to each other.

17. The system of claim 15, wherein: The pump is a dry vacuum pump.

18. The system of claim 16, wherein: The first portion has a first conductivity, the second portion has a second conductivity, and the third portion has a third conductivity, wherein the third conductivity is 95% less than the first conductivity.

19. The system of claim 16, further comprising a first valve within the first portion of the second gas line, a second valve within the second portion of the second gas line, and a third valve within the third portion of the second gas line.

20. The system of claim 19, further comprising a flow restrictor coupled to the third portion between the second junction and the third valve.

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