Method and system for preventing gas from recharging to remote plasma system

Abstract

The invention discloses a method and system for preventing gas from recharging to a remote plasma system, and the method comprises the following steps: preventing tetraethoxysilane gas flowing out of a first pipeline from recharging to the remote plasma system through a gas recharging prevention control unit arranged on a second pipeline and / or the first pipeline; or an inert gas input unit is additionally arranged through the remote plasma system, and a preset amount of inert gas flows into the inert gas input unit to maintain the gas positive pressure of the second pipeline and prevent the tetraethoxysilane gas flowing out of the first pipeline from being recharged into the remote plasma system. According to the invention, the problem that particulate matters are generated when the tetraethoxysilane gas is recharged into a remote plasma system is solved, the particulate matters in a gas pipeline are prevented from falling on the surface of a wafer, the yield of the wafer is improved, the manpower and financial costs required by preventive maintenance are reduced, and the production efficiency of a machine is accelerated.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and more specifically to a method and system for preventing gas backflow into a remote plasma system. Background Technology

[0002] In semiconductor manufacturing processes, PECVD (Plasma-Enhanced Chemical Vapor Deposition) is characterized by low deposition temperature and high deposition rate. PECVD decomposes reactive gases into a plasma state, allowing reactants to be deposited on the substrate surface as active groups, resulting in thin films with high reaction rates and low deposition temperatures. Furthermore, the density and refractive index of the thin film can be controlled through process parameters. The low-temperature deposition advantage of PECVD also reduces thermal stress and thermal damage to the substrate material during film deposition. PECVD is primarily used to deposit dielectric films between metal wiring layers in semiconductor chips. When a large number of particle defects are generated during film deposition, it can cause short circuits or open circuits in the semiconductor chip, affecting product reliability and quality. Therefore, improving particle defects in the PECVD deposition process is crucial for improving product yield.

[0003] Existing PECVD equipment suffers from an unreasonable gas pipeline design, posing a risk of reactive gas backflow into the RPS (Remote Plasma System) during thin film deposition. Taking the deposition of silicon oxide thin films as an example, when the precursor TEOS (Tetraethyl Orthosilicate) flows out of the pipeline, a portion flows into the reaction chamber, while the remaining gas flows back into the RPS pipeline. Because the vaporization temperature of TEOS is 169°C, and the gas pipeline flowing from the RPS to the chamber lacks heating for insulation, a large amount of black particulate matter is generated in the pipeline and RPS during the backflow process. The backflow-generated particulate matter does not adhere firmly to the RPS and gas pipeline, and the gas emanating from the RPS carries these particulate matter into the reaction chamber and onto the wafer, thus affecting product performance. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for preventing gas backflow into a remote plasma system. It aims to solve the problem in the prior art where tetraethoxysilane gas backflows into a remote plasma system during semiconductor film deposition, generating particulate matter and affecting wafer performance.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0006] On one hand, the present invention provides a method for preventing gas backflow into a remote plasma system, which is used in the deposition film process of semiconductor technology. During the deposition film process, tetraethoxysilane gas flows to the reaction chamber through a first pipeline, and gas output from the remote plasma system flows to the reaction chamber through a second pipeline.

[0007] The method includes: preventing tetraethoxysilane gas flowing out of the first pipeline from flowing back into the remote plasma system by means of a gas backflow prevention control unit installed on the second pipeline and / or the first pipeline; or

[0008] By adding an inert gas input unit to the remote plasma system, a predetermined amount of inert gas flows into the inert gas input unit to maintain the positive gas pressure in the second pipeline and prevent the tetraethoxysilane gas flowing out of the first pipeline from flowing back into the remote plasma system.

[0009] Preferably, the gas backflow prevention control unit is located at the intersection of the second pipeline and the first pipeline.

[0010] Preferably, the gas backflow prevention control unit includes a valve for sealing off the flow from the first pipeline to the second pipeline when tetraethoxysilane gas flows out of the first pipeline.

[0011] Preferably, the valve includes a three-way valve, which is used to regulate the flow direction of gas in the first pipeline; the three-way valve includes either a pneumatic three-way valve or an electric three-way valve.

[0012] Preferably, the inert gas input unit is located at the front end of the second pipeline.

[0013] Preferably, when the inert gas input unit is not provided, the total amount of inert gas flowing out of the first pipeline is L; when the inert gas input unit is provided, the total amount of inert gas flowing out of the first pipeline is M; and the total amount of inert gas flowing out of the inert gas input unit is N, then L = M + N.

[0014] Preferably, the inert gas includes helium.

[0015] On the other hand, the present invention proposes a system for preventing gas backflow, used in the deposition film process of semiconductor technology. During the deposition film process, tetraethoxysilane gas flows to the reaction chamber through a first pipeline, and gas output from a remote plasma system flows to the reaction chamber through a second pipeline; the system includes:

[0016] The remote plasma system;

[0017] The reaction chamber;

[0018] A gas backflow prevention control unit or an inert gas input unit;

[0019] The gas backflow prevention control unit is installed on the second pipeline and / or the first pipeline to prevent tetraethoxysilane gas flowing out of the first pipeline from backflowing into the remote plasma system;

[0020] The inert gas input unit is connected to the remote plasma system. A predetermined amount of inert gas flows into the remote plasma system through the inert gas input unit to maintain the positive gas pressure in the second pipeline and prevent the tetraethoxysilane gas flowing out of the first pipeline from flowing back into the remote plasma system.

[0021] Preferably, the gas backflow prevention control unit is located at the junction of the second pipeline and the first pipeline; the gas backflow prevention control unit includes a valve, which is used to close the flow from the first pipeline to the second pipeline when tetraethoxysilane gas flows out of the first pipeline.

[0022] Preferably, when the inert gas input unit is not provided, the total amount of inert gas flowing out of the first pipeline is L; when the inert gas input unit is provided, the total amount of inert gas flowing out of the first pipeline is M; and the total amount of inert gas flowing out of the inert gas input unit is N, then L = M + N; the inert gas includes helium.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] This invention provides a method and system for preventing gas backflow into a remote plasma system, fundamentally solving the problem of particulate matter generated by tetraethoxysilane gas backflow into the remote plasma system. It also increases the number of wafers produced by the machine within a preventive maintenance cycle. This not only prevents particulate matter in the gas pipeline from falling onto the wafer surface, improving the wafer yield, but also reduces the manpower and financial costs required for preventive maintenance cycles, enabling the machine to produce more wafers within a preventive maintenance cycle and accelerating the machine's production efficiency. Attached Figure Description

[0025] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the drawings described below are one embodiment of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort:

[0026] Figure 1 This is a schematic diagram of a method for preventing gas backflow into a remote plasma system according to Embodiment 1 of the present invention;

[0027] Figure 2 This is a schematic diagram of a method for preventing gas backflow into a remote plasma system according to Embodiment 2 of the present invention.

[0028] Explanation of reference numerals in the attached diagram: 1-First pipeline, 2-Second pipeline, 3-Prevent gas backflow control unit, 4-Third pipeline, 5-Inert gas input unit. Detailed Implementation

[0029] The following is in conjunction with the appendix Figure 1-2 The method and system for preventing gas backflow into a remote plasma system proposed in this invention will be further described in detail below. The advantages and features of this invention will become clearer from the following description. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, only for the purpose of conveniently and clearly illustrating the embodiments of this invention. Please refer to the accompanying drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention.

[0030] refer to Figure 1 and Figure 2 As shown, taking PECVD deposition of silicon oxide thin films as an example, in the prior art, when the precursor TEOS flows out from the first pipe 1, part of the TEOS flows to the reaction chamber, and the other part of the gas flows to the second pipe 2 (the second pipe 2 is the gas pipe from the remote plasma system to the reaction chamber), that is, it is fed back into the remote plasma system. Because the vaporization temperature of TEOS is 169°C, and the second pipe 2 does not have a heating belt for insulation, a large number of black particles are generated in the pipes and RPS during the process of TEOS being fed back into the RPS. When the particles generated by the backfeeding do not adhere firmly to the RPS and the gas pipes, the gas from the RPS will carry these particles to the reaction chamber and fall on the wafer, thereby affecting the product performance.

[0031] To address the issue of black particulate matter generated during TEOS reflow in the RPS and gas lines, the existing process solution is to reduce the number of wafers processed per PM (Preventive Maintenance) cycle (approximately 10,000 to 12,000 wafers) and increase the frequency of PM to remove particulate matter adhering to the RPS and gas lines, reducing the possibility of loosely adhered particles falling onto the wafers. However, this approach significantly increases the manpower and financial resources required for PM, and the increased frequency of PM also carries the risk of excessive damage to the machine hardware.

[0032] In view of the problem that tetraethoxysilane gas is fed back into the remote plasma system during the deposition process of semiconductor technology, thereby generating particulate matter and affecting the product performance of the wafer, this embodiment provides a method and system for preventing gas from being fed back into the remote plasma system.

[0033] The following specific embodiments, in conjunction with the appendix, demonstrate this process. Figure 1 and attached Figure 2 This embodiment provides a detailed description of the method and system for preventing gas backflow into the remote plasma system.

[0034] Example 1

[0035] refer to Figure 1 As shown, this embodiment provides a method for preventing gas backflow into a remote plasma system, which is used in the deposition film process of semiconductor technology. During the deposition film process, tetraethoxysilane gas flows to the reaction chamber through a first pipeline 1, and gas output from the remote plasma system flows to the reaction chamber through a second pipeline 2. The method includes: preventing the tetraethoxysilane gas flowing out of the first pipeline 1 from backflowing into the remote plasma system by means of a gas backflow prevention control unit 3 provided on the second pipeline 2 and / or the first pipeline 1.

[0036] For details, please refer to [link / reference]. Figure 1 As shown, in this embodiment, the gas backflow prevention control unit 3 is located at the intersection of the second pipeline 2 and the first pipeline 1. When tetraethoxysilane gas flows out of the first pipeline 1, the passage from the first pipeline 1 to the second pipeline 2 is blocked.

[0037] In this embodiment, the gas backflow prevention control unit 3 includes a valve, which is used to close the flow from the first pipeline 1 to the second pipeline 2 when tetraethoxysilane gas flows out of the first pipeline 1. The valve includes a three-way valve, which is used to regulate the flow direction of gas in the first pipeline 1; the three-way valve includes either a pneumatic three-way valve or an electric three-way valve.

[0038] By adding a valve at the junction of the gas pipelines from TEOS to the reaction chamber and from RPS reactants to the reaction chamber, the direction of gas flow can be controlled, thus completely preventing TEOS from flowing back into the RPS and also completely preventing the possibility of RPS reactants flowing back into other gas pipelines.

[0039] Example 2

[0040] refer to Figure 2 As shown, this embodiment provides another method to prevent gas backflow into a remote plasma system, which is used in the deposition film process of semiconductor technology. During the deposition film process, tetraethoxysilane gas flows to the reaction chamber through a first pipeline 1, and the gas output from the remote plasma system flows to the reaction chamber through a second pipeline 2. The method includes: adding an inert gas input unit 5 to the remote plasma system, wherein a predetermined amount of inert gas flows into the inert gas input unit 5 to maintain the positive gas pressure in the second pipeline 2, thereby preventing the tetraethoxysilane gas flowing out of the first pipeline 1 from backflowing into the remote plasma system.

[0041] In this embodiment, the inert gas input unit 5 is located at the front end of the second pipeline 2. When the inert gas input unit 5 is not installed, the total amount of inert gas flowing out of the first pipeline 1 is L. When the inert gas input unit 5 is installed, the total amount of inert gas flowing out of the first pipeline 1 is M; the total amount of inert gas flowing out of the inert gas input unit 5 is N, then L = M + N. In this embodiment, the preferred inert gas includes helium.

[0042] Continue to refer to Figure 2 As shown, specifically, in this embodiment, a helium gas pipeline is added to the RPS. Taking PECVD deposition of silicon oxide thin films as an example, the reaction gas consists of 1100 sccm of TEOS, 4000 sccm of He, and 4200 sccm of O2. Without the helium gas pipeline added to the RPS, 4200 sccm of O2 flows from the third pipeline 4 to the reaction chamber. After adding the helium gas pipeline to the RPS, the gas flow during the film deposition process changes to 1100 sccm of TEOS and 3500 sccm of He flowing from the first pipeline 1 to the reaction chamber, while 500 sccm of He flows from the RPS to the reaction chamber. The 4200 sccm of O2 still flows from the third pipeline 4 to the reaction chamber. This change in gas distribution ensures that as TEOS flows to the reaction chamber, 500 sccm of He also flows from the RPS to the reaction chamber simultaneously, maintaining the positive gas pressure in the RPS pipeline and preventing TEOS from flowing back into the RPS.

[0043] Example 3

[0044] refer to Figure 1 and Figure 2 As shown, this embodiment proposes a system to prevent gas backflow, which is used in the deposition film process of semiconductor technology. During the deposition film process, tetraethoxysilane gas flows to the reaction chamber through a first pipeline 1, and gas output from a remote plasma system flows to the reaction chamber through a second pipeline 2. The system includes: the remote plasma system; the reaction chamber; a gas backflow prevention control unit 3 or an inert gas input unit 5; the gas backflow prevention control unit 3 is disposed on the second pipeline 2 and / or the first pipeline 1 to prevent tetraethoxysilane gas flowing out of the first pipeline 1 from backflowing into the remote plasma system; the inert gas input unit 5 is connected to the remote plasma system, and a predetermined amount of inert gas flows into the remote plasma system through the inert gas input unit 5 to maintain the positive gas pressure in the second pipeline 2 and prevent tetraethoxysilane gas flowing out of the first pipeline 1 from backflowing into the remote plasma system.

[0045] The gas backflow prevention control unit 3 is located at the junction of the second pipeline 2 and the first pipeline 1; the gas backflow prevention control unit 3 includes a valve, which is used to control the flow of tetraethoxysilane gas from the first pipeline 1 to the second pipeline 2 when the gas flows out.

[0046] In this embodiment, when the inert gas input unit 5 is not provided, the total amount of inert gas flowing out of the first pipeline 1 is L; when the inert gas input unit 5 is provided, the total amount of inert gas flowing out of the first pipeline 1 is M; when the inert gas input unit 5 is provided, the total amount of inert gas flowing out of the inert gas input unit 5 is N, then L = M + N; the inert gas includes helium.

[0047] In this embodiment, a helium gas pipeline is specifically added to the RPS. Taking PECVD deposition of silicon oxide thin films as an example, the reaction gas consists of 1100 sccm of TEOS, 4000 sccm of He, and 4200 sccm of O2. Without the helium gas pipeline added to the RPS, 4200 sccm of O2 flows from the third pipeline 4 to the reaction chamber. After adding the helium gas pipeline to the RPS, the gas flow during film deposition changes to 1100 sccm of TEOS and 3500 sccm of He flowing from the first pipeline 1 to the reaction chamber, while 500 sccm of He flows from the RPS to the reaction chamber. The 4200 sccm of O2 still flows from the third pipeline 4 to the reaction chamber. This change in gas distribution ensures that as TEOS flows to the reaction chamber, 500 sccm of He also flows from the RPS to the reaction chamber simultaneously, maintaining the positive gas pressure in the RPS pipeline and preventing TEOS from flowing back into the RPS.

[0048] In summary, the method and system for preventing gas backflow into the remote plasma system provided in the above embodiments prevent tetraethoxysilane gas flowing out of the first pipeline from flowing back into the remote plasma system by installing a gas backflow prevention control unit on the second pipeline and / or the first pipeline; or by adding an inert gas input unit to the remote plasma system, into which a predetermined amount of inert gas flows to maintain the positive pressure of the gas in the second pipeline, thereby preventing tetraethoxysilane gas flowing out of the first pipeline from flowing back into the remote plasma system. This fundamentally solves the problem of particulate matter generated by tetraethoxysilane gas backflow into the remote plasma system, and the number of wafers processed by the machine during a preventive maintenance cycle can be increased to between 18,000 and 20,000. This not only prevents particulate matter in the gas pipeline from falling onto the wafer surface, improving wafer yield, but also reduces the manpower and financial resources required for preventive maintenance cycles, allowing the machine to produce more wafers during a preventive maintenance cycle and accelerating machine production efficiency.

[0049] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0050] It should be noted that the apparatus and methods disclosed in the embodiments herein can also be implemented in other ways. The apparatus embodiments described above are merely illustrative; for example, the flowcharts and block diagrams in the accompanying drawings show the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments herein. In this regard, each block in a flowchart or block diagram may represent a module, program, or part of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system to perform the specified function or action, or can be implemented using a combination of dedicated hardware and computer instructions.

[0051] In addition, the functional modules in the various embodiments of this article can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0052] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for preventing gas backflow into a remote plasma system, used in a semiconductor deposition process, wherein tetraethoxysilane gas flows to a reaction chamber through a first conduit during deposition, and gas output from the remote plasma system flows to the reaction chamber through a second conduit, characterized in that, The method includes: preventing tetraethoxysilane gas flowing out of the first pipeline from flowing back into the remote plasma system by means of a gas backflow prevention control unit installed on the second pipeline and / or the first pipeline; or By adding an inert gas input unit to the remote plasma system, a predetermined amount of inert gas flows into the inert gas input unit to maintain the positive gas pressure in the second pipeline and prevent the tetraethoxysilane gas flowing out of the first pipeline from flowing back into the remote plasma system.

2. The method for preventing gas backflow into a remote plasma system as described in claim 1, characterized in that, The gas backflow prevention control unit is located at the intersection of the second pipeline and the first pipeline.

3. The method for preventing gas backflow into a remote plasma system as described in claim 2, characterized in that, The gas backflow prevention control unit includes a valve for sealing off the flow from the first pipeline to the second pipeline when tetraethoxysilane gas flows out of the first pipeline.

4. The method for preventing gas backflow into a remote plasma system as described in claim 3, characterized in that, The valve includes a three-way valve, which is used to regulate the flow direction of gas in the first pipeline; the three-way valve includes either a pneumatic three-way valve or an electric three-way valve.

5. The method for preventing gas backflow into a remote plasma system as described in claim 1, characterized in that, The inert gas input unit is located at the front end of the second pipeline.

6. The method for preventing gas backflow into a remote plasma system as described in claim 1, characterized in that, When the inert gas input unit is not set, the total amount of inert gas flowing out of the first pipeline is L; when the inert gas input unit is set, the total amount of inert gas flowing out of the first pipeline is M; and the total amount of inert gas flowing out of the inert gas input unit is N, then L = M + N.

7. The method for preventing gas backflow into a remote plasma system as described in claim 6, characterized in that, The inert gas includes helium.

8. A system for preventing gas backflow, used in a semiconductor deposition process, wherein tetraethoxysilane gas flows to a reaction chamber through a first conduit during deposition, and gas output from a remote plasma system flows to the reaction chamber through a second conduit; characterized in that, The system includes: The remote plasma system; The reaction chamber; A gas backflow prevention control unit or an inert gas input unit; The gas backflow prevention control unit is installed on the second pipeline and / or the first pipeline to prevent tetraethoxysilane gas flowing out of the first pipeline from backflowing into the remote plasma system; The inert gas input unit is connected to the remote plasma system. A predetermined amount of inert gas flows into the remote plasma system through the inert gas input unit to maintain the positive gas pressure in the second pipeline and prevent the tetraethoxysilane gas flowing out of the first pipeline from flowing back into the remote plasma system.

9. The system for preventing gas backflow as described in claim 8, characterized in that, The gas backflow prevention control unit is located at the junction of the second pipeline and the first pipeline; the gas backflow prevention control unit includes a valve, which is used to close the flow from the first pipeline to the second pipeline when tetraethoxysilane gas flows out of the first pipeline.

10. The system for preventing gas backflow as described in claim 8, characterized in that, When the inert gas input unit is not set, the total amount of inert gas flowing out of the first pipeline is L; when the inert gas input unit is set, the total amount of inert gas flowing out of the first pipeline is M; when the total amount of inert gas flowing out of the inert gas input unit is N, then L = M + N; the inert gas includes helium.

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