Remote plasma source cleaning system and semiconductor process equipment

Abstract

The invention relates to the technical field of semiconductor equipment, in particular to a remote plasma source cleaning system and semiconductor process equipment. The remote plasma source cleaning system provided by the invention comprises a front-section pipeline remote plasma source which is arranged in a front-section pipeline and is used for receiving gas and dissociating the gas to generate plasma; the valve plate is directly connected with the front-section pipeline remote plasma source and is used for bearing a carbon film generated by reaction in the process cavity; the vacuum pump is connected with the valve plate and is used for extracting waste gas generated by the valve plate and residual gas after cleaning; wherein the front-section pipeline remote plasma source is used for cleaning a carbon film on the valve plate. The cleaning speed consistency of the valve plates on the two sides is achieved, the cleaning effect of the valve plates is improved, space is saved, and maintenance is convenient.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of semiconductor equipment, and in particular to a remote plasma source cleaning system and semiconductor process equipment. Background Art

[0002] In the semiconductor manufacturing process, carbon film often accumulates on the surface of the TV (Throttle Valve) valve plate due to process reactions. The front line needs to be cleaned by a remote plasma source (RPS) to maintain equipment performance.

[0003] The existing technology mainly uses an 8L large-volume, 4000W high-power remote plasma source INLINE RPS, which is connected to the front-end pipeline (Foreline) inlet through a long pipeline. However, it has the following significant defects:

[0004] 1) The large RPS and long pipeline layout result in excessive equipment space occupation and complicated maintenance operations;

[0005] 2) When oxygen (O2) is transported in a long pipeline, the active plasma generated by dissociation is largely deactivated due to path loss and temperature drop, resulting in low cleaning efficiency;

[0006] 3) Since the RPS cannot be directly connected to the TV valve plate, it needs to be transitioned through a multi-stage valve (such as the gate valve GV), resulting in significant power loss and inconsistent cleaning rates of the valve plates on both sides;

[0007] 4) It cannot be operated in conjunction with process chamber cleaning (CH Clean). Unreacted oxygen is recombined in the pipeline, further reducing cleaning efficiency.

[0008] Therefore, there is an urgent need for a front-end pipeline remote plasma source cleaning system with low power consumption and synchronous cleaning to solve the above technical bottlenecks. Summary of the Invention

[0009] The purpose of the present invention is to provide a remote plasma source cleaning system to solve the technical problems in the prior art that the remote plasma source cleaning system for the front-end pipeline occupies a large machine space, is inconvenient to maintain, has inconsistent cleaning rates of the throttle valve plates on both sides, and consumes a lot of power.

[0010] In order to achieve the above object, the present invention provides a remote plasma source cleaning system, comprising:

[0011] The front-end pipeline remote plasma source is arranged in the front-end pipeline and is used to receive gas and dissociate it to generate plasma;

[0012] A valve plate, the valve plate being directly connected to the remote plasma source of the front-end pipeline and used for controlling pressure and / or carrying the carbon film generated by the reaction in the process chamber;

[0013] a vacuum pump connected to the valve plate and used to extract waste gas generated by the valve plate and residual gas after cleaning;

[0014] Among them, the remote plasma source in the front pipeline is used to clean the carbon film on the valve plate.

[0015] In some embodiments, the front-end pipeline remote plasma source includes: a first front-end pipeline remote plasma source and a second front-end pipeline remote plasma source, which are symmetrically distributed and have consistent flow conductance;

[0016] The valve plate includes a first valve plate and a second valve plate. The first valve plate is directly connected to a remote plasma source of a first front section pipeline, and the second valve plate is directly connected to a remote plasma source of a second front section pipeline, so as to achieve consistent cleaning rates for the first valve plate and the second valve plate.

[0017] In some embodiments, a gate valve is further included, which is arranged between the valve plate and the vacuum pump to control the flow of exhaust gas and residual gas.

[0018] In some embodiments, the front-end pipeline remote plasma source further comprises:

[0019] The front-end pipeline remote plasma source is used to dissociate unreacted oxygen in the cleaning process in the secondary dissociation chamber;

[0020] The front-end pipeline remote plasma source and the cleaning process in the cavity are carried out simultaneously.

[0021] In some embodiments, the front-end pipeline remote plasma source is ignited by argon gas before secondary dissociation.

[0022] In some embodiments, a heat preservation belt is further included, which is arranged on the outside of the front section of the pipeline to reduce the temperature loss of the gas in the pipeline.

[0023] In some embodiments, the output power of the front-end pipeline remote plasma source is 50W.

[0024] In order to achieve the above object, the present invention also provides a semiconductor process equipment, comprising a remote plasma source cleaning system as claimed in any one of the above claims;

[0025] a gas supply unit connected to the remote plasma source cleaning system and configured to supply oxygen to the remote plasma source cleaning system;

[0026] An exhaust gas treatment unit is connected to the remote plasma source cleaning system and is used to treat exhaust gas discharged from the remote plasma source cleaning system.

[0027] The remote plasma source cleaning system and process equipment proposed in the present invention achieve consistency in the cleaning rates of the valve plates on both sides by directly connecting the remote plasma source of the front-end pipeline to the valve plate, thereby improving the cleaning effect of the valve plate, saving space and facilitating maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings, in which:

[0029] Figure 1 A block diagram of an existing remote plasma source cleaning system is disclosed;

[0030] Figure 2 A block diagram of a remote plasma source cleaning system according to an embodiment of the present invention is disclosed;

[0031] Figure 3 The first remote plasma source cleaning system experimental model block diagram is revealed;

[0032] Figure 4 The experimental model block diagram of the second remote plasma source cleaning system is revealed;

[0033] Figure 5 The experimental model block diagram of the third remote plasma source cleaning system is revealed.

[0034] The meanings of the reference numerals in the figures are as follows:

[0035] 110 cavity;

[0036] 121 first throttle valve plate;

[0037] 122 second throttle valve plate;

[0038] 130 front-end pipeline remote plasma source cleaning system;

[0039] 140 first gate valve;

[0040] 150 first vacuum pump;

[0041] 210 process chamber;

[0042] 221 first valve plate;

[0043] 222 second valve plate;

[0044] 231 first front section pipeline remote plasma source;

[0045] 232 second front section pipeline remote plasma source;

[0046] 240 gate valve;

[0047] 250 vacuum pump. DETAILED DESCRIPTION

[0048] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0049] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0050] As used in this application and the claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not intended to refer to the singular but may include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0051] The existing technology uses an 8L 4000W remote plasma source (RPS) connected to the air inlet of the upstream pipeline via a long pipeline. This requires a lot of space, is difficult to maintain, and causes a high degree of reactive oxygen species deactivation in the long pipeline. Furthermore, it cannot be directly connected to a TV, resulting in significant power loss and unsatisfactory cleaning results.

[0052] Foreline is usually the front part of the vacuum system.

[0053] RPS (Remote Plasma Source) remote plasma source uses plasma to dissociate gas to achieve cleaning.

[0054] Figure 1 A block diagram of an existing remote plasma source cleaning system is disclosed, such as Figure 1 As shown, the existing remote plasma source cleaning system includes a chamber (CHAMBER) 110, a throttle valve plate (TV), a front-end pipeline remote plasma source cleaning system (FL RPS) 130, a first gate valve (GV) 140 and a first vacuum pump (PUMP) 150.

[0055] Throttle valve plate (TV, Throttle Valve), a valve that controls pipeline pressure and flow.

[0056] Foreline is usually the front part of the vacuum system.

[0057] A remote plasma source (RPS) is a device used to generate plasma. It uses plasma to dissociate gas and is typically used in processes such as surface treatment, material modification, and thin film deposition in a vacuum environment to achieve cleaning.

[0058] In the prior art, a FL (Foreline) RPS (front-end pipeline remote plasma source cleaning system) is usually an 8L RPS with an output power of 4000W.

[0059] Specifically, the process chamber (CHAMBER) 110 is connected to two throttle valve plates, namely the first throttle valve plate 121 and the second throttle valve plate 122, through the A-side front section pipeline (Foreline side A) and the B-side front section pipeline (Foreline side B).

[0060] One end of the front section pipeline on the A side is connected to the process chamber 110 , and the other end is connected to the first throttle valve plate 121 ; one end of the front section pipeline on the B side is connected to the process chamber 110 , and the other end is connected to the second throttle valve plate 122 .

[0061] The front-end pipeline remote plasma source cleaning system 130 (FL (Foreline) RPS) needs to be introduced into the gas inlet of the Foreline separately through a long pipeline to provide dissociated gas for cleaning the TV.

[0062] The gas passes through the first throttle valve plate 121 and the second throttle valve plate 122 and then enters the first vacuum pump 150 (PUMP) through the first gate valve 140 (GV) to extract the exhaust gas.

[0063] Because the existing remote plasma source cleaning system has excessive space requirements and is difficult to maintain, the proportion of dissociated oxygen deactivation in the pipeline is extremely high, which is equivalent to a small horse pulling a large cart.

[0064] In response to the above-mentioned problems in the prior art, the present invention provides a remote plasma source cleaning system that solves the technical problems of the existing front-end pipeline remote plasma source cleaning system, such as occupying a large machine space, inconvenient maintenance, inconsistent cleaning rates of the throttle valve plates on both sides, and high power consumption.

[0065] The present invention provides a remote plasma source cleaning system, comprising:

[0066] The front-end pipeline remote plasma source is arranged in the front-end pipeline and is used to receive gas and dissociate it to generate plasma;

[0067] A valve plate, the valve plate being directly connected to the remote plasma source of the front-end pipeline and being used to carry the carbon film generated by the reaction in the process chamber;

[0068] a vacuum pump connected to the valve plate and used to extract waste gas generated by the valve plate and residual gas after cleaning;

[0069] Among them, the remote plasma source in the front pipeline is used to clean the carbon film on the valve plate.

[0070] The remote plasma source cleaning system provided by the present invention achieves consistency in cleaning rates of valve plates on both sides, improves the cleaning effect of the valve plates, saves space and facilitates maintenance.

[0071] The above-mentioned components of the present invention will be described in detail below. It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features specifically described below (such as in the embodiments) can be combined with each other and interrelated to form a preferred technical solution.

[0072] Figure 2 A block diagram of a remote plasma source cleaning system according to an embodiment of the present invention is disclosed. Figure 2 As shown, the remote plasma source cleaning system includes: a process chamber 200 , a front-end pipeline remote plasma source, a valve plate, a gate valve 240 and a vacuum pump 250 .

[0073] The front-end pipeline remote plasma source is arranged in the front-end pipeline and is used for receiving the oxygen and dissociating it to generate plasma.

[0074] like Figure 2 In the embodiment shown, the front-end pipeline remote plasma source includes: a first front-end pipeline remote plasma source 231 and a second front-end pipeline remote plasma source 232:

[0075] The first front-end pipeline remote plasma source 231 and the second front-end pipeline remote plasma source 232 are symmetrically distributed and have the same flow conductance.

[0076] Conductance refers to the ability of a fluid to flow through a pipe or component. It is typically expressed as conductivity, which is the ratio of flow rate to pressure difference. In vacuum systems, conductivity is related to the flow state of the gas, which is mainly divided into viscous flow and molecular flow. The conductivity probability refers to the probability that a gas molecule will escape from the component after entering the component from the inlet to the outlet. This concept is particularly important in molecular flow.

[0077] In this embodiment, the front-end pipeline remote plasma source may adopt INLINE FL RPS. INLINE FL RPS is a small cavity of a remote plasma emission source with an output power of 50W, which can be directly connected to the valve plate (TV).

[0078] The two independent INLINE FL RPS lines provided in this invention have symmetrical paths and consistent flow conductances. Directly connecting the INLINE FL RPS lines to the valve plate (TV) effectively resolves the prior art issue of inconsistent cleaning rates on both sides of the valve plate, enabling a single foreline RPS system on a single side of a single process module (PM).

[0079] The INLINE FL RPS is a miniaturized chamber with a single PM (Process Module) integrated design. This eliminates the need for a separate RPS (Remote Plasma Source), significantly reducing size and increasing integration, saving significant equipment space. Direct connection to the valve plate eliminates intermediate pressure drops, improving cleaning efficiency and process consistency.

[0080] The existing chamber (BKM FL RPS) is large (8L) and has a power of 4000W. It needs to be configured independently, which limits the equipment maintenance space and makes operation inconvenient.

[0081] Compared to the existing chamber (BKM FL RPS), the INLINE FL RPS (miniaturized chamber) not only allows direct connection to the valve plate, resulting in high integration, but also simplifies the structure, facilitating maintenance and avoiding uneven deposition or cleaning rate deviations, making it suitable for high-precision thin film preparation.

[0082] A valve plate is directly connected to the remote plasma source of the front-end pipeline and is used for controlling pressure and / or carrying the carbon film produced by the reaction in the process chamber.

[0083] In actual applications, due to different process flow rates and pressure requirements, there will be certain requirements for the valve plate opening. When the opening is too small, the carbon film on the valve plate will be blocked.

[0084] like Figure 2 In the embodiment shown, the valve plate may include a first valve plate 221 and a second valve plate 222:

[0085] The first valve plate 221 is directly connected to the first front section pipeline remote plasma source 231;

[0086] The second valve plate 222 is directly connected to the second front-end pipeline remote plasma source 232 to achieve consistent cleaning rates for the first valve plate and the second valve plate.

[0087] In this embodiment, by directly connecting the remote plasma source in the front-end pipeline to the valve plate (throttle valve), consistent cleaning rates are achieved on both valve plates, avoiding uneven deposition or cleaning caused by path differences. Directly connecting the valve plate can reduce pressure drop and contamination risks in the intermediate link, improving process stability and making it particularly suitable for high-precision thin film preparation scenarios.

[0088] The gate valve (GV) 240 is provided between the valve plate and the vacuum pump to control the flow of exhaust gas and residual gas.

[0089] A vacuum pump (PUMP) 250 is connected to the valve plate and is used to extract the waste gas generated by the valve plate and the residual gas after cleaning; wherein the front-end pipeline remote plasma source is used to clean the carbon film on the valve plate.

[0090] The remote plasma source cleaning system provided by the present invention is configured with an INLINE FL RPS piping structure. The two independent INLINE FL RPS piping chambers have symmetrical paths and consistent flow conductance, which reduces process deviations. They can also be directly connected to the valve plate to achieve consistent cleaning rates on both valve plates without power loss, realizing a single-side remote plasma source system with one set of remote plasma source systems.

[0091] The remote plasma source cleaning system provided by the present invention can also be carried out simultaneously with process chamber cleaning. The O2 gas that dissociates but does not completely react during the process chamber cleaning is recombined in the Foreline pipeline and then undergoes secondary dissociation through the INLINE FL RPS, fully utilizing the activity of the cleaning gas, improving the overall cleaning efficiency, and forming a highly efficient and energy-saving cyclic cleaning solution.

[0092] In one embodiment, the front-end pipeline remote plasma source further comprises:

[0093] The front-end pipeline remote plasma source is used to dissociate unreacted oxygen in the cleaning process in the secondary dissociation chamber;

[0094] The front-end pipeline remote plasma source and the cleaning process in the cavity are carried out simultaneously.

[0095] The front-end pipeline remote plasma source is ignited by argon gas before secondary dissociation.

[0096] Continue reading Figure 2 In this embodiment, gas (primarily O2) enters the upper air hole of the process chamber. Due to the action of the pump, the gas flows along the Foreline pipelines on the A side and the B side respectively, passes through the first front-end pipeline remote plasma source 231 (INLINE FL RPS) and the second front-end pipeline remote plasma source 232 (INLINE FL RPS), and is ignited by argon (Ar) gas to dissociate O2 to generate plasma, forming highly active oxygen plasma, which quickly acts on the carbon film accumulated on the valve plate and generates carbon dioxide, and is finally discharged through the gate valve (GV) 240 and the vacuum pump (PUMP) 250.

[0097] In one embodiment, the remote plasma source cleaning system further includes a heat preservation belt, which is arranged on the outside of the front section pipeline to reduce the temperature loss of the gas in the pipeline.

[0098] The remote plasma source cleaning system provided by the present invention has a clear and concise overall structural layout, reduces gas activity loss, and ensures consistency and high efficiency in cleaning valve plates on both sides.

[0099] To verify the performance and advantages of the INLINE FL RPS pipeline of the present invention, the following three sets of model experiments were conducted:

[0100] Figure 3 The first remote plasma source cleaning system experimental model block diagram is revealed, such as Figure 3 As shown, the first remote plasma source cleaning system experimental model uses the existing BKM FL RPS one-to-two pipe circuit:

[0101] The first model uses an 8L FL RPS as a remote plasma source, which is connected to two valve plates (TV) through a three-way pipe. After the gas (argon) enters the chamber, it is divided into two paths and discharged through the TV and gate valve (GV).

[0102] This test used the existing FL RPS cleaning formula for 10 cycles. The experimental results showed that when 8L FLRPS dissociated gas was used to clean the TV valve plate carbon film, the cleaning rates on both sides of the TV valve plate reached 0.0334mg / s and 0.0316mg / s, respectively. The cleaning effect was significant, and the rates on both sides were nearly consistent.

[0103] In this test, the Ar cooling process was too long, resulting in a decrease in the temperature of each cycle, which slightly affected the experimental results. The TV was open for too long during the cleaning process, which had a certain impact on the adhesion of the carbon film on the valve plate. There may be a large amount of carbon film falling off during the cleaning process. The actual cleaning rate is expected to be much higher than that of this test.

[0104] It can be seen that the remote plasma source cleaning system provided by the present invention can achieve consistency in the cleaning rates of the valve plates on both sides by connecting the two front-end pipeline remote plasma sources to the two valve plates.

[0105] Figure 4 The experimental model block diagram of the second remote plasma source cleaning system is revealed, such as Figure 4 As shown, the second remote plasma source cleaning system experimental model adopts a one-to-two pipe circuit, and the cavity RPS is turned on.

[0106] The second model employed an 8L RPS operating above the chamber and conducted a dual-path cleaning experiment using two INLINE RPSs. Experimental data showed that when the chamber RPS was open and the INLINE RPSs on the front-end pipeline (foreline) were fully open, the projected cleaning rate was twice that of the BKM FL RPS. Actual cleaning rates were 0.0666 mg / s and 0.06025 mg / s, respectively, significantly higher than those in Model 1. This demonstrates the significant improvement in cleaning efficiency achieved by the present invention by directly connecting the two front-end remote plasma sources to the two valve plates.

[0107] Among them, the two FL RPSs can have the same function but different brands.

[0108] Figure 5 The experimental model block diagram of the third remote plasma source cleaning system is revealed, such as Figure 5 As shown, the third remote plasma source cleaning system experimental model adopts a one-to-two pipe circuit, and the cavity RPS is closed.

[0109] The third model simulates the situation where the 8L RPS above the chamber is closed and only the INLINE RPS is used for cleaning.

[0110] The experimental results show that the cleaning rate when the cavity RPS is closed is about 60% of the BKM FL RPS, with specific values of 0.01335 mg / s and 0.00882 mg / s respectively. Due to the low pipeline temperature, the actual cleaning rate is lower.

[0111] In summary, the INLINE FL RPS piping structure proposed in this invention effectively improves the cleaning effect of the throttle valve plate by optimizing the piping layout, reducing gas loss, and coordinating the linkage control of the RPS in the cavity, while significantly improving maintainability and space occupancy issues.

[0112] In addition, the BKM structure pipeline is fully open without pressure control and has no temperature control zone, which results in low pipeline temperature and reduces the cleaning effect.

[0113] In order to achieve the above object, the present invention also provides a semiconductor process equipment, comprising the remote plasma source cleaning system as described above;

[0114] a gas supply unit connected to the remote plasma source cleaning system and configured to supply oxygen to the remote plasma source cleaning system;

[0115] An exhaust gas treatment unit is connected to the remote plasma source cleaning system and is used to treat exhaust gas discharged from the remote plasma source cleaning system.

[0116] The present invention provides a semiconductor process equipment, which improves the overall efficiency and maintenance convenience of the equipment.

[0117] The basic concepts have been described above. It will be apparent to those skilled in the art that the above disclosures are merely illustrative and do not constitute limitations on this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and amendments to this application. Such modifications, improvements, and amendments are suggested in this application and remain within the spirit and scope of the exemplary embodiments of this application.

[0118] At the same time, this application uses specific terms to describe the embodiments of this application. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "one embodiment," "an embodiment," or "an alternative embodiment" mentioned twice or multiple times in different locations in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application may be appropriately combined.

[0119] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the settings of such numerical values are as accurate as possible within the feasible range.

Claims

1. A remote plasma source cleaning system, characterized in that: include: The front-end pipeline remote plasma source is arranged in the front-end pipeline and is used to receive gas and dissociate it to generate plasma; A valve plate, the valve plate being directly connected to the remote plasma source of the front-end pipeline and used for controlling pressure and / or carrying the carbon film generated by the reaction in the process chamber; a vacuum pump connected to the valve plate and used to extract waste gas generated by the valve plate and residual gas after cleaning; Among them, the remote plasma source in the front pipeline is used to clean the carbon film on the valve plate.

2. The remote plasma source cleaning system according to claim 1, wherein: The front-end pipeline remote plasma source comprises: a first front-end pipeline remote plasma source and a second front-end pipeline remote plasma source, which are symmetrically distributed and have the same flow conductance; The valve plate includes a first valve plate and a second valve plate. The first valve plate is directly connected to a remote plasma source of a first front section pipeline, and the second valve plate is directly connected to a remote plasma source of a second front section pipeline, so as to achieve consistent cleaning rates for the first valve plate and the second valve plate.

3. The remote plasma source cleaning system according to claim 1, wherein: It also includes a gate valve, which is arranged between the valve plate and the vacuum pump and is used to control the flow of exhaust gas and residual gas.

4. The remote plasma source cleaning system according to claim 1, wherein: The front-end pipeline remote plasma source also includes: The front-end pipeline remote plasma source is used to dissociate unreacted oxygen in the cleaning process in the secondary dissociation chamber; The front-end pipeline remote plasma source and the cleaning process in the cavity are carried out simultaneously.

5. The remote plasma source cleaning system according to claim 4, wherein: The front-end pipeline remote plasma source is ignited by argon gas before secondary dissociation.

6. The remote plasma source cleaning system according to claim 1, wherein: It also includes a heat preservation belt, which is arranged on the outside of the front section pipeline and is used to reduce the temperature loss of the gas in the pipeline.

7. The remote plasma source cleaning system according to claim 1, wherein: The output power of the remote plasma source of the front section pipeline is 50W.

8. A semiconductor process equipment, characterized in that: The process equipment comprises a remote plasma source cleaning system according to any one of claims 1 to 7; as well as a gas supply unit connected to the remote plasma source cleaning system and configured to supply oxygen to the remote plasma source cleaning system; An exhaust gas treatment unit is connected to the remote plasma source cleaning system and is used to treat exhaust gas discharged from the remote plasma source cleaning system.

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