Method for cleaning process chamber and application thereof

Abstract

The present application discloses a method for cleaning a process chamber and its application, belonging to the technical field of vacuum coating production equipment. A method for cleaning a process chamber, comprising: (a) starting a remote plasma system, the cleaning process gas is excited into plasma, and the remote plasma is supplied to the process chamber; (b) when the remote plasma system reaches a stable state, the radio frequency power supply system in the process chamber is turned on again, the radio frequency power supply system excites and enhances the remote plasma located in the process chamber again, and the remote plasma system and the radio frequency power supply system are used together to clean the process chamber during the cleaning period; (c) when the cleaning of the process chamber is completed, the radio frequency power supply system in the process chamber is turned off first; (d) the remote plasma system is turned off again. The present application can alleviate the problems of slow etching rate, narrow etching range or incomplete coverage existing in the current cleaning method, and can improve the cleaning and etching efficiency and rate.

Description

Technical Field

[0001] The present application belongs to the technical field of vacuum coating production equipment, and specifically relates to a method for cleaning a process chamber and its application. Background Art

[0002] At present, in large-scale plasma coating equipment, such as chemical vapor deposition (CVD) equipment, plasma enhanced chemical vapor deposition (PECVD) equipment, atomic layer deposition (ALD) equipment, plasma enhanced atomic layer deposition (PEALD) equipment or other etching and deposition equipment, cleaning of the inside of the vacuum chamber and the coating sample carrier is a necessary operation to ensure the cleanliness of the inside of the vacuum chamber.

[0003] In the related art, for the cleaning of the vacuum coating chamber, a remote plasma system (RPS) is usually used to excite the cleaning gas into a plasma state, which is transmitted to the coating chamber through a pipeline, and the plasma reacts chemically with the film layer or particulate impurities in the chamber. In addition, some do not use RPS devices, but use the flat capacitor coupled discharge structure of the coating equipment such as PECVD equipment itself, and change the process gas such as NF3, which is a corrosive cleaning gas, to convert the original coating process into etching cleaning, thereby achieving the cleaning effect. However, when the plasma is excited by the remote plasma system to clean the process chamber, during the transmission process, the remote plasma undergoes a recombination phenomenon before reaching the process chamber, which reduces the overall cleaning effect, and the etching cleaning of the traditional flat capacitor coupled discharge structure equipment has problems such as slow etching rate, narrow etching range, or inability to fully cover. Therefore, an improved cleaning method for the process chamber of vacuum coating equipment is needed in the related art. Summary of the invention

[0004] In view of the above problems, the present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, the present invention provides a method for cleaning a process chamber and its application, which can alleviate the problems of slow etching rate, narrow etching range or incomplete coverage in the current cleaning method, and help improve the cleaning and etching efficiency and rate.

[0005] In order to solve the above technical problems, this application is implemented as follows:

[0006] The present invention provides a method for cleaning a process chamber, the method comprising the following steps:

[0007] (a) introducing a cleaning process gas into a remote plasma system, starting the remote plasma system, exciting the gas into plasma, and supplying the remote plasma to a process chamber;

[0008] (b) when the remote plasma system reaches a stable state, the radio frequency power system in the process chamber is turned on again, the radio frequency power system re-excites and enhances the remote plasma in the process chamber, and the process chamber is cleaned by using the re-excited and enhanced plasma; and

[0009] cleaning the process chamber during a cleaning period using both the remote plasma system and the RF power system to work together;

[0010] (c) after cleaning the process chamber, first shutting down the radio frequency power system in the process chamber;

[0011] (d) After shutting down the radio frequency power system, shutting down the remote plasma system. In addition, the method for cleaning a process chamber according to the present application may also have the following additional technical features:

[0012] In some embodiments, the cleaning process gas includes a purge gas and a cleaning gas, and the step (a) includes:

[0013] (a1) pre-treating the inner chamber, gas delivery pipeline and process chamber of the remote plasma system, wherein the pre-treating comprises purging the inner chamber, gas delivery pipeline and process chamber of the remote plasma system with the purge gas, and then starting the remote plasma system;

[0014] (a2) After starting the remote plasma system, a cleaning gas is introduced to supply the plasma generated by the remote plasma system to the process chamber.

[0015] In some of the embodiments, the purge gas includes at least one of Ar, He, N2 or H2.

[0016] In some of the embodiments, before starting the RF power system in the process chamber, the flow rate of the cleaning gas in the cleaning process gas is gradually increased so that the cleaning gas and the purge gas reach a certain ratio, wherein the ratio of the flow rate of the cleaning gas to the flow rate of the purge gas is gradually increased or increased in a step-by-step manner.

[0017] In some embodiments, the cleaning gas includes a corrosive gas, and the corrosive gas includes at least one of NF3, CF4, SF6, C2F6, F2, C3F8, CHF3, HF, Cl2 or HCl.

[0018] In some embodiments, the remote plasma system includes an inductive coil coupled discharge structure, and the remote plasma system uses an alternating current power supply with a frequency of 100 KHz to 13.56 MHz.

[0019] In some embodiments, in step (b), when the remote plasma system is turned on for 5 to 150 seconds and its working state reaches a stable state, the RF power supply system is turned on.

[0020] In some embodiments, the operating parameters of the RF power system include:

[0021] The frequency range of the radio frequency power source is 2 MHz to 100 MHz; and / or,

[0022] The power range of the RF power supply is 500W to 90000W; and / or,

[0023] The discharge spacing of the radio frequency power source ranges from 5 mm to 50 mm; and / or,

[0024] The working gas pressure during the cleaning process chamber is 0.01 Torr to 10 Torr.

[0025] In some embodiments, the step (d) further comprises:

[0026] After shutting down the radio frequency power supply system and before shutting down the remote plasma system, only the purge gas is introduced, and the purge gas is excited by the remote plasma system to generate plasma, and the process chamber is purged by the plasma.

[0027] The present application also provides an application of the aforementioned method for cleaning a process chamber in a vacuum coating process equipment, wherein the vacuum coating process equipment includes a chemical vapor deposition equipment or an atomic layer deposition equipment.

[0028] Implementing the technical solution of the present invention has at least the following beneficial effects:

[0029] In the embodiment of the present application, the method for cleaning the process chamber provided adopts a remote plasma system combined with a radio frequency power system in the process chamber for cleaning, and uses the remote plasma system and the radio frequency power system to work together to clean the process chamber during the cleaning period. After the plasma generated by the remote plasma system is excited and transmitted to the process chamber, it is excited and enhanced by the radio frequency power system again, which increases the input power, increases the etching rate, increases the plasma power, makes more gas molecules in an excited state, strengthens the ionization, and increases the plasma density, which can fully cover the entire plasma coating equipment process chamber, thereby greatly improving the cleaning and etching efficiency and rate. At the same time, the method of the present invention limits the opening and closing sequence or time limit of the remote plasma system and the radio frequency power system, which can ensure the cleaning quality, shorten the cleaning time, provide sufficient plasma, enhance the cleaning and etching effect, and reduce or avoid damage to the components in the chamber.

[0030] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic flow chart of a method for cleaning a process chamber provided for some exemplary embodiments of the present application;

[0032] Figure 2 Another schematic flow chart of a method for cleaning a process chamber provided for some exemplary embodiments of the present application;

[0033] Figure 3 A schematic diagram of the structure of semiconductor process equipment provided for some exemplary embodiments of the present application.

[0034] Reference numerals:

[0035] 100-RF power system; 200-remote plasma system; 300-upper plate; 400-carrier plate; 500-heating plate. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0037] In the related art, for the cleaning of the process chamber in the plasma coating equipment, a single remote plasma source (RPS) or a single RF power supply is usually used for cleaning and etching, which has certain shortcomings. For example, the use of a single RPS remote plasma source system or an RF power supply flat discharge system has a narrow etching range inside the vacuum chamber and cannot fully cover the large plasma coating chamber. In addition, during the transmission process, the remote plasma undergoes a recombination phenomenon before reaching the process chamber, which reduces the overall cleaning effect; or, a single plasma excitation method increases the consumption of cleaning gas and the cleaning effect is not good. In addition, when using an RF power supply system to in-situ excite plasma for cleaning, it has problems such as slow etching rate, narrow etching range, and inability to fully cover. Therefore, the cleaning method in the prior art needs to be further improved.

[0038] In view of this, the technical solution of the embodiment of the present application provides a method for cleaning a process chamber and its application. The technical solution of the embodiment of the present application can alleviate the problems of slow etching rate, narrow etching range, and incomplete coverage in etching cleaning in existing large-scale plasma coating equipment. The specific technical solution is described below.

[0039] See also Figures 1 to 3 As shown, in some embodiments, a method for cleaning a process chamber is provided, the method comprising the following steps:

[0040] (a) introducing a cleaning process gas into a remote plasma system, starting the remote plasma system, exciting the gas into plasma, and supplying the remote plasma to a process chamber;

[0041] (b) when the remote plasma system reaches a stable state, the radio frequency power system in the process chamber is turned on again, the radio frequency power system re-excites and enhances the remote plasma in the process chamber, and the process chamber is cleaned by using the re-excited and enhanced plasma; and,

[0042] cleaning the process chamber during a cleaning period using both the remote plasma system and the radio frequency power system;

[0043] (c) After the cleaning process chamber is completed, the RF power system in the process chamber is turned off;

[0044] (d) After shutting down the RF power system, shut down the remote plasma system.

[0045] In the prior art, the process chamber is cleaned only by plasma generated by remote plasma system excitation. During the transmission process, the remote plasma undergoes recombination before reaching the process chamber, that is, the number of dissociated particles after reaching the process chamber is less than the number of dissociated particles generated by the remote plasma system excitation. Therefore, the cleaning method provided in this embodiment uses a remote plasma source combined with a radio frequency power supply for cleaning, and simultaneously uses a remote plasma and a radio frequency in-situ excited plasma to clean the process chamber, that is, during the cleaning period, the remote plasma system and the radio frequency power supply system are used to work together to clean the process chamber. After the plasma generated after the remote plasma system is excited is transmitted to the process chamber, it is excited and enhanced by the radio frequency power supply system again. In this way, the radio frequency power supply is added on the basis of the RPS in the cleaning and etching, the input power is increased, the etching rate is increased, the power in the plasma is increased, more gas molecules are in an excited state, the ionization is enhanced, the plasma density is increased, and the process chamber of the plasma coating equipment can be fully covered, thereby greatly improving the cleaning and etching efficiency and rate.

[0046] Compared with the existing method of first using remote plasma cleaning and then using in-situ plasma cleaning, the method of the present invention can further improve the cleaning and etching efficiency and rate, shorten the cleaning time, and has a better cleaning effect, a simple process, and convenient operation. That is, compared with the existing remote plasma cleaning and radio frequency plasma cleaning methods, the present invention uses a radio frequency power supply system to re-excite and enhance the plasma in the process chamber, and uses the re-excited and enhanced plasma to clean the process chamber. In this way, the gas between the upper plate and the lower plate in the process chamber can be fully dissociated to produce a plasma discharge effect, and the dissociation rate of the gas is greatly improved, thereby enhancing the etching effect and increasing the cleaning effect of the entire chamber; and during the cleaning period, the remote plasma system and the radio frequency power supply system are used to work together to clean the process chamber. Since the active particles in the plasma react with the pollutants to generate volatile substances, the purpose of removing surface stains is achieved. In order to ensure the cleaning quality and shorten the cleaning time, the plasma is continuously introduced through the remote plasma system, which can provide a sufficient amount of plasma, thereby improving the cleaning efficiency and the cleaning effect.

[0047] At the same time, the method of the present invention limits the opening and closing sequence or time limit of the remote plasma system and the radio frequency power supply system. Specifically, the remote plasma system is started first, and when the remote plasma system reaches a stable state, the radio frequency power supply system is turned on. In this way, by making the start time of the radio frequency power supply system later than the start time of the RPS, the purpose is to make the radio frequency power supply work in a more stable state, and the plasma cleaning effect transmitted by the RPS system to the process chamber is the best, thereby helping to enhance the cleaning and etching effect and improve the cleaning and etching efficiency. Further, after the cleaning is completed, the radio frequency power supply system in the process chamber is turned off first, and then the RPS system is turned off. This can prevent the gas atmosphere in the cavity from changing after the RPS is turned off, and the radio frequency power supply parameters are unstable, which is easy to damage the radio frequency power supply and the matching system, or may also cause abnormal discharge inside the cavity and damage the accessories in the cavity. The phenomenon occurs, with good safety and stability.

[0048] It is worth noting that in this embodiment, by turning on the RF power supply system in the process chamber after the remote plasma system reaches a stable state, not only can the RF power supply system operate in a more stable state, reducing or avoiding the instability of the RF power supply, but also the plasma cleaning effect transmitted by the remote plasma system to the process chamber can be optimized, thereby improving the cleaning effect of the remote plasma, thereby greatly enhancing the cleaning and etching effect. Optionally, the RF power supply system includes a RF power supply and a matcher. The specific structure and working principle of the RF power supply system can refer to the prior art, and the embodiment of the present invention is not limited to this.

[0049] It should be noted that the cleaning method of this embodiment can be applied in the fields of photovoltaic production equipment or semiconductor device production equipment, such as in large-scale plasma vacuum coating equipment, for cleaning the process chamber in the vacuum coating equipment. For example, the vacuum coating equipment can be a chemical vapor deposition (CVD) device, an atomic layer deposition (ALD) device, etc., which is not limited in this embodiment. Further, the CVD equipment can include a plasma enhanced chemical vapor deposition (PECVD) device or a normal pressure chemical vapor deposition device, etc., and the ALD equipment can include a plasma enhanced atomic layer deposition (PEALD) device, etc. Based on the type of coating equipment, optionally, the process chamber can be used to perform CVD, or to perform PECVD, or to perform ALD, etc. Optionally, the process chamber is a plasma reaction chamber.

[0050] For the sake of brevity, the method for cleaning a process chamber of the present invention is described in detail below by taking the coating equipment as a PECVD coating equipment as an example. However, it should be understood that when the method is applied to other related equipment, it has the same or similar principles and will not be repeated here.

[0051] like Figure 3 As shown, the PECVD coating equipment includes a process chamber, a RF power system 100 and a remote plasma system 200, wherein the RF power system 100 is provided in the process chamber, the remote plasma system 200 is connected to the process chamber, or the remote plasma system 200 is coupled to the process chamber and the RF power system 100.

[0052] Optionally, the PECVD coating equipment further includes an upper plate 300, a carrier plate 400 and a heating plate 500, wherein the carrier plate 400 or the heating plate 500 can be used as a lower plate, and the upper plate 300, the carrier plate 400 and the heating plate 500 are all arranged in the process chamber. Optionally, the upper plate 300 may include a nozzle for introducing and distributing process gas and cleaning gas. Alternatively, the upper plate 300 may include a conductive plate, and the process gas may be introduced in another way.

[0053] Optionally, the RF power system 100 generates and outputs RF power to one of the upper plate 300 and the lower plate, and the other of the upper plate 300 and the lower plate can be DC grounded, AC grounded, or floating.

[0054] Optionally, the input end of the remote plasma system 200 is connected to a gas input pipeline, and the output end of the remote plasma system 200 is connected to the process chamber. The gas input pipeline can be used to transport cleaning gas or purge gas.

[0055] With reference to the above-mentioned PECVD coating equipment, the method for cleaning a process chamber according to an embodiment of the present invention will be described in detail below.

[0056] In some specific embodiments, Figure 1 or Figure 2 As shown, the method for cleaning a process chamber comprises the following steps:

[0057] (a) A cleaning process gas is introduced into a remote plasma system, the remote plasma system is started, the gas is excited into plasma, and the remote plasma is supplied to the process chamber.

[0058] Specifically, step (a) includes:

[0059] (a1) Pre-treating the inner chamber, gas delivery pipeline and process chamber of the remote plasma system, wherein the pre-treating comprises purging the inner chamber, gas delivery pipeline and process chamber of the remote plasma system with a purge gas, and then starting the remote plasma system.

[0060] Optionally, the purge gas includes at least one of Ar, He, N2 or H2. For example, the purge gas may be Ar, He, N2, H2, etc. Preferably, the purge gas is Ar, which has a wide range of sources, low cost, and can achieve better purge effects.

[0061] In addition, in other embodiments, other types of gases may be used as purge gases while meeting actual process requirements, which are not listed here one by one.

[0062] Optionally, the remote plasma system is connected to a gas delivery pipeline, and the purge gas is supplied to the process chamber through the gas delivery pipeline and the remote plasma system that is not in operation. The process chamber is fully purged by providing a purge gas such as Ar to the gas delivery pipeline and allowing the purge gas to enter the process chamber through the gas delivery pipeline and the remote plasma system that is not in operation.

[0063] Before etching and cleaning the process chamber, the chamber needs to be fully purged, usually using Ar as the purge gas, which can flow into the process chamber through the remote plasma system that is not working. In this way, the gas in the process chamber is fully replaced to reduce or avoid the impact on the subsequent cleaning and etching process, so as to ensure the etching and cleaning effect.

[0064] (a2) After starting the remote plasma system, a cleaning gas is introduced to supply the plasma generated by the remote plasma system to the process chamber.

[0065] Supplying a cleaning gas to the remote plasma system, such as supplying the cleaning gas to the remote plasma system through a gas delivery pipeline; starting the remote plasma system can excite the cleaning gas (also called cleaning gas) flowing through it into a plasma state, and the plasma cleaning gas enters the cavity, that is, supplying RPS plasma to the process chamber.

[0066] Optionally, when the remote plasma system is started, the purge gas is present in the gas delivery pipeline; during the process of cleaning the process chamber, the cleaning gas is gradually input into the gas delivery pipeline.

[0067] Optionally, during the process of cleaning the process chamber, the flow rate of the cleaning gas is gradually increased, and the ratio of the flow rate of the cleaning gas to the flow rate of the purge gas is gradually increased or increased in a stepwise manner.

[0068] In this embodiment, before starting the RF power system in the process chamber, the flow rate of the cleaning gas in the cleaning process gas is gradually increased so that the cleaning gas and the purge gas reach a certain ratio, wherein the ratio of the flow rate of the cleaning gas to the flow rate of the purge gas is gradually increased or increased in a stepwise manner. When the remote plasma system is started, the purge gas needs to be used for excitation. If the purge gas is directly switched to the cleaning gas, the cleaning gas introduced into the remote plasma system cannot be excited and is likely to damage the equipment.

[0069] In this embodiment, when the remote plasma system is started, the gas delivery pipeline contains a purge gas such as Ar. For example, before starting the remote plasma system, Ar is delivered through the gas delivery pipeline and the remote plasma system that is not working to enter the process chamber for purging. After the purging is completed, at least part of the Ar can be retained in the gas delivery pipeline so that there is Ar in the gas delivery pipeline when the remote plasma is turned on. Further, during the cleaning process, a clean gas such as a corrosive gas containing the F element can be slowly supplied to the gas delivery pipeline, and as the cleaning process continues, the flow ratio of the clean gas such as the corrosive gas containing the F element to the purge gas such as Ar gradually increases or increases in steps, and after a certain period of time, the gas delivery pipeline is completely filled with clean gas. In this way, retaining part of the Ar in the initial stage of the RPS system startup can improve the stability of the ionization of the clean gas such as the corrosive gas containing the F element, reduce or avoid the loss of the clean gas, and be safe, reliable, and stable.

[0070] Optionally, the cleaning gas includes a corrosive gas containing F, and the corrosive gas containing F includes at least one of NF3, CF4, SF6, C2F6, F2, C3F8, CHF3, and HF; in addition, the cleaning gas is not limited to the corrosive gas containing F, but other types of corrosive gases, such as Cl2, HCl, etc., can also be used. Exemplarily, the corrosive gas can be NF3, CF4, SF6, C2F6, F2, C3F8, CHF3, HF, Cl2, HCl, or a mixture of any two or more of the above gases. By using the above-mentioned corrosive gases, especially the corrosive gas containing F, as the cleaning gas, the source is wide, the cost is low, and it helps to obtain a better cleaning effect.

[0071] Optionally, the remote plasma system includes a remote plasma source with an inductive coil coupled discharge structure. Optionally, the remote plasma system uses an AC power supply with a frequency of 100KHz to 13.56MHz. That is, the RPS uses an inductive coil coupled discharge structure, and the RPS power supply uses an AC power supply with a frequency of 100KHz to 13.56MHz.

[0072] (b) When the remote plasma system reaches a stable state, the RF power system in the process chamber is turned on to excite in-situ plasma in the process chamber, and the RF power system re-excites and enhances the plasma in the process chamber, and the process chamber is cleaned by using the re-excited and enhanced plasma; and during the cleaning period, the remote plasma system and the RF power system are used together to clean the process chamber.

[0073] In this embodiment, before the cleaning process, it is necessary to set appropriate working gas pressure, gas flow, cleaning time, RF power supply power, discharge interval, and delay time for starting the RF power supply after the RPS system is started according to the situation.

[0074] Optionally, in step (b), when the remote plasma system is turned on for 5 to 150 seconds (for example, 5 seconds, 6 seconds, 7 seconds, 8 seconds, 9 seconds, 10 seconds, 30 seconds, 50 seconds, 100 seconds, 120 seconds, 150 seconds, etc.), its working state reaches stability, and then the radio frequency power supply system is turned on. It can be judged whether the remote plasma system has reached a stable working state based on the time when the remote plasma system is turned on. For example, after the remote plasma system is turned on for 5 seconds to 150 seconds, it is considered that the remote plasma system has reached a stable working state. Of course, in other embodiments, other methods can also be used to judge whether the remote plasma system has reached a stable working state.

[0075] When the remote plasma system reaches a stable state, the RF power system is turned on, and the remote plasma system can supply remote plasma to the process chamber. The RF power is located in the process chamber, and the remote plasma is transmitted to the process chamber and is re-excited and enhanced by the RF power system, so that the remote plasma system and the RF power system are used to clean the process chamber at the same time. In this way, not only can the RF power system work in a more stable state, reducing or avoiding the instability of the RF power, but also the plasma cleaning effect transmitted by the remote plasma system to the process chamber can be optimized, thereby greatly enhancing the cleaning and etching effect.

[0076] Optionally, the frequency range of the RF power supply is 2 MHz to 100 MHz. Optionally, the frequency range of the RF power supply is 5 to 80 MHz. Optionally, the frequency range of the RF power supply is 10 to 50 MHz. In some examples, the RF power supply system can operate at a frequency of 2 MHz, 5 MHz, 10 MHz, 13.56 MHz, 20 MHz, 28.5 MHz, 43.2 MHz, 50 MHz, 75 MHz, 80 MHz, 100 MHz, etc., but other frequencies can also be used.

[0077] Optionally, the power range of the RF power source is 500W to 90,000W. Optionally, the power of the RF power source is 800W to 60,000W. Optionally, the power of the RF power source is 1,000W to 20,000W. For example, the power of the RF power source may be 500W, 800W, 1,000W, 2,000W, 5,000W, 8,000W, 10,000W, 20,000W, 50,000W, 80,000W, etc., but other RF power levels may also be used.

[0078] Optionally, the discharge spacing of the RF power source ranges from 5 mm to 50 mm. Optionally, the discharge spacing of the RF power source ranges from 8 mm to 30 mm. Optionally, the discharge spacing of the RF power source ranges from 10 mm to 20 mm. In some examples, the discharge spacing of the RF power source can be 5 mm, 8 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 40 mm, 50 mm, etc., but other discharge spacings can also be used.

[0079] Optionally, the working pressure during the cleaning process chamber is 0.01 Torr to 10 Torr. Optionally, the working pressure during the cleaning process chamber is 0.1 Torr to 8 Torr. Optionally, the working pressure during the cleaning process chamber is 0.5 Torr to 5.5 Torr. For example, the working pressure during the cleaning process chamber is 0.01 Torr, 0.1 Torr, 0.3 Torr, 0.5 Torr, 1 Torr, 2 Torr, 5 Torr, 8 Torr, 10 Torr, etc.

[0080] Therefore, based on the above settings, turning on the RF power supply and the matcher after the plasma source is stable can fully dissociate the gas between the upper plate and the lower plate, produce a plasma discharge effect, and greatly improve the gas dissociation rate, thereby enhancing the etching effect and increasing the cleaning effect of the entire chamber; wherein, the two cleaning methods are used at the same time. Since the active particles in the plasma react with the pollutants to generate volatile substances, the purpose of removing surface stains is achieved. In order to ensure the cleaning quality and shorten the cleaning time, the plasma is continuously introduced through the RPS system to provide a sufficient amount of plasma.

[0081] It is worth noting that the RF power supply and the matching device must be turned on after the RPS system reaches a stable state. The start-up time of the RF power supply and the matching device is later than the start-up time of the RPS. The purpose is to make the RF power supply work in a more stable state. When the plasma cleaning effect transmitted to the cavity by the RPS system is the best, it helps to enhance the cleaning effect and make the whole system run more stably.

[0082] Optionally, the cleaning object also includes a carrier, which can be used to hold silicon wafers to be coated during coating. That is, when cleaning the process chamber, not only the environment in the process chamber or the inner wall of the process chamber can be cleaned, but also the components in the process chamber such as the carrier can be cleaned.

[0083] Optionally, the distance between the upper and lower plates, the power of the RF power supply and the matcher, the flow rate of the cleaning gas, and the gas pressure in the chamber can be adjusted to control the distribution range and intensity of the plasma glow. The temperature of the entire process chamber can be controlled by adjusting the temperature to meet different etching effects.

[0084] Optionally, when the carrier plate holding the sample to be coated is in the process chamber, the carrier plate is grounded, the carrier plate is the lower plate, and can be in contact with the heating plate or suspended. When the carrier plate is not in the process chamber, the heating plate is the lower plate.

[0085] (c) After the cleaning of the process chamber is completed, the RF power system in the process chamber is first turned off.

[0086] (d) After shutting down the RF power supply system and before shutting down the remote plasma system, only a purge gas is introduced, the purge gas is excited by the remote plasma system to generate plasma, the plasma is used to purge the process chamber, and finally the remote plasma system is shut down.

[0087] Optionally, the purge gas may be the purge gas described above, such as Ar or the like.

[0088] In this embodiment, after cleaning the process chamber, the chamber needs to be fully purged, such as by using Ar plasma or Ar. In this way, continuing to purge after cleaning is conducive to removing corrosive particles in the chamber and preventing the subsequent coating process from being affected.

[0089] It is worth noting that when the corrosion cleaning is completed, it is necessary to turn off the RF power supply in the process chamber first, and then turn off the RPS system. After turning off the RPS system, continue to pass Ar for a period of time before stopping the cleaning process. On the one hand, during operation, the RPS system should not be turned off first, and then the RF system. This is to prevent the gas atmosphere in the cavity from changing after the RPS is turned off, and the RF power supply parameters from being unstable, which may easily damage the RF power supply and matching system. It may also cause abnormal discharge inside the cavity and damage the accessories in the cavity. On the other hand, after turning off the RPS system, continue to pass Ar for a period of time. Its function is to use Ar plasma or Ar to fully purge the chamber to remove residual corrosive particles and avoid affecting the subsequent coating process.

[0090] Based on the same inventive concept, an embodiment of the present application further provides an application of the aforementioned method for cleaning a process chamber in a vacuum coating process equipment, wherein the vacuum coating process equipment includes a chemical vapor deposition equipment or an atomic layer deposition equipment.

[0091] It should be understood that the application of the method for cleaning a process chamber of this embodiment in vacuum coating process equipment is based on the same inventive concept as the aforementioned method for cleaning a process chamber, and thus has at least all the features and advantages of the method for cleaning a process chamber, which will not be repeated here.

[0092] Parts not described in detail in the specification of the present invention are well known to those skilled in the art.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for cleaning a process chamber, characterized in that: The method comprises the following steps: (a) introducing a cleaning process gas into a remote plasma system, starting the remote plasma system, exciting the gas into plasma, and supplying the remote plasma to a process chamber; (b) when the remote plasma system reaches a stable state, the radio frequency power system in the process chamber is turned on again, the radio frequency power system re-excites and enhances the remote plasma in the process chamber, and the process chamber is cleaned by using the re-excited and enhanced plasma; and cleaning the process chamber during a cleaning period using both the remote plasma system and the RF power system to work together; (c) after cleaning the process chamber, first shutting down the radio frequency power system in the process chamber; (d) after shutting down the radio frequency power system, shutting down the remote plasma system; The cleaning process gas includes a purge gas and a cleaning gas, and the step (a) includes: (a1) pre-treating the inner chamber, gas delivery pipeline and process chamber of the remote plasma system, wherein the pre-treating comprises purging the inner chamber, gas delivery pipeline and process chamber of the remote plasma system with the purge gas, and then starting the remote plasma system; (a2) after starting the remote plasma system, introducing a cleaning gas to supply plasma generated by the remote plasma system to the process chamber; Before starting the radio frequency power system in the process chamber, gradually increasing the flow rate of the cleaning gas in the cleaning process gas so that the cleaning gas and the purge gas reach a certain ratio, wherein the ratio of the flow rate of the cleaning gas to the flow rate of the purge gas increases gradually or in a stepwise manner; The step (d) further comprises: After shutting down the radio frequency power supply system and before shutting down the remote plasma system, only the purge gas is introduced, and the purge gas is excited by the remote plasma system to generate plasma, and the process chamber is purged by the plasma.

2. The method for cleaning a process chamber according to claim 1, characterized in that: The purge gas includes at least one of Ar, He, N2 or H2.

3. The method for cleaning a process chamber according to claim 1, characterized in that: The cleaning gas includes a corrosive gas, and the corrosive gas includes at least one of NF3, CF4, SF6, C2F6, F2, C3F8, CHF3, HF, Cl2 or HCl.

4. The method for cleaning a process chamber according to claim 1, characterized in that: The remote plasma system comprises an inductive coil coupled discharge structure, and the remote plasma system adopts an alternating current power supply with a frequency of 100 KHz to 13.56 MHz.

5. The method for cleaning a process chamber according to claim 1, characterized in that: In the step (b), when the remote plasma system is turned on for 5 to 150 seconds and its working state reaches a stable state, the radio frequency power supply system is turned on.

6. The method for cleaning a process chamber according to any one of claims 1 to 5, characterized in that: The operating parameters of the RF power supply system include: The frequency range of the radio frequency power source is 2 MHz to 100 MHz; and / or, The power range of the RF power supply is 500W to 90000W; and / or, The discharge spacing of the radio frequency power source ranges from 5 mm to 50 mm; and / or, The working gas pressure during the cleaning process chamber is 0.01 Torr to 10 Torr.

7. Application of the method for cleaning a process chamber according to any one of claims 1 to 6 in a vacuum coating process equipment, characterized in that: The vacuum coating process equipment includes chemical vapor deposition equipment or atomic layer deposition equipment.

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