Cleaning methods for the cavity and process devices within the cavity

Abstract

A method for cleaning a cavity and a process device within the cavity are disclosed. In the cavity cleaning method, etching ions are first introduced into the cavity to etch a thin film layer deposited on the surface of the process device, removing the film layer but leaving etching ions on the surface. Subsequently, oxygen-containing ions are introduced into the cavity to form a protective layer on the surface of the process device. This protective layer isolates the process device from the external environment, making it less susceptible to damage and preventing corrosion from direct contact with the etching ions during subsequent cavity cleaning, thus improving the service life of the process device. The cavity cleaning method provided by this invention ensures both thorough removal of the thin film on the surface of the process device and effective protection of the surface, improving the practicality of the cleaning process.

Description

Technical Field

[0001] This invention relates to the field of semiconductors, and more particularly to a method for cleaning a cavity and a process apparatus for the cavity. Background Technology

[0002] During the wafer fabrication process of chemical vapor deposition, thin film deposits continuously accumulate on the inner wall of the cavity. The thickness of these deposits ranges from several thousand angstroms to thirty micrometers. When the film thickness exceeds the set value, the cavity needs to be cleaned to restore it to its initial state. The cleaning scope includes not only the sidewalls of the cavity but also the thin film layer deposited on the surface of the process equipment inside the cavity.

[0003] Current cleaning technologies primarily employ remote plasma systems. This system first dissociates nitrogen trifluoride (NF3) gas to generate fluoride ions (F-). These fluoride ions then react with thin films of silicon dioxide (SiO2) and silicon nitride (SiN) on the surfaces of the chamber and spray heads, generating volatile fluorine-containing gaseous substances. Finally, these gaseous substances are removed by a vacuum pump, completing the cleaning process.

[0004] However, in order to ensure that the nozzles and sidewalls of the cavity are thoroughly cleaned, excessive etching is performed. However, excessive etching can cause varying degrees of damage to the process equipment. The greater the amount of excessive etching, the more severe the damage, which reduces the service life of the process equipment. Summary of the Invention

[0005] The problem solved by this invention is to provide a cleaning method for a cavity and a process device inside the cavity, which not only ensures the complete removal of the thin film on the surface of the process device, but also achieves effective protection of the surface of the process device.

[0006] To address the aforementioned problems, the present invention provides a cleaning method for a cavity, wherein the cavity contains a process device and the surface of the process device has a deposited thin film layer, comprising the following steps: providing etching ions to the cavity to etch the thin film layer deposited on the surface of the process device; after providing etching ions to the cavity, providing oxygen ions to the cavity to form a protective layer on the surface of the process device.

[0007] Optionally, the step of providing oxygen ions to the cavity includes: providing oxygen-containing gas; dissociating the oxygen-containing gas to generate oxygen ions; and introducing the generated oxygen ions into the cavity.

[0008] Optionally, a remote plasma system can be used to dissociate the oxygen-containing gas to generate oxygen ions.

[0009] Optionally, the step of providing oxygen ions to the cavity further includes: providing a dissociation gas after providing the oxygen-containing gas and before providing oxygen ions to the cavity; the step of dissociating the oxygen-containing gas to generate oxygen ions includes: dissociating the oxygen-containing gas with the dissociation gas to generate oxygen ions.

[0010] Optionally, in the step of providing the oxygen-containing gas, a dissociation gas is also provided; the step of dissociating the oxygen-containing gas to generate oxygen ions includes: dissociating the oxygen-containing gas by the dissociation gas to generate oxygen ions.

[0011] Optionally, in the step of providing the dissociation gas, the introduced gas may include argon.

[0012] Optionally, in the step of providing the dissociation gas, the flow rate of the dissociation gas is from 2000 sccm to 7000 sccm.

[0013] Optionally, in the step of providing oxygen-containing gas, the oxygen-containing gas includes one or more of nitrous oxide, oxygen, and ozone.

[0014] Optionally, in the step of providing oxygen-containing gas, the flow rate of the oxygen-containing gas is from 1000 sccm to 5000 sccm.

[0015] Optionally, the step of providing etching ions to the cavity includes: providing etching gas; dissociating the etching gas to generate the etching ions; and introducing the generated etching ions into the cavity.

[0016] Optionally, a remote plasma system can be used to dissociate the etching gas to generate etching ions.

[0017] Optionally, in the step of providing the etching gas, the etching gas includes a fluorine-containing gas; in the step of dissociating the etching gas to generate the etching ions, the etching ions include fluorine ions.

[0018] The cleaning method as described in claim 12 is characterized in that, in the step of providing etching ions into the cavity, a byproduct layer is formed on the surface of the process apparatus; and in the step of providing oxygen ions into the cavity, the byproduct layer is converted into the protective layer, and the density of the protective layer is higher than that of the byproduct layer.

[0019] Optionally, the material of the process apparatus includes aluminum; in the step of providing etching ions into the cavity, the material of the byproduct layer includes an aluminum fluoride compound; in the step of providing oxygen ions into the cavity, the material of the protective layer includes an aluminum fluoride compound.

[0020] Optionally, the fluorine-containing gas includes nitrogen trifluoride.

[0021] Optionally, in the step of providing oxygen ions into the cavity, the thickness of the protective layer is 5 nm to 30 nm.

[0022] Optionally, in the step of providing etching ions to the cavity to etch the thin film layer deposited on the surface of the process apparatus, the etching ions remain on the surface of the process apparatus; in the step of providing oxygen ions to the cavity, the etching ions on the surface of the process apparatus are removed.

[0023] Accordingly, the present invention also provides a process device within a cavity, comprising: the aforementioned cleaning method for the cavity, wherein the surface of the process device within the cavity has a protective layer.

[0024] Optionally, the material of the protective layer includes aluminum oxyfluoride compounds.

[0025] Optionally, the thickness of the protective layer is 5 nm to 30 nm.

[0026] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0027] In the cavity cleaning method provided in this embodiment of the invention, etching ions are first introduced into the cavity to etch the thin film layer deposited on the surface of the process device, removing the thin film layer but leaving etching ions on the surface of the process device. Subsequently, oxygen-containing ions are introduced into the cavity to form a protective layer on the surface of the process device. This protective layer isolates the process device from the outside environment, making it less susceptible to damage and preventing corrosion from direct contact with etching ions during subsequent cavity cleaning, thus improving the service life of the process device. The cavity cleaning method provided in this embodiment of the invention ensures both thorough removal of the thin film on the surface of the process device and effective protection of the surface, improving the practicality of the cleaning process. Attached Figure Description

[0028] Figure 1 This is a schematic diagram illustrating the provision of etching ions to the interior of the cavity in the cleaning method of the cavity according to an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the method for cleaning the cavity in an embodiment of the present invention to remove the thin film layer deposited on the surface of the process device;

[0030] Figure 3 This is a schematic diagram illustrating the supply of oxygen ions to the interior of the cavity in the cleaning method of the cavity according to an embodiment of the present invention;

[0031] Figure 4 This is a partial schematic diagram of the process apparatus inside the cavity in an embodiment of the present invention. Detailed Implementation

[0032] As can be seen from the background technology, currently, in order to ensure that the nozzles of the spray head and the side walls of the cavity can be thoroughly cleaned, excessive etching is performed. However, excessive etching will cause varying degrees of damage to the process equipment, and the greater the amount of excessive etching, the more severe the damage, thus reducing the service life of the process equipment.

[0033] To address the technical problem, this invention provides a cavity cleaning method. The cavity contains a process device with a deposited thin film layer on its surface. The cleaning method includes the following steps: providing etching ions into the cavity to etch the deposited thin film layer on the surface of the process device; and after providing the etching ions, providing oxygen ions into the cavity to form a protective layer on the surface of the process device. In this cavity cleaning method, etching ions are first provided into the cavity to etch the deposited thin film layer on the surface of the process device, removing the film layer, but leaving etching ions on the surface. Subsequently, oxygen ions are introduced into the cavity to form a protective layer on the surface of the process device. This protective layer isolates the process device from the outside environment, making it less susceptible to damage and preventing corrosion from direct contact with the etching ions during subsequent cavity cleaning, thus improving the service life of the process device. This cavity cleaning method ensures both thorough removal of the thin film on the surface of the process device and effective protection of the surface, improving the practicality of the cleaning process.

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0035] Figures 1 to 3 This is a schematic diagram of the structure corresponding to each step in the embodiment of the cleaning method for the cavity of the present invention.

[0036] refer to Figure 1 and Figure 2 The cavity (not shown in the figure) contains a process device 100, and the surface of the process device 100 has a deposited thin film layer 101. The cleaning method of the cavity includes: providing etching ions a into the cavity to etch the thin film layer 101 deposited on the surface of the process device 100.

[0037] By introducing etching ions a inside the cavity, the thin film layer 101 deposited on the surface of the process device 100 is effectively removed, restoring the surface of the process device 100 to the state before the thin film layer 101 was deposited in the cavity. This prepares the device for subsequent wafer processing and allows the entire chemical vapor deposition process to continue, which is beneficial for improving equipment utilization.

[0038] In this embodiment, the step of providing etching ions a to the cavity includes: providing etching gas; dissociating the etching gas to generate the etching ions a; and introducing the generated etching ions a into the cavity.

[0039] In this embodiment, the etching gas includes a fluorine-containing gas in the step of providing the etching gas; and the etching ion a includes fluoride ions in the step of dissociating the etching gas to generate the etching ion a. The fluorine-containing gas dissociates to generate fluoride ions, which can react with the deposited thin film layer 101 (e.g., silicon dioxide, silicon nitride, etc.) on the surface of the cavity and spray head to generate a volatile fluorine-containing gaseous substance, which is then extracted, facilitating the effective removal of the deposited thin film layer 101.

[0040] Specifically, the fluorine-containing gas includes nitrogen trifluoride (NF3). Nitrogen trifluoride has high etching selectivity, enabling precise etching of specific materials without damaging other materials; moreover, nitrogen trifluoride has low gas flow resistance and a high diffusion rate, allowing it to diffuse more quickly to the surface of semiconductor materials during the etching process, achieving faster etching.

[0041] In this embodiment, in the step of providing etching ions a into the cavity, a remote plasma system (RPS) is used to dissociate the etching gas and generate fluoride ions. The remote plasma system can generate fluoride ions at a location far from the cavity and deliver the fluoride ions to the surface of the process apparatus 100 inside the cavity; moreover, since high-energy ions are filtered out before reaching the cavity, physical damage to the surface of the process apparatus 100 is reduced.

[0042] A remote plasma system dissociates fluorine-containing gas, generating highly reactive fluoride ions. These fluoride ions react with the silicon dioxide and silicon nitride thin films 101 on the surface of the cavity and spray head, producing volatile fluorine-containing gaseous substances. This effectively removes the deposits accumulated on the inner wall of the cavity, preparing it for subsequent wafer processing. Furthermore, the use of a remote plasma system avoids direct plasma impact on the cavity, improving the controllability and safety of the cleaning process.

[0043] like Figure 2 As shown, in the step of providing etching ions a into the cavity to etch the thin film layer 101 deposited on the surface of the process apparatus 100, the etching ions a remain on the surface of the process apparatus 100. Specifically, fluoride ions (F-) are adsorbed on the surface of the process apparatus 100.

[0044] It should be noted that, in the actual cleaning process, the effective removal of different types of thin film layers 101 was ensured by selecting and controlling the etching gas, especially for silicon nitride films that are more difficult to remove.

[0045] It should be noted that the process device 100 inside the cavity includes a station heater and a shower head assembly. In this embodiment, there are four of each type of heater and shower head assembly.

[0046] Specifically, four spray head assemblies serve as gas input components, ensuring the uniform distribution of reactive gases across the wafer surface. During the process, when the thickness of the thin film layer 101 deposit exceeds a set value, a certain thickness of thin film layer 101 also accumulates on the surfaces of these spray head assemblies. Four heaters, working in conjunction with the spray head assemblies, provide the necessary temperature environment for the chemical vapor deposition reaction. During the reaction, after the gas is uniformly distributed through the spray heads, a chemical reaction occurs under the appropriate temperature conditions provided by the heaters, thereby forming the desired thin film layer 101, such as silicon dioxide or silicon nitride, on the wafer surface. The chamber sidewalls form a sealed reaction space, ensuring the entire chemical vapor deposition process is carried out under controlled conditions. This sealed design allows the reactive gases to fully contact the wafer surface at appropriate pressures and concentrations. Simultaneously, thin film layer 101 deposits also accumulate on the inner walls of the chamber.

[0047] like Figure 2 As shown, in the step of providing etching ions a into the cavity, a byproduct layer 102 is formed on the surface of the process apparatus 100.

[0048] In this embodiment, the process apparatus 100 is made of aluminum. Specifically, the spray head assembly is made of aluminum. Fluoride ions react with the aluminum surface of the spray head assembly to form a byproduct layer 102, which is made of aluminum fluoride compound. Because the aluminum fluoride compound is porous, it cannot effectively prevent the continued penetration of subsequent fluoride ions. Due to this structural characteristic, the spray head assembly is subject to continuous corrosion damage.

[0049] During the cleaning process, the aluminum spray head is susceptible to corrosion from fluoride ions, which can damage it. The greater the amount of excessive etching, the more severe the damage to the spray head orifices.

[0050] It should be noted that the etching ions a introduced into the cavity will also etch the thin film layer 101 deposited on the inner wall surface of the cavity.

[0051] refer to Figure 3 After providing etching ions a into the cavity, oxygen ions b are provided into the cavity to form a protective layer 103 on the surface of the process apparatus 100.

[0052] In the cavity cleaning method provided in this embodiment of the invention, etching ions a are first introduced into the cavity to etch the thin film layer 101 deposited on the surface of the process device 100, removing the thin film layer 101, but leaving etching ions a residue on the surface of the process device 100. Subsequently, oxygen-containing ions b are introduced into the cavity to form a protective layer 103 on the surface of the process device 100. The protective layer 103 isolates the process device 100 from the outside environment, making it less susceptible to damage and preventing corrosion from direct contact with etching ions a during subsequent cavity cleaning, thus improving the service life of the process device 100. The cavity cleaning method provided in this embodiment of the invention ensures both thorough removal of the thin film on the surface of the process device 100 and effective protection of the surface of the process device 100, improving the practicality of the cleaning process.

[0053] Furthermore, the dissociation gas is used to dissociate oxygen-containing gas into oxygen ions (b). When the dissociation gas and oxygen-containing gas are introduced simultaneously, the presence of argon gas can promote the dissociation of oxygen-containing gas and improve processing efficiency. This synergistic effect allows the oxygen-containing gas to dissociate more fully to produce oxygen ions, thereby accelerating the entire reaction process.

[0054] In this embodiment, the step of providing oxygen ions to the cavity includes: providing oxygen-containing gas; dissociating the oxygen-containing gas to generate oxygen ions b; and introducing the generated oxygen ions into the cavity.

[0055] In this embodiment, in the step of providing oxygen ions b to the cavity, a remote plasma system is used to dissociate the oxygen-containing gas and generate oxygen ions b. The remote plasma system can generate oxygen ions b at a certain distance and transport them to the surface of the process device 100; moreover, since high-energy ions are filtered out before reaching the cavity, physical damage to the surface of the process device 100 is reduced.

[0056] In this embodiment, the step of providing the oxygen-containing gas also includes providing a dissociation gas; the step of dissociating the oxygen-containing gas to generate oxygen ions includes: dissociating the oxygen-containing gas using the dissociation gas to generate oxygen ions.

[0057] The dissociation gas introduced into the cavity is used to dissociate oxygen-containing gas, thereby generating active oxygen ions, which are used to desorb fluoride ions from the surface of the process device 100, and also to transform the loose by-product layer 102 into a denser protective layer 103.

[0058] In this embodiment, the flow rate of the dissociating gas in the step of providing the dissociating gas should not be too high or too low. If the flow rate of the dissociating gas is too low, the reaction byproducts in the cavity cannot be fully removed, reducing the physical purification effect of the cavity; in addition, if the flow rate of the dissociating gas is too low, the dissociation-promoting effect of oxygen-containing gas will be weakened, affecting the oxygen ion generation efficiency. If the flow rate of the dissociating gas is too high, the proportion of oxygen-containing gas concentration in the cavity will be reduced, thus failing to provide sufficient oxygen ions inside the cavity, affecting the formation quality of the subsequent aluminum fluoride compound. In this embodiment, the flow rate of the dissociating gas in the step of providing the dissociating gas is 2000 sccm to 7000 sccm.

[0059] In this embodiment, the dissociation gas provided in the step of providing the dissociation gas includes argon gas.

[0060] It should be noted that in the step of providing oxygen ions b into the cavity, etching ions a on the surface of the process apparatus 100 are also removed.

[0061] Oxygen ions b can effectively desorb fluoride ions that remain and are adsorbed on the surface of the cavity and spray head during the cleaning process, so that the fluoride ions remaining on the surface of the process device 100 will not damage the aluminum in the process device 100, and significantly extend the service life of the aluminum components in the process device 100.

[0062] In this embodiment, the step of providing oxygen-containing gas includes one or more of nitrous oxide, oxygen, and ozone. Nitrous oxide, oxygen, and ozone can generate active oxygen ions (b) through dissociation, and these gases can be used simultaneously with argon.

[0063] In this embodiment, during the step of providing oxygen ions into the cavity, the byproduct layer 102 is converted into the protective layer 103, and the density of the protective layer 103 is higher than that of the byproduct layer 102. Thus, the protective layer 103 can effectively isolate the surface of the process device 100 from the outside world, significantly reducing corrosion damage to the process device 100, avoiding direct contact between the process device and etching ions a during subsequent cavity cleaning, and improving the service life of the process device.

[0064] In this embodiment, in the step of providing oxygen ions b to the cavity, the material of the protective layer 103 includes an aluminum oxyfluoride compound.

[0065] In the step of providing etching ions a into the cavity, fluoride ions react with the aluminum surface of the process device 100 to initially form a loose aluminum fluoride compound, which is then converted into a dense aluminum fluoride compound under the action of oxygen ions b, thereby forming a highly dense protective layer 103 on the surface of the process device 100. This protective layer 103 can effectively isolate the surface of the process device 100 from the outside environment, significantly reducing corrosion damage to the process device 100.

[0066] In the step of providing oxygen ions b to the cavity, the protective layer 103 should not be too thick or too thin. If the protective layer 103 is too thin, it cannot isolate the surface of the process device 100 from the outside, reducing the protective effect. If the protective layer 103 is too thick, it is prone to generating large internal stress, which can easily lead to cracking or peeling of the protective layer 103; in addition, forming the protective layer 103 requires a longer time, reducing process efficiency. In this embodiment, in the step of providing oxygen ions b to the cavity, the thickness of the protective layer 103 is 5 nm to 30 nm.

[0067] It should be noted that in the step of providing oxygen ions b into the cavity, the flow rate of the oxygen-containing gas should not be too high or too low. If the flow rate of the oxygen-containing gas is too high, the cavity pressure will increase, which will accelerate the reaction efficiency, increase the collision frequency between gas molecules, affect the generation efficiency of oxygen ions b, and is not conducive to the formation of a dense protective film. If the flow rate of the oxygen-containing gas is too low, the desorption of fluoride ions on the surface of the process device 100 will be insufficient, and the residual fluoride ions will continue to corrode the aluminum in the process device 100; in addition, it will also prevent the loose aluminum fluoride compound from being converted into a denser aluminum fluoride compound on the surface of the process device 100. In this embodiment, in the step of providing oxygen ions b into the cavity, the total flow rate of the oxygen-containing gas is 1000 sccm to 5000 sccm.

[0068] In other embodiments, the step of providing oxygen ions to the cavity further includes: providing a dissociation gas after providing the oxygen-containing gas and before providing oxygen ions to the cavity; the step of dissociating the oxygen-containing gas to generate oxygen ions includes: dissociating the oxygen-containing gas with the dissociation gas to generate oxygen ions.

[0069] By introducing dissociation gas and oxygen-containing gas in stages, the reaction process at each stage can be controlled more precisely. First, dissociation gas is introduced for purification to ensure the purity of the chamber environment; then, oxygen-containing gas is introduced to allow dissociation in a clean environment, generating fluoride ions on the surface of the oxygen ion desorption process device 100, which transforms the loose aluminum fluoride compound into a denser aluminum fluoride compound.

[0070] refer to Figure 4The present invention also provides a process device 100 in a cavity, which adopts the aforementioned cavity cleaning method, wherein the surface of the process device 100 in the cavity has a protective layer 103.

[0071] The surface of the process device 100 inside the cavity has a protective layer 103, which effectively isolates the surface of the process device 100 from the outside, effectively protecting the surface of the process device 100. This makes the surface of the process device 100 less susceptible to corrosion during subsequent processing, significantly extending the service life of the process device 100.

[0072] In this embodiment, the material of the protective layer 103 includes an aluminum oxyfluoride compound. Compared with aluminum oxyfluoride compounds, aluminum oxyfluoride compounds are more dense and can more effectively isolate the process device 100 from the outside world, thereby protecting the surface of the process device 100.

[0073] In this embodiment, the thickness of the protective layer 103 is 5 nm to 30 nm. The protective layer 103 should not be too thick or too thin. If the protective layer 103 is too thin, it cannot effectively isolate the surface of the process device 100 from the outside, reducing the protective effect. If the protective layer 103 is too thick, it is prone to generating large internal stress, which can easily lead to cracking or peeling of the protective layer 103; in addition, forming the protective layer 103 requires a longer time, reducing process efficiency.

[0074] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A method of cleaning a cavity, characterized by, The cavity has a process device inside, and a surface of the process device has a deposited thin film layer, including the following steps: Providing etching ions into the cavity to etch the deposited thin film layer on the surface of the process device, wherein the step of providing etching ions into the cavity includes: providing an etching gas; dissociating the etching gas to generate the etching ions; and introducing the generated etching ions into the cavity, wherein in the step of providing etching ions into the cavity, a byproduct layer is formed on the surface of the process device; After the step of providing etching ions into the cavity, oxygen ions are provided into the cavity to form a protective layer on the surface of the process device, wherein in the step of providing oxygen ions into the cavity, the byproduct layer is converted into the protective layer, and the density of the protective layer is higher than that of the byproduct layer.

2. The cleaning method according to claim 1, wherein The step of providing oxygen ions into the cavity includes: Providing an oxygen-containing gas; Dissociating the oxygen-containing gas to generate oxygen ions; Introducing the generated oxygen ions into the cavity.

3. The cleaning method according to claim 2, wherein The oxygen-containing gas is dissociated by a remote plasma system to generate the oxygen ions.

4. The cleaning method according to claim 2, wherein The step of providing oxygen ions into the cavity further includes: after the oxygen-containing gas is provided, providing a dissociation gas before the oxygen ions are provided into the cavity; The step of dissociating the oxygen-containing gas to generate oxygen ions includes: dissociating the oxygen-containing gas by the dissociation gas to generate oxygen ions.

5. The cleaning method according to claim 2, wherein The step of providing the oxygen-containing gas further provides the dissociation gas; The step of dissociating the oxygen-containing gas to generate oxygen ions includes: dissociating the oxygen-containing gas by the dissociation gas to generate oxygen ions.

6. The cleaning method according to claim 4 or 5, characterized by, In the step of providing the dissociation gas, the introduced gas includes argon.

7. The cleaning method according to claim 4 or 5, wherein In the step of providing the dissociation gas, the flow rate of the dissociation gas is 2000sccm to 7000sccm.

8. The cleaning method according to claim 2, wherein In the step of providing the oxygen-containing gas, the oxygen-containing gas includes one or more of nitrous oxide, oxygen, and ozone.

9. The cleaning method according to claim 2, wherein In the step of providing the oxygen-containing gas, the flow rate of the oxygen-containing gas is 1000sccm to 5000sccm.

10. The cleaning method of claim 1, wherein, The etching gas is dissociated by a remote plasma system to generate the etching ions.

11. The cleaning method of claim 1, wherein, In the step of providing the etching gas, the etching gas includes a fluorine-containing gas; In the step of dissociating the etching gas to generate the etching ions, the etching ions include fluorine ions.

12. The cleaning method according to claim 11, wherein The material of the process device includes aluminum; In the step of providing etching ions into the cavity, the material of the byproduct layer includes a fluorine-aluminum compound; In the step of providing oxygen ions into the cavity, the material of the protective layer includes a fluorine-oxygen-aluminum compound.

13. The cleaning method according to claim 12, wherein The fluorine-containing gas includes nitrogen trifluoride.

14. The cleaning method of claim 1, wherein, In the step of providing oxygen ions into the cavity, the thickness of the protective layer is 5nm to 30nm.

15. The cleaning method of claim 1, wherein, In the step of providing etching ions into the cavity to etch the deposited thin film layer on the surface of the process device, the etching ions remain on the surface of the process device; In the step of providing oxygen ions into the cavity, the etching ions on the surface of the process device are removed.

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