Coating method of chamber for deposition process

Abstract

A coating method of a chamber for a deposition process according to the present invention comprises the steps of: (a) forming a lower coating layer by performing an arc spraying process using an aluminum wire on an object to be coated; and (b) forming an upper coating layer by performing a physical vapor deposition process of metal compound powder on the lower coating layer formed in step (a), wherein the metal compound in step (b) has the same component as a PVD process by-product, thereby extending the maintenance and management cycle of components in the chamber so as to increase the yield of semiconductor production.

Description

Coating method for a chamber for deposition process

[0001] The present invention relates to a coating method for a chamber for a deposition process, and more specifically, to a coating method for a chamber for a deposition process applied to a semiconductor manufacturing process and a coating film manufactured using the same.

[0002] In general, PVD (Physical Vapor Deposition) coating devices are used to form various thin films such as metal wiring, barrier layers, transparent electrodes, and optical films in fields such as semiconductors, displays, and circuit boards.

[0003] This PVD coating process refers to a physical vapor deposition method that deposits particles of the same material as the thin film to be deposited on the substrate by various physical methods in a vacuum. In a vacuum, an inert gas such as argon (Ar) is injected, and a high voltage is applied to a target made of metal or a metal compound to generate plasma discharge around the target, so that positive ions within the plasma discharge area strike the target surface by electrical force, releasing atoms and coating the atoms on the substrate. By forming a thin film of particles sputtered on the surface by this PVD coating, the mechanical properties of the surface are improved.

[0004] Meanwhile, the deposition process for semiconductor manufacturing is generally a task of forming certain thin films, such as drain electrodes and gate electrodes, on the substrate surface, and is mostly carried out by sputtering.

[0005] The deposition process using this sputtering method is to generate plasma discharge within the chamber by supplying a process gas such as argon inside a vacuum chamber and applying RF voltage or DC voltage, and when ionized particles of the process gas collide with a target due to the plasma discharge, sputtering particles (also called thin film materials) for forming a thin film are ejected from the target by the collision energy, and when these sputtering particles diffuse toward a substrate placed inside the chamber, they are deposited on one surface of the substrate, thereby forming a thin film.

[0006] For deposition work using this type of sputtering method, a sputtering device (sometimes called a sputterer) is used, and this sputtering device is configured so that the film formation work by sputtering can be performed within a chamber.

[0007] At this time, it is very important to form the coating layer of the component within the chamber to have a surface structure that can suppress abnormal peeling by increasing the deposition power of sputtering particles (thin film material) dispersed on the inner wall of the chamber, thereby preventing contamination and defects on the thin film side formed by deposition on one side of the substrate during sputtering.

[0008] In addition, the above coating layer is formed by coating the inner wall of a chamber for sputtering work in a semiconductor manufacturing process, and for the work efficiency, the specific surface area of ​​the base material is mainly increased through bead blasting or an arc spray coating method is used.

[0009] This arc-spray coating method supplies metal wire, melts it through arc discharge, and then sprays it to attach it to the inner wall of the chamber to coat it. This method can increase the specific surface area and improve the ability to capture process by-products.

[0010] The above arc spray coating method is inexpensive and easier to control the process than other spray coatings, but the arc spray coating film is a different material from the target material of the semiconductor process (Ti, Ta, W, etc.), so when the initial process by-products are deposited, the material properties are different, which hinders the uniform growth of the initial process by-products and causes the occurrence of structural defects such as Hill-Lock. Although it does not cause a major problem in the initial semiconductor process, it induces asymmetrical growth and non-uniform growth of the process by-products in the later stages of the process, which shortens the maintenance and management cycle of the parts in the chamber, causing a problem of a decrease in the yield of semiconductor production.

[0011] Next, we will briefly describe prior art existing in the field to which the technology of the present invention belongs, and then explain the technical aspects that the present invention seeks to achieve differently.

[0012] Korean Patent Publication No. 10-2021-0106216 (20210830) discloses a coating technology for semiconductor equipment using metal powders that can eliminate or minimize particle generation by reducing the particle source itself on the surface of a coating layer formed on a target object constituting a semiconductor equipment using single or two types of metal powders, improve the process yield according to the coating operation, and improve the deposition efficiency when using semiconductor equipment in processes such as sputtering or PVD for semiconductor manufacturing.

[0013] However, in the coating film manufactured by the above-mentioned prior literature, the uniform growth of the initial process by-products during the PVD process is inhibited due to differences in material properties when deposited, and the problem of occurrence of structural defects still remains. Therefore, a manufacturing technology for a coating film for a chamber for a deposition process is needed to solve these problems.

[0014] Accordingly, the inventor, feeling the limitations of the coating method for such a deposition process chamber, conducted repeated research on a method for manufacturing a coating film that can solve the problem of structural defects by inhibiting the uneven growth of PVD process by-products, and as a result, arrived at the present invention.

[0015] The main purpose of the present invention is to provide a coating method for a chamber for a deposition process that can solve the problem of a decrease in yield in semiconductor production when the maintenance and management cycle of components within the chamber is shortened by inducing asymmetric growth and non-uniform growth of process by-products.

[0016] The present invention also provides a member having a coating film formed thereon, manufactured using the coating method of the chamber for the deposition process.

[0017] In order to achieve the above object, one embodiment of the present invention provides a coating method for a chamber for a deposition process, comprising the steps of: (a) performing an arc spraying process using an aluminum wire on a coating object to form a lower coating layer; and (b) performing a physical vapor deposition process of a metal compound powder on the lower coating layer formed in step (a) to form an upper coating layer; wherein the metal compound in step (b) is characterized in that it has the same component as a PVD process byproduct.

[0018] The coating method of a chamber for a deposition process according to the present invention can improve the ability to capture semiconductor process byproducts by increasing the surface roughness of an upper coating layer formed by a physical vapor deposition process by applying a lower coating layer by an arc spraying process using an aluminum wire.

[0019] In addition, the coating film manufactured according to the present invention uses the same components as the PVD process by-products, thereby suppressing non-uniform growth of the process by-product layer and structural defects such as Hill-Lock that occur due to differences in material properties when the initial by-products of the PVD process are deposited.

[0020] Figure 1 is a scanning electron microscope (SEM) photograph of a TiN byproduct deposited at the beginning of the PVD process on a part to which a coating film (Comparative Example 1) manufactured according to an aluminum arc spraying process was applied.

[0021] Figure 2 is a scanning electron microscope (SEM) photograph of a TiN byproduct deposited during / after the PVD process on a part to which a coating film (Comparative Example 1) manufactured according to an aluminum arc spraying process was applied.

[0022] Figure 3 is a scanning electron microscope (SEM) photograph of the side of a coating film (Comparative Example 2) manufactured according to an atmospheric plasma spraying process.

[0023] Figure 4 is a scanning electron microscope (SEM) photograph of the surface of a coating film (Comparative Example 2) manufactured according to an atmospheric plasma spraying process.

[0024] Figure 5 is a scanning electron microscope (SEM) photograph of a TiN byproduct deposited during a PVD process on a component to which a coating film manufactured according to Example 1 was applied.

[0025] Figure 6 is a scanning electron microscope (SEM) photograph of the surface of a TiN byproduct deposited during a PVD process of a component to which a coating film manufactured according to Comparative Example 1 and Example 1 was applied.

[0026] One embodiment of the present invention provides a coating method for a chamber for a deposition process, comprising the steps of: (a) performing an arc spraying process using an aluminum wire on a coating target to form a lower coating layer; and (b) performing a physical vapor deposition process on a metal compound powder on the lower coating layer formed in step (a) to form an upper coating layer; wherein the metal compound in step (b) is characterized in that it has the same component as a PVD process byproduct.

[0027] In a preferred embodiment of the present invention, the diameter of the aluminum wire may be 1 mm to 5 mm.

[0028] In a preferred embodiment of the present invention, the thickness of the lower coating layer may be 0.1 μm to 10 μm.

[0029] In a preferred embodiment of the present invention, the metal compound powder may be any one selected from tungsten (W), titanium (Ti), tantalum (Ta) and nitrides thereof.

[0030] In a preferred embodiment of the present invention, the physical vapor deposition may be any one selected from thermal evaporation, electron beam evaporation, and sputtering.

[0031] In a preferred embodiment of the present invention, the thickness of the upper coating layer may be 0.1 μm to 10 μm.

[0032] In a preferred embodiment of the present invention, the surface roughness of the lower coating layer may be 10 μm to 40 μm.

[0033] In addition, another embodiment of the present invention provides a coating film manufactured by the coating method of the chamber for the deposition process.

[0034] In a preferred embodiment of the present invention, the porosity of the upper coating layer in the coating film may be 0.01 vol% to 1 vol%.

[0035] In a preferred embodiment of the present invention, the hardness of the coating film may be 700 Hv or more.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In general, the nomenclature used herein is well known and commonly used in the art.

[0037] Throughout this specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0038] The arc spray coating method for forming a coating layer in semiconductor process components is inexpensive and easier to control in the process than other spray coatings. However, the arc spray coating film is a heterogeneous material with the target material of the semiconductor process (Ti, Ta, W, etc.), and when the initial process by-product is deposited, the material properties are different, which hinders the uniform growth of the initial process by-product, and causes the occurrence of structural defects such as Hill-Lock, which causes problems of asymmetric growth and uneven growth of the process by-product.

[0039] In order to overcome these problems, the present invention provides a method for manufacturing a coating film applicable to a chamber for a deposition process, which forms a dense PVD thin film as an upper coating layer using a material similar to a material (Ti, Ta, W, etc.) that is a target of a semiconductor process, and forms a lower coating layer using an arc spraying process to increase the surface roughness of the upper coating layer, thereby improving the ability to capture semiconductor process byproducts.

[0040] In one aspect of the present invention, a coating method for a chamber for a deposition process comprises the steps of (a) performing an arc spraying process using an aluminum wire on a coating object to form a lower coating layer; and (b) performing a physical vapor deposition process on a metal compound powder on the lower coating layer formed in step (a) to form an upper coating layer; wherein the metal compound in step (b) is characterized in that it has the same component as a PVD process byproduct.

[0041] First, the coating method of the chamber for the deposition process according to the present invention forms a lower coating layer by performing an arc spraying process using an aluminum wire on the coating target. [Step (a)]

[0042] The coating target object on which the lower coating layer is formed may be a plasma device component such as an electrostatic chuck, a heater, a chamber liner, a shower head for CVD & MOCVD, a shield for PVD, a cover ring, a depo ring, a shutter disk, etc. applied inside the plasma device, and the material of the coating target object may be, but is not limited to, a metal such as iron, titanium, aluminum, magnesium, chromium, an alloy thereof, a ceramic such as Al2O3, Y2O3, SiO2, Si, etc.; a polymer such as polyethylene terephthalate, polyethylene naphthalate, polypropylene adipate, polyisocyanate, etc.

[0043] At this time, the arc spraying process uses two metal wires (spraying materials) as a (+) electrode and a (-) electrode, generates arc heat, and blows the tip of the metal wire melted by the arc heat with compressed air toward the material surface to form a coating in an impact lamination manner, so that the work of forming a metal film can be carried out simply and quickly.

[0044] In one embodiment, the diameter of the aluminum wire may be 1 mm to 4 mm.

[0045] Here, in order to form the lower coating layer, it is preferable to supply aluminum so that it melts at a capacity of 1 g / s to 20 g / s, the arc voltage for arc discharge is preferably 25 V to 35 V, the arc current is preferably 100 A to 350 A, the gas is preferably compressed air, but is supplied under a pressure condition of 1 kgf / ㎠ to 8 kgf / ㎠, and the spray distance is preferably maintained at 50 mm to 250 mm.

[0046] At this time, in order to prevent the brittleness from being reduced due to the formation of aluminum (Al) oxide, compressed air is used in the present invention, but it is preferable to supply it under a pressure condition of 1 kgf / ㎠ to 8 kgf / ㎠, and to maintain the spray distance of aluminum at 50 mm to 250 mm from the coating target.

[0047] Here, when controlling the injection of compressed air, if it is supplied at less than 1 kgf / ㎠, the adhesive strength of the coating layer is poor and the size of the injected molten particles is large, so many pores are formed, which causes a problem of reduced durability. If it exceeds 8 kgf / ㎠, the collision energy of the molten particles increases, so the molten particles are destroyed, resulting in poor adhesiveness and the occurrence of micro-cracks within the coating layer. In addition, there is a limitation on the formation of a roughness (Ra) of 40 ㎛ or more.

[0048] Here, when controlling the spray distance of aluminum, if it is less than 50 mm, the surface of the molten particles is overheated and oxidized, and the collision energy of the molten particles increases, so the molten particles are destroyed, the adhesion is poor, and many pores are formed, which causes problems such as lowering the overall durability, such as brittleness. If it exceeds 250 mm, the surface temperature and spray speed of the molten particles decrease, so the contact angle increases, resulting in poor spreadability and difficulty in forming a dense structure. In addition, because it is excessively exposed to the air, there is also a problem in that many pores and oxides are created in the coating layer.

[0049] By using aluminum wire in the above arc spraying process, the adhesion of the lower coating layer is excellent, and the surface roughness of the lower coating layer can be manufactured in the range of 10 ㎛ to 40 ㎛.

[0050] The above lower coating layer can be formed to have a coating thickness in the range of approximately 30 ㎛ to 300 ㎛ on the outer surface of the coating target by an arc spraying process.

[0051] If the lower coating layer is thinner than the above-mentioned coating thickness range, it will be difficult to form a metal coating layer with an irregular surface when the aluminum raw material is fused to the outer surface of the coating target by arc spray coating. Furthermore, if it is thicker than the upper limit of the above-mentioned coating thickness, not only will the material cost be excessive, but the volume and weight of the coating target may also become abnormally large.

[0052] Afterwards, a physical vapor deposition process is performed on the lower coating layer formed in step (a) to form an upper coating layer. [Step (b)]

[0053] The upper coating layer uses a material similar to the target material of the semiconductor process (Ti, Ta, W, etc.), thereby improving the ability to capture process byproducts when applied to semiconductor equipment parts, thereby increasing the maintenance and management cycle of parts within the chamber and improving the yield of semiconductor production.

[0054] The metal compound powder used in the physical vapor deposition process of step (b) above may be any one selected from tungsten (W), titanium (Ti), tantalum (Ta), and their nitrides and oxides, but is not limited thereto.

[0055] The upper coating layer can be applied without limitation to a physical vapor deposition method for forming a coating layer that satisfies requirements such as strong bonding force and corrosion resistance between the lower coating layers, and specifically, the physical vapor deposition method can be any one selected from a thermal vapor deposition method, an electron beam evaporation method, and a sputtering method, and preferably, a sputtering method.

[0056] In one embodiment, the thickness of the upper coating layer is preferably 0.1 µm to 10 µm. If the thickness of the upper coating layer is less than 0.1 µm, the thickness may be too thin, which may reduce the bonding strength with the process by-products. If the thickness of the upper coating layer exceeds 10 µm, an economic loss may occur due to excessive use of metal compounds compared to the expected effect.

[0057] The surface roughness of the upper coating layer has a similar value to the surface roughness of the lower coating layer, and can be specifically manufactured in the range of 1 µm to 40 µm.

[0058] As the porosity of the upper coating layer increases, the mechanical strength of the ultimately formed coating film decreases, which is a problem. Therefore, the upper coating layer including the metal compound is preferably dense and has a low porosity to ensure the mechanical strength of the coating film.

[0059] In addition, the present invention provides a coating film manufactured by the coating method of the chamber for the deposition process, wherein the coating film has low porosity and exhibits improved physical strength.

[0060] In one embodiment, the pore content of the upper coating layer within the coating film may be less than 10 vol%, and preferably may be 0.01 vol% to 10 vol%.

[0061] In one embodiment, the hardness of the coating film may be 500 Hv or more depending on the material to be coated.

[0062] Hereinafter, the present invention will be described in more detail through examples. However, the following examples are intended only to illustrate the present invention and are not intended to limit the present invention.

[0063] [Comparative Example 1]

[0064] First, a bead blast process is performed on metal base materials such as Al, SUS, and Ti, and ceramic base materials such as Al2O3, and the carrier gas for Al arc coating uses CDA or the inert gas Ar. The voltage ranges from 25 V to 35 V, and the arc current is sprayed in the range of 100 A to 350 A. The coating time is adjusted so that the thickness of the final coating layer is 30 μm to 300 μm, and the coating is performed.

[0065] Scanning electron microscope (SEM) images of by-products deposited at the beginning of the PVD process in a part to which the Al arc coating film manufactured in Comparative Example 1 was applied are shown in FIGS. 1 and 2, and as a result, it was confirmed that a TiN by-product layer grew unevenly on the surface.

[0066] [Comparative Example 2]

[0067] In the above comparative example 1, an Al thin film was manufactured as a lower coating layer using the same method as the Arc coating.

[0068] Next, as the upper coating layer, a titanium powder having a size of 40 ㎛ to 160 ㎛ was used, and argon and hydrogen gases were flowed as heat source gases using a plasma gun to move the melting gun, thereby generating plasma at a power of 20 kW, and using the generated plasma, the raw material powder was melted to form a coating film on the base material at a speed of 20 g / min. The thickness of the coating film was formed to have a thickness of 30 ㎛ to 70 ㎛.

[0069] Scanning electron microscope (SEM) images of the Ti coating film manufactured in Comparative Example 2 are shown in FIGS. 3 and 4, and as a result, it was confirmed that a large number of structural defects such as cracks occurred in the Ti coating film.

[0070] [Example 1]

[0071] In the above comparative example 1, an Al thin film was manufactured as a lower coating layer using the same method as the Arc coating.

[0072] The base material on which the lower coating layer is formed and the raw material titanium (Ti) are placed in the coating chamber and a high vacuum atmosphere is maintained.

[0073] When the chamber reaches high vacuum, titanium (Ti) is deposited on the Al Arc coating.

[0074] Scanning electron microscope (SEM) images of by-products deposited at the beginning of the PVD process on a component to which the Ti coating film manufactured in Example 1 was applied are shown in FIGS. 5 and 6, and as a result, it was confirmed that a TiN by-product layer grew uniformly on the surface.

[0075] Classification Comparative Example 2 Example 1 Lower layer coating method Al Arc Coating Al Arc Coating Upper layer coating method APS Coating - Ti PVD Coating - Ti Substrate Bead Bead (Bead Sample Sa: 5.603㎛) Surface Roughness (Sa) 11.333㎛ 5.436㎛ Skewness (Ssk*) 0.242-0.175 Kurtosis (Sku**) 5 23.89 5 3.522 Hardness 3.8 HV 7 22.4 HVArea 192.92㎜ 2 32.75mm 2 Thickness36.86㎛448.5㎚Porosity4.41%0.07%

[0076] * Ssk ≒ 0, Peak height distribution is similar to normal distribution

[0077] ** Sku ≒ 3, peak shape is similar to normal distribution

[0078] As shown in Table 1 above, it was confirmed that the strength of the film formed through the PVD process (Example 1) was superior to that of the film formed through the APS spraying method (Comparative Example 1) and that the porosity was lower.

[0079] Meanwhile, as illustrated in FIG. 6 below, Example 1, a coating film manufactured according to the present invention, was confirmed to suppress non-uniform growth of a process by-product layer and structural defects such as Hill-Lock, compared to Comparative Example 2, a coating film formed by a conventional aluminum arc process.

[0080] While specific aspects of the present invention have been described in detail above, it will be apparent to those skilled in the art that these specific descriptions merely represent preferred embodiments and are not intended to limit the scope of the present invention. Therefore, the substantial scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. (a) a step of performing an arc spraying process using an aluminum wire on a coating target to form a lower coating layer; and (b) a step of forming an upper coating layer by performing a physical vapor deposition process on a metal compound powder on the lower coating layer formed in the step (a); A coating method for a chamber for a deposition process, characterized in that the metal compound in the above step (b) is the same component as a PVD process byproduct.

2. In paragraph 1, A coating method for a chamber for a deposition process, characterized in that the diameter of the aluminum wire is 1 mm to 5 mm.

3. In paragraph 1, A coating method for a chamber for a deposition process, characterized in that the thickness of the lower coating layer is 0.1 ㎛ to 10 ㎛.

4. In paragraph 1, A coating method for a chamber for a deposition process, characterized in that the metal compound powder is any one selected from among tungsten (W), titanium (Ti), tantalum (Ta) and their nitrides.

5. In paragraph 1, A coating method for a chamber for a deposition process, characterized in that the above physical vapor deposition is any one selected from thermal vapor deposition, electron beam evaporation, and sputtering.

6. In paragraph 1, A coating method for a chamber for a deposition process, characterized in that the thickness of the upper coating layer is 0.1 ㎛ to 10 ㎛.

7. In paragraph 1, A coating method for a chamber for a deposition process, characterized in that the surface roughness of the lower coating layer is 10 ㎛ to 40 ㎛.

8. A coating film manufactured by a coating method of a chamber for a deposition process among any one of claims 1 to 7.

9. In paragraph 8, A coating film characterized in that the porosity of the upper coating layer within the coating film is 0.01 vol% to 1 vol%.

10. In paragraph 8, A coating film characterized in that the hardness of the coating film is 700 Hv or more.

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