Method for improving falling of deposited film layer on inner surface of pretreatment cavity

Abstract

The invention discloses a method for improving falling of a deposited film layer on the inner surface of a pretreatment cavity, and the method comprises the steps: S1, providing a pretreatment cavity and a to-be-treated silicon wafer placed in the pretreatment cavity, enabling a top cover of the pretreatment cavity to be made of a quartz material, and enabling the surface of the to-be-treated wafer to be sequentially provided with a silicon nitride layer and a metal oxide layer; s2, depositing a nitride material on the inner surface of the top cover to form a layer of nitride film; and S3, preprocessing the wafer to be processed, and depositing generated residues on the nitride film to form a silicon nitride deposition film layer and a metal deposition film layer. According to the invention, a layer of nitride film is deposited on the inner surface of the top cover of the pretreatment cavity, so that the adsorbability of the top cover to silicon nitride and a metal deposition film layer is improved, and pollution to a wafer due to stripping of the deposition film layer is avoided, so that the frequency of preventive maintenance of the pretreatment cavity is reduced, the normal operation time of equipment is prolonged, and the maintenance cost is reduced.

Description

Technical Field

[0001] The invention relates to the field of semiconductor manufacturing, and in particular to a method for improving the shedding of a deposited film layer on the inner surface of a pretreatment chamber. Background Art

[0002] In the semiconductor metal sputtering film process, the wafer surface needs to be pre-treated before sputtering. Argon sputtering is usually used to physically etch the wafer surface to remove the oxide layer on the wafer surface. However, the residual material etched by argon will be deposited on the accessories inside the chamber. The top cover of the pretreatment chamber in the conventional chamber internal accessories is made of quartz material with a surface roughness of 50 to 70um. Most of the etching residues will be deposited on the top cover of the pretreatment chamber. After multiple cumulative depositions, the deposits on the top cover reach a certain thickness, begin to crack and peel off, and cause pollution to the wafer surface. Therefore, the adsorption performance of the top cover is very important to the chamber environment. Conventional quartz material top covers have good adsorption to silicon oxide films, but poor adsorption to silicon nitride films and metals. When the deposits are silicon nitride and metals, cracking and peeling are prone to occur, which pollutes the wafer. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a method for improving the shedding of deposited film layers on the inner surface of a pretreatment chamber, by depositing a layer of nitride film on the inner surface of a top cover of the pretreatment chamber to improve the adsorption of the top cover to silicon nitride and metal deposited film layers.

[0004] A technical solution adopted by the present invention is: a method for improving the shedding of a deposited film layer on the inner surface of a pretreatment chamber, comprising:

[0005] S1. Provide a pretreatment chamber and a silicon wafer to be processed placed in the pretreatment chamber, wherein the top cover of the pretreatment chamber is made of quartz material, and the surface of the wafer to be processed is sequentially provided with a silicon nitride layer and a metal oxide layer;

[0006] S2, depositing a nitride material on the inner surface of the top cover to form a nitride film;

[0007] S3, pre-processing the wafer to be processed, and the generated residue is deposited on the nitride film to form a silicon nitride deposition film layer and a metal deposition film layer.

[0008] Conventional quartz material top covers have good adsorption to silicon oxide films, but poor adsorption to silicon nitride films and metals. When the deposits are silicon nitride and metals, cracking and peeling are prone to occur, thereby contaminating the wafer. The present invention deposits nitride material on the inner surface of the top cover. The nitride material has better adsorption to silicon nitride and metal deposited film layers than conventional quartz materials, thereby reducing the risk of silicon nitride and metal deposits falling and contaminating the wafer.

[0009] In step S2, the nitride material is a nitride ceramic material. Preferably, the nitride material is a nitride ceramic material, such as silicon nitride, aluminum nitride or boron nitride.

[0010] The nitride ceramic material is aluminum nitride, and the nitride film is an aluminum nitride film. Preferably, the nitride ceramic material is aluminum nitride, that is, an aluminum nitride material is deposited on the inner surface of the top cover to form a layer of aluminum nitride film. On the one hand, compared with some nitride ceramic materials such as silicon nitride materials, aluminum nitride has better adhesion on the quartz top cover, and the formed aluminum nitride film is not easy to fall off from the top cover. On the other hand, the adsorption of aluminum nitride film to silicon nitride deposited film layer and metal deposited film layer is better than that of conventional quartz materials, thereby reducing the risk of silicon nitride and metal deposits falling and contaminating the wafer.

[0011] The surface roughness Ra of the nitride film is 50-100 um. When the surface roughness is less than 50 um or greater than 100 um, the top cover has a poor adsorption effect on the silicon nitride and metal deposition film layers, and the possibility of the silicon nitride and metal deposition film layers falling off increases.

[0012] The thickness of the nitride film is 100-200 um.

[0013] In step S3, the metal deposited film layer is vanadium oxide, and the silicon nitride deposited film layer is located between the nitride film and the metal deposited film layer.

[0014] In step S3, the pretreatment process uses physical sputtering and etching to process the silicon nitride layer and the metal oxide layer.

[0015] The radio frequency power used is 200-300 W, the gas flow rate of the introduced argon gas is 10-30 sccm, and the radio frequency time is 10-30 s.

[0016] The method further includes step S4, wherein when the total energy consumed by the radio frequency system exceeds 20 KWh, the nitride film, the silicon nitride deposited film layer and the metal deposited film layer are removed by sandblasting. When the total energy consumed by the radio frequency system exceeds 20 KWh, the adsorption capacity of the nitride film to the silicon nitride and metal deposited film layers becomes weak, and it is necessary to completely remove the nitride film and deposits on the top cover, and re-deposit the nitride material on the inner surface of the top cover.

[0017] The beneficial effects of the present invention are:

[0018] The present invention provides a method for improving the shedding of deposited film layers on the inner surface of a pretreatment chamber. By depositing a layer of nitride film on the inner surface of a top cover of the pretreatment chamber, the adsorption of the top cover to silicon nitride and metal deposited film layers is improved, and contamination of wafers due to the shedding of silicon nitride and metal deposited film layers is avoided, thereby reducing the frequency of preventive maintenance of the pretreatment chamber, improving the normal operation time of the equipment and reducing maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a flow chart of a method for improving the shedding of a deposited film layer on the inner surface of a pretreatment chamber provided by an embodiment of the present invention;

[0021] Figure 2 It is a schematic diagram of the pretreatment chamber top cover and nitride film.

[0022] 1. Top cover; 2. Nitride film. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the present invention clearer, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Examples of these preferred embodiments are illustrated in the accompanying drawings. The embodiments of the present invention shown in the accompanying drawings and described according to the accompanying drawings are merely exemplary, and the present invention is not limited to these embodiments.

[0024] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0025] Example 1

[0026] See also Figure 1 and Figure 2 , an embodiment of the present invention includes: a method for improving the shedding of a deposited film layer on the inner surface of a pretreatment chamber, comprising:

[0027] S1. Provide a pretreatment chamber and a silicon wafer to be processed placed in the pretreatment chamber, wherein a top cover of the pretreatment chamber is made of quartz material, and a surface of the wafer to be processed is sequentially provided with a silicon nitride layer and a metal oxide layer.

[0028] S2. Depositing a nitride material on the inner surface of the top cover to form a nitride film.

[0029] Specifically, a nitride ceramic material is deposited on the inner surface of the top cover 1 of the pretreatment chamber to form a nitride film 2 with a surface roughness Ra of 50 to 100 um and a thickness of 100 to 200 um. In this embodiment, the material of the nitride film 2 is aluminum nitride. In other embodiments, the material of the nitride film 2 can also be other nitride ceramic materials such as silicon nitride or boron nitride. The aluminum nitride in this embodiment is a preferred solution. On the one hand, compared with certain nitride ceramic materials such as silicon nitride materials, aluminum nitride has better adhesion on the quartz top cover, and the formed aluminum nitride film is not easy to fall off from the top cover. On the other hand, the adsorption of the aluminum nitride film to the silicon nitride deposited film layer and the metal deposited film layer is better than that of conventional quartz materials, thereby reducing the risk of silicon nitride and metal deposits falling and contaminating the wafer.

[0030] S3, pre-processing the wafer to be processed, and the generated residue is deposited on the nitride film to form a silicon nitride deposition film layer and a metal deposition film layer.

[0031] Specifically, the silicon nitride layer and the metal oxide layer on the wafer to be processed are processed by a physical sputtering etching process. In this process, the RF power used is 200-300W, the gas flow rate of the argon gas is 10`30sccm, and the RF time is 10-30s. The residue generated is deposited on the nitride film 2 to form a silicon nitride deposition film layer and a metal deposition film layer. The metal deposition film layer is vanadium oxide, and the silicon nitride deposition film layer is located between the nitride film and the metal deposition film layer.

[0032] The technical solution provided in this embodiment also includes step S4: when the total energy consumed by the RF system exceeds 20KWh, the nitride film, the silicon nitride deposited film layer and the metal deposited film layer are removed by sandblasting. When the total energy consumed by the RF system exceeds 20KWh, the adsorption capacity of the nitride film to the silicon nitride and metal deposited film layers becomes weak, and it is necessary to remove all the nitride film and deposits on the top cover, and re-deposit the nitride ceramic material on the inner surface of the top cover.

[0033] Experiments have found that after a layer of aluminum nitride film is deposited on the inner surface of the top cover 1, its adsorption to the deposited film layer is greatly improved, reducing the risk of the deposited film layer peeling off and contaminating the wafer, thereby reducing the frequency of preventive maintenance of the pretreatment chamber, improving the normal operation time of the equipment and reducing maintenance costs.

[0034] In addition, it should be noted that in this specification, "includes", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0035] It should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for improving the shedding of deposited film on the inner surface of a pretreatment chamber, characterized in that: The following steps are involved: S1. Provide a pretreatment chamber and a wafer to be processed placed in the pretreatment chamber, wherein a top cover of the pretreatment chamber is made of quartz material, and a surface of the wafer to be processed is sequentially provided with a silicon nitride layer and a metal oxide layer; S2, depositing a nitride material on the inner surface of the top cover to form a nitride film; S3, pre-processing the wafer to be processed, and the generated residue is deposited on the nitride film to form a silicon nitride deposition film layer and a metal deposition film layer.

2. The method for improving the shedding of the deposited film layer on the inner surface of the pretreatment chamber according to claim 1, characterized in that: In step S2, the nitride material is a nitride ceramic material.

3. The method for improving the shedding of the deposited film layer on the inner surface of the pretreatment chamber according to claim 2, characterized in that: The nitride ceramic material is aluminum nitride, and the nitride film is an aluminum nitride film.

4. The method for improving the shedding of the deposited film layer on the inner surface of the pretreatment chamber according to claim 1, characterized in that: The surface roughness Ra of the nitride film is 50-100 um.

5. The method for improving the shedding of the deposited film layer on the inner surface of the pretreatment chamber according to claim 1, characterized in that: The thickness of the nitride film is 100-200 um.

6. The method for improving the shedding of the deposited film layer on the inner surface of the pretreatment chamber according to claim 1, characterized in that: In step S3, the metal deposited film layer is vanadium oxide, and the silicon nitride deposited film layer is located between the nitride film and the metal deposited film layer.

7. The method for improving the shedding of the deposited film layer on the inner surface of the pretreatment chamber according to claim 1, characterized in that: In step S3, the pretreatment process uses physical sputtering and etching to process the silicon nitride layer and the metal oxide layer.

8. The method for improving the shedding of the deposited film layer on the inner surface of the pretreatment chamber according to claim 6, characterized in that: The radio frequency power used is 200-300 W, the gas flow rate of the introduced argon gas is 10-30 sccm, and the radio frequency time is 10-30 s.

9. The method for improving the shedding of the deposited film layer on the inner surface of the pretreatment chamber according to claim 1, characterized in that: The method further includes step S4, when the total energy consumed by the radio frequency system exceeds 20 KWh, removing the nitride film, the silicon nitride deposited film layer and the metal deposited film layer by sandblasting.

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