JP5206199B2 - Vacuum device parts and manufacturing method thereof - Google Patents

Description

  The present invention relates to a vacuum apparatus component used in a vacuum apparatus such as a film forming apparatus or a plasma processing apparatus (plasma etching apparatus) in the manufacture of a semiconductor or the like. The vacuum device component of the present invention prevents dust generation due to peeling of a film-like substance adhering to a component in the device during film formation and plasma processing.

  When a film formation process or plasma process is performed on a product substrate such as a semiconductor, particles resulting from the material used for the process adhere to and deposit on the surface of the component installed inside the apparatus, and the film-like substance Form. It is known that when film formation and plasma treatment are continuously performed in such a state, the attached film-like substances become thick and eventually peel off to generate dust in the apparatus and contaminate the apparatus and the product substrate. It has been.

  As a technique for reducing dust generation due to peeling of the film-like substance, there have been a plurality of reports, for example, forming a plasma sprayed film on an internal exposed surface in a chamber of a vacuum apparatus (for example, see Patent Document 1). ), A material having a coefficient of thermal expansion equal to or close to the coefficient of thermal expansion of the film-like substance deposited on the surface part is used as the material of the surface part of the component disposed in the film forming chamber of the vacuum apparatus (for example, As a component of a vacuum apparatus), the surface of the local mountain peaks defined by JISB0601-1994 is within a range of 50 to 150 μm, and the maximum valley depth Rv and the maximum mountain height Rp are 20 respectively. It is known to form a sprayed film having a surface roughness in the range of ˜70 μm (see, for example, Patent Document 3).

Japanese Patent Laid-Open No. 60-120515 (Claims) Japanese Patent Laid-Open No. 03-87358 (Claims) JP 2001-247957 A (Claims)

  In parts used in vacuum devices, there has always been a demand from the market for a technique that can further improve the adhesion of a film-like substance and can continuously perform a film forming process or a plasma process for a longer time.

  In particular, in the formation of nitride films such as TiN, TaN, WN, etc., as the required performance of semiconductor products increases, it is required to form a sputtered film in a fine groove. Has been devised to increase As a result, the stress of the nitride film also increases, and the film-like substance is more easily peeled off. In addition, as the film formation time increases, the film thickness deposited on the surface of the vacuum device component also increases, but abnormally grown particles of the nitride film are generated on the sprayed film formed on the surface of the vacuum device component, and the abnormally grown particles Has fallen from the sprayed film and particles are generated, which has been found to lead to a reduction in the life of vacuum device parts.

  Furthermore, in the film forming process of a barrier material of a metal such as Ta / TaN, a member sprayed with Al or Ti is used as a shielding member in order to increase the adhesion effect of the film-like substance, and the temperature of the shielding member is particularly high. In this case, a shield member subjected to Ti spraying having excellent heat resistance is widely used.

  When Ti is sprayed on the shield in the atmosphere, the Ti material is easily nitrided during spraying to become TiN. Since TiN has properties as a ceramic, it becomes harder than metal Ti and it is difficult to relieve stress of the film-like substance. For this reason, in order to prevent the nitriding reaction of Ti, generally, low-pressure plasma spraying or a cold spray method in which the atmosphere during spraying is set to an inert reduced pressure state is used. However, the low pressure plasma spraying can suppress the nitriding of the sprayed film, but the cost becomes high because the apparatus becomes large. In the cold spray method, the temperature of the sprayed powder is difficult to increase, and since the melting point of Ti is high, the powder is difficult to melt and it is difficult to obtain a film with good adhesion.

  Therefore, the present invention is a vacuum apparatus component used in a film processing apparatus or a plasma processing apparatus for a product substrate such as a semiconductor, and has a high adhesion of a film-like substance, and does not drop off particles due to abnormal growth, and continues for a long time. A vacuum device component that provides excellent components that can be used, solves the problem of reducing the life of conventional shield members, and makes it easier to manufacture a sprayed film that suppresses the nitriding reaction of Ti. It is to provide.

As a result of intensive studies in view of the above-described present situation, the present inventor has formed a thermal spray film substantially composed of Ti and a nitride of Ti (TiN _x ) on a base material. The arithmetic average roughness Ra of the sprayed film is in the range of 15 to 30 μm, and the X-ray diffraction intensity of Ti (101) and TiN _X (112) (X = 0.61) in the sprayed film is It has been found that the adhesion of a film-like substance to be deposited is more excellent than the conventional one in a vacuum apparatus component characterized in that the ratio I (I _TiN / I _Ti ) is in the range of 0.05 to 0.3. The present invention has been completed.

  Hereinafter, the present invention will be described in detail.

The present invention is a component for a vacuum apparatus in which a sprayed coating substantially composed of Ti and Ti nitride (TiN _x ) is formed on a substrate, and the arithmetic average roughness Ra of the sprayed coating is 15 to 15 The ratio I (I _TiN / I _Ti ) of the X-ray diffraction intensity between Ti (101) and TiNx (112) (X = 0.61) in the sprayed film is 0.05-0. The present invention relates to a vacuum device component characterized by being in the range of 3.

In the present invention, the meaning of “a sprayed film substantially composed of Ti and Ti nitride (TiN _x )” means that Ti powder is deposited on a substrate at the time of spraying, and a part of Ti Is deposited in the form of TiN _X by causing a nitriding reaction with nitrogen in the atmosphere, and the structure of the sprayed film is composed of Ti and TiN _X and contains inevitable impurities in the Ti powder.

In the sprayed film of the present invention, the (101) plane of Ti is observed at a position of 2θ: 40.2 degrees in X-ray diffraction measurement using Cu—Kα rays, and TiNx (x = 0.0). The (112) plane of 61) is observed at a position of 2θ: 36.8 degrees. The ratio of these X-ray diffraction intensity _{I (I} TiN _{/ I Ti)} is intended to be 0.05 to 0.3. When the ratio I of the X-ray diffraction intensity exceeds 0.3, the sprayed film becomes hard and it becomes difficult to relieve the stress of the deposited film-like substance, so that the deposited film is easily peeled off. On the other hand, when I is smaller than 0.05, the sprayed film is preferable as a sprayed film because it has almost metallic properties. However, it is practically difficult to reduce the degree of nitriding of Ti by atmospheric plasma spraying. is there. When economical spraying conditions are considered, the range of 0.1 to 0.2 is more preferable.

In the thermal sprayed film of the present invention, titanium nitride is considered to have various compositions. The reason why TiN _0.61 was selected for the definition of the thermal sprayed film is the (112) plane of TiN _0.61. This is because the ratio I with the X-ray diffraction intensity of the Ti (101) plane can be obtained with good reproducibility in relation to the position where the diffraction angle appears, its diffraction intensity, and the like.

  The arithmetic average roughness Ra as used in the present invention is Ra defined by JISB0601: 2001 and JISB0633: 2001. The Ra value in the sprayed coating of the present invention is 15 to 30 μm. When Ra is smaller than 15 μm, the nitride particles grown on the sprayed film become small, and the retention of the film-like substance on the sprayed film decreases. On the other hand, when Ra is larger than 30 μm, the nitride particles growing on the sprayed film become too large, and the coarse particles fall off, causing generation of particles. A preferable value of Ra is 18 to 25 μm. Ra can be measured based on the above-mentioned JISB0601: 2001 and JISB0633: 2001 using, for example, a surface roughness measuring instrument manufactured by Mitutoyo Corporation, trade name “SV-3100” and the like.

  The sprayed coating in the present invention is formed so as to cover at least a portion where a film-like substance may adhere to a plasma processing apparatus such as a shield or a sputtering target among vacuum device parts. do it. Although it does not specifically limit as a film thickness, It is preferable that it is 50-1000 micrometers, and it is more preferable that it is 100-400 micrometers.

  As the base material in the present invention, any materials such as general glass, quartz glass, metals such as aluminum, stainless steel and titanium, ceramics such as alumina, zirconia and mullite can be used. The sprayed film and the substrate may be made of the same material, but may be made of different materials. An undercoat layer may be provided on the base material so that the sprayed powder is well melted on the base material and a sprayed film is easily formed uniformly. The type, material, and film thickness of the substrate are not particularly limited. For example, a material of the same material as the base material is formed by changing the spraying conditions or the sprayed powder by plasma spraying, or sputtering a Ni-Cr alloy layer. Alternatively, the film may be formed by a method such as electroplating.

  Next, an example of a method for manufacturing a vacuum device component according to the present invention will be described in detail.

  The titanium raw material powder used for thermal spraying preferably has an average particle size (primary particle size) of 50 to 100 μm, and more preferably 60 to 80 μm. Furthermore, as the particle size distribution of the powder, 90 wt% or more is preferably in the range of 30 to 120 μm, and 95 wt% or more is more preferably in the range of 40 to 100 μm. The purity of the titanium powder is preferably 99 wt% or more.

  When the average particle size is less than 50 μm, the powder tends to be easily nitrided, and when the average particle size exceeds 100 μm, the sprayed powder is difficult to melt during spraying and the deposition efficiency of the sprayed film is reduced. There is. By using the sprayed powder having such an average particle size and particle size distribution, the nitriding reaction of the Ti sprayed film can be further suppressed, and the sprayed film can be efficiently produced. It is preferable that the powder has a spherical shape or an almost spherical shape. By using the spherical powder, the specific surface area of the powder decreases, so that the nitriding reaction does not proceed easily.

  A gas atomized powder can be illustrated as such a spherical powder. This gas atomized powder is a powder obtained by melting a raw material, pulverizing the molten metal with a spray gas, and solidifying the gas, and the gas atomized titanium powder is already commercially available. The particle size distribution of the powder can be measured using a laser particle size distribution measuring device manufactured by COULTER, trade name “COULTER LS” or the like.

  As a thermal spraying method, plasma spraying at atmospheric pressure can be exemplified. In order to prevent the nitriding reaction of the Ti powder, it is preferable to use a mixed gas in which the primary gas is argon and the secondary gas is helium as the plasma gas. At this time, the flow rate of the plasma gas varies depending on the apparatus to be used, but is set to 80 L / min or more, preferably 100 L / min or more in order to suppress an increase in plasma temperature. The ratio of helium gas in the mixed gas is preferably 20 to 50%, more preferably 30 to 40% with respect to the total flow rate. The reason for mixing helium is that the speed of the plasma flame can be increased and the nitriding reaction of Ti powder can be suppressed.

  When plasma spraying Ti powder, it is preferable to perform thermal spraying by controlling the temperature of the base material to be 100 to 200 ° C. When the substrate temperature exceeds 200 ° C., the nitriding reaction of the Ti powder is promoted, and the substrate may be discolored due to heat. When the substrate temperature is lower than 100 ° C., the deposition efficiency of the Ti powder may be lowered because the substrate temperature is low. A more preferable substrate temperature is in the range of 120 to 180 ° C. The method for controlling the substrate temperature is not particularly limited, and examples thereof include a method using natural cooling, compressed air, and a water cooling jig. Further, the substrate temperature during thermal spraying can be exemplified by a method in which a thermocouple is contacted to the substrate, or a non-contact method using a radiation thermometer.

  The vacuum apparatus component obtained by the present invention may be dried by further performing ultrasonic cleaning using ultrapure water after forming a sprayed film.

  The vacuum device component of the present invention is particularly superior in adhesion of a film-like substance generated at the time of forming a nitride film as compared with conventional components, so when used in a nitride film forming device or a plasma processing device, There is no product contamination due to dust generation due to exfoliation of film-like substances or particles due to abnormally grown particles, and it can be used continuously for a long time.

  The present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Example 1
After blasting the inner surface of the stainless steel bowl-shaped shield using GA # 150 made of gray alumina at a pressure of 0.5 MPa, the flow rate ratio (volume ratio) of Ar and He is 70:30 on the inner surface of the shield. Was 100 L / min, the distance between the plasma gun and the shield inner surface was 100 mm, the input power was 24 kW, and a titanium sprayed film was formed by atmospheric pressure plasma spraying. The substrate temperature during spraying was controlled at 150 ° C. with compressed air. As the thermal spray powder, a gas atomized titanium spherical powder (purity: 99.7 wt%) having an average particle diameter of 75 μm and 98 wt% of the powder in the range of 40 to 100 μm was used. After spraying, it was ultrasonically cleaned with ultrapure water and dried in a clean oven to complete the shield.

_I TiN _{/ I Ti} ratio of the sprayed film measured by X-ray diffraction apparatus is 0.15, JISB0601: 2001 and JISB0633: Ra measured based on the 2001 was 22 .mu.m.

  The bowl-shaped shield manufactured by the method described above was used by attaching it to a sputtering apparatus for TaN film formation. The substrate temperature during sputtering film formation was controlled to 450 ° C., and the chamber pressure was set to 0.1 Pa. After 240 hours had passed since the start of use, the inside of the apparatus was confirmed. As a result, peeling of TaN film-like substance and abnormally grown particles of nitride were not observed.

Example 2
The stainless steel bowl-shaped shield inner surface is blasted using gray alumina GA # 100 at a pressure of 0.5 MPa, and then the Ar and He flow ratio (volume ratio) is 80:20 on the inner surface of the shield, total gas flow rate Was 85 L / min, the distance between the plasma gun and the shield inner surface was 100 mm, the input power was 28 kW, and a titanium sprayed film was formed by atmospheric pressure plasma spraying. The substrate temperature during spraying was controlled at 200 ° C. As the thermal spray powder, a gas atomized titanium spherical powder (purity: 99.7 wt%) having an average particle diameter of 65 μm and 95 wt% of the powder in the range of 40 to 100 μm was used. After spraying, it was ultrasonically cleaned with ultrapure water and dried in a clean oven to complete the shield.

_I TiN _{/ I Ti} ratio of the sprayed film measured by X-ray diffraction apparatus is 0.20, JISB0601: 2001 and JISB0633: Ra measured based on the 2001 was 16 [mu] m.

  The bowl-shaped shield manufactured by the method described above was attached to the same apparatus as in Example 1 and used under the same sputtering conditions. After 200 hours had passed since the start of use, the inside of the apparatus was confirmed. As a result, peeling of TaN film-like substance and abnormally grown particles of nitride were not observed.

Example 3
In Example 1, the flow ratio (volume ratio) of Ar and He as the thermal spray gas is 60:40, the total gas flow rate is 150 L / min, the input power is 32 kW, the thermal spray powder has an average particle size of 90 μm, and 99 wt% of the powder. Was formed by plasma spraying under the same conditions as in Example 1 except that a gas atomized titanium spherical powder (purity: 99.7 wt%) in the range of 40 to 100 μm was used.

_I TiN _{/ I Ti} ratio of the sprayed film measured by X-ray diffraction apparatus is 0.11, JISB0601: 2001 and JISB0633: Ra measured based on the 2001 was 25 [mu] m.

  The bowl-shaped shield manufactured by the method described above was attached to the same apparatus as in Example 1 and used under the same sputtering conditions. When 280 hours passed from the start of use, the inside of the apparatus was confirmed, and peeling of TaN film-like substance and abnormally grown nitride particles were not observed.

Comparative Example 1
In Example 1, plasma spraying was performed under the same conditions as in Example 1 except that the flow ratio of Ar and H ₂ was 95: 5, the total gas flow rate was 65 L / min, and the input power was 26 kW as the spraying gas. A titanium sprayed film was formed.

_I TiN _{/ I Ti} ratio of the sprayed film measured by X-ray diffraction apparatus is 0.34, JISB0601: 2001 and JISB0633: Ra measured based on the 2001 was 13 .mu.m.

  The bowl-shaped shield manufactured by the method described above was used by attaching it to a sputtering apparatus for TaN film formation. The substrate temperature during sputtering film formation was controlled to 450 ° C., and the chamber pressure was set to 0.1 Pa. When 200 hours passed from the start of use and the inside of the apparatus was checked, it was observed that the TaN film-like substance was peeled off.

Comparative Example 2
In Example 1, the same conditions as in Example 1 were used except that a bulk titanium powder (purity: 99.5 wt%) having an average particle diameter of 70 μm and having no spherical shape was used as the thermal spray powder. A titanium sprayed film was formed by plasma spraying.

_I TiN _{/ I Ti} ratio of the sprayed film measured by X-ray diffraction apparatus is 0.4, JISB0601: 2001 and JISB0633: Ra measured based on the 2001 was 14 [mu] m.

  The bowl-shaped shield manufactured by the method described above was used by attaching it to a sputtering apparatus for TaN film formation. The substrate temperature during sputtering film formation was controlled to 450 ° C., and the chamber pressure was set to 0.1 Pa. After 140 hours had elapsed from the start of use, the inside of the apparatus was confirmed, and it was observed that the TaN film-like substance was peeled off.

Comparative Example 3
The stainless steel bowl-shaped shield inner surface was blasted using gray alumina GA # 150 at a pressure of 0.5 MPa, and then the Ar and He flow ratio was 70:30 and the total gas flow rate was 52 L / min on the inner surface of the shield. A titanium sprayed film was formed by plasma spraying with a distance between the plasma gun and the shield inner surface of 100 mm and an input power of 22 kW. The substrate temperature during thermal spraying was controlled at 180 ° C. by cooling with compressed air. As the thermal spray powder, a gas atomized titanium spherical powder (purity: 99.7 wt%) having an average particle diameter of 25 μm was used. After spraying, it was ultrasonically cleaned with ultrapure water and dried in a clean oven to complete the shield.

_I TiN _{/ I Ti} ratio of the sprayed film measured by X-ray diffraction apparatus is 1.5, JISB0601: 2001 and JISB0633: Ra measured based on the 2001 was 8 [mu] m.

  The bowl-shaped shield manufactured by the method described above was attached to the same apparatus as in Example 1 and used under the same sputtering conditions. After 100 hours had passed since the start of use, the inside of the apparatus was confirmed, and it was observed that the TaN film-like substance was peeled off.

Claims (2)

A component for a vacuum apparatus in which a thermal spray film substantially composed of Ti and Ti nitride (TiN _x ) is formed on a substrate, and the arithmetic average roughness Ra of the thermal spray film is in a range of 15 to 30 μm. And the ratio I (I _TiN / I _Ti ) of the X-ray diffraction intensity of Ti (101) and TiN _X (112) (X = 0.61) in the sprayed film is in the range of 0.05 to 0.3. A vacuum device part characterized by being. Plasma spraying a spherical Ti powder with an average particle size of 50-100 μm on a substrate at atmospheric pressure using Ar—He mixed gas as a spraying gas and a total gas flow rate of 80 L / min or more. The manufacturing method of the components for vacuum devices of Claim 1.