JPH07176597A - Manufacture of member producing little dust - Google Patents

Abstract

PURPOSE:To suppress the generation of fine particles, prevent the fine particles from adhering to the surface of a work and, further, prevent the fine particles from scattering around. CONSTITUTION:The surface of a substrate 51 made of aluminum alloy is subjected to an anode oxidation treatment to form an aluminum anode oxide film 52 and, further, a film 53 made of diamond-shaped carbon is formed on the anode oxide film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a low dust-generating member suitable for use in a transport mechanism of an exposure apparatus or an inspection apparatus used in a semiconductor manufacturing process or the like.

[0002]

2. Description of the Related Art Conventional low dust generation technology is used to suppress the generation and scattering of wear powder (fine surface breakage) due to frictional wear caused by sliding and contact between members in order to suppress the scattering between the members. By applying lubricating oil or coating a hard thin film or solid lubricating film to harden one or both of the members to reduce the coefficient of friction and increase wear resistance, low dust generation effect is realized. Was there. For example, in a wafer holding portion of a semiconductor wafer transfer mechanism, a ceramic member such as alumina is used in a contact portion with the wafer, a member obtained by subjecting aluminum to anodizing treatment, a member subjected to coating treatment by painting, and the like.

[0003]

In recent years, line widths of integrated circuits in semiconductor manufacturing have become narrower, and generally 0.5 μm for 16M-bit, 0.35 μm for 64M-bit and 0.25 for 256M-bit.
It is said to be 0.15 μm in μm and 1 G-bit. Along with this, the demand for a cleaner environment for semiconductor manufacturing is also increasing. In particular, contamination of the wafer surface by fine particles (dust) in a semiconductor manufacturing environment has become an important problem such as a deterioration in product yield. Therefore, the semiconductor manufacturing line is generally set in a clean room in which the degree of cleanliness inside is strictly controlled.

However, as described above, the conventional technique is to improve the wear resistance of one or both of the members that come into contact with each other, and does not realize complete no wear. Therefore, fine abrasion powder generated by contact between members adheres to the surfaces of both members or scatters around them, and it is not possible to highly clean the wafer surface and semiconductor manufacturing environment. It was

The present invention suppresses the generation of fine particles, suppresses the adhesion of fine particles to the surface of a work typified by a wafer, and suppresses the scattering of fine particles to the periphery. The purpose is to manufacture a dust member.

[0006]

For the above-mentioned purpose, the first
In the invention (the invention according to claim 1), the surface of a base material made of an aluminum alloy is anodized to form an anodized film of aluminum on the surface, and a film made of diamond-like carbon is formed on the anodized film. By forming a film, a low dust-generating member used in a portion where the workpiece is in sliding contact with a device for processing the workpiece was manufactured. The second invention (claim 2)
In the described invention), a chemical vapor deposition method using plasma was used when forming a film made of diamond-like carbon. In the third invention (the invention according to claim 3), the raw material gas introduced into the film formation space during the chemical vapor deposition method contains methane gas, and the flow rate of the methane gas is 5
The range was set to ~ 200cc / min. In the fourth invention (the invention according to claim 4), in the chemical vapor deposition method, the degree of vacuum during film formation in the film formation space is set within a range of 6.7 to 26.7 Pa.
In the fifth invention (the invention according to claim 5), the plasma in the chemical vapor deposition method is set to be generated in an output range of 0.1 to 1.0 kW. In the sixth invention (the invention according to claim 6), the temperature of the substrate on which the diamond-like carbon film is formed is set to 250 ° C. or lower during the chemical vapor deposition method.

[0007]

In the device that requires low dust generation as described above, each part that comes into contact with a work such as a silicon wafer is
It is necessary to use a member with excellent wear resistance,
It is not preferable that the work wears and the abrasion powder scatters. Also, a material that is worn away by the work is not preferable. That is, the low dust-generating member is required to have a characteristic that the work is not worn and is not worn by the work. In the present specification, such wear characteristics are referred to as “having mutual wear resistance”.

The low dust-generating member obtained by the present invention is used, for example, as the suction part 12 in the transfer line of the semiconductor manufacturing apparatus of FIG. 3, and when the work 13 is transferred, the work 13 slides on the suction part 12 and the like. It is possible to suppress the generation of wear debris even in dynamic contact. Therefore, by providing this low dust-generating member, it is possible to provide a low dust-generating device.

Here, the "low dust generation member" in the present invention
The evaluation method of will be described. First, as shown in FIG. 4, a combination of a substrate 1 made of various materials with a diameter of 50 mm and a spherical pin 2 made of a silicon single crystal material with a diameter of 10 mm was used to perform a pin-on-disc type friction wear test (load 100 gf, friction speed).
(Set to 50 mm / s) and compared the differences in the amount of dust generated. Fine particles (wear particles) generated and scattered due to the abrasion of the substrate 1 or the pin 2 are sucked by the suction nozzle 3 at a suction flow rate of 1 cubic foot per minute, and a laser particle counter (Met-One A249 type) Particle size of 0.1μm
The number of the above fine particles (in this evaluation method, this number was used as the amount of dust generation) was measured. The result is shown in FIG.

As shown in FIG. 5, when the material of the substrate 1 in contact with the pin 2 made of a silicon single crystal is ceramics (for example, alumina or zirconia), the pin 2 made of a silicon single crystal is compared to the ceramic substrate 1. Many of them were scraped off and scattered abrasion powder, showing dust. Further, when the material of the substrate 1 is a silicon wafer or glass, both the substrate 1 and the pin 2 are worn and dust is generated. On the other hand, the substrate 1 is composed of a base material made of an aluminum alloy (for example, JIS A5056), an anodized aluminum film formed on the surface of the base material, and a diamond-like carbon film (hereinafter referred to as DLC) formed on the base film. When it is made of a film), both the substrate 1 and the pin 2 are less worn and exhibit excellent dust generation. However, with the substrate in which the surface of the aluminum alloy was directly coated with the DLC film, the above-described effect of excellent low dusting property was not obtained. Further, even with a substrate in which only an aluminum anodic oxide film is formed on the surface of an aluminum alloy, the effect of excellent dust generation as described above cannot be obtained. From the above evaluation results, it was found that the configuration required as a member having low dust generation is the following two points. The first point is derived from the above result, and is that the DLC film is formed on the outermost surface of the member. The second point is derived from the above result and is that the base on which the DLC film is formed is hard. That is, it is considered that low dusting property was obtained by hardening the surface of the aluminum alloy as the base material by the anodized film of aluminum.

FIG. 1 is a schematic cross-sectional view showing the constitution of the "member having an aluminum alloy having an aluminum anodic oxide film formed on its surface as a base material and having a diamond-like carbon film formed on its surface". As shown in FIG. 1, this member is composed of a base material 51 made of an aluminum alloy, an aluminum anodic oxide film 52 formed on the surface of the base material 51, and a DLC film 53 formed on the oxide film 52. Has been done.

The aluminum anodic oxide coating 52 was formed by treating an aluminum alloy prepared as a base material by a known electrolytic process of electrolytic anodic oxidation. In this treatment, first, an oxalic acid, sulfuric acid, or chromic acid aqueous solution system is used as an electrolytic solution for electrolytic treatment, and immediately after electrolysis, boiling water treatment or superheated steam treatment is performed. The surface of the aluminum alloy is hardened by this anodizing treatment.

As in the second invention, the DLC film 53 has an RF
The film can be formed using a plasma CVD (chemical vapor deposition) method of forming a film in (high frequency) plasma. At this time, as in the third invention, a material gas containing methane gas (for example, a mixed gas of methane and hydrogen) is used,
It is advisable to set the flow rate of the methane gas in the range of 5 to 200 cc / min when introducing the source gas into the film formation space. If the source gas contains hydrogen gas, the flow rate of hydrogen gas should be 200
It should be set to cc / min or less. Further, as in the case of the fourth invention, when the DLC film is formed, the vacuum degree of the film formation space during film formation is set to 6.7 to 26.7 Pa, and better results are obtained. Further, as in the fifth aspect of the invention, the plasma output is set to 0.1 to
Good results were obtained when the range was set to 1.0kW (preferably 0.3kW or more). Further, the temperature of the substrate on which the DLC film is formed may be set in the range of room temperature to 250 ° C. (preferably 150 ° C. or less) as in the sixth invention, in consideration of softening of the aluminum base material. When the substrate is a silicon wafer, the substrate temperature is set to room temperature to 400 ° C., and the higher the temperature in that range, the better the result obtained. When the film forming conditions deviate from these values, the durability of the DLC film deteriorates and dust is easily generated. In addition, the DLC film has a Raman spectroscopic analysis of carbon (Raman shift 1550 cm ⁻¹ ) and diamond (1333).
Comparing the peak ratios in cm ⁻¹ ), it is preferable that the carbon film has a high diamond peak, that is, a strong diamond structure. In addition, when the densities of the coatings are compared by using small angle X-ray scattering analysis, it is preferable that the diamond-like carbon coating has a large coating density close to the bulk density of diamond.

The thickness of each film is preferably 5 μm or more for the anodic oxide film of aluminum and 0.5 μm or more for the DLC film. If the anodic oxide film is thinner than 5 μm, it is worn away and dust is easily generated. Further, even if the DLC film becomes thinner than 0.5 μm, it is easily worn and dust is easily generated. Regarding the surface roughness of the anodized aluminum base material (the surface roughness of the anodized film), the maximum roughness (Rmax) is preferably 0.5 μm or less. If Rmax is larger than this value, the contact pressure becomes large due to local contact with the work surface, the durability of the DLC film deteriorates, and dust is easily generated.

When forming a low dust-generating member, the base on which the DLC film is formed needs to be hard as described above. In addition, the surface roughness is small and it is not a heavy metal considering the influence on the semiconductor manufacturing process (for example, oxide,
Carbides, nitrides, etc.) are preferred. As described above, when an aluminum alloy is used as the base material, it is possible to reduce the processing cost when creating the shape and to reduce the weight. In that case, if an anodic oxide film is formed on the surface, it is possible to obtain the excellent effect in terms of corrosion resistance as well as hardening required for the base of the DLC film. When an aluminum alloy is used as a base material, the surface of the aluminum alloy is hardened as a base of the DLC film. In that case, in addition to the above-described anodizing treatment, for example, a ceramic sprayed coating is formed on the surface of the aluminum alloy. Or ceramics (SiC, SiC,
A method of applying a thick film dry coat of TiN, Al ₂ O ₃ or the like may be used. In addition, an oxide film is formed on the aluminum alloy surface by anodizing method using oxygen plasma, and a nitride film is formed on the aluminum alloy surface by surface nitriding method using nitrogen plasma to harden the alloy surface. Any method may be used. Hereinafter, an example of a method for manufacturing a low dust-generating member according to the present invention will be described in Examples.

[0016]

[Example] An aluminum alloy (JIS: A5056) was prepared as a substrate, and an anodized film of aluminum was formed on the surface of the aluminum alloy by electrolytic anodization treatment by a wet process. In this anodizing treatment, first, any one of oxalic acid, sulfuric acid, and chromic acid aqueous solution is used as an electrolytic solution for electrolytic treatment, and immediately after electrolysis, boiling water treatment or superheated steam treatment is performed.

After that, a DLC film was formed on the anodized film by the plasma CVD (chemical vapor deposition) method of forming the film in RF (high frequency) plasma. FIG. 2 is a schematic diagram showing the configuration of the plasma CVD apparatus used for forming the DLC film. This apparatus is called a high frequency / capacitive coupling / parallel plate type plasma CVD apparatus, which is a type of capacitive coupling type, and includes a housing 62 that forms a film formation space (chamber) 61 and a source gas (reaction gas) inside the chamber 61. A high-frequency voltage is applied to the gas supply means 63 to be introduced into the chamber, the exhaust means 64 for setting the inside of the chamber 61 to a predetermined vacuum degree (pressure), the mounting table 66 on which the substrate 65 to be deposited is mounted, and the mounting table 66. High-frequency power source 67, electrode 68 installed in chamber 61, matching circuit 69 for efficiently supplying the output (high-frequency power) of high-frequency power source 67 to the load, and heating means for maintaining substrate 65 at a predetermined temperature. (Not shown). In this device, the source gas discharge port of the gas supply means 63 also serves as the electrode 68.

When forming the DLC film, first, the gas supply means 63 introduces a source gas consisting of a mixed gas of methane gas and hydrogen gas into the chamber 61. As for the raw material gas, the flow rate of methane gas is 20cc / min and the flow rate of hydrogen gas is
It was set to be 30cc / min. And chamber 6
The chamber 61 was evacuated by the evacuation means 64 so that the degree of vacuum in the chamber 1 was about 13.3 Pa. In this state, RF plasma (frequency 13.56MHz, output 1k
W) 70 is generated, and the temperature of the base material 65 anodized during film formation is maintained at about 100 ° C. to form a DLC film on the surface of the substrate (anodized aluminum alloy) 65. A low dust-generating member as shown in FIG. 1 was manufactured.

Instead of the plasma CVD apparatus used in this embodiment, a DLC film is formed using an inductively coupled plasma CVD apparatus in which a high frequency coil is wound around a housing and high frequency power is applied. Good. Alternatively, a microwave discharge (ECR) plasma CVD apparatus may be used. Figure 3
Shows an example of the case where the low dust-generating member manufactured in this embodiment is used in a silicon wafer transfer apparatus, FIG. 3 (a) is a schematic perspective view thereof, and FIG. 3 (b) is a sectional view thereof. In FIG. 3, a passage 11a is formed inside the vacuum suction type transfer arm 11, and three suction portions 12 communicating with the passage 11a are provided at the tip thereof. The contact portion of the suction portion 12 with the silicon wafer is formed of the low dust-generating member. Therefore, when the silicon wafer 13 is transferred,
Even when the silicon wafer 13 is brought into sliding contact with the suction portion 12 of the transfer arm 11, no abrasion powder is generated, and the silicon wafer 13
The surface of the product is always kept clean, and the yield of products (for example, semiconductors) is improved. The transfer arm 11 may be made of the same material as the suction unit 12.

FIG. 6 shows an example in which the low dust-generating member manufactured in this embodiment is used for a stage chuck (holding mechanism) of a silicon wafer, and FIG. 6 (a) is a schematic perspective view thereof. (B) is a sectional view. In FIG. 6, a passage 21a is formed inside the stage chuck 21, and a plurality of suction ports 21b communicating with the passage 21a are provided at the tip thereof. Surface on which these suction ports 21b are formed (suction surface)
An arc-shaped suction portion 22 that contacts the silicon wafer 13 is provided on the top. The contact portion of the suction portion 22 with the silicon wafer is formed of the low dust-generating member. Therefore, when the silicon wafer 13 is held by vacuum suction, the silicon wafer 13 is held by the stage chuck 2
No abrasion powder is generated even when slidingly contacting the adsorption section 22 of No. 1,
The surface of the silicon wafer 13 is always kept clean. The silicon chuck 21 may be made of the same material as the suction part 22.

FIG. 7 is a schematic perspective view showing an example in which the low dust-generating member manufactured in this embodiment is used for vacuum tweezers. A passage 31 a is formed inside the vacuum tweezers 31, and a suction portion 32 that communicates with the passage 31 a is provided at the tip of the tweezers 31. Since the suction part 32 is formed of the low dust-generating member, it is possible to provide vacuum tweezers with low dust generation. The tweezers 31 may be made of the same material as the suction part 32.

FIG. 8 is a schematic perspective view showing an example in which the low dust-generating member manufactured in this embodiment is applied to a wafer positioning mechanism. Two positioning arms 41 are provided at positions facing the rotation axis of the wafer rotary table 40. The contact portion (the portion that contacts the wafer) 42 of the positioning arm 41 is formed of the low dust-generating member. Therefore, when positioning the wafer,
Even if the wafer (silicon wafer) 13 is brought into sliding contact with the contact portion 42 of the positioning arm 41, as described above, it is possible to provide a wafer positioning mechanism that does not generate abrasion powder and generates low dust. The positioning arm 41 may be made of the same material as the suction portion 42.

[0023]

As described above, the low dust-generating member obtained according to the present invention has mutual wear resistance that neither wears the work nor is it worn by the work. It is possible to suppress adhesion and scattering of fine particles into the environment where the work is used. Therefore, improvement in the reliability of equipment, which makes the adhesion and scattering of fine particles a serious problem,
Further, it is possible to suppress deterioration of cleanliness in a clean environment such as a clean room in which the device is installed.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of the structure of a low dust-generating member of the present invention.

FIG. 2 is a schematic configuration diagram of a plasma CVD apparatus used for forming a diamond-like carbon film.

FIG. 3 is a schematic view showing an example in which the present invention is applied to a silicon wafer transfer apparatus.

FIG. 4 is a schematic diagram illustrating a method for measuring scattered particles by a pin-on-disk type friction and wear test in a combination of a substrate made of various materials and a pin made of a silicon single crystal material.

5 is a diagram showing the number of fine particles scattered when the pin-on-disc type friction and wear test shown in FIG. 2 is performed.

FIG. 6 is a schematic view showing an example in which the present invention is applied to a stage chuck (wafer holding) of a silicon wafer.

FIG. 7 is a schematic perspective view showing an example when the present invention is applied to vacuum tweezers.

FIG. 8 is a schematic perspective view showing an example in which the present invention is applied to a wafer positioning mechanism.

[Explanation of symbols for main parts]

 1 Substrate 2 Pin 3 Suction Nozzle 11 Transfer Arm 12 Adsorption Part 13 Silicon Wafer 21 Stage Chuck 22 Adsorption Part 31 Tweezers 32 Adsorption Part 41 Positioning Arm 42 Adsorption Part 51 Base Material (Aluminum Alloy) 52 Anodized Film 53 Diamond-like Carbon Film ( DLC film) 61 chamber 62 housing 63 gas supply means 64 exhaust means 65 substrate (anodized aluminum alloy) 67 high frequency power supply 68 electrode

Claims (6)

[Claims] 1. A method for producing a low dust-generating member used in a portion where a workpiece is in sliding contact with an apparatus for treating the workpiece, wherein the surface of a substrate made of an aluminum alloy is anodized. 1. A method for producing a low dust-generating member, comprising forming an aluminum anodic oxide film on, and forming a film made of diamond-like carbon on the anodic oxide film. 2. The manufacturing method according to claim 1, wherein the film made of the diamond-like carbon is formed by a chemical vapor deposition method using plasma. . 3. The manufacturing method according to claim 2, wherein the raw material gas introduced into the film formation space during the chemical vapor deposition method contains methane gas, and the flow rate of the methane gas is 5 to 2
A method for manufacturing a low dust-generating member, which is set in a range of 00 cc / min. 4. The manufacturing method according to claim 2, wherein the chemical vapor deposition method sets the degree of vacuum during film formation in the film formation space within a range of 6.7 to 26.7 Pa. A method for manufacturing a dust member. 5. The manufacturing method according to claim 2, wherein the plasma in the chemical vapor deposition method has an output of 0.1 to 1.
A method for producing a low dust-generating member, which is produced in a range of 0 kW. 6. The method according to claim 2, wherein the temperature of the substrate on which the diamond-like carbon film is formed is set to 250 ° C. or lower during the chemical vapor deposition method. A method for manufacturing a dust member.