JPH07172571A - Device of low dust generating property - Google Patents

Abstract

PURPOSE:To provide a device of low dust generating property which restrains generation of fine particles, restrains sticking of the fine particles onto the surface of a work, and restrains dispersion of the fine particles for the circumference. CONSTITUTION:In a device of low dust generating property for processing a work 13 under clean environment, a member 12 slidably contacted with the work 13 is constituted of a base material of hard material, and a film consisting of diamond-like carbon formed on the surface of the base material.

Description

Detailed Description of the Invention

[0001]

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

[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. A low dust generation effect is achieved by applying lubricating oil or by coating a hard thin film or solid lubricating oil to harden one or both of the members to reduce the coefficient of friction and increase wear resistance. Was there. For example, in a wafer holding part of a semiconductor wafer transfer mechanism, a ceramic member such as alumina, a member subjected to anodizing aluminum anodized film treatment, a member subjected to film treatment by painting, etc. is used in a contact portion with the wafer. Was there.

[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. It is intended to provide a dusty device.

[0006]

To achieve the above object, according to the present invention, in a low dust generating device for treating a work in a clean environment, the member with which the work slides and contacts is made of a hard material. It is composed of a base material and a film made of diamond-like carbon formed on the surface of the base material (claim 1). The member can be composed of a base material made of an aluminum alloy, a film made of alumite formed on the surface of the base material, and a film made of diamond-like carbon formed on the alumite film. 2). When the work is a silicon wafer or a glass substrate, the diamond-like carbon film has the number of fine particles generated when these films and the work slide on each other at least three orders of magnitude less than that of alumina ( Claim 3).

[0007]

In the present invention, for example, in FIG. 1, when the work 13 is carried on the carrying line of the semiconductor manufacturing apparatus, even if the work 13 slides in contact with the suction part 12 or the like, generation of abrasion powder is suppressed. . As a result, a device with low dust generation can be provided. Here, a method for evaluating a member in the present invention will be described. First, as shown in FIG. 2, a substrate 1 made of various materials with a diameter of 50 mm and a diameter 10 mm made of a silicon single crystal material.
A pin-on-disc type friction / wear test (load 100 kgf, friction speed 50 mm / s) was carried out with the combination of the spherical pins 2 of No. 1 and the difference in the amount of dust generated due to the same was compared. Fine particles (wear particles) generated and scattered due to the wear 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 (made by Met-One)
A249 type) was used to count the number of fine particles having a particle diameter of 0.1 μm (this number was used as the amount of dust generation in this evaluation method). The result is shown in FIG.

As shown in FIG. 3, when the material of the substrate 1 that contacts 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. However, when the substrate 1 is made of an aluminum alloy (for example, JIS A5056) that is hardened by forming an alumite coating on its surface, and its surface is coated with a diamond-like carbon coating,
Both the substrate 1 and the pin 2 showed little wear and showed excellent low dusting property. However, when the substrate 1 is a material in which the aluminum alloy surface is directly coated with the diamond-like carbon film or a material in which only the alumite film is formed on the aluminum alloy surface, the above-mentioned excellent low dust generation cannot be obtained. .

As described above, in a low dust generating device, it is necessary to use a material having excellent wear resistance for each member that comes into contact with a work such as a silicon wafer. It is not preferable that the abrasion powder is scattered. Also, a material that is worn away by the work is not preferable. Therefore, by using a material that does not abrade the work and is not abraded by the work for each member, wear of the work and a portion in contact with the work is suppressed, and a device with low dust generation is provided. it can. In the present specification, such wear characteristics are referred to as “having mutual wear resistance”. The above-mentioned "member having an aluminum alloy having an alumite film formed on the surface as a base material and having a diamond-like carbon film formed on the surface thereof" is suitable as a member having "a mutual wear resistance".

For this member, for example, first, an aluminum alloy is prepared as a base material, and this is anodized in RF (high frequency) plasma using a mixed gas of methane and hydrogen as a raw material gas to form an alumite film on the surface. Further, it can be obtained by forming a diamond-like carbon film on the alumite film. The surface of the aluminum alloy is hardened by the alumite treatment. Preferably, the film thickness of the alumite film is at least 5 μm or more, and the film thickness of the diamond-like carbon film is 0.5 μm or more. Regarding the surface roughness of the anodized aluminum base material (the surface roughness of the alumite coating), the maximum roughness (Rmax) is preferably 0.5 μm or less. It is preferable that the base for forming the diamond-like carbon film is hard, has a small surface roughness, and is not a heavy metal (for example, oxide, carbide, nitride, etc.) in consideration of the influence on the semiconductor manufacturing process. It is preferable to use an aluminum alloy as the base material, because the processing cost at the time of shape creation can be reduced, and the weight and the corrosion resistance are excellent. In addition to the above-mentioned alumite treatment, for example, a ceramic sprayed film is formed on the surface of the aluminum alloy, or a ceramic (SiC, TiN, Al ₂ O ₃ ) is formed by sputtering or CVD (chemical vapor deposition). And the like) can be used.

The diamond-like carbon film is a plasma
The film is formed by CVD, and its physical properties are
Carbon (Raman shift 1550cm^-1) And diamonds (13
33 cm ^-1) Peak ratio in
Carbo with high peak, that is, strong diamond structure
It is preferable that it is a coating film. In addition, small-angle X-ray scattering analysis
Comparing the film densities using
It is preferably a mond carbon coating. plasma
When forming a diamond-like carbon film by CVD
Is the flow rate of the raw material gas to be introduced into the chamber, for example.
Mixing 20cc / min methane gas and 30cc / min hydrogen gas
Gas was used and the vacuum degree of film formation in the chamber was set to 0.1 Torr.
RF plasma (13.56MHz, 1kW) is generated in the state, and the substrate
(Base material made of anodized aluminum alloy) Temperature
Can be maintained at 100 ° C.

[0012]

Embodiment 1 FIG. 1 shows an example in which the present invention is applied to a silicon wafer transfer apparatus. FIG. 1 (a) is a schematic perspective view thereof, and FIG. 1 (b) is a sectional view thereof. In FIG. 1, a passage 11a is formed inside the vacuum suction type transfer arm 11, and three suction portions 1 communicating with the passage 11a are formed at the tip thereof.
Two are provided. As described above, the adsorption portion 12 is formed by coating the diamond-like carbon thin film on the aluminum alloy material having the alumite film formed on the surface by the alumite treatment. Therefore, when the silicon wafer 13 is transferred, even if the silicon wafer 13 makes sliding contact with the suction portion 12 of the transfer arm 11, no abrasion powder is generated and the surface of the silicon wafer 13 is always kept clean. The yield of (for example, semiconductor) is improved. The transfer arm 11 may be made of the same material as the suction unit 12.

[0013]

Second Embodiment FIG. 4 shows an example in which the present invention is applied to a stage chuck (holding mechanism) of a silicon wafer,
4A is a schematic perspective view thereof, and FIG. 4B is a sectional view thereof. In FIG. 4, 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 of the passage 21a. An arc-shaped suction portion 22 that contacts the silicon wafer 13 is provided on the surface (suction surface) where the suction ports 21b are formed. Like the suction unit 12 of the transfer arm 11 of the first embodiment, the suction unit 22 is formed by coating a diamond-like carbon thin film on an aluminum alloy material having an alumite coating formed on its surface by anodizing. Therefore,
When holding the silicon wafer 13 by vacuum suction,
The silicon wafer 13 is the suction portion 2 of the stage chuck 21.
No abrasion powder is generated even when slidingly contacting with 2, and 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.

[0014]

Third Embodiment FIG. 5 is a schematic perspective view showing an example in which the present invention is applied to vacuum tweezers. A passage 31 a is formed inside the vacuum tweezers 31, and the tweezers 31
An adsorption portion 32 that communicates with the passage 31a is provided at the tip of the. Like the suction unit 12 of the transfer arm 11 of the first embodiment, the suction unit 32 is formed by coating a diamond-like carbon thin film on an aluminum alloy material having an alumite coating formed on the surface by anodizing. Therefore, in this case as well, vacuum tweezers with low dust generation can be provided. The tweezers 31 may be made of the same material as the suction part 32.

[0015]

Fourth Embodiment FIG. 6 is a schematic perspective view showing an example in which the present invention 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
Similar to the adsorption unit 12 of the transfer arm 11 of the first embodiment, it is formed by coating a diamond-like carbon thin film on an aluminum alloy material having an alumite coating formed on its surface by alumite treatment. Therefore, also in this case, similarly, when the wafer is positioned, the wafer (silicon wafer) 13
Even if the 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 has low dust generation. The positioning arm 41 may be made of the same material as the suction section 42.

[0016]

As described above, according to the present invention, the parts which are in sliding contact with the work are formed by the materials having mutual wear resistance such that the work is not worn and is not worn by the work. It is possible to suppress the adhesion of the fine particles to the work and the scattering of the fine particles to the environment where the work is used. As a result, it is possible to improve the reliability of a device in which the adhesion and scattering of fine particles are a serious problem, and to suppress the 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 view showing an example in which the present invention is applied to a silicon wafer transfer apparatus.

FIG. 2 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.

FIG. 3 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. 4 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. 5 is a schematic perspective view showing an example when the present invention is applied to vacuum tweezers.

FIG. 6 is a schematic perspective view showing an example when 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

[Procedure amendment]

[Submission date] March 4, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 2

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[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. A low dust generation effect is achieved by applying lubricating oil or by coating a hard thin film or solid lubricating oil to harden one or both of the members to reduce the coefficient of friction and increase wear resistance. Was there. For example, in a wafer holding unit of a semiconductor wafer transfer mechanism, a ceramic member made of alumina or the like at a contact portion with the wafer, or an anodized portion of aluminum.
Materials , members subjected to film treatment by painting, etc. were used.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006]

To achieve the above object, according to the present invention, in a low dust generating device for treating a work in a clean environment, the member with which the work slides and contacts is made of a hard material. It is composed of a base material and a film made of diamond-like carbon formed on the surface of the base material (claim 1). Said member, constituted by a base material made of an aluminum alloy, and an anodized film of aluminum formed on the substrate surface, a coating of diamond-like carbon formed on the anodized film, the anodizing Cover the film with oxalic acid, sulfuric acid and
Anodic oxidation using one of romic acid aqueous solution as electrolyte
It may be formed using a method (claim 2). When the work is a silicon wafer or a glass substrate, the diamond-like carbon film has the number of fine particles generated when these films and the work slide on each other at least three orders of magnitude less than that of alumina ( Claim 3).

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

As shown in FIG. 3, when the material of the substrate 1 that contacts 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. However, if the substrate 1 is made of an aluminum alloy (for example, JIS A5056) that is hardened by forming an aluminum anodic oxide film on the surface, and the surface is coated with a diamond-like carbon film, the substrate is Both No. 1 and Pin 2 showed little wear and showed excellent low dusting property. However, when the substrate 1 is made of a material in which the aluminum alloy surface is directly coated with a diamond-like carbon film or a material in which only the aluminum anodic oxide film is formed on the aluminum alloy surface, the excellent low dust generation property as described above is obtained. I couldn't do it.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

As described above, in a low dust generating device, it is necessary to use a material having excellent wear resistance for each member that comes into contact with a work such as a silicon wafer. It is not preferable that the abrasion powder is scattered. Also, a material that is worn away by the work is not preferable. Therefore, by using a material that does not abrade the work and is not abraded by the work for each member, wear of the work and a portion in contact with the work is suppressed, and a device with low dust generation is provided. it can. In the present specification, such wear characteristics are referred to as “having mutual wear resistance”. The aforementioned "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" is suitable as a member having "mutual wear resistance".

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

For this member, for example, an aluminum alloy is first prepared as a base material, and this is subjected to a known wet process.
Aluminum is anodized by electrolytic anodization.
Form a anodic oxide film on the aluminum, and further mix methane and hydrogen.
In an RF (high frequency) plasma that uses the combined gas as the source gas,
A diamond-like carbon film is formed on the anodized film.
It is obtained by doing. Anodic acid produced by the electrolytic anodizing method
Anodizing (registered trademark) treatment is used
It was This alumite treatment is, as is well known, oxalic acid,
Either sulfuric acid or chromic acid aqueous solution as electrolyte
Electrolytic treatment, then boiling water treatment or heated steam treatment
Is to do. In addition, anodic acid other than alumite treatment
A chemical treatment may be used. The surface of the aluminum alloy looks like this
Hardened by various anodizing treatments. The alumite processing
When forming an alumite coating, it is preferable that the thickness of the alumite coating be at least 5 μm and the thickness of the diamond-like carbon coating be 0.5 μm or more. The surface roughness of the anodized aluminum base material (the surface roughness of the alumite coating) is 0.5μ in the maximum roughness (Rmax).
It is preferably m or less. It is preferable that the base for forming the diamond-like carbon film is hard, has a small surface roughness, and is not a heavy metal (for example, oxide, carbide, nitride, etc.) in consideration of the influence on the semiconductor manufacturing process. Using aluminum alloy as a base material, the form
It is possible to reduce the processing cost at the time of forming the shape and to reduce the weight. So
In the case of, if the anodic oxide film is formed on the surface, the diamond
In addition to the hardness required for the base of the carbon coating
An excellent effect can be obtained in terms of corrosion resistance. To harden the aluminum alloy, anodizing such as the alumite treatment described above
In addition to processing , for example, forming a ceramic sprayed coating on the surface, sputtering, ion plating or CVD
Ceramic (SiC, TiN)
, Al ₂ O _3, etc.) can be used. In addition, anodic acid using oxygen plasma
Forming an oxide film on the surface of the aluminum alloy by
Surface nitriding method using elementary plasma on aluminum alloy surface
Use a method to harden the alloy surface by forming a nitride film
May be.

Claims (3)

[Claims] 1. A low dust-generating device for treating a work in a clean environment, wherein the member with which the work is in sliding contact is a hard base material and diamond-like carbon formed on the base material surface. A device with low dust generation characterized by being composed of a film consisting of. 2. The apparatus according to claim 1, wherein the member is a base material made of an aluminum alloy, a film made of alumite formed on the surface of the base material, and diamond-like carbon formed on the alumite film. A device with low dust generation, which is characterized in that 3. The apparatus according to claim 1, wherein, when the film made of diamond-like carbon is a silicon wafer or a glass substrate, fine particles are generated when the film and the work slide on each other. A device with low dust generation, characterized in that the number is at least 3 digits less than that of alumina.