JP2002153824A - Cleaning sheet and method for cleaning substrate treating device by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet and a method for cleaning a substrate treating device such as a device for manufacturing or inspecting, for example, a semiconductor, a flat panel display and a printed board, into which foreign matter must be prevented from getting. SOLUTION: This cleaning sheet has a cleaning layer comprising a substance having <1.2 friction coefficient.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a sheet for cleaning various substrate processing apparatuses and a method for cleaning a substrate processing apparatus using the same. 1. Field of the Invention The present invention relates to a cleaning sheet and a cleaning method for a substrate processing apparatus that dislikes foreign substances, such as an apparatus.

[0002]

2. Description of the Related Art Various substrate processing apparatuses transport substrates while physically contacting each transport system with a substrate. At that time, if foreign matter is attached to the substrate or the transport system, the subsequent substrate is contaminated one after another, and it is necessary to periodically stop the apparatus and perform a cleaning process. For this reason, there has been a problem that the operation rate is reduced and a large amount of labor is required. In order to solve these problems, a method of cleaning and removing adhered foreign matter in a substrate processing apparatus by transporting a substrate to which an adhesive substance is adhered (Japanese Patent Laid-Open No. 10-154686) and a method of transporting a plate-like member are disclosed. (Japanese Patent Laid-Open No. 11-87458) has been proposed.

[0003]

The method of cleaning and removing the adhered foreign matter in the substrate processing apparatus by transporting the substrate to which the adhesive substance is fixed is an effective method for overcoming the above-mentioned problem. However, in this method, the sticky substance and the device contact portion may be so strongly adhered that they cannot be peeled off, and the substrate may not be transported reliably. In particular, this is a problem when a reduced pressure suction mechanism is used for the chuck table of the substrate. In addition, the method of removing foreign matter by transporting the plate-like member can perform transportation without any trouble, but has a problem that the essential dust-removing property is inferior. The present invention
In view of such circumstances, an object of the present invention is to provide a cleaning sheet that can surely transport a substrate into a substrate processing apparatus and that can easily reduce foreign substances attached to the apparatus.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, transported a cleaning member or a transport member such as a substrate provided with a cleaning sheet, thereby achieving substrate processing. In cleaning and removing foreign substances attached to the apparatus, it has been found that by setting the coefficient of friction of the cleaning layer to a value less than a specific value, it is possible to reliably transport the inside of the substrate processing apparatus and further easily reduce foreign substances. It was completed.

That is, the present invention provides a cleaning sheet wherein the cleaning layer is made of a substance having a coefficient of friction of less than 1.2 (claim 1), and a cleaning layer having a coefficient of friction of less than 1.2 on at least one surface of the support. (Claim 2), a cleaning sheet provided with a cleaning layer having a friction coefficient of less than 1.2 on one surface of a support and a normal pressure-sensitive adhesive layer on the other surface (Claim 2). Item 3) The cleaning sheet according to any one of claims 1 to 3, wherein the cleaning layer has substantially no tackiness and has a tensile modulus of 2000 MPa or less. Is a pressure-sensitive adhesive layer cured by active energy, wherein the cleaning sheet according to any one of claims 1 to 4 (claim 5) is provided. It is.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The cleaning layer of the cleaning sheet of the present invention (including a single cleaning sheet, a laminated sheet, or a laminated sheet with a support) has a coefficient of friction of less than 1.2. Preferably, it is required to be 0.3 to 1.0. If the coefficient of friction is larger than 1.2, there is a possibility that the contact portion with the device is too strongly adhered and cannot be peeled off. In the present invention, the friction coefficient (μ) of the cleaning layer means the frictional resistance (F) when a stainless steel plate (50 mm × 50 mm flat plate) is slid against the surface of the cleaning layer using a universal tensile tester,
This and the vertical load (W) applied to the steel plate at that time are obtained by introducing the following equation (1), and here means the dynamic friction coefficient.

<Equation 1> μ = F / W Here, each symbol in the equation is as follows. μ: Dynamic friction coefficient F: Friction resistance [N] W: Vertical load on steel plate [N]

The tensile modulus of the cleaning layer (according to JIS K7127 test method) is 2000 MPa
Below, it is desirable that it is preferably larger than 1 Mpa.
In the present invention, by setting the coefficient of friction and the tensile elasticity of the cleaning layer to such specific values, the cleaning layer has substantially no tackiness when the cleaning sheet or the like is conveyed, and strongly adheres to the part to be cleaned. The effect of being able to carry reliably without adhesion is obtained.

The material of the cleaning layer is not particularly limited as long as its friction coefficient is less than the above-mentioned specific value. However, the cleaning layer is cured and cross-linked by an active energy source such as ultraviolet rays or heat, and its molecular structure is three-dimensional. A pressure-sensitive adhesive layer having a network and reduced or lost in adhesive strength is preferred. When such a pressure-sensitive adhesive layer is used, the cleaning layer does not strongly adhere to the portion to be cleaned at the time of transport, and can be transported reliably. The thickness of the cleaning layer is not particularly limited, but is usually about 5 to 100 μm.

As a specific example of such a cleaning layer,
For example, a pressure-sensitive adhesive polymer containing at least a compound having at least one unsaturated double bond in a molecule and a polymerization initiator is subjected to a polymerization curing reaction by active energy to substantially eliminate tackiness. What is.
Examples of such a pressure-sensitive adhesive polymer include acrylic polymers having a main monomer of (meth) acrylic acid and / or (meth) acrylic ester selected from acrylic acid, acrylic ester, methacrylic acid, and methacrylic ester. Can be In synthesizing this acrylic polymer, a compound having two or more unsaturated double bonds in the molecule is used as a copolymerization monomer, or a compound having an unsaturated double bond in the molecule is synthesized from the synthesized acrylic polymer. By introducing an unsaturated double bond into the molecule of the acrylic polymer, for example, by chemically bonding through a reaction between functional groups, the polymer itself can be involved in the polymerization curing reaction by active energy. Can also.

Here, the compound having one or more unsaturated double bonds in the molecule (hereinafter referred to as a polymerizable unsaturated compound) is a low molecular weight compound which is nonvolatile and has a weight average molecular weight of 10,000 or less. In particular, the adhesive layer preferably has a molecular weight of 5,000 or less so that the three-dimensional network of the adhesive layer at the time of curing can be efficiently formed. The polymerization initiator to be added to the cleaning layer is not particularly limited, and a known initiator can be used. For example, when heat is used as an active energy source, a thermal polymerization initiator such as benzoyl peroxide or azobisisobutyronitrile is used. When light is used, benzoyl, benzoin ethyl ether, cibenzyl, isopropyl benzoin ether, benzophenone, Michler's ketone chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, acetophenone diethyl ketal, benzyl dimethyl ketal, α
Photopolymerization initiators such as -hydroxylcyclohexylphenyl ketone, 2-hydroxydimethylphenylpropane, and 2,2-dimethoxy-2-phenylacetophenone.

When the cleaning layer is provided on the support (claim 2), the support is not particularly limited. Examples of the support include polyethylene, polyethylene terephthalate, acetylcellulose, polycarbonate, polypropylene, polyamide, polyimide, and polycarbodiimide. Plastic films and the like can be mentioned. Its thickness is usually about 10 to 100 μm.

The present invention further provides a cleaning sheet in which a cleaning layer is provided on one side of a support and a normal pressure-sensitive adhesive layer is provided on the other side. The material of the normal pressure-sensitive adhesive layer is not particularly limited as long as the pressure-sensitive adhesive function is satisfied, and a normal pressure-sensitive adhesive (for example, acrylic or rubber-based) can be used. With this configuration, the cleaning sheet is attached to a transport member such as various substrates or other tapes / sheets with a normal pressure-sensitive adhesive layer, and is transported into the apparatus as a transport member with a cleaning function, so that the cleaning sheet is applied to a portion to be cleaned. It can be cleaned by contact. Further, in order to reuse the transfer member such as the substrate, when the substrate is peeled off from the pressure-sensitive adhesive layer after cleaning, the adhesive force of the normal pressure-sensitive adhesive layer is not particularly limited as long as the pressure-sensitive adhesive layer can be peeled off. 180 ° peel adhesion to silicon wafer (mirror surface) is 0.20 to 0.98 N / 10 mm, especially 0.40
A thickness of about 0.98 N / 10 mm is preferable because it can be easily peeled off after cleaning without peeling during transport.

The transport member to which the cleaning sheet is adhered is not particularly limited, and examples thereof include semiconductor wafers, substrates for flat panel displays such as LCDs and PDPs, and other substrates such as compact disks and MR heads.

[0015]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. Hereinafter, “parts” means “parts by weight”. Example An acrylic polymer (weight average molecular weight 280) obtained from a monomer mixture consisting of 30 parts of 2-ethylhexyl acrylate, 70 parts of methyl acrylate, and 10 parts of acrylic acid
Multifunctional urethane acrylate (trade name: UV 1700B, manufactured by Nippon Synthetic Chemical Co., Ltd.)
0 parts, polyethylene glycol 600 diacrylate (manufactured by Shin-Nakamura Chemical: trade name: NK Ester A-600) 5
0 parts, 3 parts of a polyisocyanate compound (manufactured by Nippon Polyurethane Industry: trade name: Coronate L), and benzyl dimethyl ketal (manufactured by Ciba Specialty Chemicals: trade name: Irgacure 651) 1 as a photopolymerization initiator
0 parts were uniformly mixed to prepare an ultraviolet-curable pressure-sensitive adhesive solution A. On the other hand, 2-ethylhexyl acrylate 75
Parts, 100 parts of an acrylic polymer (weight average molecular weight 700,000) obtained from a monomer mixture composed of 20 parts of methyl acrylate and 5 parts of acrylic acid, and polyethylene glycol 200 dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) : 50 parts of NK ester 4G), 50 parts of urethane acrylate (manufactured by Shin-Nakamura Chemical: trade name: UN-01), and polyisocyanate compound (manufactured by Nippon Polyurethane Industry: trade name: Coronate L) Three parts were uniformly mixed to prepare a pressure-sensitive adhesive solution B. This pressure-sensitive adhesive solution B
Is applied on one side of a polyester support film having a width of 250 mm and a thickness of 25 μm so that the thickness after drying becomes 10 μm to provide a normal pressure-sensitive adhesive layer.
An 8 μm polyester release film was applied. Next, on the other side of the support film, the above-mentioned ultraviolet-curable pressure-sensitive adhesive solution A was applied so that the thickness after drying was 10 μm, a cleaning layer was provided, and a similar release film was stuck on the surface thereof. . The sheet was irradiated with an integrated amount of light of 1000 mJ / cm ² with ultraviolet rays having a central wavelength of 365 nm to obtain a cleaning sheet of the present invention. The release film on the cleaning layer side of the cleaning sheet was peeled off, and the friction coefficient after ultraviolet curing of the cleaning layer was 1.0, and the tensile modulus was 805 MPa. Here, the friction coefficient was measured with respect to the cleaning layer surface by 50 mm × 50 m.
m was moved in parallel with the cleaning layer at a speed of 300 mm / min in a constant direction under a vertical load of 9.8 N, and the resulting frictional resistance was measured by a universal tensile tester. is there. The tensile modulus is
It was measured according to the test method JIS K7127.

The release film on the normal pressure-sensitive adhesive layer side of the cleaning sheet was peeled off and affixed to the back surface (mirror surface) of an 8-inch silicon wafer with a hand roller to produce a transport cleaning wafer having a cleaning function. This normal adhesive silicon wafer (mirror surface)
180 ° peeling adhesive strength to 0.25 N / 10
It was 0 mm.

On the other hand, using a laser type foreign substance measuring apparatus, foreign substances of 0.2 μm or more were measured on the mirror surface of two new 8-inch silicon wafers.
Was individual. After transporting these wafers to a substrate processing apparatus having separate electrostatic suction mechanisms with the mirror surface facing down,
When a foreign substance having a size of 0.2 μm or more was measured by a laser type foreign substance measuring apparatus, one was 31874 pieces and the other was 32,947 pieces in an 8-inch wafer size area.

Then, the release film on the cleaning layer side of the cleaning wafer was peeled off, and the cleaning wafer was transferred into a substrate processing apparatus having a wafer stage to which the above-mentioned 31874 foreign substances had adhered.
The cleaning layer did not strongly adhere to the part to be cleaned at all, and cleaning and transport could be performed without any problem. After that, a new 8 inch silicon wafer having 12 foreign substances of 0.2 μm or more was transported with the mirror surface facing downward, and the laser type foreign substance measuring apparatus was used to transport the new 8 inch silicon wafer.
As a result of measuring the number of foreign substances, the number was 9815 in the area of the 8-inch wafer size, and it was possible to reduce the number of foreign substances adhered before cleaning to about １ ／.

Comparative Example As an adhesive for a cleaning layer, an acrylic polymer (weight average molecular weight: 2.8 million) obtained from a monomer mixture comprising 30 parts of 2-ethylhexyl acrylate, 70 parts of methyl acrylate, and 10 parts of acrylic acid 100 parts by weight of polyethylene glycol 200 dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd .: trade name: NK ester 4G) 100
Part, polyethylene glycol 600 diacrylate (manufactured by Shin-Nakamura Chemical: trade name: NK Ester A-600) 100
Parts, 3 parts of a polyisocyanate compound (manufactured by Nippon Polyurethane Industry: trade name: Coronate L) and 10 parts of benzyldimethyl ketal (manufactured by Ciba Specialty Chemicals: trade name: Irgacure 651) as a photopolymerization initiator are uniformly mixed. The prepared UV-curable pressure-sensitive adhesive solution C was used. When the coefficient of friction of the cleaning layer after ultraviolet curing was measured in the same manner as in the example, it was 2.0 and the tensile modulus was 15 MPa.

When a transfer cleaning wafer produced from the cleaning sheet in the same manner as in the embodiment was transferred into the substrate processing apparatus, the first sheet was fixed to the wafer stage and could not be transferred.

[0021]

As described above, according to the cleaning sheet of the present invention, it is possible to reliably convey the inside of the substrate processing apparatus and to easily reduce foreign substances adhering to the inside of the apparatus.

Claims (7)

[Claims] 1. A cleaning sheet wherein the cleaning layer is made of a substance having a coefficient of friction of less than 1.2. 2. A cleaning sheet comprising at least one surface of a support and a cleaning layer having a coefficient of friction of less than 1.2. 3. A cleaning sheet in which a cleaning layer having a friction coefficient of less than 1.2 is provided on one side of a support and a normal pressure-sensitive adhesive layer is provided on the other side. 4. The cleaning sheet according to claim 1, wherein the cleaning layer has substantially no tackiness and has a tensile modulus of 2000 MPa or less. 5. The cleaning sheet according to claim 1, wherein the cleaning layer is an adhesive layer cured by activation energy. 6. The cleaning sheet according to claim 3,
A transport member with a cleaning function provided on the transport member via an adhesive layer. 7. A method for cleaning a substrate processing apparatus, comprising transporting the cleaning sheet according to claim 1 or the transport member according to claim 6 into a substrate processing apparatus.