JP3740002B2 - Cleaning sheet and substrate processing apparatus cleaning method using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet for cleaning various substrate processing apparatuses and a substrate processing apparatus cleaning method using the same, and, for example, a substrate that dislikes foreign matters, such as a manufacturing apparatus or an inspection apparatus such as a semiconductor, a flat panel display, and a printed board. The present invention relates to a cleaning sheet and a cleaning method for a processing apparatus.
[0002]
[Prior art]
Various substrate processing apparatuses transport each transport system and the substrate in physical contact with each other. At this time, if foreign substances adhere to the substrate or the transport system, subsequent substrates are contaminated one after another, and it is necessary to periodically stop the apparatus and perform a cleaning process. For this reason, there existed a problem that an operation rate fall and a lot of labor were needed. In order to solve these problems, there has been proposed a method of cleaning and removing adhered foreign substances in the substrate processing apparatus by transporting a substrate to which an adhesive substance is fixed (for example, Japanese Patent Laid-Open No. 10-154686).
[0003]
[Problems to be solved by the invention]
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-described problems. However, in this method, the adhesive substance and the apparatus contact portion are too strongly bonded and may not be peeled off, and there is a possibility that the substrate cannot be reliably conveyed.
In view of such circumstances, an object of the present invention is to provide a cleaning sheet that can reliably transport a substrate into a substrate processing apparatus and can easily reduce foreign substances adhering to the apparatus.
[0004]
[Means for Solving the Problems]
As a result of intensive investigations to achieve the above object, the present inventors have carried out a cleaning member or a conveying member such as a substrate provided with a cleaning sheet to remove and remove the adhered foreign matter in the substrate processing apparatus. In order to accomplish the present invention, the surface free energy of the cleaning layer and the contact angle of water are set to a specific range, whereby the substrate processing apparatus can be reliably transported and foreign matters can be easily reduced. I arrived.
[0005]
That is, the present invention is a cleaning sheet that is provided on a conveying member and removes foreign matters by being conveyed into a substrate processing apparatus, and has a surface free energy of 15 to 25 mJ / m ² and a water contact angle of 90. A cleaning sheet comprising a cleaning layer made of a substance exceeding the degree (Claim 1), a cleaning sheet provided on a transport member for removing foreign matter by transporting it into a substrate processing apparatus, on at least one side of the support, the surface free energy 15~25mJ / m ^2, the cleaning sheet (claim 2) the contact angle of water is in the cleaning layer is provided in excess of 90 degrees, provided the transport member substrate processing a cleaning sheet for removing foreign matter by conveying into the apparatus, the surface free energy on one surface of a support 15～25MJ / ^2, the cleaning layer is provided a contact angle of water exceeds 90 degrees, a cleaning sheet (claim 3) comprising normal adhesive layer is provided on the other surface, the cleaning layer is substantially free of adhesive The tensile strength is 2000 MPa or less, the cleaning sheet according to any one of claims 1 to 3 (claim 4), and the cleaning layer is a pressure-sensitive adhesive layer cured by active energy. The cleaning sheet according to any one of claims 1 to 4 (claim 5).
The present invention also relates to a transport member with a cleaning function (claim 6), wherein the cleaning sheet according to claim 3 is provided on the transport member via an adhesive layer. Furthermore, the present invention relates to a substrate processing apparatus cleaning method (Claim 7), wherein the cleaning sheet according to Claim 1 or 2 or the transport member according to Claim 6 is transported into the substrate processing apparatus. Is.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The cleaning layer of the cleaning sheet of the present invention needs to have a surface free energy of 15 to 25 mJ / m ² .
In the present invention, the surface free energy of the cleaning layer (solid) means that the contact angle is measured with respect to the surface of the cleaning layer using water and methylene iodide, and the measured value and the surface free energy value of the contact angle measurement liquid ( Substituting (known from the literature) into Young's formula and extended Fowkes' formula 1 below, and solving the two formulas as simultaneous linear equations means the surface free energy value of the solid Is.
[0007]
<Formula 1>
(1 + cos θ) γ _L = 2 · ■ route (γ _s ^d γ _L ^d ) + 2 · ■ route (γ _s ^p γ _L ^p )
However, each symbol in the formula is as follows.
theta: contact angle gamma _L: the surface of the contact angle measurement liquid free energy γ _L ^d: γ dispersion force component in _L γ _L ^p: polar force component gamma _s ^d in gamma _L: dispersion force component in the surface free energy of the solid gamma _s ^p : Polar force component in the surface free energy of a solid
Further, it is desirable that the contact angle of water on the cleaning layer surface exceeds 90 degrees, preferably 100 degrees or more. In the present invention, by setting the surface free energy of the cleaning layer and the contact angle of water within such specific ranges, the cleaning layer does not strongly adhere to the portion to be cleaned during transport of the cleaning sheet, etc. The effect that it can be conveyed is obtained.
Further, the tensile strength of the cleaning layer (according to the test method JIS K7127) is desirably 2000 MPa or less, preferably greater than 1 MPa. By designing within this range, the cleaning layer is substantially tacky. Therefore, foreign matters can be removed without causing a conveyance trouble.
[0009]
The material of the cleaning layer is not particularly limited as long as the surface free energy and the contact angle of water are within the specific range , but the molecular structure of the cleaning layer is cured and crosslinked by an active energy source such as ultraviolet light or heat. A pressure-sensitive adhesive layer in which the adhesive strength is reduced or disappears by forming a three-dimensional network is preferred. When such an adhesive layer is used, the cleaning layer does not strongly adhere to the portion to be cleaned at the time of conveyance, and can be reliably conveyed. The thickness of the cleaning layer is not particularly limited, but is usually about 5 to 100 μm.
[0010]
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 the molecule and a polymerization initiator is polymerized and cured by active energy. Examples include those in which adhesiveness is substantially lost. Examples of the pressure-sensitive adhesive polymer include acrylic polymers having (meth) acrylic acid and / or (meth) acrylic acid ester selected from acrylic acid, acrylic acid ester, methacrylic acid, and methacrylic acid ester as main monomers. It is done. 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 used in the synthesized acrylic polymer. By introducing an unsaturated double bond into the molecule of the acrylic polymer, for example, by chemically bonding it with a reaction between functional groups, this polymer itself is also involved in the polymerization curing reaction by active energy. You can also.
[0011]
Here, the compound having one or more unsaturated double bonds in the molecule (hereinafter referred to as a polymerizable unsaturated compound) is preferably a low molecular weight substance that is nonvolatile and has a weight average molecular weight of 10,000 or less. In particular, it is preferable to have a molecular weight of 5000 or less so that the three-dimensional network of the adhesive layer at the time of curing can be made efficiently.
The polymerization initiator added to the cleaning layer is not particularly limited, and known ones can be used. For example, when heat is used as an active energy source, thermal polymerization initiation of benzoyl peroxide, azobisisobutyronitrile, etc. Benzoyl, benzoin ethyl ether, cibenzyl, isopropyl benzoin ether, benzophenone, Michler's ketone chlorothioxanthone, dodecyl thioxanthone, dimethylthioxanthone, acetophenone diethyl ketal, benzyl dimethyl ketal, α-hydroxycyclohexyl Examples include photopolymerization initiators such as silphenyl ketone, 2-hydroxydimethylphenylpropane, and 2,2-dimethoxy-2-phenylacetophenone.
[0012]
Further, when the cleaning layer is provided on the support (Claim 2), the support is not particularly limited. For example, a plastic film such as polyethylene, polyethylene terephthalate, acetylcellulose, polycarbonate, polypropylene, polyamide, polyimide, polycarbodiimide, or the like. Is mentioned. The thickness is usually about 10 to 100 μm.
[0013]
The present invention further provides a cleaning sheet (Claim 3) 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 it satisfies the pressure-sensitive adhesive function, and a normal pressure-sensitive adhesive (for example, acrylic or rubber) can be used.
By adopting such a configuration, the cleaning sheet is attached to a transport member such as various substrates and other tapes and sheets by a normal adhesive layer, and transported into the apparatus as a transport member with a cleaning function, to be cleaned. It can be cleaned by contact. Further, when the substrate is peeled off from the pressure-sensitive adhesive layer after cleaning in order to reuse the conveying member such as the above-mentioned substrate, the adhesive force of the normal pressure-sensitive adhesive layer is not particularly limited as long as it can be re-peeled. If the 180 degree peeling adhesive strength to the silicon wafer (mirror surface) is 0.20 to 0.98 N / 10 mm, especially about 0.40 to 0.98 N / 10 mm, cleaning does not occur during transportation. This is preferable because it can be easily re-peeled later.
[0014]
The transport member to which the cleaning sheet is attached 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]
【Example】
Hereinafter, although the present invention is explained based on an example, the present invention is not limited to these. Hereinafter, “parts” means parts by weight.
EXAMPLE Dipentaerythrol with respect to 100 parts of an acrylic polymer (weight average molecular weight of 2.8 million) obtained from a monomer mixture consisting of 30 parts of 2-ethylhexyl acrylate, 70 parts of methyl acrylate, and 10 parts of acrylic acid 150 parts of hexaacrylate (manufactured by Nippon Synthetic Chemical Co., Ltd .: trade name: UV 1700B), 3 parts of a polyisocyanate compound (manufactured by Nippon Polyurethane Industry: trade name: Coronate L), and benzyldimethyl ketal (Ciba Specialty Chemicals) as a photopolymerization initiator Product: Trade name: Irgacure 651) 10 parts were mixed uniformly to prepare an ultraviolet curable adhesive solution A. When this cleaning layer pressure-sensitive adhesive was cured by irradiating ultraviolet light having a central wavelength of 365 nm with an integrated light quantity of 1000 mJ / cm ² , the surface of the cleaning layer had substantially no adhesiveness, and after the cleaning layer was cured by ultraviolet light. The tensile strength of was 1440 MPa. Here, the tensile strength was measured according to the test method JIS K7127.
On the other hand, for 100 parts of an acrylic polymer (weight average molecular weight 700,000) obtained from a monomer mixture consisting of 75 parts of 2-ethylhexyl acrylate, 20 parts of methyl acrylate, and 5 parts of acrylic acid, polyethylene glycol is used. 200 dimethacrylate (made by Shin-Nakamura Chemical: trade name: NK ester 4G), 50 parts of urethane acrylate (made by Shin-Nakamura Chemical: trade name: UN-01), and polyisocyanate compound (Nippon Polyurethane) Kogyo Co., Ltd .: Trade name: Coronate L) 3 parts was mixed uniformly to prepare a pressure-sensitive adhesive solution B.
The pressure-sensitive adhesive solution B was applied to 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 was 10 μm, and a normal pressure-sensitive adhesive layer was provided, and the thickness was 38 μm on the surface. A polyester release film was affixed. Next, on the other side of the support film, the UV 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 pasted on the surface. .
The cleaning sheet of the present invention was obtained by irradiating the sheet with ultraviolet light having a central wavelength of 365 nm and an integrated light quantity of 1000 mJ / cm ² . When the release film on the cleaning layer side of this cleaning sheet was peeled off and the surface free energy of this cleaning layer was measured, it was 18.4 mJ / m ² and the contact angle of water was 105.1 degrees.
[0016]
The release film on the normal pressure-sensitive adhesive layer side of the cleaning sheet was peeled off and attached to the back surface (mirror surface) of an 8-inch silicon wafer with a hand roller to prepare a transport cleaning wafer with a cleaning function.
[0017]
On the other hand, when the wafer stage of the substrate processing apparatus was removed and foreign matters having a size of 0.3 μm or more were measured with a laser type foreign matter measuring apparatus, the number was 21,000 in an area of 8 inch wafer size.
[0018]
Then, when the peeling film on the cleaning layer side of the cleaning wafer is peeled off and transported into the substrate processing apparatus, even if 100 sheets are transported continuously, the cleaning layer does not adhere strongly to the portion to be cleaned. It was possible to carry it without cleaning.
Also, after that, the wafer stage was removed, and a foreign substance measuring 0.3 μm or more was measured with a laser type foreign substance measuring device. As a result, the number of foreign substances adhered before cleaning became 20000 within an 8-inch wafer size area. It was possible to reduce.
[0019]
Comparative Example As an adhesive for the cleaning layer, 100 parts of an acrylic polymer (weight average molecular weight of 2.8 million) obtained from a monomer mixture composed of 30 parts of 2-ethylhexyl acrylate, 70 parts of methyl acrylate, and 10 parts of acrylic acid In contrast, 100 parts of polyethylene glycol 200 dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd .: trade name: NK ester 4G), polyethylene glycol 600 diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd .: trade name: NK ester A-600) A pressure-sensitive adhesive solution C prepared by uniformly mixing 100 parts and 3 parts of a polyisocyanate compound (manufactured by Nippon Polyurethane Industry: trade name: Coronate L) was used. The tensile strength of the cleaning layer was measured in the same manner as in the example and found to be 0.1 MPa.
A cleaning sheet was prepared in the same manner as in the Example, and the surface free energy of this cleaning layer was measured. As a result, the contact angle of water was 59.4 mJ / m ² and 49.4 degrees.
[0020]
When a transfer cleaning wafer produced from this cleaning sheet by the same method as in the example was transferred into the substrate processing apparatus, the first wafer adhered to the wafer stage and could not be transferred.
[0021]
【The invention's effect】
As described above, according to the cleaning sheet of the present invention, the inside of the substrate processing apparatus can be reliably conveyed, and foreign substances adhering to the inside of the apparatus can be easily reduced.

Claims (7)

A cleaning sheet that is provided on a conveying member and removes foreign matters by being conveyed into a substrate processing apparatus, and is made of a material having a surface free energy of 15 to 25 mJ / m ² and a contact angle of water exceeding 90 degrees. A cleaning sheet comprising a cleaning layer. A cleaning sheet that is provided on a transport member and removes foreign matter by transporting it into a substrate processing apparatus, and has a surface free energy of 15 to 25 mJ / m ² and a water contact angle on at least one surface of a support. A cleaning sheet provided with a cleaning layer exceeding 90 degrees. A cleaning sheet that is provided on a conveying member and removes foreign matters by being conveyed into a substrate processing apparatus, and has a surface free energy of 15 to 25 mJ / m ² and a water contact angle of 90 degrees on one side of a support. A cleaning sheet in which a cleaning layer exceeding 30 mm is provided and a normal pressure-sensitive adhesive layer is provided on the other surface.   The cleaning sheet according to any one of claims 1 to 3, wherein the cleaning layer has substantially no adhesiveness and has a tensile strength of 2000 MPa or less.   The cleaning sheet according to claim 1, wherein the cleaning layer is a pressure-sensitive adhesive layer cured by active energy.   A conveying member with a cleaning function, wherein the cleaning sheet according to claim 3 is provided on the conveying member via an adhesive layer.   A cleaning method for a substrate processing apparatus, comprising: transporting the cleaning sheet according to claim 1 or 2 or the transporting member according to claim 6 into the substrate processing apparatus.