JP4248018B2 - Cleaning sheet and cleaning method for substrate processing apparatus - Google Patents

Description

The present invention relates to a cleaning sheet for cleaning a transfer system of various substrate processing apparatuses that dislike foreign matters such as metal impurities such as a semiconductor manufacturing apparatus and an inspection apparatus, and a cleaning method for the substrate processing apparatus using the same. .

In various types of substrate processing apparatuses, each transport system and the substrate are transported while being in physical contact. At that time, if foreign matter adheres to the substrate or the transport system, subsequent substrates are successively contaminated. Therefore, it is necessary to periodically stop the apparatus and perform a cleaning process. As a result, there has been a problem that the operation rate is reduced and a great deal of labor is required.

In order to solve these problems, a method of transporting a substrate to which an adhesive substance is adhered and cleaning and removing foreign substances adhering to the inside of the substrate processing apparatus (see Patent Document 1), or a plate-shaped member is transported to back the substrate. There has been proposed a method (see Patent Document 2) for removing foreign substances adhering to the surface.

JP-A-10-154686 (pages 2 to 4) Japanese Patent Laid-Open No. 11-87458 (pages 2 to 3)

According to the above proposed method, since it is not necessary to stop the apparatus and perform the cleaning process, there is no problem that the operation rate is reduced and a great deal of labor is required. In particular, the former method is excellent in the removal of foreign matters. However, the degree of vacuum is reduced when a substrate or the like to which an adhesive substance is fixed is transported into a vacuum-type substrate processing apparatus, making it impossible to use the apparatus or taking too much time to return to the specified degree of vacuum. There was a problem that.

In light of such circumstances, the present invention suppresses a decrease in the degree of vacuum when transported into a vacuum-type substrate processing apparatus, does not hinder the use of the apparatus, and shortens the time required to reach a specified degree of vacuum. An object of the present invention is to provide a highly practical cleaning member.

In order to achieve the above object, the present inventors have intensively investigated the cause of the decrease in the degree of vacuum when the cleaning member is transported into the vacuum-type substrate processing apparatus. The relationship between the moisture content and the decrease in the degree of vacuum was examined in detail, and in various forms of cleaning members, the normal moisture absorption rate and the normal state at a temperature of 23 ° C. and a relative humidity of 50% were found. By using a material whose moisture absorption amount is not more than a specific value, and by setting the normal moisture absorption rate and the normal moisture absorption amount to optimum values according to various forms of the cleaning member, Highly practical cleaning that ensures that the vacuum level when transported is suppressed, does not hinder the use of the device, and shortens the time to reach the specified vacuum level. I learned that member can be obtained.

The present invention is based on these findings, it has been completed.

The present invention relates to a cleaning sheet for transporting into a vacuum type substrate processing apparatus and cleaning and removing foreign matter adhering to the apparatus. (1) A cleaning layer is provided on one side of a support, and the opposite side is provided. The cleaning sheet has either a three-layer structure having an adhesive layer, (2) a two-layer structure having an adhesive layer on one side of the cleaning layer, or (3) a single-layer structure consisting of a single cleaning layer. In addition, the present invention relates to a cleaning sheet having a normal moisture absorption of 1.0% or less at a temperature of 23 ° C. and a relative humidity of 50%, and a normal moisture absorption of 100 μg / cm ² or less.

In particular, the present invention relates to the cleaning sheet of the form (1), wherein the normal moisture absorption is 0.7% or less and the normal moisture absorption is 100 μg / cm ² or less. The cleaning sheet having a moisture absorption rate of 0.9% or less, a normal moisture absorption rate of the pressure-sensitive adhesive layer of 0.8% or less, and a substrate substrate having a normal moisture absorption rate of 0.4% or less; and the cleaning sheet of the form (2) The above-described cleaning sheet having a normal moisture absorption of 0.8% or less and a normal moisture absorption of 50 μg / cm ² or less, in particular, the normal moisture absorption of the cleaning layer is 0.9% or less, and the normal state of the pressure-sensitive adhesive layer. The cleaning sheet having a moisture absorption rate of 0.7% or less, and the cleaning sheet of the form (3), wherein the normal moisture absorption rate is 1.0% or less and the normal moisture absorption amount is 40 μg / cm ² or less. Cleaning sea The door, in which can be provided.

The present invention also provides a transport member with a cleaning function, wherein the cleaning sheet having the above-described configuration is provided on a transport member, and transports the transport member into a vacuum-type substrate processing apparatus. It is possible to provide a cleaning method for a substrate processing apparatus characterized in that foreign matter adhering to the substrate is removed by cleaning, and a substrate processing apparatus characterized in that the substrate processing apparatus is cleaned by this cleaning method.

When the cleaning sheet according to any one of the above (1) to (3) is used as a cleaning member, the present invention has a normal moisture absorption rate of 1.0% or less at a temperature of 23 ° C. and a relative humidity of 50%. By setting the moisture absorption amount to be 100 μg / cm ² or less, particularly in the cleaning sheet of the form (1), the normal moisture absorption rate is 0.7% or less, and the normal moisture absorption amount is 100 μg / cm ² or less. Thus, in the cleaning sheet of the form (2), the normal moisture absorption is 0.8% or less and the normal moisture absorption is 50 μg / cm ² or less. above normal moisture absorption of 1.0% or less, as normal moisture amount is 40 [mu] g / cm ² or less, by setting, the degree of vacuum when conveying these cleaning members in the substrate processing apparatus of a vacuum system Under is suppressed not disturb the use of the device, also can reduce the time to reach prescribed vacuum degree, the effect is achieved that the foreign matter adhering to the substrate processing apparatus can be easily and reliably cleaned removed.

The cleaning sheet used as a cleaning member in the present invention is either (1) a three-layer structure having a cleaning layer on one side of the support and an adhesive layer on the opposite side, or (2) an adhesive layer on one side of the cleaning layer. Or (3) a single-layer structure consisting of a single cleaning layer, and any of these forms is a normal state at a temperature of 23 ° C. and a relative humidity of 50%. It is necessary to set the moisture absorption rate to be 1.0% or less and the normal moisture absorption amount to be 100 μg / cm ² or less, and the above-described effect is exhibited only when the moisture absorption rate is set in this way. That is, in the cleaning sheet having the normal moisture absorption rate exceeding 1.0% or the normal moisture absorption amount exceeding 100 μg / cm ² , it is caused by degassing from the cleaning sheet when the cleaning sheet is conveyed into a vacuum type substrate processing apparatus. It takes too much time for the vacuum level of the apparatus to return to the specified value, and a serious problem that the vacuum level cannot be recovered tends to occur.

In this specification, “normal moisture absorption” and “normal moisture absorption” are obtained by cutting a sample into a size of 3 cm ² (1 cm × 3 cm) and subjecting it to a normal temperature at a temperature of 23 ° C. and a relative humidity of 50%. It is a value when the moisture absorption amount is saturated after being left for 10 days. For example, this saturated sample is heated and vaporized (coulometric titration moisture measuring device CA-06 type + heated vaporizer VA-06 type). Is obtained by introducing a gas heated at 150 ° C. into the titration cell and measuring the amount of water. Specifically, when the total weight of the sample in the saturated state is W1, and the water content measured by the above method is W0, it is obtained as “normal moisture absorption” = (W0 / W1) × 100. Further, the “normal moisture absorption amount” is obtained by converting the moisture amount measured by the above method into a value per unit area (1 cm ² ) of the sample. Therefore, the “normal moisture absorption” is a value specific to the sample, while the “normal moisture absorption” is a value that depends on the thickness of the sample.

In the present invention, since the cleaning sheet of the form (1) has a three-layer structure of cleaning layer / support / adhesive layer, the normal moisture absorption is an average value of the three layers, and the normal moisture absorption is a unit area. This is the total value of the above three layers. Similarly, since the cleaning sheet of the form (2) has a two-layer structure of cleaning layer / adhesive layer, the normal moisture absorption is an average value of the two layers, and the normal moisture absorption is the above two per unit area. The total value of the layer. On the other hand, since the cleaning sheet of the form (3) has a single layer structure of the cleaning layer alone, both the normal moisture absorption rate and the normal moisture absorption value are values of the cleaning layer alone.

Here, since the thickness of each layer or the total thickness differs depending on each form of (1) to (3), there is naturally an optimum normal moisture absorption rate and normal moisture absorption amount depending on each form. . The present inventors considered the thickness of each form and examined it in detail, and as a result, found that it is optimal to set the following for each form.

That is, in the cleaning sheet of the form (1), the normal moisture absorption is 0.7% or less, particularly 0.5% or less, and the normal moisture absorption is 100 μg / cm ² or less, particularly 60 μg / cm ² or less. Good. In this case, the normal moisture absorption of each layer is 0.9% or less of the normal moisture absorption of the cleaning layer, 0.8% or less of the normal moisture absorption of the pressure-sensitive adhesive layer, and 0.4% or less of the normal moisture absorption of the support. There should be. In the cleaning sheet of the form (2), it is preferable that the normal moisture absorption is 0.8% or less, particularly 0.7% or less, and the normal moisture absorption is 50 μg / cm ² or less, particularly 40 μg / cm ^2. . In this case, the normal moisture absorption rate of each layer is preferably 0.9% or less for the cleaning layer and 0.7% or less for the pressure-sensitive adhesive layer. Further, in the cleaning sheet of the form (3), the normal moisture absorption is 1.0% or less, particularly 0.9% or less, and the normal moisture absorption is 40 μg / cm ² or less, particularly 30 μg / cm ² or less. Good.

In the present invention, the cleaning layer, the pressure-sensitive adhesive layer, and the support are such that the entire normal moisture absorption rate and normal moisture absorption amount in the respective forms are the above-described optimum values in accordance with the respective forms (1) to (3). In addition, the material and thickness are set, and the material and thickness of each layer are not particularly limited as long as they are set in this way. Below, the structure of each layer is demonstrated.

First, the cleaning layer has a tensile elastic modulus (test method JIS K7127) of 10 MPa or more, preferably 10 to 2,000 MPa. When the pressure is 10 MPa or more, protrusion of the cleaning layer and cutting failure during label cutting can be suppressed, and a label sheet with a cleaning function free of contamination can be manufactured by a pre-cut method. There is no risk of causing. Moreover, a favorable result is acquired in the removability of the adhering foreign material of a conveyance system as it is 2,000 Mpa or less.

Such a cleaning layer is not particularly limited in material, but is preferably composed of a resin layer polymerized and cured by an active energy source such as ultraviolet rays or heat. This is because the molecular structure becomes a three-dimensional network due to the above-described polymerization and curing, so that there is substantially no stickiness, and it does not adhere strongly to the apparatus contact portion at the time of conveyance, and a cleaning member that can be reliably conveyed in the substrate processing apparatus is obtained. It is. Examples of the polymer-cured resin layer include, for example, a compound having at least one unsaturated double bond in the molecule (hereinafter referred to as a polymerizable unsaturated compound) and a polymerization initiator in a pressure-sensitive adhesive polymer, and crosslinking if necessary. And a curable resin composition containing an agent and the like cured by an active energy source, particularly ultraviolet rays.

Examples of the pressure-sensitive adhesive polymer include acrylic polymers having (meth) acrylic acid and / or (meth) acrylic acid ester as a main monomer. 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 functionalized in the synthesized acrylic polymer. An unsaturated double bond may be introduced into the molecule of the acrylic polymer, for example, by a chemical bond between the groups. As a result, the acrylic polymer itself can be involved in the polymerization curing reaction by the active energy source.

The polymerizable unsaturated compound is preferably a non-volatile and low molecular weight material having a weight average molecular weight of 10,000 or less, particularly 5,000 or less so that three-dimensional networking can be efficiently performed during curing. It is preferable to have a molecular weight of

Examples of such polymerizable unsaturated compounds include phenoxy polyethylene glycol (meth) acrylate, ε-caprolactone (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane tri ( (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, oligoester (meth) acrylate, and the like. Among these, one or more are used. .

It does not specifically limit as a polymerization initiator, A well-known thing can be used.

For example, when using heat as an active energy source, a thermal polymerization initiator such as benzoyl peroxide or azobisisobutyronitrile, and when using light, benzoyl, benzoin ethyl ether, cibenzyl, isopropyl benzoin ether, benzophenone, Photopolymerization of Michler's ketone chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, acetophenone diethyl ketal, benzyl dimethyl ketal, α-hydroxycyclohexyl phenyl ketone, 2-hydroxymethylphenylpropane, 2,2-dimethoxy-2-phenylacetophenone, etc. Initiators are mentioned.

The cleaning layer described above has a 180-degree peeling adhesive force (measured according to JIS Z0237) of 0.2 N / 10 mm width or less, preferably about 0.01 to 0.1 N / 10 mm width to the silicon wafer (mirror surface). There should be. By setting the cleaning layer to such a low adhesion or non-adhesion, it does not adhere to a contacted part in the apparatus during conveyance, and there is no possibility of causing a conveyance trouble. Further, the thickness of such a cleaning layer is not particularly limited, but usually it is preferably about 5 to 30 μm.

Next, the pressure-sensitive adhesive layer has a 180-degree peeling adhesive strength to the silicon wafer (mirror surface) of 0.01 to 10 N / 10 mm width, preferably 0.05 to 5 N / 10 mm width. If the adhesive strength is too high, the support film or the like may be torn when the cleaning sheet is peeled off from the substrate or the like. Although the thickness of an adhesive layer is not specifically limited, Usually, 5-100 micrometers, Preferably it is about 5-30 micrometers.

Such a pressure-sensitive adhesive layer is not particularly limited in terms of its material structure, and any ordinary pressure-sensitive adhesive such as acrylic or rubber-based can be used. Among these, as the acrylic pressure-sensitive adhesive, those mainly composed of an acrylic polymer having a component having a weight average molecular weight of 100,000 or less and 10% by weight or less are particularly preferable. The above acrylic polymer can be synthesized by polymerizing a monomer mixture in which (meth) acrylic acid alkyl ester is a main monomer and another copolymerizable monomer is added as necessary.

Supports are polyolefins such as polyethylene, polypropylene, polybutene, polybutadiene, polymethylpentene, polyvinyl chloride, vinyl chloride copolymer, polyethylene terephthalate, polybutylene terephthalate, polyurethane, ethylene / vinyl acetate copolymer, ionomer. Examples include films made of resins, ethylene / (meth) acrylic acid copolymers, ethylene / (meth) acrylic acid ester copolymers, polystyrene, polycarbonate, and the like. A single layer film of each of the above resins or a laminated film may be used. Further, one or both surfaces may be subjected to a surface treatment such as corona treatment. Particularly preferred is a low hygroscopic film made of an ethylene / vinyl acetate copolymer, polyolefin, or the like, and a low hygroscopic cleaning sheet can be produced by these. The thickness of the support is usually about 10 to 200 μm.

In the present invention, in the cleaning sheet of the form (3), the above-described cleaning layer is formed by itself into a sheet shape or a tape form, and in the cleaning sheet of the form (2), the above-described forming is performed. By providing a pressure-sensitive adhesive layer on one side of the cleaning layer, and in the cleaning sheet of the form (1), by providing the cleaning layer on one side of the support and providing the pressure-sensitive adhesive layer on the opposite side, Can be produced. These production methods are not particularly limited, and known methods can be employed.

In these cleaning sheets, a protective film may be bonded to the surface of the cleaning layer or the pressure-sensitive adhesive layer until the cleaning sheet is used.

Examples of the protective film include polyolefins such as polyethylene, polypropylene, polybutene, polybutadiene, and polymethylpentene, which have been subjected to a release treatment using a silicone-based, long-chain alkyl-based, fluorine-based, fatty acid amide-based, or silica-based release agent. Vinyl chloride, vinyl chloride copolymer, polyethylene terephthalate, polybutylene terephthalate, polyurethane, ethylene / vinyl acetate copolymer, ionomer resin, ethylene / (meth) acrylic acid copolymer, ethylene / (meth) acrylic acid ester copolymer Examples thereof include plastic films made of coalesced polystyrene, polycarbonate, and the like. In addition, a film made of polyolefin such as polyethylene or polypropylene has releasability without being subjected to a release treatment with a release agent, so that it can be used alone as a protective film. The thickness of such a protective film is usually 10 to 100 μm.

In the present invention, when these cleaning sheets are transported as cleaning members into the substrate processing apparatus, each cleaning sheet is provided on the transporting member to form a transporting member with a cleaning function. At that time, in the cleaning sheets of the forms (1) and (2), the pressure-sensitive adhesive layer may be used to adhere to the conveying member. In the cleaning sheet of the form (3), the sheet alone may be pressure-bonded and stacked on the conveying member, or may be bonded and stacked using an appropriate adhesive (adhesive) as necessary. . In the case of the latter adhesive lamination, it is desirable that the entire normal moisture absorption rate and the normal moisture absorption amount including the adhesive (adhesive) to be used are the above set values.

The transport member provided with the cleaning sheet is not particularly limited, and various types of substrates are used according to the type of substrate processing apparatus that is a target for removing foreign matter. Specifically, semiconductor wafers, flat panel display substrates such as LCDs and PDPs, other compact discs, substrates such as MR heads, and the like can be given.

In the present invention, by transporting such a transport member with a cleaning function into the substrate processing apparatus, the foreign matter adhering to the transport system in the substrate processing apparatus is removed by cleaning. Here, since the conveyance member with a cleaning function to be used is configured to suppress a decrease in the degree of vacuum, the substrate processing apparatus is preferably a high vacuum type. However, it can be applied to other substrate processing apparatuses. Specific examples include an exposure apparatus, a resist coating apparatus, a developing apparatus, an ashing apparatus, a dry etching apparatus, an ion implantation apparatus, a PVD apparatus, a CVD apparatus, an appearance inspection apparatus, and a wafer blower.

The present invention can provide each of the above-described substrate processing apparatuses in which the transport member with the cleaning function is transported to remove foreign substances in the apparatus.

Next, examples of the present invention will be described in more detail.

However, the present invention is not limited only to the following examples. In the following, “parts” means parts by weight.

An example of the cleaning sheet in the form (1) will be described in comparison with Comparative Example 1.

Example 1
Polyethylene glycol 200 dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) was added to 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. (Trade name “NK ester 4G”) 200 parts, polyisocyanate compound (trade name “Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) 3 parts, epoxy compound (trade name “Tetrad C” manufactured by Mitsubishi Gas Chemical Co., Ltd.) 2 And 3 parts of benzyl dimethyl ketal (trade name “Irgacure 651” manufactured by Ciba Specialty Chemicals) as a photopolymerization initiator were uniformly mixed to prepare an ultraviolet curable resin composition A.

Separately, in a three-necked flask type reactor having an internal volume of 500 ml equipped with a thermometer, a stirrer, a nitrogen inlet tube and a reflux condenser, 73 parts of 2-ethylhexyl acrylate and 10 parts of n-butyl acrylate , 15 parts of N, N-dimethylacrylamide and 5 parts of acrylic acid, 0.15 part of 2,2′-azobisisobutyronitrile as a polymerization initiator and 100 parts of ethyl acetate, resulting in a total of 200 g The mixture was added and stirred while introducing nitrogen gas for about 1 hour, and the air inside was replaced with nitrogen. Thereafter, the internal temperature was set to 58 ° C., and the polymerization was carried out in this state for about 4 hours to obtain an adhesive polymer solution. To 100 parts of this pressure-sensitive adhesive polymer solution, 3 parts of a polyisocyanate compound (trade name “Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) was uniformly mixed to prepare pressure-sensitive adhesive solution A.

On the silicone release treatment surface of a protective film consisting of a long polyester film (trade name “MRF50N100” manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., thickness 50 μm, width 250 mm) treated on one side with a silicone release agent The pressure-sensitive adhesive solution A was applied so that the thickness after drying was 15 μm and dried. On the pressure-sensitive adhesive layer, a long polyester film (having a thickness of 25 μm and a width of 250 mm) was laminated as a support. Furthermore, the ultraviolet curable resin composition A is applied onto the film so that the thickness after drying is 30 μm, and is dried to provide a resin layer. A protective film made of a polypropylene film (trade name “Trephan BO2500” manufactured by Toray Industries, Inc., 30 μm in thickness and 250 mm in width) was bonded to obtain a laminated sheet A1.

The laminated sheet A1 was irradiated with ultraviolet light having a center wavelength of 365 nm at an integrated light quantity of 1,000 mJ / cm ² to obtain a cleaning sheet A1 having a cleaning layer made of a polymerized and cured resin layer. The protective film on the cleaning layer side of this cleaning sheet A1 was peeled off, and the 180 ° peel adhesion to the silicon wafer (mirror surface) (measured according to test method JIS Z0237) was measured. there were. Further, the tensile strength (measured according to the test method JIS K7127) of this cleaning layer was measured, and as a result, it was 440 MPa. Further, the protective film on the cleaning layer side and the adhesive layer side of the cleaning sheet A1 were peeled off, and the normal moisture absorption and the normal moisture absorption were determined by the following method. The normal moisture absorption was 0.7%, The normal moisture absorption was 70 μg / cm ² .

<Measurement of normal moisture absorption and normal moisture absorption>
The sample made of the cleaning sheet A1 is cut out to a size of 3 cm ² (1 cm × 3 cm), the protective films on both sides are peeled off, and left for 10 days under normal conditions (temperature 23 ° C., relative humidity 50%). ) The entire amount of moisture absorption was saturated. Next, this is put into an aluminum foil, put into a heating vaporizer (coulometric titration type moisture measuring device CA-06 type + heating vaporizer VA-06 type) and heated at 150 ° C., and the released gas is titrated. By introducing into the cell and measuring the water content, the normal moisture absorption rate and the normal moisture absorption amount were determined.

Next, the protective film on the pressure-sensitive adhesive layer side of the cleaning sheet A1 was peeled off and attached to the mirror surface of an 8-inch silicon wafer with a hand roller to produce a conveying member A1 with a cleaning function. The adhesive strength of the adhesive layer to the silicon wafer (mirror surface) was 180 N and the adhesive strength was 1.5 N / 10 mm width. Using this conveying member A1 with a cleaning function, the substrate processing apparatus was cleaned by the following method.

First, foreign matters of 0.2 μm or more on the mirror surface of 12 new 8-inch silicon wafers were measured with a laser surface inspection apparatus, and all were 10 or less.

Next, six of these 8-inch silicon wafers were transferred to separate vacuum sputtering devices with the mirror surface facing downward, and the mirror surface was measured with a laser surface inspection device. In this area, there were 15,553, 15,561, 15,212, 17,050, 16,500, and 15,201 foreign matters of 0.2 μm or more, respectively.

Next, the transport member A1 with the cleaning function is transported to the vacuum sputtering apparatus having the wafer stage to which the 15,553 foreign substances have adhered, with the protective film on the cleaning layer side peeled off, Foreign matter was removed by cleaning. At that time, the degree of vacuum was stable and could be transported without any problem. After repeating this transfer operation five times, a new 8-inch silicon wafer was transferred with the mirror surface facing downward, and a foreign object of 0.2 μm or more was measured with a laser particle inspection device. The foreign matter was removed. In addition, when the conveying member A1 with a cleaning function was repeatedly conveyed five times, the degree of vacuum in the apparatus was not reduced, and the degree of vacuum was stable, and no problem was caused in using the apparatus.

Comparative Example 1
A 1 liter flask equipped with a stirrer is charged with a monomer mixture consisting of 75 parts of 2-ethylhexyl acrylate, 45 parts of methyl acrylate and 180 parts of acrylic acid, and 450 parts of methanol, heated to 60 ° C. in a nitrogen gas atmosphere, and used as a polymerization initiator. 0.6 parts of azoisobutyronitrile was added and polymerized for 8 hours. The polymerization rate was almost 100%, and the obtained acrylic polymer had a weight average molecular weight of 200,000. An ultraviolet curable resin composition B was prepared in the same manner as in Example 1 except that this acrylic polymer was used.

Separately, 10 parts of acrylic acid, 45 parts of 2-ethylhexyl acrylate and 45 parts of butyl acrylate were placed in a three-necked flask type reactor having an internal volume of 500 ml equipped with a thermometer, a stirrer, a nitrogen introduction pipe and a reflux condenser. A monomer mixture consisting of 1 part, 0.15 part of 2,2'-azobisisobutyronitrile as a polymerization initiator and 45 parts of toluene as a solvent were added in a total amount of 200 g. While stirring for 1 hour, the air inside was replaced with nitrogen. Thereafter, the internal temperature was set to 58 ° C., and the polymerization was carried out in this state for about 4 hours to obtain an adhesive polymer solution. To 100 parts of this pressure-sensitive adhesive polymer solution, 3 parts of a polyisocyanate compound (trade name “Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) and 2 parts of an epoxy compound (trade name “Tetrad C” manufactured by Mitsubishi Gas Chemical Co., Ltd.) The pressure-sensitive adhesive solution B was prepared by mixing uniformly.

On the silicone release treatment surface of a protective film consisting of a long polyester film (trade name “MRF50N100” manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., thickness 50 μm, width 250 mm) treated on one side with a silicone release agent The pressure-sensitive adhesive solution B was applied so that the thickness after drying was 15 μm and dried. On the pressure-sensitive adhesive layer, a polyimide film (trade name “Kapton Film” manufactured by Toray DuPont, thickness 25 μm, width 250 mm) was laminated as a support. Furthermore, on the film, the ultraviolet curable resin composition B is applied so that the thickness after drying is 30 μm, and is dried to provide a resin layer. A protective film made of a polypropylene film (trade name “Trephan BO2500” manufactured by Toray Industries, Inc., 30 μm in thickness and 250 mm in width) was bonded to obtain a laminated sheet B1.

The laminated sheet B1 was irradiated with ultraviolet light having a center wavelength of 365 nm at an integrated light quantity of 1,000 mJ / cm ² to obtain a cleaning sheet B1 having a cleaning layer made of a polymerized and cured resin layer. The protective film on the cleaning layer side of the cleaning sheet B1 was peeled off, and the 180 ° peel adhesion to the silicon wafer (mirror surface) was measured (measured according to test method JIS Z0237). there were. Further, the tensile strength (measured according to the test method JIS K7127) of this cleaning layer was measured, and as a result, it was 500 MPa. Further, the protective film on the cleaning layer side and the adhesive layer side of the cleaning sheet B1 were peeled off, and the normal moisture absorption and the normal moisture absorption were determined in the same manner as in Example 1. The normal moisture absorption was 3.0%. The normal moisture absorption was 210 μg / cm ² .

Next, the protective film on the pressure-sensitive adhesive layer side of the cleaning sheet B1 was peeled off and attached to the mirror surface of an 8-inch silicon wafer with a hand roller to prepare a conveying member B1 with a cleaning function. Note that the adhesive strength of the adhesive layer to the silicon wafer (mirror surface) was 180 N peel and the width was 1.2 N / 10 mm.

The transfer member B1 with the cleaning function was transferred to a vacuum sputtering apparatus having a wafer stage on which 15,561 foreign substances were adhered, and the substrate processing apparatus was cleaned in the same manner as in Example 1. However, during the first transfer, the degree of vacuum in the apparatus did not recover from the specified value, and the subsequent transfer had to be stopped.

The cleaning sheet having the form (2) will be described in comparison with the comparative example 2.

Example 2
On the silicone release treatment surface of a protective film consisting of a long polyester film (trade name “MRF50N100” manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., thickness 50 μm, width 250 mm) treated on one side with a silicone release agent The pressure-sensitive adhesive solution A prepared in Example 1 was applied and dried so that the thickness after drying was 15 μm. On the pressure-sensitive adhesive layer, the ultraviolet curable resin composition A prepared in Example 1 was applied so that the thickness after drying was 30 μm, and was dried to provide a resin layer. A protective film made of a long biaxially stretched polypropylene film (trade name “Treffan BO2500” manufactured by Toray Industries, Inc., 30 μm thick and 250 mm wide) was laminated to obtain a laminated sheet A2.

The laminated sheet A2 was irradiated with ultraviolet light having a central wavelength of 365 nm and an integrated light quantity of 1,000 mJ / cm ² to obtain a cleaning sheet A2 having a cleaning layer made of a polymerized and cured resin layer. The protective film on the cleaning layer side and the adhesive layer side of this cleaning sheet A2 were peeled off, and the normal moisture absorption and the normal moisture absorption were determined in the same manner as in Example 1. The normal moisture absorption was 0.8%, The normal moisture absorption was 50 μg / cm ² .

Next, the protective film on the pressure-sensitive adhesive layer side of the cleaning sheet A2 was peeled off and attached to the mirror surface of an 8-inch silicon wafer with a hand roller to produce a conveying member A2 with a cleaning function.

The transfer member A2 with a cleaning function was transferred to a vacuum sputtering apparatus having a wafer stage to which 15,212 foreign substances had adhered, and the substrate processing apparatus was cleaned in the same manner as in Example 1. At that time, the degree of vacuum was stable and could be transported without any problem. After repeating this transfer operation five times, a new 8-inch silicon wafer was transferred with the mirror surface facing downward, and a foreign object of 0.2 μm or more was measured with a laser particle inspection device. The foreign matter was removed. In addition, when the conveying member A2 with a cleaning function was repeatedly conveyed five times, the degree of vacuum in the apparatus was not reduced, and the degree of vacuum was stable, and no problem was caused in using the apparatus.

Comparative Example 2
On the silicone release treatment surface of a protective film consisting of a long polyester film (trade name “MRF50N100” manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., thickness 50 μm, width 250 mm) treated on one side with a silicone release agent The pressure-sensitive adhesive solution B prepared in Comparative Example 1 was applied and dried so that the thickness after drying was 15 μm. On the pressure-sensitive adhesive layer, the ultraviolet curable resin composition B prepared in Comparative Example 1 was applied so that the thickness after drying was 30 μm, and dried to provide a resin layer. A protective film made of a long biaxially stretched polypropylene film (trade name “Torphan BO2500” manufactured by Toray Industries, Inc., 30 μm thick and 250 mm wide) was laminated to obtain a laminated sheet B2.

The laminated sheet B2 was irradiated with ultraviolet light having a central wavelength of 365 nm and an integrated light quantity of 1,000 mJ / cm ² to obtain a cleaning sheet B2 having a cleaning layer made of a polymerized and cured resin layer. The protective film on the cleaning layer side and the adhesive layer side of the cleaning sheet B2 were peeled off, and the normal moisture absorption and the normal moisture absorption were determined in the same manner as in Example 1. The normal moisture absorption was 4.0%. The normal moisture absorption was 150 μg / cm ² .

Next, the protective film on the adhesive layer side of the cleaning sheet B2 was peeled off and attached to the mirror surface of an 8-inch silicon wafer with a hand roller to prepare a conveying member B2 with a cleaning function.

The transfer member B2 with the cleaning function was transferred to a vacuum sputtering apparatus having a wafer stage on which 17,050 foreign substances had adhered, and the substrate processing apparatus was cleaned in the same manner as in Example 1. However, during the first transfer, the degree of vacuum in the apparatus did not recover from the specified value, and the subsequent transfer had to be stopped.

The cleaning sheet having the form (3) will be described in comparison with the comparative example 3.

Example 3
The ultraviolet curable resin composition A prepared in Example 1 was applied to a protective film composed of a long biaxially stretched polypropylene film (trade name “Treffan BO2500” manufactured by Toray Industries, Inc., thickness 30 μm, width 250 mm). The thickness after drying is applied to be 30 μm and dried to provide a resin layer. On the surface, a long biaxially stretched polypropylene film (trade name “Torphan BO2500” manufactured by Toray Industries, Inc. A protective film having a thickness of 60 μm and a width of 250 mm was bonded to obtain a laminated sheet A3.

This laminated sheet A3 was irradiated with ultraviolet light having a central wavelength of 365 nm and an integrated light quantity of 1,000 mJ / cm ² to obtain a cleaning sheet A3 made of a cleaning layer alone made of a polymerized and cured resin layer. The protective films on both sides of the cleaning sheet A3 were peeled off, and the normal moisture absorption and the normal moisture absorption were determined in the same manner as in Example 1. The normal moisture absorption was 1.0%, and the normal moisture absorption was 40 μg / cm ² .

Next, the protective film on one side of the cleaning sheet A3 was peeled off, and the sheet was pressure-bonded to a mirror surface of an 8-inch silicon wafer with a hand roller to prepare a conveying member A3 with a cleaning function.

This transport member A3 with a cleaning function was transported to a vacuum sputtering apparatus having a wafer stage on which 16,500 foreign substances had adhered, and the substrate processing apparatus was cleaned in the same manner as in Example 1. At that time, the degree of vacuum was stable and could be transported without any problem. After repeating this transfer operation five times, a new 8-inch silicon wafer was transferred with the mirror surface facing downward, and a foreign object of 0.2 μm or more was measured with a laser particle inspection device. The foreign matter was removed. In addition, when the conveying member A3 with a cleaning function was repeatedly conveyed five times, the degree of vacuum in the apparatus was not lowered, showed a stable degree of vacuum, and caused no problems in using the apparatus.

Comparative Example 3
The ultraviolet curable resin composition B prepared in Comparative Example 1 was applied to a protective film made of a long biaxially stretched polypropylene film (trade name “Treffan BO2500” manufactured by Toray Industries, Inc., thickness 30 μm, width 250 mm). The thickness after drying is applied to be 30 μm and dried to provide a resin layer. On the surface, a long biaxially stretched polypropylene film (trade name “Torphan BO2500” manufactured by Toray Industries, Inc. A protective film having a thickness of 60 μm and a width of 250 mm was bonded to obtain a laminated sheet B3.

The laminated sheet B3 was irradiated with ultraviolet light having a central wavelength of 365 nm and an integrated light quantity of 1,000 mJ / cm ² to obtain a cleaning sheet B3 made of a cleaning layer alone made of a polymerized and cured resin layer. The protective films on both sides of this cleaning sheet B3 were peeled off, and the normal moisture absorption and the normal moisture absorption were determined in the same manner as in Example 1. The normal moisture absorption was 4.5%, and the normal moisture absorption was 130 μg / cm ² .

Next, the protective film on one surface side of the cleaning sheet B3 was peeled off, and the sheet was pressure-bonded to the mirror surface of an 8-inch silicon wafer with a hand roller to prepare a transport member B3 with a cleaning function.

The transfer member B3 with a cleaning function was transferred to a vacuum sputtering apparatus having a wafer stage on which 15,201 foreign substances had adhered, and the substrate processing apparatus was cleaned in the same manner as in Example 1. However, at the time of the first transfer, it took more than twice as long as the degree of vacuum in the apparatus to return to the specified value as compared with the transfer member A3 with the cleaning function of Example 3. Further, during the second and subsequent transports, the degree of vacuum of the apparatus did not recover to the specified value, and the subsequent transports had to be stopped.

Claims (9)

In a cleaning sheet for transporting into a vacuum-type substrate processing apparatus and cleaning and removing foreign matter adhering to the apparatus, (1) having a cleaning layer on one side of the support and an adhesive layer on the opposite side A cleaning sheet having either a three-layer structure, (2) a two-layer structure having an adhesive layer on one side of the cleaning layer, or (3) a single-layer structure comprising a single cleaning layer, and having a temperature of 23 A cleaning sheet having a normal moisture absorption of 1.0% or less at a temperature of 50 ° C. and a relative humidity of 50%, and a normal moisture absorption of 100 μg / cm ² or less.

The cleaning sheet according to claim 1, wherein the normal moisture absorption is 0.7% or less and the normal moisture absorption is 100 µg / cm ² or less.
The cleaning sheet according to claim 2, wherein the normal moisture absorption of the cleaning layer is 0.9% or less, the normal moisture absorption of the pressure-sensitive adhesive layer is 0.8% or less, and the normal moisture absorption of the support is 0.4% or less.
The cleaning sheet according to (2), wherein the normal moisture absorption is 0.8% or less and the normal moisture absorption is 50 μg / cm ² or less.
The cleaning sheet according to claim 4, wherein the normal moisture absorption of the cleaning layer is 0.9% or less, and the normal moisture absorption of the pressure-sensitive adhesive layer is 0.7% or less.
2. The cleaning sheet according to claim 1, wherein the normal moisture absorption is 1.0% or less and the normal moisture absorption is 40 μg / cm ² or less.
A conveying member with a cleaning function, wherein the cleaning sheet according to claim 1 is provided on a conveying member.
A cleaning method for a substrate processing apparatus, wherein the transport member with a cleaning function according to claim 7 is transported into a vacuum type substrate processing apparatus, and foreign substances adhering to the apparatus are cleaned and removed .

A substrate processing apparatus cleaned by the cleaning method according to claim 8.