JP2004235172A - Cleaning sheet and method for cleaning substrate treatment equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning member which does not generate contamination equipment by metallic impurities when a cleaning sheet is carried into the substrate treatment equipment and foreign substances in the equipment are cleaned and removed. <P>SOLUTION: The cleaning sheet having a cleaning layer in which the contents of each metallic element of Na, K, Mg, A1, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu and Zn or their compounds are 5 ppm (μg/g) or less respectively in terms of the metallic elements, on one surface of a supporter for the substrate treatment equipment and having a pressure-sensitive adhesive layer on the other surface and a carrying member having a cleaning function, in which the cleaning sheet is laminated on the carrying member through the pressure-sensitive adhesive layer, are carried into the equipment. Accordingly, the cleaning member is obtained which does not generate the contamination of the equipment by the metallic impurities and has a high practicality. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a sheet for cleaning various types of substrate processing apparatuses that dislike foreign substances, such as a manufacturing apparatus and an inspection apparatus for semiconductors, flat panel displays, and printed circuit boards, and a cleaning method for the substrate processing apparatus using the sheet, and cleaning by the cleaning method. To a processed substrate processing apparatus.
[0002]
[Prior art]
In various substrate processing apparatuses, each transport system and the substrate are transported while being in physical contact with each other. At this time, if foreign matter is attached to the substrate or the transport system, the subsequent substrate will be contaminated one after another. For this reason, it is necessary to stop the apparatus periodically to perform the cleaning process, which requires a decrease in the operation rate and a great amount of labor.
[0003]
In order to solve these problems, a method of transporting a substrate to which an adhesive substance is adhered and cleaning and removing foreign matter adhering in the substrate processing apparatus (see Patent Document 1), and a method of transporting a plate-shaped member to a back surface of the substrate A method of removing adhering foreign matter (see Patent Document 2) has been proposed. According to these methods, there is no need to stop the substrate processing apparatus and perform the cleaning process, so that there is no problem such as a decrease in the operation rate or a large amount of labor is required. It is excellent.
[0004]
[Patent Document 1]
JP-A-10-154686 (pages 2 to 4)
[Patent Document 2]
JP-A-11-87458 (pages 2-3)
[0005]
[Problems to be solved by the invention]
However, according to the study of the present inventors, in the above proposed method, if the cleaning member transported into the apparatus contains a metal such as an alkali metal or an alkaline earth metal or a compound thereof as an impurity, the expected In addition to not being able to obtain a cleaning effect, these impurities may contaminate the inside of the apparatus. In this case, the product wafer is contaminated, and serious problems such as corrosion of device wiring and deterioration of transistor characteristics are caused. It turns out that a problem occurs.
[0006]
In view of such circumstances, it is an object of the present invention to provide a cleaning member which does not cause contamination of a device due to metal impurities when the substrate is transported into a substrate processing apparatus to remove foreign matter in the apparatus.
[0007]
[Means for Solving the Problems]
The present inventors have conducted intensive studies in order to achieve the above-mentioned object, and as a result, when transporting the substrate into the substrate processing apparatus and cleaning and removing foreign matter in the apparatus, a specific metal contained in a cleaning layer to be brought into contact with the apparatus. Using a cleaning member with a regulated amount of elements or its compounds can reduce equipment contamination due to metal impurities, and can cause serious problems such as contaminating product wafers, corroding device wiring, and degrading transistor characteristics. Knowing that it can be prevented, the present invention has been completed.
[0008]
That is, according to the present invention, the content of each metal element of Na, K, Mg, Al, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn or a compound thereof is 5 ppm (μg / G) a cleaning sheet characterized by having a cleaning layer having the following properties, in particular, a cleaning sheet having the above-described configuration in which the cleaning layer has substantially no tackiness, and a cleaning sheet having the cleaning layer on a support. It relates to a cleaning sheet. Further, the present invention relates to a method for cleaning a substrate processing apparatus, wherein the cleaning sheet is transported into the substrate processing apparatus.
[0009]
Further, the present invention relates to a cleaning sheet having the above-described configuration having a cleaning layer on one side of a support and having an adhesive layer on the other side, and further includes the cleaning sheet having a pressure-sensitive adhesive layer interposed on a conveying member. The present invention relates to a transporting member with a cleaning function, which is adhered and adhered. Further, the present invention relates to a method of cleaning a substrate processing apparatus, wherein the transporting member having a cleaning function configured as described above is transported into a substrate processing apparatus.
Further, the present invention can provide a substrate processing apparatus cleaned by each of the above cleaning methods.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
In the present invention, the cleaning layer has a content of each metal element of Na, K, Mg, Al, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn or a compound thereof as a metal impurity. It is necessary that they are each 5 ppm (μg / g) or less in terms of conversion, preferably 2 ppm or less, and more preferably 1 ppm or less. By regulating the content of metal impurities in this manner, device contamination due to metal impurities when the substrate processing apparatus is cleaned can be reduced, and problems such as contamination of product wafers can be prevented.
[0011]
In addition, the said content can be measured as follows.
The cleaning layer is cut into 4 cm ² (2 cm × 2 cm), weighed in a platinum dish, and burned by heating with a gas burner. Thereafter, the mixture is placed in an electric furnace and heated at 550 ° C. for 1 hour and at 600 ° C. for 1 hour until there is no remaining charcoal. After cooling, 2 ml of concentrated hydrochloric acid is added, and the mixture is heated at 50 ° C. to dissolve the obtained ash. After allowing this to cool, ultrapure water was added to dilute it to 50 ml, and for Na and K, Mg, Al, Ca, Ti, Cr, Mn were determined by atomic absorption analysis ("Z-6100" manufactured by Hitachi, Ltd.). For Fe, Co, Ni, Cu, and Zn, the amounts of the respective elements are measured by ICP spectroscopy (“SPS-1700HVR” manufactured by Seiko Instruments Inc.).
[0012]
When such a cleaning layer has a tensile modulus of elasticity (test method: JIS K7127) of 10 MPa or more, preferably 10 to 2,000 MPa, it is possible to suppress protrusion and defective cutting of the cleaning layer during label cutting. This is preferable because a label sheet with a cleaning function free from contamination can be manufactured by the precut method. If the tensile elastic modulus is too small, the above problem at the time of cutting or the contact portion (the part to be cleaned) in the apparatus at the time of transport may cause a transport trouble, and if the tensile elastic modulus is too large, the transport system The performance of removing the adhered foreign matter on the surface is reduced.
[0013]
Such a cleaning layer is not particularly limited in its material and the like, but is desirably formed of a resin layer polymerized and cured by an active energy source such as ultraviolet light or heat. This provides a cleaning member that can be reliably transported into the substrate processing apparatus without having a molecular structure three-dimensionally reticulated due to the above-mentioned polymerization and curing, and substantially eliminating tackiness, not strongly adhering to the apparatus contact portion during transport. Because.
Here, “substantially non-adhesive” means that there is no pressure-sensitive tack representing the function of the adhesive when the essence of the adhesive is friction, which is resistance to slippage. This pressure-sensitive tack is such that, for example, according to Dahlquist's standard, the adhesive substance has an elastic modulus of up to 1 MPa.
[0014]
The polymerized and cured resin layer includes a compound having one or more unsaturated double bonds in the molecule of the pressure-sensitive adhesive polymer (hereinafter, referred to as a polymerizable unsaturated compound), a polymerization initiator, and, if necessary, a crosslinking agent. And the like. A curable resin composition containing such a material is cured with an active energy source, particularly ultraviolet light.
[0015]
In this curable resin composition, by regulating the content of the specific metal element or the compound thereof contained in each component, that is, selecting the material of each component to be used, or selecting the metal element or the compound thereof The content of the metal element or the compound thereof in the polymerized and cured resin layer is set to 5 ppm or less in terms of the metal element by performing an appropriate treatment for reducing the amount of the metal element.
When a protective film described later is bonded to a cleaning layer formed of a polymerized and cured resin layer or the like, the metal element or the compound thereof may be transferred from the protective film into the cleaning layer. In this case, the content of the metal element or its compound in the cleaning layer is set to 5 ppm or less in terms of the metal element, including the regulation of the transfer amount.
[0016]
As the pressure-sensitive adhesive polymer, an acrylic polymer having (meth) acrylic acid and / or (meth) acrylate as a main monomer is preferable. In synthesizing the acrylic polymer, a compound having two or more unsaturated double bonds in the molecule is used as a copolymer 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 groups. With this introduction, the acrylic polymer itself can also participate in the polymerization curing reaction.
[0017]
The polymerizable unsaturated compound is preferably a non-volatile, low-molecular weight compound having a weight-average molecular weight of 10,000 or less, and especially 5,000 or less so as to efficiently form a three-dimensional network upon curing. It is preferred to have a molecular weight of
Examples of such a polymerizable unsaturated compound include phenoxy polyethylene glycol (meth) acrylate, ε-caprolactone (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and trimethylolpropane tri ( (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, oligoester (meth) acrylate, and the like. One or more of these are used. .
[0018]
When heat is used as the active energy source, a thermal polymerization initiator such as benzoyl peroxide and azobisisobutyronitrile is used as the polymerization initiator. When light is used, benzoyl, benzoin ethyl ether, cibenzyl, isopropyl benzoin ether, benzophenone, Michler's ketone chlorothioxanthone, dodecylthioxanthone, cimethylthioxanthone, acetophenone diethyl ketal, benzyl dimethyl ketal, α-hydroxycyclohexyl phenyl ketone, A photopolymerization initiator such as hydroxymethylphenylpropane and 2,2-dimethoxy-2-phenylacetophenone is used.
[0019]
The cleaning layer composed of such a polymerized and cured resin layer has a 180-degree peel adhesion (measured according to JIS Z0237) to a silicon wafer (mirror surface) of 0.2 N / 10 mm width or less, preferably 0.1 N / mm. The width is preferably from 01 to 0.1 N / 10 mm. By making the adhesive low or non-adhesive, the adhesive does not adhere to the device contact portion at the time of transport, so that a transport trouble does not occur.
[0020]
In the present invention, the cleaning sheet of the present invention can be obtained by forming such a cleaning layer alone into a sheet or tape, or by providing it on an appropriate support. The cleaning sheet is transported to various substrate processing apparatuses as it is or in a state where it is adhered to a transport member using an adhesive, and the cleaning layer is brought into contact with a portion to be cleaned, so that foreign substances adhering to the portion can be easily removed. In addition, cleaning can be reliably performed.
[0021]
In the present invention, as a particularly preferred embodiment, a cleaning sheet in which a cleaning layer is provided on one side of the support and an adhesive layer is provided on the other side of the support is preferable. In this case, the thickness of the support is usually 10 to 100 μm, the thickness of the cleaning layer is usually 5 to 100 μm, and the thickness of the pressure-sensitive adhesive layer is usually 5 to 100 μm (preferably 10 to 50 μm). Good.
This sheet is adhered to the conveying member via the pressure-sensitive adhesive layer on the other side to form a conveying member with a cleaning function. By transporting the transport member to various substrate processing apparatuses in the same manner as described above, and bringing the cleaning layer into contact with the portion to be cleaned, foreign substances attached to the portion can be easily and reliably removed by cleaning.
[0022]
The support is not particularly limited in its material, for example, polyethylene, polypropylene, polybutene, polybutadiene, polyolefins such as polymethylpentene, polyvinyl chloride, vinyl chloride copolymer, polyethylene terephthalate, polybutylene terephthalate, polyurethane And a plastic film made of a resin such as an ethylene / vinyl acetate copolymer, an ionomer resin, an ethylene / (meth) acrylic acid copolymer, an ethylene / (meth) acrylate copolymer, polystyrene, or polycarbonate.
These plastic films may be a single-layer film made of the above resin or a laminated film. Further, one or both surfaces may be subjected to a surface treatment such as a corona treatment.
[0023]
The material of the pressure-sensitive adhesive layer provided on the other surface of the support is not particularly limited, and any material composed of a normal pressure-sensitive adhesive such as an acrylic or rubber-based material can be used. Among them, a component having a weight average molecular weight of 100,000 or less, which is obtained by polymerizing a monomer mixture containing an alkyl (meth) acrylate as a main monomer and other copolymerizable monomers as necessary, as an acrylic adhesive. Of which the main component is an acrylic polymer having a content of not more than 10% by weight.
Such a pressure-sensitive adhesive layer has a 180 ° peeling adhesive strength to a 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 may be torn when the cleaning sheet is peeled off from the conveying member.
[0024]
A protective film (separator) may be attached to the surface of the cleaning layer or the pressure-sensitive adhesive layer until the cleaning sheet is used. The material is not limited, for example, silicone-based, long-chain alkyl-based, fluorine-based, fatty acid amide-based, polyolefins such as polyethylene, polypropylene, polybutene, polybutadiene, polymethylpentene, etc. Polyvinyl 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 A plastic film made of a resin such as a polymer, polystyrene, or polycarbonate and having a thickness of usually 10 to 100 μm is used.
[0025]
In the transporting member with a cleaning function of the present invention, the transporting member to which the cleaning sheet is adhered is not particularly limited, and various types of substrates are used according to the type of the substrate processing apparatus from which foreign matter is to be removed. Specific examples include semiconductor wafers, substrates for flat panel displays such as LCDs and PDPs, and other substrates such as compact disks and MR heads.
[0026]
In the present invention, the substrate processing apparatus to be cleaned is not particularly limited, for example, an exposure irradiation apparatus for forming a circuit, a resist coating apparatus, a sputtering apparatus, an ion implantation apparatus, a dry etching apparatus, a wafer prober, and the like. Various inspection devices are included. According to the present invention, it is possible to provide each of the above substrate processing apparatuses cleaned by the above method.
[0027]
【Example】
Next, examples of the present invention will be described in more detail. However, the present invention is not limited only to these examples. In the following, “parts” means “parts by weight”.
[0028]
Example 1
100 parts of an acrylic polymer A (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 are mixed with 200 parts of polyethylene glycol. 200 parts of methacrylate (trade name "NK Ester 4G" manufactured by Shin-Nakamura Chemical Co., Ltd.), 3 parts of polyisocyanate compound (trade name "Coronate L" manufactured by Nippon Polyurethane Industry Co., Ltd.) and benzyl dimethyl ketal (Ciba. Three parts of Irgacure 651 (trade name, manufactured by Specialty Chemicals Co., Ltd.) were uniformly mixed to prepare an ultraviolet-curable resin composition A.
[0029]
Separately from this, 73 parts of 2-ethylhexyl acrylate and n-acrylic acid were placed in a three-neck flask-type reactor having a capacity of 500 ml and equipped with a thermometer, a retreating machine, a nitrogen inlet tube and a reflux condenser. 10 parts of butyl, 15 parts of N, N-dimethylacrylamide, 5 parts of acrylic acid, 0.15 part of 2,2'-azobisisobutyronitrile as a polymerization initiator, and 100 parts of ethyl acetate. The mixture was charged as described above, and stirred while introducing nitrogen gas for about 1 hour, and the air inside was replaced with nitrogen.
Thereafter, the internal temperature was adjusted to 58 ° C., and this state was maintained for about 4 hours to carry out polymerization to obtain a polymer solution. To 100 parts of this polymer solution, 3 parts of a polyisocyanate compound (trade name “Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) was uniformly mixed to prepare an adhesive solution A.
[0030]
The pressure-sensitive adhesive solution A has a thickness of 15 μm on the release-treated surface of the separator A made of a long polyester film (thickness 38 μm, width 250 mm), one side of which is treated with a silicone-based release agent. After drying, a long polyester film (thickness: 25 μm, width: 250 mm) is laminated as a support on the pressure-sensitive adhesive layer, and the ultraviolet-curable resin composition A is further coated on the film. And a resin layer was provided thereon, and the same separator-treated surface as described above was attached to the surface of the resin layer to form a laminated sheet.
[0031]
The laminated sheet was irradiated with ultraviolet light having a central wavelength of 365 nm and an integrated light amount of 1,000 mJ / cm ² to produce a cleaning sheet A having a cleaning layer composed of a polymerized and cured resin layer. The separator A on the cleaning layer side of the cleaning sheet A was peeled off, and the 180 ° peeling adhesion (measured according to JIS Z0237) to the silicon wafer (mirror surface) was examined. As a result, it was 0.06 N / 10 mm. The cleaning layer had a tensile strength (tensile elastic modulus: measured in accordance with JIS K7127 of test method) of 440 MPa.
[0032]
The separator A on the pressure-sensitive adhesive layer side of the cleaning sheet A was peeled off, and affixed to a mirror surface of an 8-inch silicon wafer with a hand roller, thereby producing a transporting member A with a cleaning function. The 180 ° peeling adhesive strength of the adhesive layer to the silicon wafer (mirror surface) was 1.5 N / 10 mm width.
[0033]
In addition, in order to examine the content of metal impurities in the cleaning layer in the transport member A with the cleaning function, a sample for measuring metal impurities was separately prepared according to the following procedure, and the content of the metal impurities was measured.
First, an ultraviolet-curable resin composition A is applied on the separator A so as to have a thickness of 40 μm, another separator A is bonded thereon, and ultraviolet light having a central wavelength of 365 nm is irradiated with an integrated light amount of 1,000 mJ /. The resin composition A was polymerized and cured by irradiation with cm ² to prepare a sample for measuring metal impurities.
[0034]
Next, the sample was cut into 4 cm ² (2 cm × 2 cm), the separators A on both sides were peeled off, placed in a platinum dish, weighed, and burned by heating with a gas burner.
Thereafter, the mixture was placed in an electric furnace and heated at 550 ° C. for 1 hour and at 600 ° C. for 1 hour until no residual coal remained. After cooling, 2 ml of concentrated hydrochloric acid was added, and the mixture was heated to 50 ° C. to dissolve the obtained ash. After allowing this melt to cool, ultrapure water was added to dilute the solution to 50 ml. For Na and K, Mg, Al, Ca, Ti, Cr were determined by atomic absorption analysis ("Z-6100" manufactured by Hitachi, Ltd.). , Mn, Fe, Co, Ni, Cu, and Zn were measured for the amount of each element by ICP spectroscopy ("SPS-1700HVR" manufactured by Seiko Instruments Inc.).
The results were as follows: Na: 0.9 ppm, K: 0.5 ppm, Mg: 0.1 ppm, Al: 0.2 ppm, Ca: 0.2 ppm, Ti: 0.1 ppm, Cr: 0.1 ppm, Mn: 0.1 ppm. 1 ppm, Fe: 0.1 ppm, Co: 0.1 ppm, Ni: 0.1 ppm, Cu: 0.1 ppm, Zn: 0.8 ppm.
[0035]
Using a laser surface inspection device, the number of foreign substances having a size of 0.2 μm or more on the mirror surfaces of two new 8-inch silicon wafers was 5 and 5, respectively. After transferring these silicon wafers to an oxide film dry etching apparatus having separate electrostatic chucking mechanisms with the mirror surface facing down, the mirror surface was measured by a laser surface inspection device. In the area, there were 30,576 and 31,563 foreign particles having a size of 0.2 μm or more, respectively.
[0036]
The transport member A with the cleaning function was peeled off the separator A on the cleaning layer side and transported to the oxide film dry etching apparatus having the wafer stage to which 30,576 foreign substances had adhered. did it. This operation was repeated five times. After that, a new 8-inch silicon wafer is transported with the mirror surface facing downward, and a foreign substance of 0.2 μm or more is measured by a laser surface inspection apparatus. As a result, 90% of the foreign substance can be removed from the initial stage. I was
After that, the product wafer was processed, and it was found that the product wafer could be manufactured without any problem without being contaminated by metal impurities.
[0037]
Comparative Example 1
Instead of 100 parts of the acrylic polymer A in the ultraviolet-curable resin composition A, 100 parts of an acrylic polymer (“Reocoat R-1020” manufactured by Toray Cotex) was used, and benzyldimethyl as a photopolymerization initiator was used. An ultraviolet-curable resin composition was prepared in the same manner as in Example 1, except that 3 parts of a ketal was used and 3 parts of a thioxanthone-based photopolymerization initiator ("KAYACURE DETX-S" manufactured by Nippon Kayaku Co., Ltd.) was used. B was prepared.
A cleaning sheet B was prepared in the same manner as in Example 1 except that this resin composition B was used. Was prepared.
[0038]
The separator A on the cleaning layer side of the transporting member B having the cleaning function was peeled off, and the 180 ° peeling adhesive force (measured according to JIS Z0237) on the silicon wafer (mirror surface) was measured. there were. The tensile strength of this cleaning layer was 420 MPa.
[0039]
Further, in order to examine the content of metal impurities in the cleaning layer, a sample for measuring metal impurities was prepared in the same manner as in Example 1, and the content of the metal impurities was measured. As a result, Na: 7.1 ppm, K: 6.5 ppm, Mg: 5.2 ppm, Al: 5.8 ppm, Ca: 5.1 ppm, Ti: 5.0 ppm, Cr: 6.1 ppm, Mn: 5. 0 ppm, Fe: 5.1 ppm, Co: 5.7 ppm, Ni: 5.3 ppm, Cu: 7.0 ppm, Zn: 7.3 ppm.
[0040]
Next, the transport member B with the cleaning function was transported to the oxide film dry etching apparatus having the wafer stage to which the 31,563 foreign substances had adhered, with the separator A on the cleaning layer side being peeled off. It could be transported without any problems. This operation was repeated five times. After that, a new 8-inch silicon wafer was transported with the mirror surface facing downward, and a laser surface inspection device measured foreign matter of 0.2 μm or more. As a result, 88% of the foreign matter was removed from the initial stage. I was
However, when the product wafer was subsequently processed, the apparatus was contaminated with metal impurities, so that the product wafer was contaminated, resulting in frequent occurrence of defects due to deterioration of device characteristics. Therefore, in order to remove metal contamination of the apparatus, a great deal of labor was required, such as shutting down the apparatus and opening and cleaning the apparatus.
[0041]
【The invention's effect】
As described above, according to the present invention, Na, K, Mg, Al, Ca, Ti, Cr, Mn, Fe, Co , Ni, Cu, and Zn are set so that the content of each metal element or its compound is 5 ppm or less (μg / g) or less in terms of the metal element, so that the apparatus can be practically used without causing metal contamination. Cleaning member can be provided.

Claims (7)

The content of each metal element of Na, K, Mg, Al, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn or a compound thereof is 5 ppm (μg / g) or less in terms of the metal element. A cleaning sheet having a cleaning layer. The cleaning sheet according to claim 1, wherein the cleaning layer has substantially no tackiness. The cleaning sheet according to claim 1, further comprising a cleaning layer on the support. The cleaning sheet according to claim 3, wherein the support has a cleaning layer on one side and an adhesive layer on the other side. A conveying member with a cleaning function, wherein the cleaning sheet according to claim 4 is attached to 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 the transporting member with a cleaning function according to claim 5 into a substrate processing apparatus. A substrate processing apparatus cleaned by the cleaning method according to claim 6.