JP2003142370A - Method for cleaning apparatus with reticle in contact - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for cleaning an apparatus brought into contact with a reticle or a reticle-like article such as an exposure mask or the like used, when exposing with a projection aligner. SOLUTION: The method for cleaning the aligner which is brought into contact with the reticle comprises the steps of providing a material, having a cleaning layer which has a tensile elastic modulus (in compliance with the testing method of JIS K7127) of 0.98 to 4,900 MPa, and conveying the material in the aligner to be cleaned.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning an apparatus which is in contact with a reticle-like object such as a reticle or an exposure mask used for exposure of a projection exposure apparatus.

[0002]

2. Description of the Related Art For fine processing of semiconductors and the like, etching and ion implantation are carried out using a resist material formed on a wafer as a mask. In order to use the resist material as a desired mask, a projection exposure apparatus that exposes a reticle having a desired pattern as a mask is generally used. At that time, if the wafer or reticle is slightly tilted, the pattern may be blurred due to the depth of focus. Regarding the tilt of the wafer, if the wafer or the chuck table has flatness, the main cause is that particles adhere to the back surface of the wafer or the transfer system.Therefore, dozens of new dummy wafers It was necessary to carry out a cleaning process by continuously carrying or stopping the apparatus, and using a special wiping cloth and a chemical solution in which a person suppressed dust generation in the carrying system. Therefore, there is a problem that the operating rate is reduced and a great deal of labor is required. In order to solve these problems, a method of physically cleaning and removing the back surface of the wafer with a brush or the like has been devised.

[0003]

A method of physically rubbing and removing the back surface of a wafer with a brush or the like is an effective method for overcoming the above-mentioned problems. However, this method only removes the particles from the substrate to which the particles adhere, and there is a problem in that there is no effect on the tilt of the reticle. Therefore, manual wiping is required, but normally the reticle setting part of the exposure device and reticle stocker has a structure that is not easily accessible, and disassembly and reassembly are required during cleaning. Yes,
There was also a problem that it required a lot of time and effort. Further, since the target particles are extremely small, there is a fear that the particles cannot be completely removed by manual wiping and that particles are newly attached. In view of such circumstances, it is an object of the present invention to provide a method for easily and surely cleaning foreign matter attached to a contact portion of a reticle.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to achieve the above-mentioned object, and as a result, as a result, a reticle or a reticle-like material is attached to a portion in contact with a device to be cleaned.
A material provided with a cleaning layer having a tensile elastic modulus (according to the test method JIS K7127) of 0.98 to 4900 MPa is provided and conveyed in the apparatus to be cleaned without causing the above-mentioned problems, and further foreign matter can be easily and easily obtained. They have found that they can be reliably cleaned, and have completed the present invention.

That is, according to the present invention, the reticle or the reticle-like material has a tensile elastic modulus (according to the test method JIS K7127) of 0.98 to 4 at the portion in contact with the device to be cleaned.
A method for cleaning an apparatus in contact with a reticle, characterized in that a material provided with a cleaning layer having a pressure of 900 MPa is provided and conveyed in an apparatus to be cleaned (claim 1), an apparatus in contact with a reticle or a reticle-like object is The cleaning method according to claim 1 (claim 2), and the apparatus with which the reticle or reticle-like object is in contact is an exposure apparatus (claim 3). ), The material provided with the cleaning layer has a tensile elastic modulus (according to the test method JIS K7127) of 0.98 to 4 on one surface of the support.
The cleaning method according to claim 1 (claim 4), wherein a 900 MPa pressure-sensitive adhesive layer is provided as a cleaning layer, and a normal pressure-sensitive adhesive layer is provided on the other surface.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the tensile modulus of elasticity is 0.98 to 4900 MPa, preferably 9.8 to 300.
By using a cleaning layer having a pressure of 0 MPa, more preferably 100 to 2000 MPa, it is possible to reliably remove fine foreign matters without collecting and dropping them by the cleaning layer having an appropriate insulating property without causing a transport trouble. can do. Further, when the tensile elastic modulus is 0.98 to 4900 MPa, there is substantially no tackiness. Here, “having substantially no tackiness” means that, when the essence of tackiness is friction, which is resistance to sliding, there is no pressure-sensitive tack that is representative of the tackiness function. According to Dahlquist's standard, for example, this pressure-sensitive tack develops in the range where the tensile elastic modulus of the adhesive substance is up to 1 MPa. Therefore, in the present invention, the tensile modulus of the cleaning layer is set to a specific range, that is, 0.98 to 4 so that the tensile modulus of the cleaning layer becomes larger than about 1 MPa.
By designing the pressure in the range of 900 MPa, it is possible to remove foreign substances without causing a transportation trouble. Here, the tensile modulus is the test method JIS K712.
It was measured according to 7. The thickness of the cleaning layer having a tensile elastic modulus of 0.98 to 4900 MPa is not particularly limited, but is usually about 5 to 100 μm.

The material of the cleaning layer is not particularly limited as long as its tensile elastic modulus is within the above-mentioned range, but the crosslinking reaction and curing are promoted by an active energy source such as ultraviolet rays and heat, and the tensile strength of the cleaning layer is increased. It is preferable that the elastic modulus can be increased. Further, it is preferable that the molecular structure is three-dimensionally reticulated due to such crosslinking or curing to reduce the adhesive force, and for example, the 180 ° peeling adhesive force to a silicon wafer (mirror surface) is 0.20 N (20 g) /
10 mm or less, preferably 0.010 to 0.10 N (1
It is about 10 g) / 10 mm. This adhesive strength
If it exceeds 0.20 N (20 g) / mm, it may adhere to the portion to be cleaned in the apparatus during transportation, resulting in transportation trouble.

Specific examples of such a cleaning layer include:
For example, a pressure-sensitive adhesive polymer containing a compound having at least one unsaturated double bond in the molecule is preferable. Examples of the pressure-sensitive adhesive polymer include acrylic polymers containing (meth) acrylic acid and / or (meth) acrylic acid ester selected from acrylic acid, acrylic acid ester, methacrylic acid, and methacrylic acid ester as a main monomer. Is mentioned. 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 acrylic polymer after synthesis. By introducing an unsaturated double bond into the molecule of the acrylic polymer, such as by chemically bonding it through a reaction between functional groups, so that this polymer itself also participates in the polymerization-curing reaction with active energy. You 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, it preferably has a molecular weight of 5,000 or less so that the three-dimensional reticulation of the pressure-sensitive adhesive layer can be efficiently performed during curing.

The polymerization initiator added to the pressure-sensitive adhesive layer is not particularly limited, and known ones can be used. For example, when heat is used as an active energy source, benzoyl peroxide, azobisisobutyronitrile, etc. In the case of using a thermal polymerization initiator of benzoyl, benzoin ethyl ether, cibenzyl, isopropyl benzoin ether, benzophenone, Michler's ketone chlorothioxanthone, dodecyl thioxanthone, dimethyl thioxanthone, acetophenone diethyl ketal, benzyl dimethyl ketal, α-hi Examples include photopolymerization initiators such as dorxycyclohexyl phenyl ketone, 2-hydroxydimethylphenyl propane, and 2,2-dimethoxy-2-phenylacetophenone.

As a material to be provided on a reticle or the like in the cleaning method of the present invention, the above-mentioned specific pressure-sensitive adhesive layer is provided as a cleaning layer on one surface of the support, and a normal pressure-sensitive adhesive layer is provided on the other surface. Is preferred. The material of the pressure-sensitive adhesive layer on the other surface side is not particularly limited as long as it satisfies the pressure-sensitive adhesive function, and a normal pressure-sensitive adhesive (for example, acrylic type, rubber type, etc.) can be used. With such a configuration, the material provided with the cleaning layer is
It can be attached to a specific site such as a reticle by a normal pressure-sensitive adhesive layer, conveyed to the inside of the device to be cleaned, and brought into contact with the site to be cleaned for cleaning.

The support is not particularly limited, but examples thereof include plastic films such as polyethylene, polyethylene terephthalate, acetyl cellulose, polycarbonate, polypropylene and polyamide. Its thickness is usually about 10 to 100 μm.

Examples of materials to which the material provided with the cleaning layer is attached include reticle and reticle-like materials such as exposure masks.

[0014]

EXAMPLES The present invention will be described below based on examples, but the present invention is not limited thereto. In the following, "parts" means "parts by weight". Example 1 Acrylic polymer (weight average molecular weight 70%) obtained from a monomer mixture liquid consisting of 75 parts of 2-ethylhexyl acrylate, 20 parts of methyl acrylate, and 5 parts of acrylic acid.
10,000) For every 100 parts, 50 parts of urethane acrylate,
Further, 3 parts of diphenylmethane diisocyanate and 3 parts of benzyl dimethyl ketal (manufactured by Ciba Specialty Chemicals: trade name: Irgacure-651) were uniformly mixed to obtain a UV-curable adhesive solution. On the other hand, an ordinary pressure-sensitive adhesive solution was obtained in the same manner as above except that benzyl dimethyl ketal was removed from the above adhesive.

This UV-curable adhesive solution has a width of 250
A long polyester film A having a thickness of 25 μm and a thickness of 25 μm is coated on one surface (corona-treated surface) so that the thickness after drying is 15 μm to provide a pressure-sensitive adhesive layer as a cleaning layer, and one surface is silicone-based peeling. Polyester film B (thickness 38 μm, width 250 m
The release-treated surface of the release film consisting of m) was attached to obtain a sheet A.

A normal adhesive solution is applied to the other surface of the sheet A so that the thickness after drying becomes 10 μm, and the polyester film having one surface treated with a silicone-based release agent on the adhesive is peeled off. The surfaces were stuck together to obtain a tape with a reticle adhesive layer.

Ultraviolet rays having a central wavelength of 365 nm are integrated into the tape with a reticle adhesive layer produced above as an integrated light amount of 1000 m.
J / cm ² irradiation was performed to obtain a reticle adhesive layer-attached tape having a UV-cured cleaning layer. The tensile elastic modulus of this cleaning layer was 600 MPa. The polyester film on the cleaning layer side of the reticle adhesive layer-attached tape was peeled off, and a reticle having a cleaning function was prepared by laminating the reticle adhesive layer so that the reticle adhesive layer was in contact with a quartz plate having a diagonal length of 150 mm.

Next, the polyester film B of the cleaning layer of the transport reticle with a cleaning function is peeled off, and the cleaning surface is directed to the lower surface (the surface in contact with the apparatus), which is a stepper (NSR) which is an exposure apparatus for semiconductor manufacturing.
-2205EX10B), set a reticle on which a pattern is formed, and expose a 1 μm-thick positive resist provided on a silicon wafer under predetermined conditions,
After the development, the resist pattern shape was observed with a metallurgical microscope. As a result, there was no collapse of the pattern due to particles, and the cleaning effect of the portion where the reticle was in contact with the apparatus was confirmed.

[00119]

[Embodiment 2] In the same manner as described above, the transport reticle with a cleaning function was automatically stored in the reticle stocker by the transport robot and then immediately put out, and the surface of the cleaning layer in contact with the apparatus was observed with a metal microscope and SEM. Particles of various sizes which were not attached before the transfer were found, and the cleaning effect of the part in contact with the device was confirmed.

[0020]

As described above, according to the cleaning method of the present invention, the cleaning reticle can be reliably transported, and the particles adhering to the device with which the reticle is in contact can be easily and reliably removed.

Claims (4)

[Claims] 1. A reticle or a reticle-like material has a tensile elastic modulus (Test Method JIS
A method for cleaning an apparatus in contact with a reticle, characterized in that a material provided with a cleaning layer having a K7127) of 0.98 to 4900 MPa is provided and the material is conveyed inside the apparatus to be cleaned. 2. The cleaning method according to claim 1, wherein the device with which the reticle or the reticle-like object contacts is a reticle stocker. 3. The cleaning method according to claim 1, wherein the device with which the reticle or reticle-like object contacts is an exposure device. 4. A material provided with a cleaning layer has a tensile modulus of elasticity (Test method JIS K7127) on one surface of a support.
The cleaning method according to claim 1, wherein an adhesive layer having a pressure of 0.98 to 4900 MPa is provided as a cleaning layer, and a normal adhesive layer is provided on the other surface.