JPH0768574A - Manufacture of optical resin thin film - Google Patents

Abstract

PURPOSE:To provide a method for manufacturing a high quality optical resin thin film in a good yield wherein inferiority due to sticking of foreign matters is small, and flaws, wrinkles, etc., are not generated. CONSTITUTION:An organic solvent capable of dissolving a resin is discharged from a nozzle toward a peripheral fringe part of a support substrate under a state wherein the support substrate 1 is rotated in succession to spin coating, and a coating of a side surface part of the support substrate 1 in resin coating 2 formed on the support substrate 1 and the coating within a range of 0-5mm toward an inside from an outer peripheral edge part of the support substrate 1 are dissolved to be removed. Thereafter, the coating is separated from the support substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a high-quality optical resin thin film with little foreign matter attached, defects such as scratches and wrinkles with a good yield, and the optical produced by the method of the present invention. The resin thin film for use is particularly used as a film for a pellicle mounted for protection and dust proof of a photomask, a reticle, etc. used in a lithography process in a manufacturing process of a semiconductor device such as an LSI or a VLSI.

[0002]

2. Description of the Related Art A pellicle is usually manufactured by forming a resin film on a smooth substrate by a spin coating method or the like, then peeling the resin film and stretching it on one side of a pellicle frame.

Conventionally, as a method for peeling off a pellicle film, a frame-like body for peeling is directly attached to a film formed on a substrate, and the film is peeled off by lifting the frame-like body to form a frame-like film. A method of transferring to the body has been proposed (JP-A-2-84646, JP-A-2-272550, etc.).

[0004]

However, these methods have been problematic because innumerable minute foreign matters are generated and the phenomenon that they adhere to the film occasionally occurs.

It is presumed that the cause of generation of foreign matter is as follows. When a film is formed on a substrate by spin coating, the film is usually formed even on the side surface portion of the substrate as shown in FIG. When the peeling frame is attached to this and the coating film is peeled off, the coating film may be torn off at the boundary surface between the substrate side surface portion and the substrate surface portion, and foreign matter is generated from this portion. It is considered that the generated foreign matter is caught in the inside of the film due to the air flow when peeling the film and adheres to the film.

In addition to the problem of foreign matter, the above method
Although the probability of occurrence is lower than that of foreign matter, problems such as scratches and wrinkles occur in the film when the film is peeled off.As the demand for quality of pellicle has increased recently, high quality pellicle film with extremely few defects is produced with good yield. A method of manufacturing has been sought.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a high-quality optical resin thin film which has few defects due to the adhesion of foreign matter and is free from scratches and wrinkles. It is to provide a method of manufacturing well.

[0008]

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found a method capable of reducing the generation of the above-mentioned minute foreign matter, and this method has a scratch, a wrinkle, etc. Acknowledged that the quality of
The present invention has been completed. That is, according to the present invention, following spin coating, an organic solvent capable of dissolving a resin is discharged from a nozzle toward a peripheral portion of the supporting substrate while the supporting substrate is rotated, and a resin coating formed on the supporting substrate. Among them, the coating on the side surface portion of the support substrate and the coating in the range of 0 to 5 mm from the outer peripheral end of the support substrate toward the inside are dissolved and removed, and then the coating is peeled from the support substrate. It is a manufacturing method of a resin thin film for automobiles.

The present invention will be described in more detail below.

The method for producing an optical resin thin film according to the present invention comprises a step of removing the coating film on the side surface portion and the peripheral portion of the substrate and a step of peeling the coating film from the supporting substrate after drying. In the step of removing the film, the film is dissolved and removed with an organic solvent.

As a method of dissolving and removing the coating film, an organic solvent capable of dissolving the resin is discharged from a nozzle toward the peripheral portion of the supporting substrate in a state where the supporting substrate is rotated, and after dissolving the coating film in this portion, It is carried out by centrifuging the solution by centrifugation.

The rotation speed of the supporting substrate at the time of removal is preferably in the range of 100 to 2500 rotations per minute,
The range of 1500 to 2500 revolutions per minute is more preferable because the dissolved solution of the resin film can be removed more reliably with sufficient centrifugal force. When the rotation speed was less than 100 revolutions per minute, the centrifugal force for flowing away the solvent for dissolving the coating from the substrate was insufficient, and the solvent further eroded the inner coating, which was obtained. The outer peripheral edge of the coating is not smooth. As a result, when peeling off, the coating of this part falls off,
On the contrary, foreign matter may be generated. Further, when the rotation speed is higher than this range, when the solvent is discharged near the side surface of the supporting substrate, the solvent in contact with the substrate is splashed up, which may dissolve the film outside the removal range, Each is not preferable.

The discharge rate of the organic solvent is preferably in the range of 5 to 30 ml per second. If it is less than this range, the coating cannot be sufficiently removed, and if it is more than this range, the coating outside the removal range may be dissolved, which is not preferable.

The discharge time of the solvent is preferably in the range of 5 to 20 seconds. When the length is shorter than this range, the coating cannot be sufficiently removed, and when the length is longer, the coating outside the removal range may be dissolved, which is not preferable.

After the solvent has been discharged, the substrate is continuously heated to 5-2.
It is preferable to rotate in the range of 0 seconds. As a result,
The outer peripheral edge of the coating can be immediately dried, and the shape of the outer peripheral edge of the coating can be finished more smoothly. The rotation speed of the substrate at this time is preferably in the range of 100 to 2500 rotations per minute, and since it can be dried more sufficiently,
It is more preferable to rotate in the range of 500 to 2500 rotations. The rotation speed in this case may be the same as or different from the rotation speed of the supporting substrate when the coating is dissolved and removed.

Although the removal solvent varies depending on the type of coating,
Nitrocellulose, ethyl cellulose, cellulose acetate, a film made of a cellulose resin derivative such as cellulose propionate, polyvinyl acetoacetal, polyvinyl propional, when removing a film made of a polyvinyl acetal resin such as polyvinyl butyral,
Examples thereof include acetone, methyl ethyl ketone, methyl isobutyl ketone, butyl acetate, isobutyl acetate, and the like. In the case of an amorphous fluorine-containing resin having a cyclic ether structure (fluorine resin “Cytop” (trademark), manufactured by Asahi Glass) Is, for example, perfluorotributylamine, perfluoro-2-methyltetrahydrofuran, CT-sol.
v. (Trademark) 100, Asahi Glass, "Aflude" (trademark) E-10, Asahi Glass, "Fluorinert" (trademark) F
C-75, FC-77, FC-84, 3M, "EF
TOP ”(trademark) EF-L102, manufactured by Mitsubishi Materials, and the like.

As shown in FIG. 2, the area to be removed is a film on the side surface of the supporting base material and a film in the range of 0 to 5 mm from the outer peripheral end of the supporting substrate toward the inside. If the film is not completely removed, the film in this portion may become foreign matter in the subsequent peeling step, which is not preferable. Further, if the removal range exceeds this range, the frame-shaped body is directly adhered to the supporting base material when the frame-shaped body for peeling is adhered in the subsequent peeling step, and peeling becomes difficult, which is not preferable.

The substrate thus removed is dried and then peeled off.

The peeling method is preferably carried out by attaching a peeling frame member to the coating film and lifting it from the substrate to transfer it to the frame member. This method can be carried out according to the methods disclosed in JP-A-2-84646 and JP-A-2-272550. At this time, according to the present invention, since the coating film on the side surface of the support substrate is removed, the stress applied to the frame-like body at the time of peeling can be significantly reduced, and the peeling can be performed more smoothly. As a result, the occurrence of scratches and wrinkles can also be reduced.

[0020]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 10 g of polyvinyl propional resin represented by the following general formula (1) (weight average molecular weight Mw; 157,000, ratio Mw / Mn of weight average molecular weight Mw and number average molecular weight Mn;
2.07)

[0022]

[Chemical 1]

(Numbers in the formula are values showing the composition ratio (molar fraction) of each repeating unit) and cyclohexanone 9
A solution consisting of 5 ml was applied to a membrane filter (“Fluoropore” (trademark) FP- with a pore size of 0.22 μm).
22, manufactured by Sumitomo Electric Co., Ltd.) to obtain a coating solution. A circular synthetic quartz glass substrate (200 mm in diameter) having a metal chromium thin film formed on the surface by sputtering
φ) was spin-coated on top. Then, the substrate is added at 20 per minute.
While rotating at 00 rotations, methylisobutylketone was discharged from the nozzle at a discharge rate of 20 ml per second for 10 seconds toward the peripheral edge of the base material, and the side surface of the support substrate out of the resin coating formed on the support substrate. The coating and the coating within a range of about 2 mm from the outer peripheral edge of the support substrate were dissolved and removed. After the completion of the solvent discharge, the coating was further continuously rotated at 2000 rpm for 10 seconds to dry the end portion of the coating film. Next, this substrate was heated and dried with a hot plate to obtain a resin film.

Next, the inner and outer circumferences are circular and the inner diameter is 185.
A frame-shaped body having a diameter of mmφ, an outer diameter of 205 mmφ, a material of aluminum, and a thickness of 0.5 mm was prepared, and a double-sided adhesive tape (571, manufactured by Nitto Denko) was attached to one side of the frame-shaped body to obtain a frame-shaped body for peeling.

After the peeling frame was attached to the coating on the supporting substrate, the frame was lifted and separated from the supporting substrate, and the coating was peeled off.

By repeating the same operation as above, 50 resin thin films were manufactured.

The resin thin film thus obtained was applied to a projector (YP-105).
I, made by Yamada Optical Co., Ltd.) and observed at an illuminance of 200,000 lux.
The number of adhered foreign matters corresponding to 5 μm or more and less than 30 μm was 0.1. Further, no foreign matter having a size of 30 μm or more was observed. No other scratches or wrinkles were observed on all 50 sheets.

Example 2 A solution of an amorphous fluorine-containing resin (“CYTOP” (trademark), manufactured by Asahi Glass) having a cyclic ether structure in the main chain and a perfluoro solvent was added to a circular synthetic quartz glass substrate (20).
0 mmφ) was spin coated. Subsequently, while rotating the substrate at 2200 revolutions per minute, toward the peripheral edge of the substrate, a perfluoro solvent (“Aflude” (trademark) E-1 was used).
0, manufactured by Asahi Glass Co., Ltd.) was discharged from the nozzle for 15 seconds at a discharge rate of 20 ml per second, and the resin film formed on the supporting substrate was directed inward from the side surface of the supporting substrate and the outer peripheral edge of the supporting substrate. To dissolve and remove the coating in the range of about 2 mm. After completion of solvent discharge, it is 1 at 2,200 rpm.
Rolling was continued for 0 seconds to dry the edges of the coating. Next, this substrate was heated and dried with a hot plate to obtain a resin film.

Next, the inner and outer circumferences are circular and the inner diameter is 185.
A frame-like body having a diameter of mmφ, an outer diameter of 220 mmφ, a material of polycarbonate, and a thickness of 2 mm was prepared, and a double-sided adhesive tape (501 L, manufactured by Nitto Denko) was attached to one side of the frame-shaped body to obtain a frame-shaped body for peeling.

After the peeling frame was attached to the coating on the supporting substrate, the frame was lifted and separated from the supporting substrate, and the coating was peeled off.

The same operation as above was repeated to produce 50 resin thin films.

The resin thin film thus obtained was applied to a projector (YP-105
I, manufactured by Yamada Kogaku Kogyo Co., Ltd.) and observed at an illuminance of 200,000 lux. As a result, the number of adhered foreign substances corresponding to a size of 5 μm or more and less than 15 μm is 3.6 on average for all resin thin films, and a size of 15 μm or more and less than 30 μm The number of foreign substances attached is 0.1
It was five. Further, no foreign matter having a size of 30 μm or more was observed. No other scratches or wrinkles were observed on all 50 sheets.

Comparative Example 1 The polyvinyl propional solution used in Example 1 was
It was spin-coated on a circular synthetic quartz glass substrate (200 mmφ) on the surface of which a metal chromium thin film was formed by sputtering. Next, this substrate was heated and dried with a hot plate to obtain a resin film. With respect to this coating, the work of removing the coating on the side surface of the substrate and the peripheral portion as in Example 1 was not carried out, and the frame-shaped body used in Example 1 was stuck as it was. Next, the coating film was peeled off in the same manner as in Example 1 to obtain a resin thin film.

The same operation as above was repeated to produce 50 resin thin films.

The resin thin film thus obtained was applied to a projector (YP-105).
I, manufactured by Yamada Kogaku Kogyo Co., Ltd.), and as a result of total visual observation at an illuminance of 200,000 lux, 6 out of 50 thin films having innumerable foreign matters having a size of less than 5 μm were observed. Further, the number of adhered foreign matters corresponding to a size of 5 μm or more and less than 15 μm is 15.3 on average for all resin thin films.
The number of adhering foreign matters corresponding to m or more and less than 30 μm was 2.3 on average for all resin thin films, and 1.2 foreign matters corresponding to the size of 30 μm or more were also observed on average for all resin thin films.
Further, with respect to 3 out of 50 sheets, scratches caused by stretching of the resin film near the peeling start portion were also observed.

Comparative Example 2 A solution (“CYTOP” (trademark), manufactured by Asahi Glass) consisting of the amorphous fluorine-containing resin and the perfluoro solvent used in Example 2 was placed on a circular synthetic quartz glass substrate (200 mmφ). Was spin coated. Next, this substrate was heated and dried with a hot plate to obtain a resin film. This For coating, without performing the work of removing the coating of the substrate side and the peripheral portion as performed in Example 2 was stuck to frame-shaped body is used as it is in Example 2. Next, the coating was peeled off in the same manner as in Example 2 to obtain a resin thin film.

The same operation as above was repeated to produce 50 resin thin films.

The resin thin film thus obtained was applied to a projector (YP-105).
I, manufactured by Yamada Kogaku Kogyo Co., Ltd.), and as a result of total visual observation at an illuminance of 200,000 lux, 12 out of 50 thin films having innumerable foreign matters having a size of less than 5 μm were observed. Further, the number of adhered foreign matters corresponding to a size of 5 μm or more and less than 15 μm is 18.6 on average for all resin thin films.
The number of adhering foreign matters corresponding to m or more and less than 30 μm was 5.2 on average for all resin thin films, and 3.6 for the foreign matters corresponding to size of 30 μm or more was detected on average for all resin thin films.
Further, in 22 out of 50 sheets, scratches caused by the extension of the resin film near the peeling start portion were observed.

[0039]

Industrial Applicability The present invention provides a method for producing an optical resin thin film, in which there are few defects due to the adhesion of foreign matter and, in addition, scratches and wrinkles do not occur. According to the method for producing an optical resin thin film of the present invention, it is possible to produce an optical resin thin film (particularly for a pellicle film) of which quality is being demanded year by year with high quality and high yield.

[Brief description of drawings]

FIG. 1 is a cross-sectional view when a coating film is formed on a supporting substrate by a spin coating method.

FIG. 2 is a cross-sectional view showing a state in which, of the coating film formed by spin coating, the coating film on the peripheral portion within a range of 0 to 5 mm from the side surface portion and the outer peripheral end portion of the support substrate is removed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Supporting substrate 2 ... Resin coating 3 ... Coating in a state where the coatings on the side surface and outer peripheral edge of the supporting substrate are removed

Claims (2)

[Claims] 1. A resin thin film for optics is manufactured by spin-coating a solution of a resin and a coating solvent on a circular supporting substrate, drying the resin coating, and then peeling the coating from the supporting substrate. In doing so, following the spin coating, an organic solvent capable of dissolving the resin is discharged from a nozzle toward the peripheral portion of the support substrate while the support substrate is rotated,
Of the resin coating formed on the support substrate, the coating on the side surface of the support substrate and the coating in the range of 0 to 5 mm from the outer peripheral edge of the support substrate to the inside are dissolved and removed, and then the coating is provided on the support substrate. A method for producing an optical resin thin film, which comprises peeling from an optical resin. 2. The method for producing an optical resin thin film according to claim 1, wherein the rotation speed of the supporting substrate when the coating is dissolved and removed is in the range of 1500 to 2500 rotations per minute.