JPH06236022A - Pellicle - Google Patents

Abstract

PURPOSE:To prevent the transfer of the dust generated from an adhesive to a resist film in an exposing stage and to eliminate the generation of deffective semiconductor elements, etc., by the adhesion of this dust so that the defects of semiconductor elements, etc., are eliminated by fixing pellicle frames and a reticule by a magnetic force, thereby forming the pellicle. CONSTITUTION:This pellicle is made of a quartz plate and an iron magnet 3 is placed on the reticule 1 provided by providing circuit patterns 2 thereon. The iron pellicle frame 4a is placed on this magnet 3. There is the pellicle frame 4b under the reticule 1 as well and these pellicle frames 4a, 4b are provided with pellicle films 5 by the conventional method. The pellicle frames 4a, 4b and the reticule 1 are fixed by the magnet 3 placed on the reticule 1 and a tacky adhesive agent is not used and, therefore, the peeling of the tacky adhesive by the degraded tacky adhesive power of the adhesive does not arise. The trouble that the semiconductor elements are made defective by the dust generated from the tacky adhesive does not arise either.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to pellicles, and in particular to LS.
The present invention relates to a pellicle for lithography, which is used in the production of semiconductor devices such as I and VLSIs or liquid crystal display panels, and which is used in the exposure method using light having a wavelength of substantially 500 nm or less.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices such as LSI and VLSI, or liquid crystal display plates, a semiconductor wafer or a liquid crystal original plate is irradiated with light to form a pattern. The exposure original plate used in this case is used. When dust adheres to the surface, the dust absorbs light, or the transferred pattern is deformed due to bending of light, resulting in sharp edges, which impairs dimensions, quality, and appearance. There is a disadvantage. Therefore, this kind of work is usually performed in a clean room, but it is difficult to always keep the exposure master plate clean even in this clean room. A method of mounting a pellicle that allows the vehicle to pass through well is adopted.

Usually, this pellicle has a structure in which a pellicle film for exposure is attached to a metal or resin frame with an adhesive or an adhesive tape. This frame is attached to the reticle with an adhesive or an adhesive tape. It is pasted and used. Since this pellicle is used after being fixed to the reticle, it is necessary to remove the pellicle from the reticle surface for replacement of the pellicle. It is carried out with a substance having a temporary fixing material such as an adhesive without using.

[0004]

However, these known pressure-sensitive adhesives are used as g-line and i-line used in photolithography.
When ultraviolet rays like a line or an excimer laser is irradiated, the adhesive strength gradually decreases, and finally the pellicle cannot be fixed, causing the problem that the pellicle falls off the reticle during use. When it is irradiated, there is a disadvantage that the adhesive strength is reduced to less than practical after irradiation for several hours. Regarding this, when the pellicle is attached to the reticle, dust is released inside or outside of the adhesive, and the dust released inside adheres to the surface of the mask and the inside of the pellicle. There is also a problem that the semiconductor element becomes defective because it is transferred to the resist film in the process.

[0005]

The present invention relates to a pellicle which solves the above disadvantages and problems, and is characterized in that a pellicle frame and a reticle are fixed by magnetic force. .

That is, the inventors of the present invention have made various studies as to how to solve the disadvantage of the method of fixing the pellicle frame and the reticle with an adhesive or an adhesive tape. As a result, the pellicle frame and the reticle are magnetically fixed. It has been found that the above disadvantages due to the use of adhesives and pressure sensitive adhesives can be solved, and various methods can be used for fixing by this magnetic force, which makes it possible to easily and inexpensively achieve the object. Was confirmed to complete the present invention. This will be described in more detail below.

[0007]

The present invention relates to a pellicle frame fixed to a reticle, which is characterized in that the pellicle frame and the reticle are fixed by a magnetic force. There is an advantage that the mounting defect due to the deterioration can be eliminated, and the contamination of the circuit pattern on the reticle caused by the adhesive can be prevented.

According to the present invention, the pellicle frame and the reticle are fixed by magnetic force. 1) The pellicle frame is made of a magnetic material such as iron-based metal, cobalt, nickel or rare earth metal. Method for fixing the pellicle and reticle using a substance having magnetic force using 2) The pellicle frame is made of a non-magnetic material such as copper, aluminum, tin, or carbon, and the frame and reticle are in contact with each other. There is a method in which the magnetic material used in 1) above is attached to the surface, or these are formed by means such as fusion and the pellicle and reticle are fixed via a substance having magnetic force.

The substance having a magnetic force used herein may be an ordinary permanent magnetic substance, and therefore, an iron-based material magnetized by applying a strong magnetic field is exemplified. This is samarium- It may be a rare earth magnet such as cobalt. The shape of the substance having this magnetic force is not particularly limited, but this does not hinder the transfer of the reticle lithography pattern, and the pellicle and reticle can be easily and surely fixed. It is desirable to use a flat plate like the frame.

In order to fix the substance having the magnetic force to the frame on the reticle surface, these may be adhered, and this may be fixed by using an adhesive or the like. The substance having the magnetic force is fixed. If the force is sufficient, the frame may be fixed to the reticle on the opposite surface, avoiding the reticle surface to which the frame adheres. In this pellicle frame, a pellicle frame is usually mounted on the upper and lower surfaces of one reticle, but in this case, a pellicle frame is made of a magnetic material or a non-magnetic material provided with a magnetic material plate. A frame in which a substance having a magnetic force is provided on the end surface of the frame can be used.

Incidentally, in order to more strongly fix the pellicle frame and the reticle, a magnetic force may be used and a known adhesive may be used in combination therewith. In this case, foreign matter from the adhesive layer may be removed. It is necessary to reduce the thickness of this adhesive layer as compared with the conventional method of fixing with only an adhesive to prevent generation.

The pellicle frame and the reticle of the present invention fixed to a magnetic force are shown in FIG. 1, for example. FIG. 1 shows a vertical cross-sectional view of a pellicle of the present invention. This is made of, for example, a synthetic quartz plate, and an iron-based magnet 3 is mounted on a reticle 1 on which a circuit pattern 2 is provided. The pellicle frame 4a made of, for example, iron is placed on the magnet 3, and the pellicle frame 4b is also provided under the reticle 1.
A pellicle film 5 is provided on a and 4b by a conventional method. The pellicle frames 4a and 4b and the reticle 1 are supposed to be fixed by a magnet 3 placed on the reticle 1. In this case, since the adhesive is not used, it does not peel off due to the decrease in the adhesive strength of the adhesive,
The disadvantage that the semiconductor element becomes defective due to the dust generated from the adhesive does not occur.

[0013]

EXAMPLES Next, examples and comparative examples of the present invention will be described. Example A sheet-shaped iron-based magnet having an outer dimension of 100 mm square, a width of 2 mm and a thickness of 0.5 mm is fixed to a stainless steel pellicle frame having an outer dimension of 100 mm square, a width of 2 mm and a height of 6 mm. Then, on the opening surface of this pellicle frame, a fluororesin CYTOP with a thickness of 0.85 μm was manufactured by a known method [Asahi Glass Co., Ltd.
In addition to the pellicle film of [Product name], an aluminum pellicle frame with external dimensions of 100 mm square, width of 2 mm and height of 6 mm is separately prepared. A pellicle film having a thickness of 0.85 μm was provided.

Next, the external dimensions are 152 mm square and the thickness is 2.3.
Mount the pellicle frame obtained above on the upper and lower surfaces of the reticle with a circuit pattern made of chrome on a synthetic quartz substrate of mm,
After fixing these with an iron-based magnet, this was irradiated with a low-pressure mercury lamp (wavelength 254 nm) with irradiation energy of 20 mw / cm ² for 50 hours, and the foreign matter on the pellicle film after irradiation was measured using a condenser lamp. This was 0.

Comparative Example Instead of fixing the pellicle frame and reticle by magnetic force in the examples, an epoxy resin adhesive, Araldite Trap [trade name, manufactured by Showa High Polymer Co., Ltd.] was used.
An irradiation test was conducted using a low-pressure mercury lamp after processing in the same manner as in Example except that the foreign matter was applied to a thickness of 0.5 mm. In this case, 150 foreign substances were measured on the pellicle film by irradiation for 1 hour, and 2 hours were measured. The number of foreign matters on the surface was measured innumerable by the irradiation.

[0016]

The present invention relates to a pellicle,
This is characterized in that the pellicle frame and the reticle are fixed by magnetic force as described above. However, according to this, since the pellicle frame and the reticle are not fixed to each other with an adhesive or an adhesive. The disadvantages of adhesive strength of adhesives and adhesives are avoided, and this adhesive
Since transfer to the resist film is prevented in this exposure step due to adhesion of dust generated from the pressure-sensitive adhesive, there is an advantage that a semiconductor device or the like does not become defective.

[Brief description of drawings]

FIG. 1 shows a vertical cross-sectional view of a pellicle according to the present invention.

[Explanation of symbols]

1 ... Reticle, 2 ... Circuit pattern, 3 ... Magnet,
4a, 4b ... Pellicle frame, 5 ... Pellicle film.

Front Page Continuation (72) Inventor Shu Kashida 2-13-1, Isobe, Annaka-shi, Gunma Shin-Etsu Chemical Co., Ltd., Institute for Precision Materials (72) Inventor Yoshihiro Kubota 2-chome, Isobe, Gunma Prefecture No. 13-1 Shin-Etsu Chemical Co., Ltd., Precision Materials Research Laboratory

Claims (3)

[Claims] 1. A pellicle comprising a pellicle frame and a reticle fixed by magnetic force. 2. The pellicle according to claim 1, wherein the pellicle frame is made of a magnetic material. 3. The pellicle according to claim 1, wherein the pellicle frame made of a non-magnetic material is formed by using a magnetic material.