JP2001092113A - Pellicle for semiconductor lithography - Google Patents

Abstract

(57) [Problem] To provide a pellicle for semiconductor lithography capable of easily performing a pellicle film cutting step in a pellicle manufacturing process and further easily handling a pellicle frame. A pellicle for semiconductor lithography comprising a pellicle film stretched at least on one end surface of a pellicle frame via a pellicle film adhesive, and an exposure original adhesive provided on another end surface. C-chamfering is performed at a corner formed between the film adhesion surface and the exposure original plate adhesion surface and the inner and outer surfaces of the frame, and the dimension of the chamfer is set to be larger than C0.25 and C0.35 or less. It is a pellicle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LSI,
The present invention relates to a pellicle for lithography, which is used as dust for a lithography mask when manufacturing a semiconductor device such as a liquid crystal display plate or the like.

[0002]

2. Description of the Related Art In the manufacture of semiconductors such as LSIs and VLSIs, or the manufacture of liquid crystal display plates, etc., a semiconductor wafer or a liquid crystal master is irradiated with light to form a pattern. If dust is attached to the photomask, reticle, and the like in this specification, the transferred pattern is deformed because the dust absorbs or bends the light. In addition to this, there are problems that the size, quality, appearance, and the like are impaired due to the fact that the base is stained black and the edge becomes rough.

[0003] For this reason, these operations are usually performed in a clean room, but it is difficult to keep the exposure master clean even in this clean room. A method is used in which a pellicle that transmits light well is attached.

In this case, the dust does not directly adhere to the surface of the exposure master, but adheres to the pellicle film. Therefore, if the focus is adjusted on the pattern of the exposure master during lithography, the dust on the pellicle film is reduced. Be independent of transcription.

In general, the basic structure of a pellicle is, as shown in FIG. 1, a transparent pellicle film 2 made of nitrocellulose, cellulose acetate, etc., which transmits light used for exposure well, made of aluminum, stainless steel, polyethylene or the like. A good solvent for the pellicle film is applied to the upper part of the pellicle frame 1 (hereinafter, sometimes referred to as “frame”) and air-dried (see JP-A-58-219023), or an acrylic resin or an epoxy resin. And the like via a pellicle film adhesive layer 5 (US Pat. No. 486140).
No. 2, Japanese Patent Publication No. 63-27707), and since an exposure master is attached to the lower part of the pellicle frame, an exposure master consisting of a polybutene resin, a polyvinyl acetate resin, an acrylic resin or the like is bonded. It comprises an agent layer 3 and a release layer 4 for protecting the adhesive layer.

[0006]

Since pellicles are used in the process of semiconductor lithography, high cleanliness is required for pellicle films, pellicle frames, adhesives and the like. The pellicle film must basically be free of foreign matter, dirt, and the like, and the pellicle frame is also problematic in terms of surface contamination, spots, and the like, in addition to foreign matter adhesion. Further, when a solvent is used for cutting an unnecessary film, the solvent may stain the surface of the conventional film in some cases, and the film may not be used as a product. Further, during cutting and removing the unnecessary film, the solvent may drip on the outer surface of the frame to stain the outer surface of the frame or other places, thereby causing dust and contamination of the original plate for exposure.

[0007] The pellicle may be attached to the original plate for exposure by an automatic attaching device (auto mounter), or may be manually handled and attached. When sticking manually, that is, when handling by hand, the pellicle frame is so thin that it may inevitably touch the original adhesive for exposure, causing contamination and sticking trouble. There was something.

Japanese Patent Publication No. 8-12418 discloses that, of the corners at which the end surface to which the pellicle film is adhered and the inner surface or the outer surface intersect, the corners at which the inner surface intersects with the outer surface are chamfered. Proposed. this is,
When the pellicle film is bonded, the pellicle film adhesive is intentionally protruded into the C-plane, and when the adhesive is applied, the adhesive swells and the film swells around the frame. It is something that prevents that.

However, in the case of the above method,
Since the chamfer is made only at the corner between the pellicle frame adhesive surface of the pellicle frame and the inner and outer surfaces of the frame (the upper corner of the pellicle frame), touch the exposure master adhesive during handling of the pellicle frame to expose the exposure master. There has been a problem that the function of the adhesive and other parts may be impaired or contaminated. Also, in the above description, the pellicle film adhesive is extruded to the inside and outside of the frame, and the extruded adhesive protrudes to the C surface portion and is absorbed, but once the pellicle film adhesive protrudes to the C surface portion,
Contamination of the film surface and the outer surface of the frame by the solvent during unnecessary film cutting was inevitable.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is intended for a semiconductor lithography capable of easily performing a pellicle film cutting step in a pellicle manufacturing process and further easily handling a pellicle frame. The main purpose is to provide a pellicle.

[0011]

Means for Solving the Problems The present invention has been made as a result of intensive studies to solve the above-mentioned object, and the invention described in claim 1 of the present invention has at least one end face of a pellicle frame. In a pellicle for semiconductor lithography, in which a pellicle film is stretched via a pellicle film adhesive and an exposure original adhesive is provided on another end surface, the pellicle film adhesive surface of the pellicle frame and the exposure original adhesive surface and the frame A chamfer is formed at a corner formed between the inner and outer surfaces, and the dimension of the chamfer is larger than C0.25 and C0.35.
A pellicle for semiconductor lithography characterized by the following.

As described above, the corners (upper and lower corners of the pellicle frame) formed by the pellicle frame adhesion surface and the exposure original plate adhesion surface of the pellicle frame and the inner and outer surfaces of the frame are chamfered. Is set to be larger than C0.25 and equal to or smaller than C0.35, it is possible to prevent contamination of the film surface and the outer surface of the frame by the solvent at the time of unnecessary film cutting. Also, at the position where the lithographic adhesive is applied, it is possible to prevent the lithographic adhesive from touching the lithographic adhesive during handling of the pellicle frame to impair or contaminate the function of the lithographic adhesive and other parts. it can. Here, if the C is not more than 0.25, the above effect is not obtained. If the C is larger than C 0.35, the bonding surface of the pellicle frame becomes small, and a sufficient bonding force cannot be obtained.

According to the present invention, since the C-chamfer is formed at the corners (upper and lower corners of the pellicle frame) formed by the pellicle film bonding surface of the pellicle frame and the exposure original plate bonding surface and the inner and outer surfaces of the frame. The technical idea is completely different from that of the conventional invention (Japanese Patent Publication No. 8-12418) in the method of bonding the film, the application of the adhesive, the form of bonding, and the method of cutting the unnecessary film.

In this case, as set forth in claim 2, the pellicle film adhesive is formed so as not to protrude from the pellicle film adhesion surface to the C surface side, and the exposure original plate adhesive is formed on the exposure original plate adhesion surface. It is preferable that it is formed so as not to protrude further to the C-plane side.

As described above, the pellicle film adhesive is formed so as not to protrude from the pellicle film bonding surface to the C surface side, and the exposing original adhesive is not protruded to the C surface side from the exposure original plate bonding surface. If it is formed, contamination of the film surface and the outer surface of the frame by the solvent at the time of unnecessary film cutting can be reliably prevented. At the same time, since the application position of the exposure master adhesive is located inside, the touch of the exposure master adhesive may damage the function of the exposure master adhesive and other parts during handling of the pellicle frame, or may cause contamination. I do not even do.

Further, as described in claim 3, the material of the pellicle frame is preferably an aluminum alloy whose surface is anodized.

Thus, if the material of the pellicle frame is an aluminum alloy whose surface is anodized,
A lightweight, high-strength pellicle frame that can be blackened to prevent stray light can be economically manufactured. Therefore, if such a pellicle frame is chamfered according to the present invention,
An extremely useful pellicle can be obtained.

Further, as described in claim 4, the pellicle film is a fluorine-based polymer, and the pellicle film adhesive is made of a polymer of tetrafluoroethylene and a fluorine-containing monomer having a cyclic perfluoroether group. Preferably, it is an adhesive.

As described above, when the pellicle film uses a fluorine-based polymer, a pellicle film having excellent light transmittance and light resistance can be obtained. Further, by using an adhesive made of a polymer of tetrafluoroethylene and a fluorine-containing monomer having a cyclic perfluoroether group as the pellicle film adhesive, even if the film material is a fluorine-based polymer having a strong release property, Since the adhesive strength is high and there is no light deterioration or decomposition, a pellicle with a long life and high performance can be manufactured.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments. The present inventors have conducted various investigations and studies in order to solve the above-mentioned problems, and as a result, in a pellicle for semiconductor lithography, an angle formed between a pellicle film bonding surface of a pellicle frame and an exposure original plate bonding surface and inner and outer surfaces of the frame. Part is chamfered and the dimension of the chamfer is larger than C0.25.
It was found that setting the content to 0.35 or less was extremely effective, and the present inventors completed the present invention after close examination.

Hereinafter, the pellicle frame of the present invention will be described in detail. The basic configuration of the pellicle of the present invention is substantially the same as that shown in FIG. 1 described above, and a pellicle film 2 is stretched on an upper surface of a pellicle frame 1 with a pellicle film adhesive layer 5 interposed therebetween. Is formed with an original adhesive layer 3 for exposure (hereinafter, in the present case, a "reticle" is used as an example of the original master for exposure), and a release layer 4 can be peeled from the lower end surface of the original adhesive layer 3 for exposure. It is the thing which is pasted on.

In such a pellicle, the present invention provides:
For example, as shown in the enlarged cross-sectional view of FIG. 2, the upper and lower corners of the pellicle frame are chamfered, and the size of the chamfer is larger than C0.25 and C0.35.
It has the features specified below. That is, the C chamfering is made at the corner between the pellicle film bonding surface of the pellicle frame and the exposure original plate bonding surface and the inner and outer surfaces of the frame, and there are four surfaces at the upper and lower portions of the pellicle frame. By defining the size of the chamfer to be greater than C0.25 and not more than C0.35, contamination of the film surface and the outer surface of the frame by the solvent at the time of unnecessary film cutting can be prevented. In addition, at the application position of the exposure master adhesive, the handling of the pellicle frame should also prevent the exposure master adhesive and the function of the exposure master adhesive and other parts from being damaged or contaminated. Can be.

Further, the pellicle film adhesive and the exposure original plate adhesive are formed so as not to protrude to the C side (particularly, the C side a and b portions of the frame outer side) from the respective bonding surfaces. Thus, the contamination of the film surface and the outer surface of the frame by the solvent at the time of cutting the unnecessary film can be reliably prevented. At the same time, the application position of the exposure master adhesive is surely on the inner side, so that when the pellicle frame is handled, it touches the exposure master adhesive and impairs or contaminates the functions of the exposure master adhesive and other parts. I do not even do.

In this case, the size of these pellicle constituent members is the same as that of a normal pellicle, and the material thereof can be a known material as described above. More specifically, the type of the pellicle membrane is not particularly limited, and for example, conventionally used nitrocellulose, cellulose acetate, cellulose propionate, amorphous fluoropolymer, etc. are used. It is particularly preferable to use a system polymer. Examples of the amorphous fluorine-based polymer include CYTOP (trade name, manufactured by Asahi Glass Co., Ltd.) and Teflon AF (trade name, manufactured by Dupont Co., Ltd.). These polymers may be used by dissolving them in a solvent as needed at the time of preparing the pellicle film. For example, the polymers may be appropriately dissolved in a fluorine-based solvent or the like.

There is no particular limitation on the pellicle frame used in the present invention, and the material may be a conventionally used aluminum alloy material (A7075-T6).
51, a 7000 series aluminum alloy), etc., anodized, stainless steel, polyacetal, polycarbonate, polymethyl methacrylate (PMMA), resins such as acrylic resin, blue plate glass, etc. Treated aluminum alloy materials are particularly preferred. The pellicle frame surface is usually roughened by sandblasting or chemical polishing. For example, when an aluminum material is used, the surface is blasted with carborundum, glass beads, etc.
There is known a method of roughening the surface by performing chemical polishing using aOH or the like.

A known release layer (separator) may be used as the release layer (separator) attached to the lower end surface of the reticle adhesive.

As the pellicle film adhesive, a fluoropolymer is preferable, and among them, a polymer of tetrafluoroethylene and a fluoromonomer having a cyclic perfluoroether group is particularly preferable. Specifically, a fluorine-based polymer CT69 (trade name, manufactured by Asahi Glass Co., Ltd.) may be mentioned.

Examples of the reticle adhesive include a double-sided adhesive tape, a silicone resin adhesive, and an acrylic adhesive.

In the pellicle of the present invention, a pellicle film is stretched on the upper end surface of the pellicle frame via a pellicle film adhesive by a usual method, and a reticle adhesive layer is formed on the lower end surface. It can be manufactured by sticking a release layer to the lower end face in a releasable manner. Here, the pellicle film adhesive layer can be formed by diluting with a solvent if necessary, applying the diluted solution to the upper end surface of the pellicle frame, heating, drying, and curing. In this case, as a method of applying the adhesive, brush coating, spraying, a method using an automatic dispenser, or the like is employed.

[0030]

The present invention will be described below with reference to examples and comparative examples. (Example 1) First, as a pellicle frame, the outer dimensions of the frame were 100 mm x 100 mm x 6 mm in width, and 2 m in thickness.
m of an aluminum alloy frame was prepared. As shown in FIG. 2, the frame was C-chamfered, and the C-plane dimensions of the aluminum alloy frame were all C0.3. After the surface was washed, the surface was roughened by using glass beads having a particle size of 90 μm for 10 minutes using a sand blasting device with a discharge pressure of 1.5 kg. Then, after treating and washing in a NaOH treatment bath for 10 seconds, anodizing, black dyeing,
Sealing was performed to form a black oxide film on the surface.

This aluminum alloy frame was cleaned using both pure water and an ultrasonic cleaning device. Next, a silicone-based pressure-sensitive adhesive was coated on the inner wall surface of the frame with a spray coating device at a thickness of 1 μm.

Next, Teflon AF1600 (trade name, manufactured by DuPont, USA) was added to a fluorine-based solvent, Fluorinert FC-
75 (trade name, manufactured by 3M, USA) and a concentration of 8
% Solution was prepared. Thereafter, the solution was used to remove the diameter 2
A 0.8 μm thick transparent film was formed using a spin coater on the mirror-polished silicon substrate surface having a thickness of 00 mm and a thickness of 600 μm. Next, an outer diameter of 200 mm
A frame having a width of 5 mm and a thickness of 5 mm was adhered and peeled off using an epoxy-based adhesive Aralditrapid (trade name, manufactured by Showa Polymer Co., Ltd.).

Next, the aluminum alloy frame prepared as described above was brought into contact with the film surface of the formed Teflon AF1600 using CT-69 (trade name, manufactured by Asahi Glass Co., Ltd.). It was heated for 10 minutes to bond.
The two frames were attached to a fixing jig with the bonding surface of the pellicle frame facing upward, and fixed so that the positions did not shift relatively. Next, the frame outside the pellicle frame was pulled up and fixed, and a tension of 0.5 g / cm was applied to the film portion outside the pellicle frame.

As another instrument for cutting the membrane, a scalar robot was equipped with a stainless steel cutter having a thickness of 0.25 mm.
Was attached. Using a tube type dispenser for this cutter, while moving Florinert FC75 (trade name, manufactured by DuPont, USA) at a rate of 10 μl per minute while moving the cutter along the periphery of the adhesive portion of the pellicle frame, the outside of the pellicle frame was removed. Was cut and removed.

Next, the surface of the completed pellicle film was inspected in a dark room using a condensing lamp (illuminance 300,000 lux). No stain was found on the pellicle membrane surface.

Further, the pellicle was handled by holding the outer surface of the completed pellicle, placed on a dummy photomask substrate, and pasted. However, the reticle adhesive did not protrude to the portion b on the side C in FIG. It did not stain the reticle bonding surface.

The same operation as in this example was repeated 50 times, but no film breakage or stain was found due to the solvent used for cutting the pellicle film surface. Also, when handling the pellicle frame, touch the reticle adhesive to impair the function of the reticle adhesive or other parts,
There was no contamination.

Comparative Example 1 First, as a pellicle frame, the outer dimensions of the frame were 100 mm × 100 mm × 6 m in width.
An aluminum alloy frame having a thickness of 2 mm and a thickness of 2 mm was prepared. The corner between the pellicle frame adhesive surface of the pellicle frame and the inner and outer surfaces of the frame (upper corner of the pellicle frame)
Only the C-chamfering was performed, and the C-plane dimension of the aluminum alloy frame was C0.15. In this case, C in FIG.
The surface b does not exist. After cleaning the surface, the particle size is 9
Surface treatment was carried out for 10 minutes using a sand blasting device with a discharge pressure of 1.5 kg using glass beads of 0 μm to roughen the surface. Next, after treating in an NaOH treatment bath for 10 seconds and washing, anodizing, black dyeing and sealing treatment were performed to form a black oxide film on the surface.

This aluminum alloy frame was cleaned using both pure water and an ultrasonic cleaning device. Next, a silicone-based pressure-sensitive adhesive was coated on the inner wall surface of the frame with a spray coating device at a thickness of 1 μm.

Next, Teflon AF1600 (trade name, manufactured by DuPont, USA) was added to a fluorine-based solvent, Fluorinert FC-
75 (trade name, manufactured by 3M, USA) and a concentration of 8
% Solution was prepared. Thereafter, the solution was used to remove the diameter 2
A 0.8 μm thick transparent film was formed using a spin coater on the mirror-polished silicon substrate surface having a thickness of 00 mm and a thickness of 600 μm. Next, an outer diameter of 200 mm
A frame having a width of 5 mm and a thickness of 5 mm was adhered and peeled off using an epoxy-based adhesive Aralditrapid (trade name, manufactured by Showa Polymer Co., Ltd.).

Next, the aluminum alloy frame prepared as described above was brought into contact with the film surface of the formed Teflon AF1600 using CT-69 (trade name, manufactured by Asahi Glass Co., Ltd.), and heated at 100 ° C. It was heated for 10 minutes to bond.
The two frames were attached to a fixing jig with the bonding surface of the pellicle frame facing upward, and fixed so that the positions did not shift relatively. Next, the frame outside the pellicle frame was pulled up and fixed, and a tension of 0.5 g / cm was applied to the film portion outside the pellicle frame.

[0042] Separately, as a device for cutting the membrane, a scalar robot was equipped with a stainless steel cutter having a thickness of 0.25 mm.
Was attached. Using a tube type dispenser, 10 μl of Florinert FC75 (trade name, manufactured by DuPont, USA) is dropped on the cutter, and the cutter is moved along the periphery of the adhesive portion of the pellicle frame while dropping 10 μl per minute. Was cut and removed.

Next, the surface of the completed pellicle film was inspected in a dark room using a condensing lamp (illuminance: 300,000 lux). And stains were observed, and stains due to the solvent were slightly observed on the film surface.

Next, handling was carried out by holding the outer surface of the completed pellicle, and placed on a dummy photomask substrate and pasted. However, in all cases, traces of handling (foreign matter) remained on the reticle adhesive. The reticle adhesive adhered to the gloves.

The same operation as in this comparative example was repeated 50 times, but some of the film was broken or stained due to the solvent used for cutting the pellicle film surface. In addition, when handling the pellicle frame, the reticle adhesive was touched and the functions of the reticle adhesive and other parts were impaired and contaminated. Table 1 shows the above results.

[0046]

[Table 1]

As is clear from Table 1, the pellicle obtained in Example 1 in which the upper and lower corners of the aluminum alloy frame were C-chamfered and the C-plane dimensions were all C0.3, showed an unnecessary film. The contamination of the film surface and the outer surface of the frame by the solvent at the time of cutting could be prevented. At the same time, it was possible to prevent the reticle adhesive from touching the reticle adhesive during handling of the pellicle frame to impair or contaminate the functions of the reticle adhesive and other parts.

On the other hand, only the corners (upper corners of the pellicle frame) formed between the pellicle frame bonding surface of the pellicle frame and the inner and outer surfaces of the frame are chamfered, and the C-plane dimensions of the aluminum alloy frame are reduced. In the pellicle obtained in Comparative Example 1 having a C of 0.15, contamination of the film surface and the outer surface of the frame by the solvent at the time of unnecessary film cutting could not be completely prevented. In addition, since the corner formed between the reticle bonding surface of the pellicle frame and the inner and outer surfaces of the frame (the lower corner of the pellicle frame) is not chamfered, the reticle adhesive may be touched during handling of the pellicle frame by touching the reticle adhesive. Other parts were impaired and contaminated. In this case, it is difficult to perform an unnecessary film cutting step of the pellicle frame, and particularly to handle the pellicle frame by handling.

The material of the pellicle frame is an aluminum alloy whose surface is treated with alumite, the pellicle film is made of a fluoropolymer, and the pellicle film adhesive is made of a polymer of tetrafluoroethylene and a fluorine-containing monomer having a cyclic perfluoroether group. It can be seen that the use of such an adhesive facilitates the pellicle film cutting step by improving the controllability of the solvent, and also allows easy and reliable handling of the pellicle frame.

The present invention is not limited to the above embodiment. The above embodiment is an exemplification, and has substantially the same configuration as the technical idea described in the claims of the present invention. Within the technical scope of

[0051]

According to the present invention, the upper and lower corners of the pellicle frame are chamfered, and the size of the chamfer is set to C0.2.
5 and C0.35 or less, and furthermore, the pellicle film adhesive and the exposure original plate adhesive are formed so as not to protrude from the respective bonding surfaces to the C surface side. Contamination of the film surface and the outer surface of the frame can be prevented. At the same time, at the application position of the exposure original adhesive, it is possible to prevent the exposure original adhesive and other parts from being damaged and contaminated by touching the exposure original adhesive when handling the pellicle frame. it can.

In this manner, in the unnecessary film cutting step around the pellicle frame, the controllability of the solvent for cutting the unnecessary film can be improved, and the handling of the pellicle frame can be easily and reliably performed. Therefore, if photolithography is performed using the pellicle for semiconductor lithography of the present invention, a normal transfer pattern can be obtained, and as a result, the performance and manufacturing yield of a semiconductor device or a liquid crystal display plate can be improved. it can.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration example of a general pellicle.

FIG. 2 is an enlarged cross-sectional view of the pellicle of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pellicle frame, 2 ... Pellicle film, 3 ... Original exposure adhesive layer, 4 ... Release layer, 5 ... Pellicle film adhesive layer. C surface a portion: a chamfered portion formed between the pellicle film bonding surface and the frame outer surface (upper corner of the pellicle frame), and C surface b portion: formed between the exposure original plate bonding surface and the frame outer surface. A chamfer made at the corner (the lower corner of the pellicle frame).

Claims (4)

[Claims] 1. A pellicle for semiconductor lithography comprising a pellicle film stretched at least on one end surface of a pellicle frame via a pellicle film adhesive, and an exposure original adhesive provided on another end surface of the pellicle frame. A semiconductor lithography, wherein a C-chamfer is formed at a corner formed between the pellicle film bonding surface and the exposure original plate bonding surface and the inner and outer surfaces of the frame, and the size of the chamfer is larger than C0.25 and C0.35 or less. For pellicle. 2. The pellicle film adhesive is formed such that it does not protrude from the pellicle film adhesion surface to the C surface side, and the exposure master adhesive does not protrude to the C surface from the exposure original plate adhesion surface. The pellicle for semiconductor lithography according to claim 1, wherein the pellicle is formed. 3. The pellicle for semiconductor lithography according to claim 1, wherein a material of the pellicle frame is an aluminum alloy whose surface is anodized. 4. The pellicle membrane is a fluoropolymer, and the pellicle membrane adhesive is an adhesive composed of a polymer of tetrafluoroethylene and a fluorine-containing monomer having a cyclic perfluoroether group. The pellicle for semiconductor lithography according to any one of claims 1 to 3.