JPH06100826B2 - Pellicle for lithograph - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a lithographic pellicle, particularly an LSI or VLSI.
The present invention relates to a dust protection pellicle for lithographic use in an exposure method using light of substantially 500 nm or less, which is used when manufacturing a semiconductor device such as.

(Prior Art) In the manufacture of LSI and VLSI semiconductor devices, a semiconductor wafer is irradiated with light to form a pattern. However, if dust is attached to the exposure master used in this case, this dust will be exposed to light. Are absorbed, or the transferred pattern is deformed because it bends the light, the edges become rough, and the white background is stained black,
The disadvantage is that the dimensions, quality and appearance are impaired.

Therefore, this kind of work is usually performed in a clean room, but it is difficult to keep the exposure master always clean even in this clean room. A method of sticking a pellicle that allows the water to pass through is used, and a thin film of nitrocellulose, cellulose acetate, or the like is used as the pellicle.

(Problems to be solved by the invention) However, this pellicle made of nitrocellulose, cellulose acetate, etc. has a large absorption edge in a short wavelength range of 210 to 400 nm, has poor stability, and yellows during use. In order to achieve this, the semiconductor device is exposed to light with a wavelength range of 210 to 400 nm, such as excimer laser and i-line ultraviolet rays.
It has the disadvantage that it cannot be used as a lithographic printer for I, and the emergence of a lithographic pellicle that can be used in such a short wavelength region is required.

(Means for Solving the Problems) The present invention is directed to solving such disadvantages and to a lithographic pellicle, which is a high molecular weight organosilicon compound in an exposure method using light of substantially 500 nm or less. It is characterized in that the film is used as a pellicle for preventing dust.

That is, the present inventors have variously studied to develop a lithographic pellicle suitable for use in a short wavelength region,
When a polymer organic silicon compound film is used in place of conventionally known nitrocellulose and cellulose acetate, this film also allows light of 500 nm or less to pass therethrough, and may generate an absorption edge even in a short wavelength range of 210 to 400 nm. Therefore, it was found to be useful as a pellicle for lithography in the short wavelength region of 500 nm or less, and the shape and structure of the polymer organic silicon compound thin film as this pellicle, its manufacturing method, and polymer organic silicon compound. The present invention has been completed by conducting research on the types of

(Function) The lithographic pellicle of the present invention uses a polymer organic silicon compound film as described above. This polymer organic silicon compound film contains a polymer organic silicon compound such as Belzene or toluene. After being appropriately dissolved in a solvent such as, the solution is cast by the solution caster method using a spin coater or knife coater, or the high molecular organosilicon compound is melt-extruded by the T-die method, the inflation method or the like. It can be manufactured by forming into a film by a known method such as a method.

The polymer organic silicon compound used here may be a polymer of a known organic silicon compound having a film forming ability, and particularly good light transmittance in a short wavelength region such as 210 to 400 nm,
From the fact that a film with sufficient film strength is given, the general formula And R ¹ , R ² and R ³ are the same or different alkyl groups such as methyl group, ethyl group, propyl group, butyl group and octyl group, and n is a positive integer. Preferably, this includes polytrimethylvinylsilane,
Examples thereof include polytriethylvinylsilane and polyethyldimethylvinylsilane.

The high molecular weight organic silicon compound film produced by the above method should have a thickness of 0.5 μm or more in order to have mechanical strength when used as a pellicle, but this is also 249 nm or more. Even when surface anti-reflection treatment is performed to pass 96% or more of ultraviolet rays in the wavelength range of
It is desirable that the thickness is 300 μm or less.

This polymer organic silicon compound film has a high ultraviolet transmittance,
Since it also transmits light in the short wavelength range of 210 to 400 nm well, it is particularly useful as a pellicle for lithography in the short wavelength range, but in this use, it should be fixed by adhesion to a frame such as aluminum. Good to use.

(Example) Next, the Example of this invention is given.

Example 1, Comparative Example Polytrimethylvinylsilane having an intrinsic viscosity of 0.95 dl / g in a toluene solution at 20 ° C. was dissolved in toluene to obtain 3%.
The solution was cast on a smooth glass plate using a knife coater with a clearance of 50 μm, dried at room temperature for 24 hours, then dried at 60 ° C. for 2 hours and at 100 ° C. for 1 hour.

Then, this polytrimethylvinylsilane thin film is adhered to a product coated with epoxy adhesive Araldite Rapid [trade name of Showa High Polymer Co., Ltd.] on the end surface of an aluminum frame having an inner diameter of 130 mm, and cured for 1 hour, and then a glass plate. After soaking in water for 5 minutes, take out the naturally peeled glass plate, air-dry it, and cut off the film that sticks out of the aluminum frame. A lithograph with a uniform thickness of 1.3 μm A polytrimethylvinylsilane thin film as an e-pellicle was obtained.

Next, when the light transmittance of this thin film was examined, it showed a transmittance of 90% or more in the wavelength range of 240 to 500 nm, and the antireflection treatment on both sides of the film was 436 nm g.
Line 98.4%, 365nm i-line 98.2%, 249nm excimer laser 98.1% transmission, 210nm transmission 90%, which also did not yellow during use Therefore, it was confirmed to be an excellent pellicle.

However, for comparison, a 1.4 μm thick lithographic pellicle obtained by the same treatment as above except that an ethyl acetate solution of nitrocellulose / HIG-20 (trade name, manufactured by Asahi Kasei Co., Ltd.) was used. The transmittance of g-line of 436 μm is 97.9%, 365
The transmittance of the i-line of nm was 97.5%, but the transmittance of the excimer laser of 249 nm is 41.1%, which is also a pellicle that cannot be used as a pellicle because it yellows while using the i-line Met.

Example 2 The polytrimethylvinylsilane used in Example 1 was dissolved in toluene to give a 25% solution, which was cast on a smooth glass plate using a knife coater with a clearance of 1 mm, and the temperature was 40 ° C.
After being dried at 70 ° C. for 4 hours and at 100 ° C. for 2 hours, the polytrimethylvinylsilane film was naturally peeled off to form a film having a thickness of 249 μm.

Next, this film is adhered to the end surface of aluminum using an epoxy adhesive (previously mentioned) so that it becomes smooth, and the part protruding to the outside of the aluminum frame is cut off to make a lithographic pellicle. When the transmittance was examined, it showed a transmittance of 90% or more in the wavelength range of 240 to 500 nm.
6nm g line 98.3%, 365nm i line 98.0%, 249nm excimer laser shows 96.6% light transmittance, which also has sufficient mechanical strength, and the pellicle turns yellow during use. It never happened.

Example 3 A 1.2 μm thick lithographic pellicle was prepared in the same manner as in Example 1 except that polyethyldimethylvinylsilane having an intrinsic viscosity of 0.91 dl / g in a toluene solution at 20 ° C. was used. After examining the transmittance,
It shows a transmittance of 90% or more in the wavelength range of 260 to 500 nm, and the film with antireflection treatment on both sides of the film has a 436 nm g-line of 98.
5%, 98.0% with 365 nm i-line and 90.0% with 249 nm excimer laser, which is also excellent as a lithographic pellicle because the pellicle does not yellow during use. Was done.

(Effects of the Invention) The lithographic pellicle of the present invention uses the high molecular weight organic silicon compound film as a dust protection pellicle as described above, and has a short wavelength range of 210 to 500 nm. Since it has a high ultraviolet ray transmittance and does not turn yellow during use, it is useful as an exposure pellicle for large-scale integrated circuits such as LSI and VLSI, and also has excellent light transmittance. Therefore, the exposure time can be shortened and the strength of the pellicle film can be improved by increasing the film thickness.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Toyohisa Sakurada Inventor, Toyohisa, 28, Nishi-Fukushima, Chugiki-mura, Nakakubiki-gun, Niigata Prefecture Shin-Etsu Chemical Co., Ltd. Synthetic Technology Laboratory (72) Inventor Masaaki Iguchi Otemachi, Chiyoda-ku, Tokyo 2-6-1, Shin-Etsu Chemical Co., Ltd.

Claims (2)

[Claims] 1. A lithographic pellicle characterized by using a high molecular organic silicon compound film as a dust protection pellicle in an exposure method using light of substantially 500 nm or less. 2. A polymer organic silicon compound is represented by the general formula (Wherein R ¹ , R ² and R ³ are the same or different alkyl groups, n
Is a positive integer), and the lithographic pellicle according to claim 1.