JPH08292552A - Production of pellicle film - Google Patents

Abstract

PURPOSE: To easily and efficiently obtain a pellicle film by controlling the temp. of a substrate to be slightly higher than the dew point when a pellicle film formed on the substrate is peeled from the substrate surface. CONSTITUTION: The material for formation of a pellicle film is dissolved in a solvent to prepare a soln. of 3-10% concn. The obtd. soln. is applied to form a pellicle film on a silicon substrate or glass substrate by soln. casting method using a spin coating or knife coating device. And, when the pellicle film is peeled from the substrate to obtain a pellicle film, the temp. of the substrate is controlled to be a slightly higher than the dew point and the film is peeled from the substrate. For example, when the film is formed in a clean room at 23 deg.C and 50% relative humidity, a cooling plate is maintained at 11 deg.C, which is slightly higher than the dew point 10.8 deg.C under those conditions. Then, the substrate is mounted on the cooling plate and cooled to peel the pellicle film from the substrate. Thereby, only the substrate surface necessary for peeling can be selectively exposed to a water vapor environment and the film can be easily peeled.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a method for producing a pellicle film,
In particular, the present invention relates to a method for manufacturing a pellicle film used as a dust shield when manufacturing a semiconductor device such as an LSI or VLSI or a liquid crystal display panel.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices such as LSI and VLSI, or liquid crystal display plates, patterning is performed by irradiating a semiconductor wafer or a liquid crystal original plate with light. If dust is attached, it absorbs light or reflects light, which may cause deformation of the transferred pattern,
There is a problem in that the edges become rough and the dimensions, quality, and appearance are impaired, and the performance and manufacturing yield of semiconductor devices, liquid crystal display panels, and the like are reduced. For this reason, these tasks are usually done in a clean room,
Even in this clean room, it is difficult to always keep the original exposure plate normal. Therefore, a method has been used in which a pellicle that allows the light for exposure to pass therethrough to pass dust well is attached to the surface of the original exposure plate.

In this case, since dust does not directly adhere to the surface of the exposure original plate but adheres to the pellicle film, if the focus is aligned with the pattern of the exposure original plate during lithography,
The dust on the pellicle is unrelated to the transfer, but the attachment of this pellicle consists of a transparent pellicle film made of nitrocellulose, cellulose acetate, etc. that allows light to pass well, and a pellicle frame made of aluminum, stainless steel, etc. placed on top of the pellicle. A good solvent for the film is applied and air-dried for adhesion (JP-A-58-219023) or an adhesive such as acrylic resin or epoxy resin (US Pat. No. 4.861.402, JP-B-63-27,707). No.) is adopted.

[0004]

However, the production of the pellicle membrane is carried out by using these membrane materials in a solvent in an amount of 3 to 10%.
After making the solution with the concentration of, the solution casting method using a spin coater or a knife coater is used to form a film on a silicon wafer or a glass substrate. After being deposited on
Although it is peeled from the substrate, a method of peeling in water and a method of peeling in water vapor have been proposed as the method. However, peeling in water not only stains water, but also foreign matter generated from a portion such as the back surface of the substrate that comes into contact with water contaminates the film using water as a medium. In addition, peeling in water vapor can suppress the generation of foreign matter such as peeling in water, but it is necessary to completely make the space where peeling occurs in a steam atmosphere, and pellicle manufacturing is generally performed in a clean room. However, it is difficult to change the environment such as the steam atmosphere in only a part of it. Considering that an apparatus for creating a large water vapor atmosphere is required especially when a large film for liquid crystal is peeled off, there are many difficulties in industrialization.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a method for manufacturing a pellicle film which solves such disadvantages, in which the step of peeling a pellicle film from a substrate is carried out by setting the temperature of the substrate slightly higher than the dew point temperature. It is characterized in that the temperature is lowered to the temperature.

That is, as a result of various studies on the method for peeling the pellicle film formed on the substrate from the substrate, the present inventors have decided that the step of peeling the pellicle film from the substrate is water or water vapor as in the conventional case. Without removing the temperature of the substrate to a temperature slightly higher than the dew point temperature and peeling in air, in this case, contamination diffusion such as underwater peeling disappears, and special environmental equipment such as water vapor peeling is also required. Therefore, the present invention has been completed by finding that the target pellicle film can be obtained easily and efficiently. This will be described in more detail below.

[0007]

The present invention relates to a method for manufacturing a pellicle film, which is characterized in that the step of peeling the pellicle film from the substrate is performed by lowering the temperature of the substrate to a temperature slightly higher than the dew point temperature. This provides the advantage that the diffusion of contamination is less than the method of performing the peeling process of the pellicle film from the substrate in water, and creates a steam atmosphere compared to the method of performing this peeling process in steam. The advantage is given that it is not necessary.

Therefore, in the production of the pellicle film according to the present invention, the pellicle film forming material is dissolved in a solvent according to a conventional method to prepare a solution having a concentration of 3 to 10%, and this solution is used with a spin coater or a knife coater. When a pellicle film is formed on a silicon or glass substrate by the solution caster method and then peeled off from the substrate to form a pellicle film, the peeling of the pellicle film from the substrate depends on the substrate temperature as a dew point. It may be lowered to a temperature slightly higher than the temperature.

In this case, the peeling of the pellicle film from the substrate lowers the temperature of the substrate to a temperature slightly higher than the dew point temperature. In an actual method, the cooling plate is brought close to the dew point temperature to a constant temperature, and Although it is only necessary to place the substrate on the substrate and lower the temperature of the substrate, since the pellicle is generally manufactured in a clean room and the clean room is at constant temperature and humidity, the dew point is usually constant. For example, the temperature in a clean room
Since the dew point temperature at 23 ° C and relative humidity 50% is 10.8 ° C, if this cooling plate is set to 11 ° C and the substrate is placed on this cooling plate to cool, the substrate is slightly higher than 10.8 ° C.
Can be kept at ° C.

When the pellicle film is peeled off from the substrate after the substrate temperature is cooled to a temperature slightly higher than the dew point temperature in this way, the peeling is performed without making the entire environment for peeling the substrate into a water vapor atmosphere. The pellicle film can be stripped easily and efficiently because only the surface of the substrate necessary for heat treatment can be selectively exposed to the water vapor atmosphere. However, if the temperature of the substrate is below the dew point temperature, water drops will form on the surface of the substrate. The substrate temperature is required not to be lower than the dew point because it contaminates the film.

[0011]

EXAMPLES Next, examples and comparative examples of the present invention will be described. Examples, Comparative Examples 1 and 2 Cytop CTX-S [trade name of Asahi Glass Co., Ltd.] as a membrane material was dissolved in its solvent, CTsolv 180 [trade name of Asahi Glass Co., Ltd.] to prepare a 5 wt% solution. did. Then, this solution was formed as a transparent film having a film thickness of 0.82 μm on a surface-polished quartz substrate having a diameter of 200 mm and a thickness of 3 mm by using a spin coater, and dried at 180 ° C. for 15 minutes to form a pellicle film.

Next, in a clean room at a temperature of 23 ° C. and a relative humidity of 50%, the substrate on which the pellicle film was formed was placed on a cooling plate cooled to 11 ° C., and the substrate was cooled to 11 ° C. Upon peeling, a good pellicle film was easily obtained as shown in Table 1. However, for comparison, the temperature of this cooling plate is set to 16 ° C and 23 ° C, which is higher than the dew point temperature of 10.8 ° C under the conditions of 23 ° C and relative humidity of 50%, and the temperature of the substrate is set to 16 ° C and 23 ° C by this cooling plate. When the pellicle film was peeled off, as shown in Table 1, peeling was possible at 16 ° C, but wrinkles were generated in the film, and at 23 ° C, there was a disadvantage that the film was broken.

[0013]

[Table 1]

[0014]

INDUSTRIAL APPLICABILITY The present invention relates to a method for producing a pellicle film, which eliminates contamination diffusion such as in the case of underwater stripping, and does not require special environmental equipment such as steam stripping. It is possible and the advantage that the target pellicle film can be obtained easily and efficiently is given.

Claims (1)

[Claims] 1. A method for producing a pellicle film, which comprises removing the pellicle film formed on the surface of the substrate from the surface of the substrate by lowering the temperature of the substrate to a temperature slightly higher than the dew point temperature.