JP3223022B2 - Plate making method of master for forming fine patterns - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for making an original plate for forming a fine pattern, and more particularly to a method for forming an original plate for forming a fine pattern in which a fine pattern can be efficiently formed with high precision in a fine processing step such as a semiconductor process. Related to plate making method.

[0002]

2. Description of the Related Art Conventionally, in a process of manufacturing a thin film transistor, a thin film diode, a solar cell, a thin film sensor, various semiconductor elements, a printed circuit board, and the like, a fine pattern is formed on a work, and then the work is etched. Processing was done.

As one of the methods for forming a fine pattern on a workpiece, there is a method using an original plate having a concave portion. The master used in this method is a masking layer formed by exposing and developing a resist film formed on a stainless steel substrate through a photomask having a predetermined fine pattern. Then, the electrodeposited material deposited on the portion of the original plate where the masking layer is not formed (the concave conductive pattern) is transferred to the workpiece.

[0004]

The stainless steel substrate used for the fine pattern forming master as described above is rolled in the manufacturing stage to be formed into a long plate shape, and then, usually, tensioned into a roll shape. It has been rolled up. And
When making a master for forming a fine pattern, a roll-shaped stainless steel plate is cut into a predetermined length to form a substrate, and the stainless substrate has residual stress due to the rolling direction and residual stress due to tension when the roll is wound up. are doing. For this reason, after the master for fine pattern formation is made, the stainless substrate shrinks, and the phenomenon of shrinking the size of the fine pattern compared to the size of the photomask is observed. There was a problem that it could not be obtained. Further, since the shrinkage of the stainless steel substrate varies in the range of about 40 to 100 μm / 400 mm depending on the production lot, a high-precision micropattern forming master using a photomask previously created in consideration of the shrinkage of the stainless steel substrate is used. Even if it is attempted to manufacture, it is necessary to use a different photomask for each production lot of the stainless steel substrate or for each of the outside and inside of the roll state, and there is a problem that the process management is complicated and not suitable for mass production.

The present invention has been made in view of the above circumstances, and provides a plate making method of a fine pattern forming master plate capable of efficiently forming a fine pattern on a workpiece with high accuracy. The purpose is to:

[0006]

In order to achieve the above object, according to the present invention, a heat treatment is performed on a stainless steel substrate, and then a resist film is formed on the stainless steel substrate to obtain a desired fine pattern. The resist film was exposed and developed through a photomask to form a fine resist pattern on the stainless steel substrate.

In the present invention, the conditions of the heat treatment applied to the stainless steel substrate can be set to a heating temperature of about 150 to 300 ° C. and a heating time of 1 to 3 hours. If the heating temperature and the heating time are less than the above ranges, the residual stress due to the rolling direction or the residual stress due to the tension during roll winding existing on the stainless steel substrate cannot be completely removed, and the plate making of the fine pattern forming master plate is not performed. After the completion of the above, the contraction of the stainless steel substrate occurs. Also,
Even if the heat treatment is performed so as to exceed the above-mentioned heating temperature and heating time, no further effect is obtained by the heat treatment, and only the production cost is increased, which is not preferable.

The stainless steel substrate to which the present invention is applied is not particularly limited, and examples thereof include those conventionally used as a substrate of a master for forming a fine pattern. Specifically, SUS304, SUS301, SUS43
0, SUS405, SUS403, SUS410 and the like.

In the present invention, it is preferable that the stainless steel substrate is washed before the heat treatment is performed on the stainless steel substrate. For the cleaning of the stainless steel substrate, known cleaning means such as organic solvent cleaning, electrolytic degreasing in an alkaline solution, and water cleaning can be used.

The resist used in the present invention may be a known organic resist, for example, gelatin, casein,
Glue, natural proteins such as ovalbumin, carboxymethylcellulose, polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone,
Polyethylene oxide, a mixture of two or more of a maleic anhydride copolymer and a carboxylic acid-modified or sulfonic acid-modified product of the above resin, for example, a diazonium compound having a diazo group and a paraformaldehyde Reaction products such as diazo resin, azide compound having azide group, cinnamic acid condensed resin obtained by condensing cinnamic acid with polyvinyl alcohol, resin using stilbazolium salt, photocurable photosensitive group such as dichromate By adding a compound having the following, a compound having photosensitivity can be given. Incidentally, the photosensitive group is not limited to the above-mentioned photocurable photosensitive group.

The thickness of a resist film formed using the above-described resist is preferably about 0.5 to 4 μm.
The formation of the resist film can be performed by a spin coating method, a roll coating method, a dipping / pulling-up method, a pouring method, a spray method, or the like.

[0012]

[Action] A resist film is formed on a stainless steel substrate,
The resist film is exposed and developed through a photomask having a desired fine pattern to form a resist fine pattern, and the stainless steel substrate is subjected to a heat treatment to form a resist film. The residual stress due to the direction or the residual stress due to the tension when the roll is wound up has been removed in advance, so that the formed resist fine pattern maintains the dimensional accuracy of the photomask, and a high precision can get.

[0013]

EXAMPLE A stainless steel substrate (SUS304-H, length 8)
(60 mm, width 400 mm, thickness 0.25 mm). First, the stainless steel substrate was immersed in a bath of an organic solvent (acetone) for 1 minute, and the organic solvent was mechanically rubbed with a gauze. Thereafter, the same cleaning was performed using ethanol as an organic solvent. After the completion of the solvent washing, the stainless steel substrate was washed with running water for 30 seconds, and dried by blowing nitrogen. Next, the stainless steel substrate was immersed in an alkaline solution of the following composition kept at 60 to 80 ° C., and subjected to electrolytic degreasing under the following conditions.

(Composition of alkaline solution) Sodium triphosphate: 25 g / l Sodium metasilicate: 25 g / l Surfactant (sodium salt of dodecylbenzenesulfonic acid manufactured by Junsei Chemical Co., Ltd.): 0.7 g / l (degreasing conditions) current density: 10A / dm ² · degreasing time: 1 minute after the electrolytic degreasing is completed, the stainless steel substrate was sufficiently immersed in pure water and then immersed for 5 seconds in hydrochloric acid (concentration 10 vol%) alkali Was neutralized. Thereafter, the substrate was washed with pure water and dried by blowing nitrogen to complete the cleaning.

Next, the stainless steel substrate was heated in a 200 ° C. oven for 2 hours. Thereafter, a negative resist (OMR85 manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied on a sufficiently cooled stainless steel substrate by a roll coater to form a resist film (1.0 μm thick). After pre-baking the resist film at 85 ° C. for 30 minutes, a photomask (length 400 mm, width 300 mm, thickness 5.
0 mm), the resist film on the stainless steel substrate was exposed. The light source for exposure was an electrodeless lamp, which was irradiated for 15 seconds.

Next, a developing solution (O, manufactured by Tokyo Ohka Kogyo Co., Ltd.)
After developing and rinsing using an MR developer,
A post-baking treatment at 30 ° C. for 30 minutes was performed to obtain a master for forming a fine pattern (Example 1).

A master for forming a fine pattern (Example 2) was prepared in the same manner as in Example 1 except that the heat treatment was performed at 150 ° C. for 1 hour.

Further, a master for forming a fine pattern (Example 3) was prepared in the same manner as in Example 1 except that the heat treatment was performed at 300 ° C. for 3 hours.

The length of the master for forming a fine pattern formed as described above (Examples 1 to 3) and the length of the photomask used for plate making of the master for forming a fine pattern were measured. As shown in FIG. 1, the measurement was performed at eight measurement points (a ₁ , a ₂ , a ₃ , b ₁ , b ₂ , c ₁ , c ₂₎ on the master for forming a fine pattern and on the photomask. , C ₃ )
Was determined, and the long dimension between two points was measured at each of the following six measurement points. The measurement results are shown in Table 1 below.

(Measurement points) between a _{1 and} a _3, between b _{1 and} b ₂ , c _{1 and} c ₃
Between between ... _{a 1} -c 1 ..., between _{a 2 -c 2 ..., a 3} -c 3
while…

[0021]

[Table 1] As shown in Table 1, the long dimension change of the fine pattern forming master and the photomask was within the range of ± 5 μm / 400 mm, and it was confirmed that high precision master making of the fine pattern forming master was possible. Was.

On the other hand, a master for forming a fine pattern (Comparative Example 1) was prepared in the same manner as in Example 1 except that the heat treatment was performed at 100 ° C. for 1 hour.

A master for forming a fine pattern (Comparative Example 2) was prepared in the same manner as in Example 1 except that the heat treatment was not performed on the stainless steel substrate.

Next, the lengths of the fine pattern forming masters (Comparative Examples 1 and 2) produced as described above and the photomask used for the plate making of the fine pattern forming masters were as described above. The measurement was performed at six measurement points, and the measurement results are shown in Table 2 below.

[0025]

[Table 2] As shown in Table 2, when the heat treatment of the stainless steel substrate is insufficient or the heat treatment is not performed, the original for forming a fine pattern shrinks, and particularly, the rolling direction of the stainless steel substrate, the tension at the time of winding, and the like. 40 μm / 400 mm at measurement points (（) along the direction
A degree of shrinkage occurred, and it was confirmed that the precision of the master for forming a fine pattern was lowered.

[0026]

As described above in detail, according to the present invention, the stainless steel substrate is subjected to a heat treatment before the formation of the resist film, and the residual stress due to the rolling direction existing in the stainless steel substrate or the tension at the time of rolling the roll. Since the residual stress due to the above is removed in advance, even if the production lot of the stainless steel substrate is different, the formed resist fine pattern will maintain the dimensional accuracy of the photomask, making it possible to efficiently use the high precision fine pattern forming master. Plate making is possible.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a measurement point of a long dimension of a master for forming a fine pattern and a photomask.

Claims (3)

(57) [Claims] After subjecting a stainless steel substrate to a heat treatment,
Forming a resist film on the stainless steel substrate, exposing and developing the resist film through a photomask having a desired fine pattern to form a resist fine pattern on the stainless steel substrate, Plate making method of the original plate for forming. 2. The method according to claim 1, wherein the stainless steel substrate is one of austenite, martensite, and ferrite. 3. The heat treatment according to claim 1, wherein the heat treatment is performed in a temperature range of 150 to 300 ° C.
The plate making method of the master for forming a fine pattern according to any one of the above.