JPH02166448A - Method for correcting pattern - Google Patents

Abstract

PURPOSE:To enable accurate pattern correction by forming a thin Al film on a light shielding film, applying a photoresist, removing the photoresist and the Al film on the pattern defect of the light shielding film, forming a light shielding film again and removing the photoresist and the Al film. CONSTITUTION:When a pattern defect 3 is caused in a light shielding film 2 on a glass substrate 1, a thin Al film 6 is formed on the substrate 1 and the light shielding film 2 and a photoresist 4 is applied to the Al film 6. The photoresist 4 on the defect 3 is spot-exposed and the photoresist 4 is developed with a developing soln. The photoresist 4 of the exposed part and the Al film are dissolved and removed by the development and an opening 5 is formed. A light shielding film 2 is formed again in the opening 5 and the photoresist 4, the film 2 on the photoresist 4 and the Al film 6 are removed with an NaOH soln. A light shielding film 2 having an accurate pattern is formed on the glass substrate 1 and accurate pattern correction can be performed.

Description

[Detailed Description of the Invention] [Summary J] Regarding a method for modifying a light-shielding film pattern formed on a photomask or reticle, the purpose is to prevent peeling of non-exposed portions of a photoresist, and to repair a patterned light-shielding film on a glass substrate. A thin aluminum film is formed on the aluminum thin film, a photoresist is applied on the aluminum thin film, and then the photoresist on the pattern defect of the light-shielding film is spot-exposed to create an opening, and the aluminum (il) film in the opening is removed. The photoresist and aluminum thin film are removed after the light shielding film is re-formed in the area.

[Industrial Application Field] The present invention relates to a method for correcting a light-shielding film pattern formed on a photomask or reticle.

Photomasks and reticles are used to apply a predetermined pattern on a wafer by photoetching during the wafer process. Usually, a chromium film is formed as a light-shielding film on a glass substrate by sputtering, and the predetermined patterning is applied to the light-shielding film. It has been subjected. Since the pattern of the light-shielding film requires high pattern accuracy, it is necessary to accurately correct pattern defects that occur during the manufacture or use of the photomask or reticle.

[Conventional technique'#i] Conventionally, photomasks and reticles are shown in Figure 2 (a).

As shown in (b), a pattern of a light shielding film 2 made of chrome is formed on a glass substrate 1.
During patterning, various particles cause pattern defects 3 of about 2 to 3 microns as shown in the same figure.
These pattern defects 3 are corrected by a lift-off correction process. Further, the pattern defect 3 may be caused by rubbing of a photomask or reticle during use.

In the lift-off correction process, a photoresist 4 is coated on the glass substrate 1 as shown in FIG.
As shown in b), the three pattern defects are spot exposed to ultraviolet light. That is, the spot exposure
As shown by the chain line in Figure (a), the area that follows the predetermined pattern and covers the three pattern defects, that is, the length of each side is 10
A square area of about micron size is exposed to light. Then, the exposed photoresist 4 is developed and shown in FIGS.
) is formed, and using the photoresist 4 as a mask, the light-shielding film 2 is again formed in the opening 5 by sputtering, thereby correcting the pattern defect 3.

[Problems to be solved by the discussion] However, in the pattern correction method described above, the surface of the glass substrate 1 has excellent hydrophilicity and has weak adhesion to the photoresist 4, so the current I of the photoresist 4 after spot exposure is
At time m, the developer enters between the photoresist 4 and the glass substrate 1, and as shown in FIGS. 4(a) and 4(b), the photoresist 4 in the non-exposed area is peeled off to form a pattern 4a, making it impossible to correct the pattern accurately. The problem was that it was impossible.

An object of the present invention is to provide a pattern correction method that prevents unexposed portions of a photoresist from peeling off due to a developer and enables accurate pattern correction.

[Means for solving the problem] The above object is to form an aluminum layer on a glass substrate patterned with a light-shielding film, apply a photoresist on the aluminum thin film, and then apply the photoresist on the pattern defect of the light-shielding film. This is accomplished by spot exposing the area to open an opening, removing the aluminum FIIIll in the opening, re-forming a light-shielding film in the opening, and then removing the photoresist and the aluminum thin film.

[Function] Aluminum 1Ill adheres well to the glass substrate and photoresist, and prevents unexposed portions of the photoresist from peeling off during development after exposure of the photoresist.

[Embodiment] An embodiment in which the present invention is embodied in a reticle pattern correction method will be described below with reference to the drawings.

a3. Components that are the same as those of the conventional example are given the same numbers and their explanations will be omitted.

As shown in FIG. 2(8)(b), when a pattern defect 3 occurs in the light shielding film 2 on the glass substrate 1, as shown in FIG.
), aluminum 31M is placed on the glass substrate 1 and the light-shielding WA2! Approximately 200% J6 by sputtering method
The aluminum s
A photoresist 4 is applied on the membrane 6 to a thickness of about 1 micron. This aluminum thin film 6 has excellent adhesion to the photoresist 4 and the glass substrate 1. and,
The photoresist 4 is prebaked at 95° C. for about 10 minutes.

Next, as shown in FIG. 1(b), the photoresist 4 in the portion of the pattern defect 3 is spot exposed.

The exposure range is a range that follows a predetermined pattern and covers 3 portions of the pattern defect, similar to the conventional example shown by the chain line in FIG. 2(a). Then, when the exposed area is developed with a developer, the photoresist 4 and aluminum 11116 in the exposed area are dissolved and removed, forming an opening 5, as shown in FIG. 1(C). At this time, since the aluminum thin film 6 has excellent adhesion to the photoresist 4 and the glass substrate 1, only the exposed portion 11 of the photoresist 4 is removed, and the unexposed portion is not peeled off.

When chromium is sputtered again in this state, the light-shielding film 2 is again formed in the opening 5 and the pattern defect 3 is corrected, as shown in FIG. 1(d). Then, the photoresist 4, the light-shielding film 2 thereon, and the aluminum film 6 are coated with Na.
When removed with an OH solution, a precise pattern of light shielding Ill 2 is formed on the glass substrate 1, as shown in FIG. 1(e), and the pattern correction process is completed.

[Effect of the Invention 1] As detailed above, the pattern correction method of the present invention exhibits an excellent effect of preventing peeling of the unexposed portions of the photoresist and performing accurate pattern correction.

[Brief explanation of the drawing]

1(a) to 1(e) are process diagrams showing a pattern repair method embodying the present invention, FIG. 2(a) is a plan view of a reticle with a pattern defect, and FIG. 2(b) is the same. 3(a) and 3(b) are process diagrams showing the conventional pattern correction method, and FIG. 4(a) is a plan view showing peeling of the photoresist by the conventional pattern correction method. (
b) is also a sectional view. In the figure, 1 is a glass substrate, 2 is a light-shielding film, 3 is a pattern defect, 4 is a photoresist, 5 is an opening, 6(a) Fig. 1 Invention of the present invention Cause (c) Drawing 1 (d) (e) Cross-sectional view of the Bataans Peng reticle Drawing 2 (a)

Claims (1)

[Claims] 1. Glass substrate (1) patterned with light shielding film (2)
An aluminum thin film (6) is formed on top, a photoresist (4) is applied on the aluminum thin film (6), and then the photoresist (4) on the pattern defect (3) of the light shielding film (2) is spot exposed. After removing the aluminum thin film (6) in the opening (5) and re-forming the light shielding film (2) in the opening (5), the photoresist (4) and the aluminum thin film (6) are removed. A pattern correction method characterized by removing.