JPS6046556A - Manufacture of photomask - Google Patents

Abstract

PURPOSE:To enable correction of whited defects by exposing a light transmitting base plate provided with a light intercepting metal film having whited defects and a photoresist layer formed on this film to light cast from the reverse side of these laminated layers, removing the resist layer at the whited defects with a developing soln., and forming a new metal film on the disclosed parts. CONSTITUTION:A light intercepting thin metal film pattern 2 is formed in a prescribed form, such as F, one of the main surface of a light transmitting glass base plate 1, and all the same surface of the plate 1 including the pattern 2 is covered with a positive type photoresist 4. The parts of the photoresist 4 are exposed to light in the F pattern cast from the other side of the plate 1 through whited defects 3 present on the pattern 2, and developed to remove the exposed parts of the resist 4. A light intercepting thin metal film 10 is newly formed on the resist-covered part and these resist-removed disclosed parts 9 of the plate 1. Only the whited defects can easily corrected without leaving any of a thin metal film used for correction on the already corrected metal pattern 2 by peeling the resist 4 after forming the metal film 10.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a photomask used in the manufacturing process of semiconductor integrated circuits, etc., and particularly to a method for correcting white defect portions of a photomask. This white defect is a lack of a gold-plated thin film in an area where a metal thin film pattern is to be formed.For example, as shown in FIG. 2 is formed, the metal thin film pattern 2
The white defect portion 3 exists in the area where the defective portion 3 should exist. A photomask having such a white defect portion 3 is
When this is used in the manufacturing process of a semiconductor integrated circuit, the white defect portion 3 must be corrected because it causes disconnection or the like in the integrated circuit pattern.

As a method for repairing a photomask having such a white defect portion 3, a process as shown in FIG. 2 has been proposed. That is, in FIG. 2(a), a positive resist 4 is coated on the main surface of the glass substrate 1 on the metal thin film pattern 2 side and on the gold ml film pattern 2 including the white defect portion 3, and as shown in FIG. In b), set the stage of the exposure machine (not shown) from the positive type 1 nozzle 4 side at The resist portion 8 around the white defect portion 3 is partially exposed with light from a high-pressure mercury lamp, for example, with an opening larger than the width dimension of the metal thin film pattern 2 and less than the width dimension of the metal thin film pattern 2.

Next, in the same figure (C), J is developed with a developer,
The above-mentioned resist portion 8 is removed and white defect portions 3 and 1 are removed.
The nosist removal part 9 is formed, and in the same figure (d),
A metal thin film 10 is formed on the resist 4 side, and the same figure (0
), remove Reresist 4 with a remover
? gold on resist 4 by l ffl #ls
! 10G peeled off at the same time as the white defect area 3 mentioned above.
Metal thin film portions 11 and 12 adhere to the resist-removed portions 9 around them, leaving t, l::I:.

Here, the metal thin film portion 11 is a modified white defect portion 3, but the metal n film portion 12 is formed on the metal ITL film pattern 2, which is a non-defective portion around the white defect portion 3. Therefore, it has a protruding shape when viewed in cross section as shown in FIG. 2(e).

Such a protruding metal thin film portion 12 may be chipped or shortened.
There is a risk that white defects will occur again, and the chipped metal thin film will eventually land on the glass substrate 1, causing the black defect area (meaning the metal n film part that exists outside the area where the metal thin film pattern is to be formed). tended to occur. On the other hand, in order to make this metal thin film portion 12 smaller, please refer to the previous)! It is conceivable to make the slit size of the exposure mask 5 as close to the size of the white defect portion 3 as possible, but adjusting the slit size as shown in A is not only complicated, but also causes a decrease in step υ1. Cheap.

The present invention has been made in order to remove the above-mentioned defects, and the gold RFyJli for correction is not left on the formed metal thin film pattern -1-, but is formed only on the white defect part, and It is an object of the present invention to provide a photomask manufacturing method that can be easily performed.

In order to achieve such an object, the present invention provides a culm for forming a light-shielding metal thin film pattern in a predetermined shape on one main surface of a light-shielding glass substrate, and a method for forming nine metal film patterns. A positive photoresist is coated on one main surface of the glass substrate and the metal thin film pattern in an area other than the area where the metal thin film pattern is coated from the other main surface side of the glass substrate. a T-balance for exposing a portion of the positive type 741-resist to light through the white defect portion existing in the photoresist; a step of developing and removing the portion of the positive type photoresist; Forming a new light-shielding metal thin film on the surface and on the exposed portion of the glass 44 plate by the removal (Ru1 culm, the above-mentioned positive type) A photo film having the essential structure of the first to T culm for peeling off the resist. This is a method for manufacturing a mask.

An embodiment of the present invention will be described below.

Figure 3 shows that transparent aluminoborosilicate is lath ((
A thin layer of light-shielding metal is coated on the entire surface of a glass substrate 1 made of l-[-30) (manufactured by Hoya Glass Co., Ltd.).
((Cr) @ metal thin film pattern 2 (film thickness: approx. 7
．． 00 persons) into a predetermined shape by vacuum evaporation etc., white defects N1/3 (size =
In the same figure (a), positive photoresist 4 (for example, 10μm) is shown.
AZ-1350 of Play Inc.) on the side where the metal 11 removed pattern 2 is formed, that is, the area other than where the metal thin film pattern 2 is formed, on one main surface of the glass substrate M1 (white defects (including a glass substrate surface portion having portion 3) and a metal thin IQ film pattern. This resist is 1 of 4! ! Thickness (,1 is approximately 700OA.

Next, in FIG. 2B, from the other main surface side of the glass substrate 1, the resist portion 8 is exposed through the slit of the exposure mask 5 and the white defect portion 3 existing in the metal thin film pattern 2 using a spot exposure machine. Expose. In this case, the slit size does not need to be as close as possible to the dimension of the white defect portion 3 (this example + 1011s), but it should be larger than that dimension and smaller than the width dimension of the metal thin film pattern 2 (this example: 100 μm). Example: A haze diameter of 30III11) is sufficient. In the spot exposure machine of this example, only the light 6.7 after # of the exposure mask 5 is shown for the sake of explanation, but in detail,
A light source such as a mercury lamp, a shutter that blocks light from each light source, a slit (-J) exposure mask that adjusts the irradiation range of light from the light source, and a resist part that reduces the irradiation range of the light. The IM consists of a reduction lens etc. that exposes the image to light.

(:, 17) J Uku T exposure] Gold ft in two culms
Since the white defect portion 3 in the 1itll film pattern 2 is affected by the slimmer 1 of the exposure mask,
The exposed part 8 of the lettuce 1 has the same shape and dimensions as the white defect part 3, and in the next figure <C>, the current film and liquid (this example: A
The exposed portion 9 is removed by development using a developer for Z-1350.

Next, in the same figure (d), similarly to the metal thin film 2 described above, metal thin II #10, 11 (such as a chromium (Cr') film) (
A film V: approx. 700 layers) is formed on the exposed portion 9 on the top of the resist 4 (). By peeling off the resist 4 with a mixture of sulfuric acid),
The metal thin film 1-0 film 11 on the resist 4 is j! I! As described above, according to the present invention, the cross-sectional protruding portion on the metal thin film pattern that causes re-defects is removed, and the metal thin film to be repaired is formed only on the white defect area. and exposure 1
The work of adjusting the exposure diameter on the culm can be easily done in one step.

Note that the material in the present invention is not limited to the above-mentioned embodiments, and for example, soda lime glass,
Thin metals such as synthetic quartz, 1dl19 of chromium chloride, molybdenum, tungsten, titanium, etc. may be used for the film, and sputtering, ion blating, etc. may be used as the film forming method.

[Brief explanation of drawings]

FIG. 1 shows a photomask on which a metal thin film pattern with white defects is formed, and FIG. 1(a) is an IR surface and FIG. 1(b) is a cross-sectional view. FIG. 2 is a sectional view showing a conventional photomask manufacturing process for correcting white defect portions. FIG. 3 is a sectional view showing the manufacturing process of a photomask according to an embodiment of the present invention. 1...Glass V plate, 2...Metal thin film pattern, 3...
・White defect area, 4 ・Positive photo 1 to resist 18
...Exposed resist part, 9...Exposed part), 1
0...Metal HD formed on resist 4 for correction
Theory, 11...Exposed part 9 (white defect part 3) for correction
) Gold taU crotch °°゛ Town Map 2 (b) ゛Fig. 3

Claims (1)

[Claims] (1) A step of forming a metal thin film pattern of light-shielding H in a predetermined shape on one main surface of the glass substrate of light-transmitting ↑11;
a step of coating one main surface of the glass substrate and the metal thin film pattern with a positive type 741 to resist [.yj] in an area other than where the metal oil film pattern is formed; a step of exposing a portion of the positive photoresist from the main surface side through a white defect portion existing in the metal thin film pattern; a step of actually removing a portion of the positive photoresist; The method includes the steps of forming a new light-shielding metal thin film on the resist-covered surface and the exposed portion of the glass substrate resulting from the removal, and peeling off the positive photoresist. VJ manufacturing method for a photomask.