JPH0619111A - Production of mask for phase shift - Google Patents

Abstract

PURPOSE:To enable the dimensional control of a light shielding film with high accuracy by forming shifter patterns and light shielding film patterns on respectively separate substrates and sticking the two substrates to each other in such a manner that the shifters and the light shielding films come into contact with each other, then using such substrates. CONSTITUTION:The shifter 3 is formed on the glass substrate 1 and a resist 4 is applied thereon. This resist 4 is patterned and the shifter 3 is eched with the resist 4 as a mask. The resist 4 is then removed and the substrate A consisting of the patterns of only the shifters 3 is formed. On the other hand, the light shielding film 2 is formed on the glass substrate 1 and the resist 4 is formed thereon. The resist 4 is patterned and the light shielding film 2 is etched with the resist 4 as a mask. The resist 4 is then removed and the substrate B consisting of the patterns of only the light shielding films 2 is produced. The substrates A and B are subjected to a defect inspection at the point of this time and thereafter the substrates A and B are so stuck to each other in such a manner that the respective front surfaces of the shifers 3 and the light shielding film 2 come into contact with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a photomask used for lithography using a phase shift method.

[0002]

2. Description of the Related Art Conventionally, a photomask used for a phase shift method (hereinafter referred to as a phase shift mask) is formed by a shifter (for example, spin-on glass (SOG)) and a light shielding film (for example, chromium film) being in contact with each other on the same substrate. Was to do.

FIG. 2 shows a conventional method for manufacturing a phase shift mask.

First, a shifter 3 is formed on a blank having a light-shielding film 2 formed on a glass substrate 1, and a resist 4 is formed thereon (FIG. 2 (a)). Next, the resist 3 is patterned, and the shifter 3 is patterned by etching using the resist 4 as a mask (FIG. 2).
(B)).

Next, the light shielding film 2 is etched by using the resist 4 and the shifter 3 as a mask. Wet etching is used as the etching (FIG. 2C).

The etching of the light-shielding film 2 progresses from the upper surface, that is, the shifter 3 side in the direction of the glass 1 with time, but the etching is continued even after the progress of the etching reaches the surface of the glass 1 (referred to as over-etching). By doing so, the light shielding film 2 is laterally etched (see FIG. 2).
(D)). After that, the resist 4 is removed to obtain the structure of FIG.

The shifter 3 and the light-shielding film 2 are formed on the same substrate 1 by the manufacturing method described above.

[0008]

However, the phase shift mask manufactured by the above method has the following problems.

1. Since the progress of the lateral etching of the light-shielding film in the over-etching changes depending on the adhesion between the shifter and the light-shielding film and the film thickness and film quality of the light-shielding film, it is difficult to control with high accuracy.

2. Due to the variation in the size of the light-shielding film caused by the above 1, variation occurs in the pattern dimension of the transferred image using the phase shift mask.

3. When defects occur in the shifter and the light shielding film, it is impossible to inspect and repair.

In order to eliminate the above-mentioned problems, the present invention forms a shifter and a light-shielding film on different substrates,
It is an object of the present invention to provide a method for manufacturing a mask for phase shift, which uses the above substrates in an overlapping manner.

[0013]

To achieve the above object, the present invention manufactures a substrate A having a pattern of shifters only and a substrate B having a pattern of light-shielding films only, and thereafter, the substrates are made up of shifters and light-shielding films. It is designed to be used by overlapping so as to be in contact with each other.

[0014]

As described above, according to the present invention, the shifter pattern and the light shielding film pattern are formed on different substrates, and the respective substrates are used so that the shifter and the light shielding film are in contact with each other. No over-etching is required, and therefore, highly accurate dimensional control of the light-shielding film is possible. Therefore, when this is used, the dimensional variation in the transferred image becomes small. Moreover, since a single-layer pattern of only the shifter or only the light-shielding film is formed on different substrates, inspection and correction are easy.

[0015]

FIG. 1 shows a manufacturing method of an embodiment of the present invention.

First, as the substrate A, the glass substrate 1 is placed on the glass substrate 1.
Is formed, and the resist 4 is applied thereon (see FIG.
a)) and patterning the resist 4 (see FIG.
b)), the shifter 3 is etched using the resist 4 as a mask (FIG. 1 (Ac)).

Then, the resist 4 is removed to manufacture a substrate A having a pattern of only the shifter 3 (FIG. 1 (Ad)).

On the other hand, as the substrate B, the light shielding film 2 is formed on the glass substrate 1, and the resist 3 is formed thereon (see FIG. 1).
(Ba)) and patterning the resist 4 (see FIG.
b)), and then using the resist 4 as a mask, the light shielding film 2
Are etched (FIG. 1 (Bc)). At this time, over etching is not performed.

Next, the resist 4 is removed, and a substrate B having a pattern of only the light shielding film 2 is manufactured (see FIG.
d)).

At this time, the defect inspection of the substrates A and B is performed. After that, the substrates A and B are bonded together so that the upper surfaces of the shifter 3 and the light shielding film 2 are in contact with each other. It is sufficient to carry out the bonding with an adhesive that is usually used.

The phase shift mask manufactured by the method described above has the same effect as the conventional phase shift mask in which the shifter and the light shielding film are formed on the same substrate.

[0022]

As described above, according to the present invention,
The shifter pattern and the light-shielding film pattern are formed on different substrates, and the substrates are used so that the shifter and the light-shielding film are in contact with each other. Therefore, the following effects can be obtained.

1. Over-etching of the light-shielding film is not necessary, so that the light-shielding film can be controlled with high accuracy.

2. Due to the above 1, when this phase shift mask is used, the dimensional variation in the transferred image is reduced.

3. Since a single layer pattern of only the shifter or only the light shielding film is formed on separate substrates, inspection and correction are easy.

[Brief description of drawings]

FIG. 1 Example of the present invention

FIG. 2 Conventional example

[Explanation of symbols]

 1 glass substrate 2 light-shielding film 3 shifter 4 resist

Claims (1)

[Claims] 1. A substrate A having only a shifter pattern formed on a glass substrate and a substrate B having only a light-shielding film pattern formed on a glass substrate are manufactured, and the substrates A and B are formed on the shifter pattern upper surface and the light-shielding film. A method for manufacturing a phase shift mask, which is characterized in that the mask and the pattern are bonded so as to be in contact with the upper surface of the pattern.