JPH02143513A - Manufacture of mask pattern - Google Patents

Abstract

PURPOSE:To eliminate the irregurality on a split boundary line when a large area mask pattern is formed by the syntheses of a split pattern by a method wherein the boundary line between small divisions is formed in a non-linearly and irregular shape. CONSTITUTION:When the desired large area mask pattern such as a liquid crystal electrode mask pattern, for example, is going to be divided into a plurality of small divisions, a boundary line C is formed in irregular shape, especially, it is formed into an irregular saw-tooth shape, and small area mask patterns (a) and (b) corresponding to the split small divisions are formed. When the above-mentioned small-area mask pattern (a) and (b) are compositely formed on a large area substrate, as both mask patterns are connected by an irregularlyformed boundary line C, the deviation and the like generating along the boundary line does not have regularity and continuity, or as the deviation is small, it is not recognized as a deviation by human eyes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a large-area photomask, particularly a photomask for forming an image information input/output device and its parts.

[Conventional technology]

As a method for producing a large-area mask pattern, there is a method of drawing directly on a large-area substrate using a photo block, a laser plotter, or the like. However, large-area drawing devices generally have performance problems in terms of accuracy and resolution;
It cannot be used for purposes that require high resolution. In addition, high-precision lithography equipment for large areas is being developed, but there are high technical barriers to achieving large size, high precision, and high resolution, resulting in huge equipment development costs and, in turn, huge equipment prices. There's a problem.

On the other hand, in recent years, the size of photomasks for wafer processing has increased! j) At the same time, the technology for manufacturing with extremely high precision and high definition has been established. In addition, using photomask technology for wafer processing, a part of a large-area mask pattern is formed with high precision into the size of a photomask for wafer processing, and these patterns divided into small-sized mask patterns are used to form a part of a large-area mask pattern on a single large-area substrate. A technology had been developed to synthesize and print the images. This technique uses a large stepper developed in recent years, and is capable of synthesizing highly accurate and fine patterns on a small-sized photomask on a large-area substrate with high precision.

(Problems to be Solved by the Invention) However, drawbacks have also been found in the technology using this stepper.This is particularly true for components in the same field such as image information input/output devices such as liquid crystal displays and color filters. This is related to unevenness, which is an important item.In other words, unevenness tends to occur at the boundary line portions where the printing is done separately.

This unevenness is mainly caused by minute positional deviations between the divided sections, and secondly, due to extremely minute differences in the pattern dimensions of each section. In any case, although it is caused by an extremely small difference of about 1 micron or less, the appearance of such unevenness on pixel electrodes of liquid crystal displays and color filter patterns is extremely problematic.

This is a problem common to devices that input and output image information and their components.

For example, when one large-area mask pattern, which is a liquid crystal display electrode pattern, is divided into upper and lower halves as shown in FIG. 1, and small masks a and b corresponding to small sections A and B are created and synthesized, An enlarged view of the pattern is shown in Figure 2-1, and this is divided into upper and lower sections by small sections A and B as shown in Figure 2-2.
be divided. When two mask patterns a and b corresponding to these small sections A and B are synthesized on one large-area substrate using a large stepper, on the boundary line C between the small sections A and B, A, Figure 3-1 due to the error that occurred in the joint part of B.
, 2, 3, and 4 occur. This amount of deviation is only about 1 micron or less. Figure 3-1
The deviation shown in is a case where the upper and lower subdivision patterns A and B are relatively shifted in the horizontal direction. Figure 3-
A deviation as shown in 2 is a case where there is no relative positional deviation between the upper and lower subdivision patterns A and B, but a deviation occurs in the pattern dimensions (line widths) of each. Misalignment as shown in FIGS. 3-3 and 4 occurs when the upper and lower subdivision patterns A and B are relatively misaligned in the vertical direction. Figure 3-1, 2, 3,
4. In either case, an error of only 1 micron or less will cause linear unevenness. As in this example, if such unevenness occurs in the electrode pattern mask pattern, similar unevenness will occur in the transferred electrode pattern, and although there is no major problem in terms of electrical characteristics, it may cause problems with the liquid crystal panel. This is later recognized by the human eye as unevenness, which poses an extremely serious quality problem as an image information input/output device.

As a result of intensive study, the inventors of the present invention found that although this unevenness is caused by an error of only 1 micron or less, it is visible to the human eye because the deviations are regularly and continuously arranged along the boundary line. Therefore, they found that the problem of unevenness can be solved by eliminating or reducing the regularity and continuity of the arrangement such as the deviation caused by this error, leading to the present invention.

The present invention has been made based on the above studies, and provides a method for eliminating unevenness on division boundaries when producing a large-area mask pattern by combining division patterns.

[Means to solve the problem]

That is, in forming a mask pattern in which fine patterns are continuously arranged over a large area, the present invention divides this large area into a plurality of small sections, and creates a small area mask corresponding to each of the divided small sections. Create a pattern, synthesize it on a large-area substrate using a stepper method,
The present invention is a method for producing a large-area mask pattern, which is characterized in that the boundaries between small sections are made into a non-linear and irregular shape, particularly an irregular sawtooth shape.

Furthermore, in forming a mask pattern in which fine patterns are continuously arranged over a large area, the present invention includes:
This large area is divided into a plurality of small sections, a small area mask pattern is created corresponding to each of the divided small sections, and these are combined on a large area substrate using a stepper method to create a large area mask pattern. In this method, when a large area is divided into a plurality of subdivisions, adjacent subdivisions have a shared boundary area, and each fine pattern within this shared area is attached to one of the adjacent subdivisions. This is a method for producing a mask pattern characterized by belonging to a random number array.

The present invention will be explained in detail below.

In the mask pattern manufacturing method of the present invention, small-area mask patterns corresponding to each small section obtained by dividing a desired large-area mask pattern are formed using electron beam writing or the like using photomask technology for wafer processing. A corner photomask is drawn, developed, and etched to create a highly accurate photomask pattern, and then the small-area mask pattern is printed on a photoresist at a predetermined position on the large-area substrate using a large stepper. Develop, etch,
- A large-area mask pattern is produced by synthesizing on two large-area substrates.

In the mask pattern manufacturing method of the present invention, when dividing a desired large-area mask pattern, for example, a liquid crystal electrode mask pattern as shown in FIG. 4-2, and small area mask patterns a and b corresponding to the divided small sections as shown in FIG. 4-2 are prepared. When such small-area mask patterns a and b are synthesized on a large-area substrate, they are joined by an irregularly shaped boundary line C, so any misalignment that occurs along the boundary line is due to regularity.
Since there is no continuity or it is small, it is not recognized as unevenness by the human eye.

Furthermore, in the method for manufacturing a mask pattern of the present invention,
When dividing a desired large-area mask pattern into multiple subdivisions, instead of dividing adjacent subdivisions by border lines,
As schematically shown in Fig. 5-1, each fine pattern m is assigned to one of the adjacent subdivisions P and Q in a random number arrangement, and as schematically shown in Fig. 5-2. Small area mask patterns p and q corresponding to such divided small sections are prepared. When such small-area mask patterns p and q are synthesized on a large-area substrate, there is no boundary line, and each fine pattern m belonging to either of the small-area mask patterns p or q
are arranged randomly within the shared boundary area e, so that regular and continuous deviations along the boundary lines, unlike in conventional methods, do not occur and are not perceived as unevenness by the human eye.

〔Example] Hereinafter, a more specific explanation will be given with reference to Examples.

Example-1 Electrode length 240 mm, electrode width 24 as shown in Figure 4-1
To prepare a 400 x 400 transparent electrode mask pattern for a liquid crystal with an electrode pitch of 0 μm and an electrode pitch of 250 μm, the mask pattern was divided into upper and lower halves, and two divided mask patterns, a and b, were fabricated using a photomask technique for wafer processing with an external dimension adjustment. The upper and lower boundaries were irregularly sawtoothed as shown in Figure 4-2. At this time, the length d of the sawtooth is up to 20 mm.
The length of each sawtooth was set as a random number array. These two divided mask patterns were synthesized on a large 300 mm square substrate using a large stepper. At this time, the relative position accuracy of the upper and lower patterns was 1 μm, and the line width accuracy of the upper and lower patterns was 0.5 μm, but no unevenness was observed near the boundary. Similarly, the method shown in FIG. 6, in which the boundary line is a straight line, causes unevenness at the boundary.

Example-2 Screen size 240 x 15 as shown in Figure 7-1
To prepare a TPT pixel electrode mask pattern with a pixel electrode pitch of 120 x 360 μm and a pixel electrode size of 100 x 300 μm, it was divided into upper and lower halves.
a, b Two divided mask patterns were fabricated using photomask technology for wafer processing with external dimensions of Twift. The upper and lower boundaries were irregularly sawtoothed as shown in Figure 7-2. At this time, the length d of the sawtooth was set at a maximum of 20 cylinders, and the length of each sawtooth was arranged as a random number.

These two divided mask patterns were synthesized on a large 300 mm square substrate using a large stepper. At this time, the relative position accuracy of the upper and lower patterns was 1 μm, and the line width accuracy of the upper and lower patterns was 0.5 μm, but no unevenness was observed near the boundary.

Similarly, the method shown in FIG. 6, in which the boundary line is a straight line, causes unevenness at the boundary.

Example-3 Screen size 240 x 15 as shown in Figure 8-1
0 mm, pixel electrode pitch 120 x 360 μm, and pixel electrode size 100 x 350 μm. When making a mask pattern for a color filter for liquid crystal, it was divided into upper and lower halves, and the two divided mask patterns a and b were made into a photo frame for wafer processing using an external dimension controller. Manufactured using mask technology. The upper and lower boundaries were irregularly sawtoothed as shown in Figure 8-2. At this time, the length d of the sawtooth is at most 20 m.
m, and the length of each sawtooth was a random number array. These two divided mask patterns were synthesized on a large 300 mm square substrate using a large stepper.

At this time, the relative position accuracy of the upper and lower patterns was 1 μm, and the line width accuracy of the upper and lower patterns was 0°5 μm, but no unevenness was observed near the boundary. Similarly, the method shown in FIG. 6, in which the boundary line is a straight line, causes unevenness at the boundary.

Example-4 Screen size 240 x 180m as shown in Figure 9
m, pixel electrode pitch 240 x 290 μm, fine pattern m pixel electrode size 200 x 250 μm TP
To prepare a mask pattern for the T pixel electrode, it was divided into four parts: top, bottom, left, right, P, QSR, and S, and four corresponding divided mask patterns were made using a photomask technique for wafer process with external dimensions being adjusted. As shown in FIG. 5, the upper, lower, left, and right boundaries are randomly assigned with individual fine patterns m by random number arrangement.

At this time, the width e of the dividing boundary common area was set to 20 mm, and the electrode pattern at the center E of the boundary sharing area was also irregularly divided into four divided mask patterns. These four divided mask patterns were synthesized on a large 300 mm square substrate using a large stepper. At this time, the relative position accuracy of the upper and lower patterns was 1 μm, and the line width accuracy of the upper and lower patterns was 0.5 μm, but no unevenness was observed near the boundary. Similarly, the dividing method in which the boundary line is a straight line causes unevenness at the boundary.

Example-5 Screen size 240 x 15 as shown in Figure 7-1
0 cylinder, pixel electrode pitch 120X 3601Im, fine pattern m pixel electrode size 100X 300μm TP
In producing the mask pattern for the T pixel electrode, the mask pattern was divided into upper and lower parts, and two divided mask patterns were produced using a photomask technique for wafer process with an external dimension adjustment. As shown in FIG. 5, the upper and lower boundaries were randomly assigned with individual fine patterns m arranged in random numbers. At this time, the width e of the division boundary common area was set to 20 mm. These two divided mask patterns are processed using a large stepper.
It was synthesized on a large substrate of 0 mm square. At this time, the relative position accuracy of the upper and lower patterns was 1 μm, and the line width accuracy of the upper and lower patterns was 0.5 μm, but no unevenness was observed near the boundary. Similarly, the dividing method in which the boundary line is a straight line causes unevenness in the boundary area.

Example-6 Screen size 240 x 15 as shown in Figure 8-1
0 mm, pixel electrode pitch 120 x 360 μm, fine pattern m, pixel electrode size 100 x 350 μm, to produce a mask pattern for a color filter for liquid crystal.It is divided into upper and lower halves, and the two divided mask patterns are used for wafer processing by external dimension adjustment. Manufactured using photomask technology. As shown in FIG. 5-2, the upper and lower boundaries are randomly assigned with individual fine patterns m arranged in random numbers. At this time, the width e of the division boundary common area was set to 20 mm. These two divided mask patterns were synthesized on a large 300 mm square substrate using a large stepper. At this time, the relative position accuracy of the upper and lower patterns was 1 μm, and the line width accuracy of the upper and lower patterns was 0.5 μm, but no unevenness was observed near the boundary. Similarly, the dividing method in which the boundary line is a straight line causes unevenness at the boundary.

[Effects of the Invention] As is clear from the above, according to the present invention, it is possible to produce a large-area mask pattern without unevenness by using a small section pattern with an irregular boundary line, particularly an irregular saw-like shape. can.

Further, according to the present invention, by providing a shared boundary area at the boundary between adjacent small area patterns, and using a small area pattern in which individual fine patterns within the common area are irregularly assigned to one of the areas. A large area mask pattern without unevenness can be produced.

Further, according to the present invention, it is possible to form a pattern on a large-area substrate with high precision and high definition.

[Brief explanation of the drawing]

Figures 1, 2-1 and 2-2 are schematic diagrams showing the conventional mask pattern manufacturing method;
Figure 2, Figure 3-3 and Figure 3-4 are schematic diagrams showing misalignment at the joints of patterns;
Figure-2, 5th-1 and Figure 5-2, Figure 6, Figure 7-
1, FIG. 7-2, FIG. 8-2, FIG. 8-2, and FIG. 9 are schematic diagrams showing the method of manufacturing a mask pattern of the present invention. A, B...Small section a, b...Small area mask pattern C...Boundary line d...Sawtooth length e...Shared area m...Fine pattern P, Q, R, S...Small section p, q...Small area mask pattern

Claims (3)

[Claims] (1) When forming a mask pattern in which fine patterns are continuously arranged over a large area, this large area is divided into a plurality of small sections, and a small area mask pattern corresponding to each of the divided small sections is formed. The method is characterized in that the boundaries between the small sections are made non-linear and irregular in shape. A method for creating a mask pattern. (2) The method for producing a mask pattern according to claim 1, wherein the boundaries between the small sections are irregularly sawtoothed. (3) When forming a mask pattern in which fine patterns are continuously arranged over a large area, this large area is divided into a plurality of small sections, and a small area mask pattern corresponding to each of the divided small sections is created. In this method, when a large area is divided into multiple small sections, adjacent small sections have border-sharing areas. and a method for producing a mask pattern, characterized in that each fine pattern within the shared area belongs to one of the adjacent subdivisions in a random number arrangement.