JP2874261B2 - Projection exposure mask - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention relates to a projection exposure mask, and more particularly to a projection exposure mask having an element formation pattern including a plurality of sub-patterns or repeated sub-patterns, and inspects a pattern formed on a resist or a wafer. In order to provide a projection exposure mask that can be accurately performed in a short time, a projection exposure mask having an element forming pattern and an inspection pattern, wherein the element forming pattern includes a plurality of sub-patterns, The inspection pattern is formed in a scribe area and is the same as a part of the element forming pattern, and is constituted by a projection exposure mask including one sub-pattern and a plurality of sub-patterns surrounding the same. A projection exposure mask having an element forming pattern and an inspection pattern, wherein the element forming pattern includes a plurality of sub-patterns repeated in a vertical direction and a horizontal direction;
The inspection pattern is formed in a scribe area, and is identical to a part of the plurality of repeated sub-patterns. Three or more odd-numbered sub-patterns in the vertical direction and three or more odd-numbered sub-patterns in the horizontal direction are provided. It is composed of projection exposure masks arranged repeatedly.

[Industrial applications]

The present invention relates to a projection exposure mask, and more particularly to a projection exposure mask having an element forming pattern including a plurality of sub-patterns or repeated sub-patterns.

Semiconductor devices are steadily miniaturized. In the manufacture of semiconductor devices, it is no exaggeration to say that the quality of an inspection method determines the quality of a semiconductor device. 2. Description of the Related Art Microfabrication of semiconductor devices is an important process in a wafer process, and inspection is increasingly important in a photolithography process for forming a pattern and an etching process for processing a pattern.

There are various items in the contents of inspection in both processes,
With miniaturization, attention has been paid to inspection of pattern processing accuracy, that is, length measurement, and the accuracy has become a problem.

[Conventional technology]

FIG. 3 is a view for explaining a projection exposure mask for forming an element pattern on a wafer.
Indicates an inspection pattern, and 4a to 4d indicate exposure corner marks. The inspection pattern 3 is formed in a subscribe area of the wafer.

FIG. 4 schematically shows a part of the element forming pattern 1, and 1a to 1i show a part of a plurality of sub-patterns constituting the element forming pattern 1. FIG.

FIG. 5 shows a conventional example of an inspection pattern formed in a subscribe area, and 31 to 35 represent sub-patterns.

The length measurement in the conventional wafer process can be divided into two as follows.

How to measure the actual pattern in the chip with a length measuring device Form a pattern that is easy to measure in the scribe area,
How to measure it with a length measuring device The advantages and disadvantages of these two methods are briefly described as follows.

According to the method of (1), since the actual pattern is measured, the measured value of the actual width or diameter of the pattern to be obtained can be obtained. On the other hand, when the same pattern is repeated, as is apparent from the example of a memory, it is not easy to determine the measurement position. For example, even if the position 1a in FIG. In addition, there is a risk that other positions may be measured during work. In addition, moving the field of view to a predetermined measuring position using a measuring instrument such as a microscope or an SEM is very time-consuming.

In addition, according to the method, it is much easier to search for the measured position than in the case of, and the danger of erroneously measuring the position is greatly reduced. In general, since the actual pattern is different from the actual pattern, for example, when the length measurement at the time of forming the transistor gate is performed on the central sub-pattern 33 of this pattern, a value different from the actual length of the transistor gate is often obtained. . To explain in more detail, in general, a dense pattern is formed in an actual pattern, whereas a conventional length measurement pattern in a scribe area is sparse because of a simple pattern. As a result, due to the difference in development speed at the time of pattern development and the sparse / dense effect called the microloading effect of etching,
Since the process shift amount is different, the measured value differs from the actual measured value of the transistor gate.

[Problems to be solved by the invention]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a projection exposure mask having a pattern that can easily find a length measurement position and accurately obtain a length measurement value corresponding to an actual pattern.

[Means for solving the problem]

1 and 2 show an inspection pattern according to the embodiment I of the present invention and an inspection pattern according to the embodiment II.

The problem is a projection exposure mask having element forming patterns 1 and 2 and an inspection pattern 3, wherein the element forming patterns 1 and 2 are composed of complicated sub-patterns 1a to 1i.
The inspection pattern 3 is formed in a scribe area and is the same as a part of the element forming patterns 1 and 2; one sub-pattern 3a and a plurality of sub-patterns 3b to
The problem is solved by a projection exposure mask consisting of 3i.

A projection exposure mask having element forming patterns 1 and 2 and an inspection pattern 3, wherein the element forming patterns 1 and 2 include a plurality of sub-patterns 1 a to 1 i repeated in a vertical direction and a horizontal direction; The inspection pattern 3 is formed in a scribe area and is the same as a part of the plurality of repeated sub-patterns 1a to 1i, and has three or more odd sub-patterns in the vertical direction and three or more odd-numbered sub-patterns in the horizontal direction. Is solved by a projection exposure mask in which the sub-patterns are repeatedly arranged.

[Action]

In the projection exposure mask of the present invention, the inspection pattern 3 is formed in a subscribe area of the wafer. Therefore, by determining the location to be formed in the subscribe area in advance, the location can be easily and quickly found.

In the present invention, since the same pattern as a part of the actual element forming patterns 1 and 2 is formed as the inspection pattern 3, the density effect is minimized, and the width and diameter of the actual element forming pattern are reduced. The length measurement that reflects the size can be performed.

Further, when the element forming patterns 1 and 2 include a plurality of sub-patterns 1a to 1i which are repeated in the vertical and horizontal directions, the inspection pattern 3 is a plurality of sub-patterns which are repeated.
It is the same as a part of 1a to 1i, that is, three or more odd sub-patterns in the vertical direction and three or more odd sub-patterns in the horizontal direction are repeated. If such an inspection pattern is used, the length measurement position can be uniquely defined by determining the rule that the length measurement position is the middle sub-pattern 3a of the length measurement pattern. In this way, the measurement position can be quickly found without hesitation.

〔Example〕

FIG. 1 is a diagram for explaining an inspection pattern of Example I, where 3a to 3i represent sub-patterns. These sub-patterns are a part 1a to a part of the sub-pattern of the element forming pattern.
Same as 1i. For example, the sub-pattern of the inspection pattern
Focusing on 3a, subpatterns 3b to 3i surrounding it
There are sub-patterns surrounding them. If the actual length measurement is performed by using the sub-pattern 3a, the surrounding situation is the same as that of the sub-pattern 1a of the actual device forming pattern, and the inspection pattern formed on the wafer also has the shape and dimensions of the actual device pattern. It reflects well and enables highly accurate length measurement.

FIG. 2 is a view for explaining the inspection pattern of the embodiment II, and is particularly effective when the element forming pattern is a memory or the like including the repetition of the same sub-pattern.
Reference numerals 3a to 3o denote sub-patterns of the inspection pattern. These sub-patterns are copies of part of the sub-patterns of the element forming pattern as they are.

In this embodiment, the inspection pattern is an array of subpatterns of the same shape in 5 rows and 3 columns, and the central subpattern 3a is determined as a length measurement pattern.

In this case, as in the case of the embodiment I, the inspection pattern formed on the wafer reflects the shape and dimensions of the actual element pattern well, so that highly accurate length measurement can be performed.

By arranging the sub-patterns in odd rows and odd columns, the center length measurement position is uniquely determined, and the length measurement pattern 3a can be quickly found without hesitation.

When the projection exposure masks shown in the embodiment I and the embodiment II are used, not only the shape of the element pattern formed on the wafer but also the pattern formed on the resist mask can be measured quickly and accurately.

〔The invention's effect〕

As described above, according to the present invention, by using a projection exposure mask having an inspection pattern at a position corresponding to a scribe area of a wafer and having the same shape as a part of an actual element pattern, The workability of the length measurement can be improved, and the length measurement value corresponding to the actual element pattern can be obtained with high accuracy.

The use of the projection exposure mask of the present invention can improve the workability of semiconductor device manufacturing and the inspection accuracy, and can greatly contribute to the improvement of the reliability and performance of the semiconductor device.

[Brief description of the drawings]

 1 is an inspection pattern of Example I, FIG. 2 is an inspection pattern of Example II, FIG. 3 is a view for explaining a projection exposure mask, FIG. 4 is an element forming pattern, and FIG. This is a conventional example of a pattern. In the figure, 1 and 2 are element forming patterns, 1a to 1i are element forming sub-patterns, 3 is an inspection pattern, 3a to 3o are inspection pattern sub-patterns, 31 to 35 are inspection pattern sub-patterns, 4a To 4d represent exposure corner marks.

Claims (2)

(57) [Claims] 1. A projection exposure mask having an element forming pattern and an inspection pattern, wherein said element forming pattern comprises a plurality of sub-patterns, wherein said inspection pattern is formed in a scribe area, and said element forming pattern is And a sub-pattern and a plurality of sub-patterns surrounding the sub-pattern. 2. A projection exposure mask having an element forming pattern and an inspection pattern, wherein the element forming pattern includes a plurality of sub-patterns repeated in a vertical direction and a horizontal direction, and the inspection pattern is located in a scribe area. The same as a part of the plurality of sub-patterns formed and repeated, three or more odd-numbered sub-patterns in the vertical direction and three or more odd-numbered sub-patterns in the horizontal direction are repeatedly arranged. Characteristic projection exposure mask.