JPH09127680A - Mask for exposure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to correct the deviation in rotation with good accuracy by providing the corner parts of scribing line-forming regions with check patterns for detecting the deviation quantity in a rotating direction. SOLUTION: The check patterns 4 are formed perpendicularly to the longitudinal direction of the scribing line-forming regions and are composed of the first check patterns 4a formed at specified intervals and second check patterns 4b of the intervals narrowed at a specified ratio as the patterns part from the corners of the first check patterns 4A. The first check patterns 4A and the second check patterns 4B are so arranged as to face each other across the boundary lines 7A, 7B of the respective corner parts of the scribing lines 2A when the four corner parts 5A to 5D are contacted with each other at one point '0' to expose and to form patterns. Then, the respective patterns (a) of the first, second check patterns 4A, 4B in the respective corner parts 5A to 5D are line symmetrical at the boundary line 7A or 7B and four pieces of the third patterns 6a to 6d generate an X character unless there is the deviation in the rotating direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure mask, and more particularly, to an exposure mask used in an exposure apparatus in a photolithography process for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art Conventionally, in the process of manufacturing a semiconductor device,
In some cases, misalignment or the like may occur due to the exposure apparatus. In this case, a method of detecting a shift in the rotational direction of the exposure mask or a shift due to lens distortion may be performed, for example, by checking a scribe line forming area of the mask. JP-A-63-151948 discloses a method in which a pattern is provided, exposed, and these check patterns are brought into contact with each other to detect the shift amount.

More specifically, when exposure is performed by a step-and-repeat method using an exposure mask in which check patterns 14A to 14D are formed in scribe line regions at each corner portion, a semiconductor substrate is exposed as shown in FIG. On the scribe line 2A, check patterns 14A to 14D are formed so as to contact and overlap the boundary lines 7A and 7B.

At this time, if there is no rotational direction shift in the device,
The adjacent pattern and the overlapping pattern are line-symmetric in both the X-axis direction and the Y-axis direction around the boundary of the scribe line. On the other hand, if there is a rotation direction deviation, as shown in FIG.
There is no line symmetry in the X-axis direction and the Y-axis direction with respect to the intersection of the scribe line boundaries. Therefore, since the deviation in the rotation direction can be easily detected, the correction can be performed.

[0005]

However, in this conventional exposure mask, since the check patterns are formed at equal intervals, even if a deviation occurs in the rotational direction, the deviation amount cannot be immediately known. There is a problem that it takes a long time to correct the exposure apparatus and the accuracy of the correction is lowered.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an exposure mask capable of easily detecting a rotational shift of an exposure apparatus and improving the accuracy of correcting the shift.

[0007]

An exposure mask of the present invention is provided with a pattern forming region of a semiconductor element, a scribe line forming region provided around the pattern forming region, and four corners of the scribe line forming region. In a mask for exposure, which has a check pattern for detecting an overlay deviation amount in a rotation direction by an exposure device which is provided in a portion perpendicular to the longitudinal direction of the scribe line formation region, the check patterns are formed at regular intervals. And a second pattern in which the distance becomes narrower at a constant rate as the distance from the corner increases, and when the four corners are exposed by contacting at one point to form a pattern, each corner The first pattern and the second pattern across the boundary line of
The pattern is arranged so as to face the pattern.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a top view of an exposure mask for explaining a first embodiment of the present invention, and FIG. 2 is a top view of a corner portion of a scribe line when a wafer is exposed by an exposure apparatus using this mask. is there.

In FIG. 1, a mask 10 includes an element pattern forming region 1, a scribe line forming region 2 provided around the pattern forming region 1, and a chrome layer formed around the scribe line forming region 2. Shield area 3 and four corners 5A of scribe line forming area 2
5D mainly includes a check pattern 4 for detecting the amount of misalignment in the rotational direction by the exposure device provided in each of .about.5D. Then, as shown in FIG. 2, the check pattern 4 is provided perpendicular to the longitudinal direction of the scribe line forming region, and furthermore, the first check pattern 4A formed at regular intervals and the constant as the distance from the corner increases. When the pattern is formed by exposing the four corner portions 5A to 5D in contact with one point "0" and forming a scribe line 2,
A, with the boundary lines 7A and 7B of each corner of
The check pattern 4A and the second check pattern 4B are arranged so as to face each other. That is, the interval between the patterns a to d forming the first check pattern 4A is constant, and the interval between the patterns a to d forming the second check pattern 4B is a constant ratio toward the side (for example, 0.1 to 0.1).
0.2 μm). The patterns a constituting each check pattern are provided at the same position from the corners with the same size.

In the mask 10 shown in FIG. 1, the check pattern of the first corner portion 5A and the third corner portion 5C is as follows.
The first check pattern 4A is also used in the X-axis direction and the Y-axis direction.
The second corner portion 5B and the fourth corner portion 5
The check pattern of D is the second in both the X-axis direction and the Y-axis direction.
It consists of a check pattern 4B. Each corner has a third diagonal line from the corner toward the center.
Patterns 6a to 6d are provided. This third pattern is used for detecting the rotation direction.

Using the mask 10 configured as described above,
When exposed on the wafer by the step and repeat method,
The patterns a constituting the check pattern at each corner overlap. At this time, if there is no shift in the rotation direction, as shown in FIG. 2, each pattern a of the first and second check patterns 4A and 4B in each of the corner portions 5A to 5D becomes line-symmetric at the boundary line 7A or 7B. The four third patterns 6a to 6d form an X character.

If a rotation shift occurs in the exposure apparatus, the third
When the shift is counterclockwise, the first and second corners 5A, 5B and 3rd for checking the shift in the Y-axis direction are shown in FIG. , The fourth corner portions 5C and 5D have the same check pattern, for example, the pattern d. Similarly, when the shift is clockwise, as shown by the arrow in FIG. 4, the pattern d of each check pattern for checking the shift in the X-axis direction matches.
Therefore, it is narrower than this matched pattern (0.1-0.
Since the shift amount of the provided second check pattern can be easily detected, the shift of the rotation can be immediately obtained. For example, when the chip size is W × W, the length from the center is 2 ^1/2 W / 2. Therefore, when the deviation amount is detected as x, the rotation angle θ of the device becomes Sin ⁻¹ (2x) /
(2 ^1/2 W).

FIG. 5 is a top view of a corner portion of an exposure pattern for explaining a second embodiment of the present invention. The mask has the same configuration as that of FIG.

As is clear from FIG. 5, the max check patterns in the second embodiment are the first check pattern 4A, the second check pattern 4B and the first check pattern 4A at the first corner portion 5A and the third corner portion 5C. The second corner portion 5B includes two second check patterns 4B, and the fourth corner portion 5D includes two first check patterns 4A. When the pattern is exposed using the mask configured as described above, the first check pattern 4A and the second check pattern 4B are adjacent to each other with the boundary lines 7A and 7B interposed therebetween. The pattern a constituting each check pattern is line-symmetric, and if there is a deviation, the other patterns match.

FIG. 6 is a top view of a corner portion of an exposure pattern for explaining a third embodiment of the present invention. The mask has the same structure as that of FIG. As is clear from FIG. 6, the mask check pattern in the third embodiment is composed of first and second check patterns 4A and 4B at the first to fourth corner portions 5A to 5D. When exposed, the first check pattern 4A and the second
The check pattern 4B is adjacent to each other across the boundary lines 7A and 7B, and the patterns forming the first check pattern and the second check pattern match according to the presence or absence of a rotation shift of the apparatus.

In the above embodiment, the case where the third pattern 6 is present has been described. However, even when there is no third pattern, the detection of the amount of rotation deviation is easier than in the conventional example.

[0017]

As described above, according to the present invention, the first pattern having a constant interval and the second pattern having a narrow interval at a constant rate are used as the check patterns for detecting the shift amount in the rotational direction. By providing the corners of the scribe line forming area so that the first pattern and the second pattern are opposed to each other, the amount of deviation in the rotation direction of the exposure apparatus can be easily detected. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a top view of a mask for explaining a first embodiment of the present invention.

FIG. 2 is a top view of a scribe line corner when exposed with the mask of the first embodiment.

FIG. 3 is a top view of a scribe line corner when exposed by the mask of the first embodiment.

FIG. 4 is a top view of a scribe line corner when exposed with the mask of the first embodiment.

FIG. 5 is a top view of a scribe line corner when exposed with a mask according to the second embodiment.

FIG. 6 is a top view of a scribe line corner when exposed by a mask according to the third embodiment.

FIG. 7 is a top view of a scribe line corner when exposed with a conventional mask.

FIG. 8 is a top view of a scribe line corner when exposed with a conventional mask.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Element pattern formation area 2 Scribe line formation area 2A Scribe line 3 Shielding area 4 Check pattern 4A First check pattern 4B Second check pattern 5A-5D Corner 6,6a-6d Third pattern 7A, 7B Boundary line 10 Mask 14A ~ 14D Check pattern

Claims (2)

[Claims] 1. A pattern formation region of a semiconductor element, a scribe line formation region provided around the pattern formation region, and four corners of the scribe line formation region perpendicular to the longitudinal direction of the scribe line formation region. In an exposure mask having a check pattern for detecting the amount of misalignment in the rotational direction by the provided exposure device, the check pattern has a first pattern formed at a constant interval and a constant ratio at a distance from the corner. When the pattern is formed by exposing the four corner portions at one point in contact with each other to form a pattern, the first pattern and the second pattern are formed with the boundary line of each corner portion interposed therebetween. An exposure mask, which is arranged so as to face the second pattern. 2. The exposure mask according to claim 1, wherein the scribe line forming region is provided with a third pattern which is a diagonal line directed toward the center from the corner portion of the corner portion.