KR100871799B1 - A mask of a semiconductor device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mask of a semiconductor device, and more particularly, to a mask of a semiconductor device capable of effectively compensating for a pattern distortion phenomenon due to an optical proximity effect and producing an accurate line width. The mask according to the present invention for forming the photoresist pattern is formed around the main pattern and the main pattern which is larger than the photoresist pattern to be formed using the mask, and is separated from the main pattern by a predetermined distance. It characterized in that it comprises a first auxiliary pattern.

Optical proximity compensation, mask, optical proximity effect

Description

A mask of a semiconductor device

1 is a view showing a mask of a semiconductor device according to the prior art

2 is a view showing a mask attached to the auxiliary pattern according to an embodiment of the present invention to the main pattern

3 is a diagram illustrating a compensation state of a line width end by an optical proximity compensation method using the mask of FIG. 2 as a contour image; FIG.

4 illustrates a mask according to another embodiment of the present invention.

<Description of Drawing>

10: outline of the photoresist pattern to be formed using a mask

12: auxiliary pattern

14: main pattern outline of the mask pattern according to the present invention

18: inner corner

D: fine spacing

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mask of a semiconductor device, and more particularly, to a mask of a semiconductor device capable of effectively compensating for a pattern distortion phenomenon due to an optical proximity effect and producing an accurate line width.

In general, the mask pattern forming technique has a close influence on the accuracy of the pattern formed on the semiconductor substrate.

In particular, when the optical proximity effect of the mask pattern is not accurately considered, a pattern line width distortion occurs due to the lithography original exposure intention, resulting in a shortening of line width linearity, which adversely affects semiconductor device characteristics.

The semiconductor photolithography technology developed accordingly refines the mask design, and thus, it is possible to appropriately control the amount of light emitted through the mask.

The photo lithography process is an essential process for manufacturing a semiconductor device. The photolithography process is uniformly applied to a photoresist film on a wafer, and then an exposure process is performed using a photo mask formed in a predetermined layout, and the exposed photoresist film is developed. To form a specific pattern.

However, as the design rules have been refined due to the recent high integration of semiconductor devices, a problem occurs in the pattern due to the optical proximity effect with adjacent patterns when performing the photo lithography process. It has emerged. That is, when forming a rectangular pattern, a corner rounding phenomenon occurs in which the corners of the rectangular pattern are rounded by light diffraction. In addition, a phenomenon occurs in that patterns of regions (isolated regions) in which patterns are isolated (patterned regions) are smaller in size than patterns (dense regions) in which patterns are dense, which is also due to the optical proximity effect.

As a result, optical proximity compensation technology (OPC), which compensates for diffraction problems of light using patterns, and phase shifting mask technology, which improves resolution by improving optical contrast, is drawn on the mask. Several methods have been sought to minimize the distortion of light caused by patterns.

In addition, by using a chemically amplified resist having excellent photosensitivity to light of far ultraviolet wavelength (248 nm or 194 nm wavelength), resolution can be increased, and an auxiliary pattern (a kind of dummy pattern) that controls the optical proximity effect in a form separate from the pattern Various techniques have been developed, including

1 is a view showing a mask of a semiconductor device according to the prior art.

In FIG. 1, a main pattern 1 and an exposure contour image 2 of a poly line by a mask of a semiconductor device are superimposed. However, as shown in the exposure contour image, there is a problem in that, when exposed, the line width end of the polyresist pattern is shortened due to the step difference effect and the optical proximity effect (E) and the pattern distortion of the edge occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a mask of a semiconductor device capable of effectively compensating for the pattern distortion caused by the optical proximity effect and making accurate line width.

In order to solve this problem, the mask of the present invention for forming the photoresist pattern is formed around the main pattern and the main pattern which is larger than the photoresist pattern to be formed using the mask, and is a predetermined distance from the main pattern. It characterized in that it comprises a first auxiliary pattern which is formed separately.

Specifically, the first auxiliary pattern is formed near the outer edge of the main pattern.

The main pattern of the mask pattern is formed by oversizing the size of the main pattern by about 0.005 to 0.01 μm / side than the photosensitive film pattern to be formed using the mask when the minimum line width of the pattern is 0.15 μm. It is done.

And the predetermined distance is characterized in that the fine interval less than the limit pattern resolution of the exposure light.

The second auxiliary pattern is characterized in that the light blocking portion of the main pattern is reduced.

DETAILED DESCRIPTION Embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily practice the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

Meanwhile, the definition of the pattern resolution may be determined by Rayleigh's Equation as shown in Equation 1 below.

Equation 1

R (Resolution) = k * λ / N.A.

Where k is a constant,? Is an illumination wavelength, and N.A. is an illumination lens diameter. For example, when k is 0.5, lambda is 0.248, and N.A. is 0.65, the resolution R = 0.19 m. Therefore, when a fine pattern having a line width smaller than the above value is independently applied to a mask, only a mask may be physically transmitted, and a pattern in which an image does not appear on the photoresist may be defined.

Example 1

The optical proximity compensation method attaches a complementary auxiliary pattern to the main pattern to prevent pattern distortion of line width and edges.

2 is a view showing a mask according to an embodiment of the present invention.

As shown in Fig. 2, the line width end is compensated by attaching the auxiliary pattern 3 (serif) to the line width end of the main pattern 1 as the light shielding pattern.

The compensation state of the end of the line width by the optical proximity compensation method is shown in FIG. 3 as a contour image.

As shown in FIG. 3, when the exposure contour image 2 is seen, an auxiliary pattern 3 and a serif are attached to the line width end of the main pattern 1 by using the optical proximity compensation technique. It can be seen that this shrinkage does not compensate for the line width and edge pattern distortion because the length of the auxiliary pattern (3, serif) is not sufficient even when compensating. In addition, it can be seen that the pattern distortion phenomenon of the part 5 protruding finely from the main pattern is not properly compensated.

That is, the edge length of the pattern is very short, so that it is difficult to attach a sufficient size of the secondary pattern (serif), and in particular, the finely protruding portion (5) in the main pattern (serif) to compensate for both the inner and outer corners There is a problem in that it is not possible to attach an auxiliary pattern of sufficient size in the case of attaching the optical proximity compensation is not properly made.

Example 2

4 is a view showing a mask according to another embodiment of the present invention.

As shown in FIG. 4, reference numeral 10 denotes an outline of a photoresist pattern to be formed using a mask, and reference numeral 14 denotes a main pattern outline of a mask pattern according to the present invention. In this way, the size of the main pattern of the mask pattern is made larger than that of the photosensitive film pattern to be formed using the mask. For example, when the minimum line width is 0.15 μm, the pattern is oversized by 0.005 to 0.01 μm / side. At this time, the auxiliary patterns (serif, 12, 18) are formed at the corners of the main pattern. Since the size of the main pattern is increased, the size of the auxiliary patterns (serif, 12, 18) can also be large. The auxiliary patterns serif 12 and 18 may be formed to have an area of about 20% larger than that of the first embodiment of FIG. 2. Here, the auxiliary pattern 12 formed at the outer edges of the main pattern (the corners of which two edges form an angle of less than 180 degrees) adds a light shielding portion, and the inner edges of the main pattern (the two edges forming the corners 180). The auxiliary pattern 18 formed in the corner of an angle exceeding the degree is to reduce the light shielding portion.

The auxiliary pattern 12 formed near the outer edge of the main pattern is separated from the main pattern at a predetermined fine spacing D. FIG. In this way, the auxiliary pattern serif 12 is spaced apart from the main pattern 14 at a fine interval D, so that the effect of preventing the distortion of the pattern of the auxiliary pattern serif 12 can be increased.

In addition, since the size of the main pattern is increased, the auxiliary pattern 18 formed near the inner edge can be formed larger, thereby increasing the compensating effect of the auxiliary pattern.

As described above, in the present invention, the size of the main pattern of the mask pattern is larger than the size of the photosensitive film pattern to be formed by using the mask, thereby increasing the size of the auxiliary pattern and increasing the size of the exposure light between the main pattern and the auxiliary pattern. By spacing a margin below the limit pattern resolution, a margin is spatially formed and the size of the auxiliary pattern is increased to effectively compensate for the pattern distortion caused by the optical proximity effect.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, the mask of the semiconductor device of the present invention can effectively compensate for the pattern distortion caused by the optical proximity effect by increasing the size of the pattern and expanding the size of the auxiliary pattern, thereby making it possible to manufacture the line width. Lose.

Claims (6)

A mask for forming a photosensitive film pattern extending in a first direction and a second direction orthogonal to the first direction, A main pattern enlarged than the photosensitive film pattern to be formed using the mask, and It is formed around the main pattern, and includes a first auxiliary pattern formed separately from the main pattern, The main pattern may be formed to be smaller than the photoresist pattern in a portion where the photoresist pattern is orthogonal to the first and second directions. In claim 1, The first auxiliary pattern is spaced apart from the outer edge of the main pattern, the mask is disposed in parallel with the main pattern in the first direction and the second direction. In claim 1, The main pattern of the mask pattern is formed by oversizing from 0.005 to 0.01 ㎛ / side over the photosensitive film pattern to be formed using the mask when the minimum line width of the pattern is 0.15㎛. In claim 2, And the first auxiliary pattern is separated from the main pattern at minute intervals equal to or less than a limit pattern resolution of exposure light. In claim 1, The main pattern is a mask in which the width of the start end of the portion extending in the second direction is formed narrower than the end of the portion of the photosensitive film pattern extending in the second direction. In claim 2, The first auxiliary pattern is formed spaced apart from the outer edges of both ends extending in the first direction of the main pattern, The main pattern has a width in the first direction is greater than the width in the second direction, the first auxiliary pattern is spaced apart in parallel with the main pattern in a second direction than the first direction is disposed in parallel.

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