KR100284069B1 - Exposure mask for semiconductor device and manufacturing method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure mask for a semiconductor device and a method of manufacturing the same, wherein an interference prevention film pattern for inverting the phase of transmitted light is formed in a portion of the exposure mask, which is intended to be a cell block, and a light blocking film pattern is formed thereon. Since the light transmitted through the cell block edge portion is opposite to the adjacent portion of the transmitted light and the diffracted light disappears from each other, the proximity effect due to diffraction is prevented, so that the pattern thinning at the edge of the cell block or reduction of the critical size are prevented. It is advantageous to the high integration of the present invention, and the process yield and the reliability of device operation can be improved.

Description

Exposure Mast for Semiconductor Device and Manufacturing Method Thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure mask for a semiconductor device and a method of manufacturing the same. In particular, the phase of the exposure mask used in an exposure process for manufacturing a semiconductor device including a cell region and a peripheral circuit region is reversed from that of other portions. Exposure mask for semiconductor device and method of manufacturing the same, which is advantageous to high integration of device by preventing process margin reduction due to proximity effect by diffraction by providing interference prevention film pattern to improve process yield and device operation reliability It is about.

In recent years, the trend of high integration of semiconductor devices has been greatly influenced by the development of micropattern forming technology, and miniaturization of photoresist patterns, which are widely used as masks such as etching or ion implantation processes, is essential in the manufacturing process of semiconductor devices.

A general photoresist pattern manufacturing process is to apply a photoresist by dissolving a photoresist dissolved in a predetermined ratio in a solvent containing a photoresist, resin, and the like on a substrate on which a pattern is to be formed, and applying a photoresist pattern on a transparent substrate. After selectively irradiating light using the formed exposure mask to polymerize a predetermined portion in a pattern, a weakly alkaline developer mainly containing tetra methylammonium hydroxides (TMAH) is used to selectively remove the exposed / non-exposed areas of the photosensitive film. It dries and forms a photosensitive film pattern.

In this case, the resolution R of the photoresist pattern is proportional to the wavelength λ and the process variable k of the light source of the reduction exposure apparatus, and inversely proportional to the numerical aperture NA of the exposure apparatus.

Here, the wavelength of the light source is reduced to improve the optical resolution of the reduced exposure apparatus. For example, the G-line and i-line reduced exposure apparatus having wavelengths of 436 and 365 nm have a process resolution of about 0.7 and 0.5 µm, respectively. Degree is the limit.

Therefore, an exposure apparatus using a deep ultra violet, for example, a KrF laser having a wavelength of 248 nm or an ArF laser having a wavelength of 193 nm, is used as a light source to form a fine pattern of 0.5 μm or less, or an image A contrast enhancement layer (CEL) method or a phase shift mask (PSM) may be used to form a separate thin film on the wafer to improve contrast.

However, there is a limit in converting the light source of the equipment to a fine wavelength, and the CEL method has a complicated process and a low yield, and the phase inversion mask is difficult to align between the phase inversion layer and the light blocking layer pattern. Each effort has its own problems.

FIG. 1 is a schematic diagram illustrating a method of manufacturing a micropattern using an exposure mask for a semiconductor device according to the prior art, using an exposure mask 10 having a light blocking film 14 pattern formed on a transparent substrate 12. When exposed, the pattern located at the outside of the cell region where the light blocking film 14 patterns are densely formed has a proximity effect caused by interference, and thus the outside pattern of the photosensitive film pattern 18 formed on the substrate 16. Is narrowly formed.

In the method of manufacturing a micropattern of a semiconductor device according to the prior art as described above, the edge pattern of the cell block is formed thinly or the threshold size is reduced due to the proximity effect, making it difficult to integrate the device, process yield and device There is a problem of reducing the reliability of the operation.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to prevent the pattern thinning or the reduction of the critical size due to the proximity effect at the cell block edge, which is advantageous for the high integration of the device, and the process yield and the operation of the device. It is to provide an exposure mask for a semiconductor device that can improve the reliability.

Another object of the present invention is to provide a method of manufacturing an exposure mask for a semiconductor device which can prevent the proximity effect at the cell block edge.

1 is a schematic view for explaining a pattern manufacturing method using an exposure mask for a semiconductor device according to the prior art.

2 is a cross-sectional view of an exposure mast for a semiconductor device according to the present invention.

3 is a schematic view for explaining a pattern manufacturing method using an exposure mask for a semiconductor device according to the present invention.

* Explanation of symbols for main parts of the drawings

10, 20: exposure mask 12: transparent substrate

14 light blocking film 16 substrate

18, 24: photosensitive film pattern 22: interference prevention film

A feature of the exposure mask for a semiconductor device according to the present invention for achieving the above object is formed on a portion of the exposure mask transparent substrate, which is intended to be a cell block, the interference prevention film pattern for inverting the phase of the transmitted light And a light blocking film pattern formed on the interference prevention film pattern.

A feature of the method for manufacturing an exposure mask for a semiconductor device according to the present invention for achieving another object is a step of forming an interference prevention film for inverting the phase of the light transmitted on the transparent substrate for the exposure mask, and a light blocking film on the interference prevention film Forming a pattern, forming a photoresist pattern that protects a portion of the transparent substrate as a cell block, and removing an interference prevention layer exposed by the photoresist pattern to form an interference prevention pattern. It's in the box.

Hereinafter, an exposure mask for a semiconductor device and a method of manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic view for explaining a micropattern manufacturing process using an exposure mask for a semiconductor device according to the present invention.

In the exposure mask 20 according to the present invention, an anti-interference film 22 pattern is formed on a portion of the transparent substrate 12 that is intended to be a cell block, and the light-blocking film 14 is formed on the anti-interference film 22 pattern. Patterns are formed.

When the exposure mask 20 is used, the phases of transmitted light between the inside and the outside of the cell block are inverted to each other so that a proximity effect due to interference at the edge of the cell block does not occur, and thus the photosensitive film pattern formed on the substrate 16 ( No edge thinning or threshold size reduction of 18) occurs.

The method of manufacturing the exposure mask 20 will be described with reference to FIGS. 3A to 3D as follows.

First, a material similar to a mask material such as quartz, glass, or a transparent material 12, such as quartz, glass or plastic, which is light transmissive, for example, quartz, oxide film, nitride film, S.O. As a material such as spin on glass (SOG), the thickness is formed of an interference prevention film 22 in consideration of the degree of phase reversal according to the transmittance of each material, and a material having excellent light reflectance on the interference prevention film 22, for example For example, the light blocking film 14 made of chromium or Al is formed. (See also section 3 (a)).

Then, the light blocking film 14 is patterned to form a light blocking film 14 pattern (see also third (b)), and a photoresist pattern is formed on a portion of the transparent substrate 12 that is intended to be a cell block. 24) (see also third (c)), and remove the interference prevention film 22 exposed by the photosensitive film pattern 24 to form an interference prevention film 22 pattern remaining only in the cell block portion. (See also section 3 (d)).

As described above, the exposure mask for a semiconductor device and the method of manufacturing the same according to the present invention form an interference prevention film pattern for inverting the phase of transmitted light in a portion of the exposure mask intended to be a cell block, and the light blocking film pattern thereon. Since the light transmitted through the edge portion of the cell block is opposite to the adjacent portion of the transmitted light, the diffracted light disappears from each other, and thus the proximity effect due to diffraction is prevented, thereby reducing the pattern thinning or reducing the critical size at the edge of the cell block. Is prevented, which is advantageous for high integration of the device, and has an advantage of improving process yield and reliability of device operation.

Claims (5)

An exposure mask for a semiconductor device for preventing thinning phenomenon in which the cell block edge portion pattern is formed thinner than the pattern inside the cell block in an exposure mask including a plurality of cell blocks having a higher pattern density than a peripheral circuit portion. And an anti-interference film pattern for inverting the phase of transmitted light is provided on the entire cell block on the transparent substrate for the exposure mask, and the light-blocking film pattern is provided on the interference prevention film pattern. The exposure mask of claim 1, wherein the transparent substrate is formed of any one of quartz, glass, and plastic. The exposure mask of claim 1, wherein the anti-interference film pattern is formed of any one of a material having a transmittance similar to a mask material such as quartz, an oxide film, a nitride film, or an SOG. The exposure mask for a semiconductor device according to claim 1, wherein the light blocking film pattern is made of chromium or Al. In a method of manufacturing an exposure mask for a semiconductor device for preventing thinning phenomenon at the edge part by using a phase inversion effect at a cell block edge part which is a boundary part with a peripheral circuit part, it is transmitted on a transparent substrate for an exposure mask. Forming an interference prevention film for inverting the phase of light, forming a light blocking film pattern on the interference prevention film, and forming a photoresist pattern for coating only the cell block region in the transparent engine and using the mask as a mask. A method of manufacturing an exposure mask for a semiconductor device comprising etching a top structure to form a phase inversion mask having an anti-interference film on an entire surface of the cell block on the transparent substrate and having a light blocking film pattern thereon.

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