KR101094488B1 - Method of forming a pattern of a semi conductor - Google Patents

Abstract

The present invention is a, picture photoresist pattern or the photoresist film H ⁺ ion resist to form the secondary film on a pattern forming film photoresist on the auxiliary membrane, through the heat-treating step or the exposure process relates to a pattern forming method of the semiconductor element After diffusion into an auxiliary layer, the auxiliary layer is separated into a denatured portion and an undenatured portion, and then a development process for the photoresist layer diffuses H ⁺ ions so that the denatured auxiliary layer is also removed together to prevent denaturation between the photoresist patterns. Unused auxiliary film may be left.

Photoresist, auxiliary film, diffusion, hydrogen ion

Description

Method of forming a pattern of a semi conductor

The present invention relates to a method of forming a pattern of a semiconductor device, and more particularly to a method of forming a pattern of a semiconductor device for forming a fine pattern.

A plurality of elements such as gates or device isolation layers are formed on the semiconductor substrate, and metal wirings are formed to electrically connect the gates. The junction region (eg, source or drain of the transistor) of the metal wiring and the semiconductor substrate is electrically connected by the contact plug.

Most of these gates and metal wirings are formed through a pattern forming process. That is, an etching target layer, for example, a gate stacking layer, a conductive layer, or an insulating layer, on which the patterning is to be formed is formed on the semiconductor substrate, and an etching mask pattern is formed on the etching target layer, followed by etching using an etching mask pattern. Pattern the subject film. Forming a fine pattern through such a pattern forming process is very important as an essential step for forming a microminiature and high performance semiconductor device. However, due to the limitations of the equipment used in the pattern forming process, the size of the pattern that can be formed is limited and there are many difficulties in overcoming the limitation of such equipment.

The present invention provides a method of forming a pattern of a semiconductor device for forming a fine pattern.

According to an aspect of the present invention, there is provided a method of forming a pattern of a semiconductor device, the method comprising: forming a photoresist pattern on an etching target layer on an upper surface of a semiconductor substrate; Forming an auxiliary layer on the semiconductor substrate including the photoresist pattern; Changing a region of the auxiliary layer in contact with the surface of the photoresist pattern to form a first auxiliary pattern surrounding the surface of the photoresist pattern; Forming a photoresist film on the auxiliary film including the first auxiliary pattern; Changing a region of the auxiliary layer in contact with the photoresist layer to form a second auxiliary pattern in contact with an upper surface of the first auxiliary pattern, wherein the auxiliary layer remains only between the photoresist patterns; And removing the photoresist layer, the first and second auxiliary patterns to form an etch mask pattern including the photoresist pattern and the auxiliary layer.

According to another aspect of the present invention, there is provided a method of forming a pattern of a semiconductor device, the method including: providing a semiconductor substrate including a first region and a second region in which a pattern having a width or pitch larger than that of the first region is formed; Sequentially forming an etching target layer and a photoresist pattern on the semiconductor substrate; Forming an auxiliary layer on the semiconductor substrate including the photoresist pattern; Changing a region of the auxiliary layer in contact with the surface of the photoresist pattern to form a first auxiliary pattern surrounding the surface of the photoresist pattern; Forming a photoresist film on the auxiliary film including the first auxiliary pattern; Changing a region of the auxiliary layer in contact with the photoresist layer to form a second auxiliary pattern in contact with an upper surface of the first auxiliary pattern, wherein the auxiliary layer remains only between the photoresist patterns; And removing the photoresist layer, the first and second auxiliary patterns to form an etch mask pattern including the photoresist pattern and the auxiliary layer.

It is preferable that the photoresist pattern is formed using a fat-soluble one, and the auxiliary film is formed using a water soluble one.

After the forming of the auxiliary layer, the method may further include performing a baking process at a temperature higher than the glass transition temperature of the photoresist pattern and the auxiliary layer.

The first and second auxiliary patterns are removed at the same time as the photoresist film. The first and second auxiliary patterns are removed during the development process of the photoresist film.

The first and second auxiliary patterns are formed by diffusion of H ⁺ ions into the auxiliary layer.

The first auxiliary pattern is formed by a heat treatment process.

The distance between the photoresist patterns is formed three times the width of the photoresist pattern.

The distance between the photoresist patterns formed in the first region is three times the width of the photoresist pattern formed in the first region.

The thickness of the first auxiliary pattern is equal to the width of the photoresist pattern.

The second auxiliary pattern is formed by exposing the photoresist film.

During the exposure process of the photoresist film for forming the second auxiliary pattern, an exposure amount irradiated to the first region and the second region is set differently.

The exposure amount irradiated to the first region during the exposure process to the photoresist film is preferably smaller than the exposure amount irradiated to the second region.

The greater the exposure amount irradiated to the first region during the exposure process to the photoresist film, the lower the height of the auxiliary film remaining in the first region.

The second auxiliary pattern is formed in the entirety of the second region except for a boundary portion with the first region.

In the exposing process of the photoresist film, the photoresist film between the first region and the second region is not exposed.

According to another aspect of the present invention, there is provided a method of forming a pattern of a semiconductor device, the method including: forming a photoresist pattern on a semiconductor substrate; Forming an auxiliary layer on the photoresist pattern; Performing a heat treatment process on the semiconductor substrate to modify a region of the auxiliary layer in contact with a surface of the photoresist pattern to surround the photoresist pattern so as to be removable during a development process with respect to the photoresist; Forming a photoresist film on the auxiliary film; An exposure process is performed on the photoresist film to modify a region of the auxiliary film in contact with the photoresist film so that the photoresist film may be removed during a development process for the photoresist, and the unmodified auxiliary film remains between the photoresist patterns. step; And performing a development process on the exposed photoresist film, wherein the modified auxiliary film is removed together to leave the photoresist pattern and the unmodified auxiliary film.

The auxiliary film is modified so that an acid is diffused from the photoresist pattern or the photoresist film so that the auxiliary film can be removed during the development process for the photoresist.

The auxiliary film is modified to be removable during development of the photoresist by diffusing H ⁺ ions from the photoresist pattern or the photoresist film.

It is preferable that the photoresist pattern is formed using a fat-soluble one, and the auxiliary film is formed using a water soluble one.

After the forming of the auxiliary layer, the method may further include performing a baking process at a temperature higher than the glass transition temperature of the photoresist pattern and the auxiliary layer.

According to another aspect of the present invention, there is provided a method of forming a pattern of a semiconductor device, the method comprising: forming an etching assistant pattern on an etching target layer on an upper surface of a semiconductor substrate; Forming an auxiliary layer on the semiconductor substrate including the etching assistant pattern; Forming a first auxiliary pattern surrounding the etch auxiliary pattern by changing a region of the auxiliary layer in contact with the surface of the etch auxiliary pattern; Forming a second auxiliary pattern by modifying a region of the auxiliary layer in contact with an upper surface of the first auxiliary pattern such that the auxiliary layer remains only between the etching auxiliary patterns; And removing the first and second auxiliary patterns to form an etching mask pattern including the etching assistant pattern and the remaining auxiliary layer.

In the method of forming a pattern of a semiconductor device according to the fifth aspect of the present invention, an etching target layer and an etching assistant pattern are sequentially formed on a semiconductor substrate including a first region and a second region, and the etching assistant pattern is formed in the second substrate. Forming a wider width or pitch in the second region than in one region; Forming an auxiliary layer on the semiconductor substrate including the etching assistant pattern; Forming a first auxiliary pattern surrounding the etch auxiliary pattern by changing a region of the auxiliary layer in contact with the surface of the etch auxiliary pattern; Forming a second auxiliary pattern by modifying a region of the auxiliary layer in contact with an upper surface of the first auxiliary pattern such that the auxiliary layer remains only between the etching auxiliary patterns; And removing the first and second auxiliary patterns to form an etching mask pattern including the etching assistant pattern and the remaining auxiliary layer.

The forming of the second auxiliary pattern may include forming a material film identical to the etch auxiliary pattern on the auxiliary film, and forming the auxiliary film in contact with the same material film as the etch auxiliary pattern as a second auxiliary pattern. It further comprises a step.

The first and second auxiliary patterns are formed by diffusing H ⁺ ions into the auxiliary layer from the same material layer as the etching assistant pattern or the etching assistant pattern.

The etching assistant pattern is formed using a fat-soluble, and the auxiliary layer is preferably formed using a water-soluble one.

After the forming of the auxiliary layer, the method may further include performing a baking process at a temperature higher than a glass transition temperature of the etching assistant pattern and the auxiliary layer.

According to the method for forming a pattern of a semiconductor device of the present invention, after forming a photoresist pattern, an auxiliary film is formed between the photoresist patterns through one exposure and development process of the photoresist film, thereby halving the pitch of the photoresist pattern. It is possible to form a fine etching mask pattern having a.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention.

However, the present invention is not limited to the embodiments described below, but may be implemented in various forms, and the scope of the present invention is not limited to the embodiments described below. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. In addition, when an arbitrary film is described as being formed on another film or on a semiconductor substrate, the arbitrary film may be formed in direct contact with the other film or the semiconductor substrate, or may be formed with a third film interposed therebetween. . In addition, the thickness or size of each layer shown in the drawings may be exaggerated for convenience and clarity of description.

1A to 1I are cross-sectional views of devices illustrated to explain one embodiment of a method for forming a pattern of a semiconductor device according to the present invention.

Referring to FIG. 1A, a semiconductor substrate 100 including a first region A and a second region B is provided. The first region A is a region in which a denser pattern is formed than the second region B. The width or pitch of the pattern formed in the second region B is the width of the pattern formed in the first region A. FIG. Or larger than the pitch. For example, the first region A may be a cell region of the NAND flash memory device, and the second region B may be a peripheral circuit area of the NAND flash memory device. In addition, an area between the first area A and the second area B may be an area for forming a pad of the NAND flash memory device.

An etching target layer 102 is formed on the semiconductor substrate 100. The etching target layer 102 may be a pattern for forming a pattern, and may include an insulating layer for forming a contact hole, a gate stacked layer for forming a gate, or the like.

The hard mask film 104, the antireflection film 106, and the first photoresist film 108 are formed on the etching target film 102 to pattern the etching target film 102. The anti-reflection film 106 serves as an anti-reflection film that can reduce the light reflected from the lower portion of the photoresist film 108 during the exposure process to the photoresist film 108 to increase the resolution of the exposure process.

On the other hand, the hard mask film 104 and the anti-reflection film 106 are formed of a fluid film like the first photoresist film 108, whereby the hard mask film 104, the anti-reflection film 106 and the first photoresist are formed. It is desirable to form the film 108 continuously in the same process apparatus. To this end, the hard mask film 104 may be formed of an SOC (Spin On Carbon) film, and the anti-reflection film 106 may be formed of a Si-containing BARC (Bottom Anti-Reflection Coating) film.

Referring to FIG. 1B, an exposure and development process is performed on the first photoresist film 108 (see FIG. 1A) to form an etch assist pattern, that is, the first photoresist pattern 108a.

At this time, the pitch or width of the first photoresist pattern 108a formed on the first region A of the semiconductor substrate 100 where the dense pattern is formed is formed to a minimum size that can be realized through an exposure and development process. It is desirable to. The width W1 and the pitch of the first photoresist pattern 108a formed in the first region A are formed to be similar to the width and pitch of the pattern to be formed in the etching target layer 102. The distance W2 between the first photoresist patterns 108a formed in A) is preferably about three times the width W1 of the first photoresist pattern 108a. Meanwhile, the width of the first photoresist pattern 108a formed in the first region A adjacent to the second region B is the width of the other first photoresist pattern 108a formed in the first region A. FIG. By forming larger, problems such as dishing due to a difference in pattern density from the second region B can be minimized.

In addition, the pitch or width of the first photoresist pattern 108a formed on the second region B of the semiconductor substrate 100 may be the first photo formed on the first region A of the semiconductor substrate 100. The resist pattern 108a may be formed to be larger than the pitch or width of the resist pattern 108a, and is preferably similar to the etching mask pattern formed to pattern the etching target layer 102 of the second region B of the semiconductor substrate 100. Can be formed.

The first photoresist pattern 108a may be dissolved by an auxiliary film coated in a subsequent process. To prevent this, after the first photoresist pattern 108a is formed, a process of curing the first photoresist pattern 108a is performed. The process of curing the first photoresist pattern 108a may be performed through a heat treatment process. When the first photoresist pattern 108a is heat treated, the first photoresist pattern 108a is cross linked and cured. The thermal acid generator (TAG) included in the first photoresist pattern 108a may be activated through the above-described heat treatment process.

Further, in order to facilitate cross linking or TAG activation of the first photoresist pattern 108a, the first photoresist film 108 (see FIG. 1A) is formed when the first photoresist film 108 (see FIG. 1A) is formed. A cross linker or TAG can be further added to the.

And forming the first photoresist film 108 (see FIG. 1A) to prevent the first photoresist pattern 108a from being dissolved by the auxiliary film coated in a subsequent process. 1a) may be formed using a material having a different property from that of the auxiliary film. For example, when the auxiliary film formed in the subsequent process is water-soluble, the first photoresist film 108 (see FIG. 1A) is formed fat-soluble so that the first photoresist pattern 108a is dissolved by the auxiliary film coated in the subsequent process. This phenomenon can be further improved.

Referring to FIG. 1C, the auxiliary layer 110 is formed on the anti-reflection film 106 including the first photoresist pattern 108a. The auxiliary layer 110 is formed to have a thickness sufficient to cover the first photoresist patterns 108a while completely filling the space between the first photoresist patterns 108a formed in the first region A. FIG. Meanwhile, an interval between the first photoresist patterns 108a formed in the second region B is wider than an interval between the first photoresist patterns 108a formed in the first region A. FIG. Therefore, the auxiliary layer 110 formed in the second region B does not fill the space between the first photoresist patterns 108a formed in the second region B and thus follows the step of the first photoresist pattern 108a. Can be formed.

The auxiliary layer 110 may not only function as an anti-reflection film but also may be formed using a developer soluble BARC (DBARC) which is modified to react with an acid and be dissolved in a developer when an acid such as hydrogen ion (H ⁺ ) is supplied. Can be.

FIG. 2 is a SEM (Scanning Electron Microscope) photograph in which a developing process is simultaneously performed on a DBARC film and a photoresist film.

Referring to FIG. 2, in the case where the photoresist film is formed on the DBARC film D, the photoresist film is exposed and developed to form the photoresist pattern P, the DBARC film D is formed. Even if a separate etching process is not performed, the DBARC film D is also etched and patterned in the development process for the photoresist pattern P. FIG. This is because an acid such as hydrogen (H ⁺ ) ions generated in the photoresist pattern P through the exposure process is diffused to the boundary between the DBARC film D and the photoresist pattern P, thereby acid. This is because the DBARC film D in the diffused region is denatured to a developable state and removed together during the development process for the photoresist film.

In addition, referring to FIG. 1C, the auxiliary film 110 formed using the DBARC film exhibiting the characteristics described above with reference to FIG. 2 may be formed using a material that is water-soluble different from the fat-soluble first photoresist pattern 108a. desirable. In contrast, when the first photoresist pattern 108a is water-soluble, the auxiliary layer 110 may be fat-soluble. When the auxiliary layer 110 is formed using a material having a different characteristic from the first photoresist pattern 108a as described above, the auxiliary layer 110 in a fluid state is formed on the upper portion of the first photoresist pattern 108a. Even if formed, the problem that the first photoresist pattern 108a is dissolved does not occur.

After the auxiliary layer 110 is formed, a baking process may be further performed to improve surface roughness of the first photoresist pattern 108a. In order to improve the surface roughness of the first photoresist pattern 108a, a baking process may be performed at a glass transition temperature (Tg) or higher of the first photoresist pattern 108a and the auxiliary layer 110. Since the first photoresist pattern 108a and the auxiliary layer 110 have different characteristics (that is, water solubility and fat soluble), the interfacial energy of the first photoresist pattern 108a and the auxiliary layer 110 is high. Therefore, when the baking process is performed at or above the glass transition temperature, the molecules of the first photoresist pattern 108a are moved to minimize the interfacial energy between the first photoresist pattern 108a and the auxiliary layer 110. The surface roughness of the resist pattern 108a may be improved.

Referring to FIG. 1D, a first auxiliary pattern 110a is formed at an interface between the first photoresist pattern 108a and the auxiliary layer 110. In order to form the first auxiliary pattern 110a, an auxiliary layer (eg, an acid such as hydrogen ions (H ⁺ ) included in the first photoresist pattern 108a) is in contact with the first photoresist pattern 108a. 110). Diffusion of an acid included in the first photoresist pattern 108a may occur through a heat treatment process. As such, when an acid such as hydrogen ion (H ⁺ ) is diffused into the auxiliary film 110, the first auxiliary pattern 110a in which the auxiliary film 110 in the acid diffused portion may be dissolved in the developer. To be denatured. Since the first auxiliary pattern 110a is formed through an acid diffused from the first photoresist pattern 108a, the first auxiliary pattern 110a is formed on the surface of the first photoresist pattern 108a.

The thickness of the first auxiliary pattern 110a is preferably formed to be similar to the thickness of the first photoresist pattern 108a. Since the thickness of the first auxiliary pattern 110a is increased as the temperature of the heat treatment process is high or the process time is long, the thickness of the first auxiliary pattern 110a may be adjusted by adjusting the temperature and the process time of the heat treatment process.

Subsequently, a process of forming the second auxiliary pattern on the auxiliary layer 110 so that the auxiliary layer 110 remains only between the first photoresist pattern 108a will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1E, a second photoresist film 112 is formed on the auxiliary film 110. In this case, the surface of the second photoresist film 112 formed in the second region B may be formed along the step of the auxiliary film 110 formed on the lower portion. The second photoresist layer 112 may generate an acid such as hydrogen ion (H ⁺ ) by reacting with light including a photo acid generator (PAG).

Referring to FIG. 1F, a second auxiliary pattern 110b is formed at an interface between the second photoresist film 112 (see FIG. 1E) and the auxiliary film 110 (see FIG. 1E). To form the second auxiliary pattern 110b, an acid such as hydrogen ion (H ⁺ ) is diffused into the auxiliary film 110 (see FIG. 1E) in contact with the second photoresist film 112 (see FIG. 1E). You have to. Diffusion of the acid included in the second photoresist film 112 (see FIG. 1E) may occur through an exposure process using a reticle 200.

After the formation of the second auxiliary pattern 110b, some auxiliary layers are defined as the third auxiliary pattern 110c remaining only between the first auxiliary patterns 112a and separated from each other. Therefore, according to the present invention, the third auxiliary pattern 110c formed to be spaced apart from the first photoresist pattern 108a between the first photoresist patterns 108a formed at limited intervals in the first region A according to the exposure resolution limitation. Can be formed. The third auxiliary pattern 110c is used as an etching barrier in a subsequent process together with the first photoresist pattern 108a.

On the other hand, it is preferable that the third auxiliary pattern 110c is formed in the first region A in which a pattern that is denser than the second region B is to be formed. In addition, it is preferable that the third auxiliary pattern 110c is not formed in a portion of the second region B where the pattern is to be formed at a wider interval than the first region A. FIG. A third auxiliary pattern 110c having a stepped shape may also be formed between the first photoresist patterns 108a formed at a wider distance than the first photoresist patterns 108a formed in the first region A. FIG. have. In order to form the third auxiliary pattern 110c in various regions as described above, diffusion of an acid such as hydrogen ions (H ⁺ ) is controlled when the second auxiliary pattern 110b is formed.

In order to control the diffusion of the acid when forming the second auxiliary pattern 110b, a reticle 200 having a different light transmittance is used. The reticle 200 may include a halftone phase shift mask. The reticle 200, such as a halftone phase reversal mask, has a first light transmitting portion M1 that transmits light below 0% and less than 100%, a second light transmitting portion M3 transmitting 100% of light, and blocks the light. The light shielding part M2 is included.

When the second photoresist film is exposed using the reticle 200 including the first and second light transmitting parts M1 and M3 and the light transmitting part M2, the second photoresist film corresponds to the light blocking part M2. The non-exposed area 112a, the first exposure area 112b corresponding to the first light-emitting part M1, and the second exposure area 112c corresponding to the second light-emitting part M3 are divided.

Since a greater amount of light is incident on the second exposure area 112c than the first exposure area 112a, the amount of H ⁺ ions generated inside the second exposure area 112c is lower than that of the first exposure area 112b. many. Accordingly, the amount of H ⁺ ions diffused into the auxiliary film 110 (see FIG. 1E) in contact with the second exposure area 112c is diffused into the auxiliary film 110 (see FIG. 1E) in contact with the first exposure area 112b. That is a lot compared to the amount of H ⁺ ions. As a result, even though the auxiliary layer 110 (see FIG. 1E) does not remain under the second exposure region 112c and thus the third auxiliary pattern 110c is not formed, the third auxiliary region is disposed under the first exposure region 112b. The pattern 110c may be formed. The first exposure area 112b should have a third auxiliary pattern 110c formed therein and be formed in an area where the thickness of the auxiliary film 110 (see FIG. 1E) is thicker than the first photoresist pattern 108a. . In addition, the second exposure area 112c is preferably formed in an area where the third auxiliary pattern 110c should not be formed.

In addition, H ⁺ ions are not generated in the non-exposed region 112a corresponding to the light shielding portion M1. Accordingly, since H ⁺ ions are not diffused into the auxiliary layer 110 (see FIG. 1E) in contact with the non-exposed region 112a, the second auxiliary pattern 110b is not formed under the non-exposed region 112a. As a result, the auxiliary layer 110 (see FIG. 1E) remains under the non-exposed area 112a to form the third auxiliary pattern 110c. The non-exposed area 112a should have a third auxiliary pattern 110c formed therein and be formed in an area where the thickness of the auxiliary film 110 (see FIG. 1E) is lower than the thickness of the first photoresist pattern 108a. desirable.

Meanwhile, in order to adjust the height h of the third auxiliary pattern 110c formed under the first exposure area 112b, the light transmittance of the first light transmitting part M1 corresponding to the first exposure area 112b is controlled. can do. That is, the higher the light transmittance, the lower the height h of the third auxiliary pattern 110c and the lower the transmittance of the exposure, the higher the height h of the third auxiliary pattern 110c. In the present invention, it is preferable that the height h of the third auxiliary pattern 110c is lower than the height of the first auxiliary pattern 110a so that the third auxiliary patterns 110c are formed to be separated from each other. For this purpose, it is preferable to control the transmittance of the first light transmitting portion M1 to be 6% to 8%.

The light blocking part M2 may correspond to a boundary between the first area A and the second area B of the semiconductor substrate 100. As a result, the non-exposed region 112a is formed at the boundary between the first region A and the second region B of the semiconductor substrate 100. This non-exposed area 112a is not removed in a subsequent development process and is defined as the second photoresist pattern 112a. The second photoresist pattern 112a may remain in the boundary between the first region A and the second region B of the semiconductor substrate 100 in a subsequent etching process, thereby forming the first region A of the semiconductor substrate 100. ) And the third auxiliary pattern 110c formed at the boundary between the second region B is excessively etched to prevent the second auxiliary pattern 110c from being removed.

In addition, the first light transmitting part M1 may correspond to the first area A. FIG. As a result, a third auxiliary pattern 110c is formed between the first photoresist patterns 108a in the first region A of the semiconductor substrate 100.

The second exposure part M3 may be formed to correspond to the second area B of the semiconductor substrate 100. That is, the exposure amount may be set to the maximum in the second region B of the semiconductor substrate 100. As a result, the H ⁺ ions of the second exposure region 112c formed in the second region B of the semiconductor substrate 100 are formed in the auxiliary layer 110 formed in the second region B of the semiconductor substrate 100 (see FIG. 1E). So that it can spread to all parts of the

The first light transmitting part M1 may correspond to a part of the second area B adjacent to the first area A. FIG. As a result, the heights of the third auxiliary patterns 110c on both sides of the second photoresist pattern 112a may be the same.

Referring to FIG. 1G, a development process is performed on a conventional photoresist film to remove first and second exposure regions including H ⁺ ions. At this time, the first and second auxiliary patterns are also removed.

As a result, an etching mask pattern including the third auxiliary pattern 110c and the first photoresist pattern 108a is formed on the first region A of the semiconductor substrate 100. In this case, since the first photoresist pattern 108a is formed with the minimum pitch and width that can be realized through the exposure and development processes, the first photoresist pattern 108a is formed due to the third auxiliary pattern 110c formed between the first photoresist patterns 108a. On the first region A of the semiconductor substrate 100, an etch mask pattern having a density more than that of the minimum pitch that can be realized by the exposure and development processes, that is, half the pitch, may be formed.

In addition, only the first photoresist pattern 108a remains on the second region B of the semiconductor substrate 100. In the above-described process, since the first photoresist pattern 108a formed in the second region B of the semiconductor substrate 100 has a pitch and width similar to that of the target pattern, the first photoresist pattern 108a is etched by the mask. Can be used as a pattern.

In addition, the second photoresist pattern 112a remains between the first region A and the second region B of the semiconductor substrate 100 so that the third auxiliary pattern 110c formed below is not removed. Can be. Since a pattern must be formed between the first region A and the second region B of the semiconductor substrate 100, the etching mask is also formed between the first region A and the second region B of the semiconductor substrate 100. A pattern should be formed. However, since the thickness of the third auxiliary pattern 110c is thin due to the difference in the distance between the patterns formed in the first region A and the second region B of the semiconductor substrate 100, the third auxiliary pattern If the etching mask pattern is formed only at 110c, the pattern may be unstable and may be removed through development and etching processes. Therefore, in the embodiment of the present invention, the second photoresist pattern 112a is formed on the third auxiliary pattern 110c between the first region A and the second region B of the semiconductor substrate 100 to develop. And it is possible to form a more stable etching mask pattern during the etching process.

Referring to FIG. 1H, an etching process is performed on the antireflection film 106 and the hard mask film 104 by using the first photoresist pattern 100a, the third auxiliary pattern 110c, and the second photoresist pattern 112a. Is carried out. As a result, the antireflection film pattern 106a and the hard mask pattern 104a are formed.

Referring to FIG. 1I, an etch target layer 102 is patterned by an etching process using an anti-reflection layer pattern 106a and a hard mask pattern 104a to form an etch target layer pattern 102a.

1A to 1I are cross-sectional views of a device for explaining a method of forming a pattern of a semiconductor device according to the present invention.

Description of the Related Art [0002]

100 semiconductor substrate 102 etching target film

104: hard mask film 104a: hard mask pattern

106: antireflection film 106a: antireflection film pattern

108: first photoresist film 108a: first photoresist pattern

110: auxiliary film 110a: first auxiliary pattern

110b: second auxiliary pattern

112: second photoresist film 112a: second photoresist pattern

Claims (28)

Forming a photoresist pattern on the etching target layer on the semiconductor substrate; Forming an auxiliary layer on the semiconductor substrate including the photoresist pattern; Changing a region of the auxiliary layer in contact with the surface of the photoresist pattern to form a first auxiliary pattern surrounding the surface of the photoresist pattern; Forming a photoresist film on the auxiliary film including the first auxiliary pattern; Changing a region of the auxiliary layer in contact with the photoresist layer to form a second auxiliary pattern in contact with an upper surface of the first auxiliary pattern, wherein the auxiliary layer remains only between the photoresist patterns; And And removing the photoresist layer, the first and second auxiliary patterns to form an etch mask pattern including the photoresist pattern and the auxiliary layer. Providing a semiconductor substrate comprising a first region and a second region in which a pattern having a width or pitch wider than that of the first region is formed; Sequentially forming an etching target layer and a photoresist pattern on the semiconductor substrate; Forming an auxiliary layer on the semiconductor substrate including the photoresist pattern; Changing a region of the auxiliary layer in contact with the surface of the photoresist pattern to form a first auxiliary pattern surrounding the surface of the photoresist pattern; Forming a photoresist film on the auxiliary film including the first auxiliary pattern; Changing a region of the auxiliary layer in contact with the photoresist layer to form a second auxiliary pattern in contact with an upper surface of the first auxiliary pattern, wherein the auxiliary layer remains only between the photoresist patterns; And And removing the photoresist layer, the first and second auxiliary patterns to form an etch mask pattern including the photoresist pattern and the auxiliary layer. The method according to claim 1 or 2, The photoresist pattern is formed using a fat-soluble, and the auxiliary film is a pattern forming method of a semiconductor device formed by using a water-soluble. The method of claim 3, After the step of forming the auxiliary film, And performing a baking process at a temperature higher than a glass transition temperature of the photoresist pattern and the auxiliary layer. The method according to claim 1 or 2, And the first and second auxiliary patterns are removed at the same time as the photoresist film. The method according to claim 1 or 2, And the first and second auxiliary patterns are removed during the development process of the photoresist film. The method according to claim 1 or 2, The first and second auxiliary patterns may be formed by diffusing H ⁺ ions in the auxiliary layer. The method according to claim 1 or 2, The first auxiliary pattern is a pattern forming method of a semiconductor device formed by a heat treatment process. The method of claim 1, And a distance between the photoresist patterns is three times the width of the photoresist pattern. 3. The method of claim 2, And a distance between the photoresist patterns formed in the first region is three times the width of the photoresist pattern formed in the first region. The method according to claim 1 or 2, And a thickness of the first auxiliary pattern is equal to a width of the photoresist pattern. 3. The method of claim 2, And the second auxiliary pattern is formed by exposing the photoresist film. The method of claim 12, The pattern formation method of the semiconductor element which sets the exposure amount irradiated to the said 1st area | region and the said 2nd area | region differently at the time of the exposure process of the said photoresist film for forming said 2nd auxiliary pattern. The method of claim 13, And a light exposure amount irradiated to the first region during the exposure process to the photoresist film is smaller than a light exposure amount to the second region. The method of claim 13, And the height of the auxiliary film remaining in the first region decreases as the exposure amount irradiated to the first region increases during the exposure process to the photoresist film. The method of claim 13, And the second auxiliary pattern is formed on the entirety of the second region except for a boundary portion with the first region. The method of claim 13, And the photoresist film between the first region and the second region is not exposed during the exposure process to the photoresist film. Forming a photoresist pattern on the semiconductor substrate; Forming an auxiliary layer on the photoresist pattern; Performing a heat treatment process on the semiconductor substrate to modify a region of the auxiliary layer in contact with a surface of the photoresist pattern to surround the photoresist pattern so as to be removable during a development process with respect to the photoresist; Forming a photoresist film on the auxiliary film; An exposure process is performed on the photoresist film to modify a region of the auxiliary film in contact with the photoresist film so that the photoresist film may be removed during a development process for the photoresist, and the unmodified auxiliary film remains between the photoresist patterns. step; And Performing a development process on the exposed photoresist film, wherein the modified auxiliary film is removed together so that the photoresist pattern and the unmodified auxiliary film remain. The method of claim 18, And the auxiliary layer is modified to be removable so that an acid is diffused from the photoresist pattern or the photoresist film so as to be removed during a development process for the photoresist. The method of claim 18, The auxiliary film is a pattern forming method of a semiconductor device that is modified to be removed during the development process for the photoresist by diffusion of H ⁺ ions from the photoresist pattern or the photoresist film. The method of claim 18, The photoresist pattern is formed using a fat-soluble, and the auxiliary film is a pattern forming method of a semiconductor device formed by using a water-soluble. The method of claim 21, After the step of forming the auxiliary film, And performing a baking process at a temperature higher than a glass transition temperature of the photoresist pattern and the auxiliary layer. Forming an etching assistant pattern on the etching target layer on the semiconductor substrate; Forming an auxiliary layer on the semiconductor substrate including the etching assistant pattern; Forming a first auxiliary pattern surrounding the etch auxiliary pattern by changing a region of the auxiliary layer in contact with the surface of the etch auxiliary pattern; Forming a second auxiliary pattern by modifying a region of the auxiliary layer in contact with an upper surface of the first auxiliary pattern such that the auxiliary layer remains only between the etching auxiliary patterns; And And removing the first and second auxiliary patterns to form an etch mask pattern including the etch auxiliary pattern and the remaining auxiliary layer. An etching target layer and an etching assistant pattern are sequentially formed on the semiconductor substrate including the first region and the second region, and the etching assistant pattern is formed in a wider width or pitch in the second region than in the first region. step; Forming an auxiliary layer on the semiconductor substrate including the etching assistant pattern; Forming a first auxiliary pattern surrounding the etch auxiliary pattern by changing a region of the auxiliary layer in contact with the surface of the etch auxiliary pattern; Forming a second auxiliary pattern by modifying a region of the auxiliary layer in contact with an upper surface of the first auxiliary pattern such that the auxiliary layer remains only between the etching auxiliary patterns; And And removing the first and second auxiliary patterns to form an etch mask pattern including the etch auxiliary pattern and the remaining auxiliary layer. The method of claim 23 or 24, Forming the second auxiliary pattern, Forming the same material layer on the auxiliary layer as the etching assistant pattern; And And forming the auxiliary layer in contact with the same material layer as the etch auxiliary pattern as a second auxiliary pattern. The method of claim 25, The first and second auxiliary patterns may be formed by diffusing H ⁺ ions into the auxiliary layer from the same material as the etching auxiliary pattern or the etching auxiliary pattern. The method of claim 23 or 24, The etching auxiliary pattern is formed using a fat-soluble, and the auxiliary film is a pattern forming method of a semiconductor device formed by using a water-soluble. The method of claim 27, After the step of forming the auxiliary film, And performing a baking process at a temperature higher than a glass transition temperature of the etching assistant pattern and the auxiliary layer.

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