KR100663115B1 - Gray tone mask and method for manufacturing the same - Google Patents

Abstract

A gray tone mask having a pattern adjacent in one direction in order of a light transmitting portion, a light blocking portion, and a semi-transmissive portion, having a good transmittance distribution of the semi-transmissive portion, a good pattern cross-sectional shape of a light blocking portion adjacent to the light transmitting portion, Provided are a gray tone mask and a method for producing a gray tone mask having good pattern accuracy. A gray tone mask (10) having a pattern consisting of a light blocking portion, a light transmitting portion, and a semi-transmissive portion, wherein the pattern has a pattern adjacent to one direction in the order of the light transmitting portion, the light blocking portion, and the semi-light transmitting portion, and the light blocking portion The light shielding film 13a to form and the semi-transmissive film 12a formed in the area | region except the desired margin area | region on the light shielding part side in the adjoining part with the said light transmitting part on the said light shielding film 13a are laminated | stacked.

Gray tone mask

Description

Gray tone mask and method for manufacturing the same

1 is a cross-sectional view of a gray tone mask according to Embodiment 1 of the present invention;

2 is a partially enlarged view of a gray tone mask according to Embodiment 1 of the present invention;

3 is a manufacturing process chart of a gray tone mask according to Example 1 of the present invention;

4 is a manufacturing process diagram of a gray tone mask according to Example 2 of the present invention;

5 is a partially enlarged view of a gray tone mask according to Embodiment 2 of the present invention;

6 is a partially enlarged view of a gray tone mask according to a comparative example.

7 is a plan view of a gray tone mask according to another embodiment;

8 is a plan view of a conventional gray tone mask.

9 is a manufacturing process diagram of a conventional TFT substrate.

10 is a plan view of a conventional gray tone mask.

11 is a plan view of a TFT substrate in a conventional manufacturing step.

12 is a cross-sectional view of a conventional gray tone mask.

13 is a partially enlarged view of a conventional gray tone mask.

14 is a manufacturing process diagram of a conventional gray tone mask.

15 is a manufacturing process diagram of a conventional gray tone mask.

16 is a manufacturing process diagram of a conventional gray tone mask.

(Explanation of reference numerals for the main parts of the drawings)

10 gray tone mask

11 transparent substrate

12 translucent membrane

12a translucent film pattern

13 light shielding film

13a shading pattern

14 mask blank

15, 16 resist film

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a gray tone mask suitably used for thin film transistor substrates (hereinafter referred to as TFT substrates) and the like used in the production of thin film transistor liquid crystal displays.

TFT-LCDs are currently being commercialized rapidly due to the advantages of being thinner and having lower power consumption than CRTs (cathode ray tubes). The TFT-LCD has a TFT substrate having a structure in which TFTs are arranged in each pixel arranged in a matrix shape, and a color filter in which red, green, and blue pixel patterns are arranged corresponding to each pixel under superposition on a liquid crystal. It has a schematic structure. In TFT-LCD, there are many manufacturing processes, and it manufactures using 5-6 photomasks only by a TFT substrate.

Under these circumstances, a method of reducing the number of photolithographic processes has been proposed by a method of manufacturing a TFT substrate using four photomasks, that is, a method using two types of photoresist patterns having two film thicknesses.

For example, Japanese Patent Laid-Open No. 2000-165886 discloses a photoresist having a first thickness between a source electrode and a drain electrode (channel portion), a photoresist having a second thickness thicker than the first thickness, and a first thickness. It is disclosed to have a process using a photoresist having a thin third thickness (including zero thickness).

In addition, Japanese Patent Application Laid-Open No. 2000-165886 discloses a method of forming a photoresist pattern having two kinds of film thicknesses, which includes two methods, (1) a gray tone mask having a light transmitting portion, a light blocking portion, and a semi-light transmitting portion. The method of using and (2) the method of modifying a resist by reflow of a resist are disclosed.

As the gray tone mask, there is a method in which the semi-transmissive portion is formed by a pattern smaller than the resolution of an exposure apparatus using a mask, for example, a slit or a lattice pattern, or a semi-transmissive film is provided to control the amount of light irradiation. In the case of a semi-transmissive film, the light-shielding chromium layer is not completely removed, leaving a certain thickness and reducing the amount of light entering through this portion.

FIG. 8A illustrates an example in which regions corresponding to the source electrode and the drain electrode are the light blocking portions 204, and regions corresponding to the channel portions therebetween are slit-shaped semi-transmissive portions 203. ) Is an example in which a region corresponding to the channel portion is formed of a translucent film.

Japanese Patent Laid-Open No. 2000-165886 discloses a gray tone mask in which a region corresponding to a channel portion is a translucent portion.

On the other hand, as another example of the method for manufacturing a TFT substrate, for example, Japanese Patent Application Laid-Open No. 2002-261078 discloses a method for manufacturing a TFT substrate using a combination of a method using a gray tone mask and a method of modifying a resist by reflow. It is.

Hereinafter, with reference to FIG. 9, an example of the method of Unexamined-Japanese-Patent No. 2002-261078 is demonstrated.

As shown in FIG. 9A, the gate electrode 102 is formed on the glass substrate 101, the gate electrode 102 is covered on the glass substrate 101, and the gate insulating layer 103 is formed. The silicon film 104, the n + silicon film 105, and the metal film 106 are sequentially deposited and stacked on the insulating film 103.

Next, a positive photoresist is applied on the metal film 106 to form a resist film 107. As shown in FIG. 9B, the resist film 107 is applied to the resist film 107 through a gray mask 201. The exposure light is irradiated. 9 is a plan view of a gray tone mask. The light shielding portion 204 is formed as an opposing portion of the source electrode and the drain electrode to correspond to an area adjacent to the channel portion, and the remaining portions of the source electrode and the drain electrode are formed of the translucent portion 203, and between the source electrode and the drain electrode. The channel portion is formed of the light transmitting portion 205.

Next, when developing the positive photoresist after exposure, the part of the back mask pattern 107a hardly melt | dissolves, the part of the thin mask pattern 107b melt | dissolves to some extent, and all other parts melt | dissolve. It disappears. As a result, as shown in Fig. 9C, after the film thickness is thick, the mask pattern 107a and the thin film mask pattern 107b can be formed simultaneously.

Next, etching is performed using the post mask pattern 107a and the thin mask pattern 107b as a mask, and the ohmic contact layers 105a and 105b and the source on the silicon film 104 as shown in Fig. 9D. The electrode 106a and the drain electrode 106b are formed.

After the ohmic contact layers 105a and 105b are formed, the post mask pattern 107a and the thin mask pattern 107b are reflowed by heating or the like. Accordingly, each mask pattern, which is an organic resin, is widened to the silicon film 104 plane, and on the silicon film 104 between the ohmic contact layer 105a and the ohmic contact layer 105b, the back mask pattern 107a and the thin mask pattern ( 107b is connected, and a reflow mask pattern 108 is formed as shown in the plan views of Figs. 9E and 11. 9 (e) shows the x-x cross section of FIG.

Next, the silicon layer 104 is etched and removed using the reflow mask pattern 108 as a mask, and the ohmic contact layers 105a and 105b and the source electrode on the semiconductor island are removed. 106a, the state in which the drain electrode 106b is formed is obtained (not shown). Thereafter, a protective film is formed, and contact holes are respectively formed on the source electrode 106a and the drain electrode 106b and connected to the pixel electrode and the drain electrode 106b connected to the source electrode 106a at the bottom of these contact holes. Terminal electrode is formed (not shown).

Japanese Patent Laid-Open No. 2002-261078 discloses a gray tone mask in which a region except for opposing portions of a source electrode and a drain electrode is a semi-transmissive portion.

As described in Japanese Patent Laid-Open No. 2002-261078, the gray tone mask in which the region except the opposing portions of the source electrode and the drain electrode is a semi-transmissive portion has a large area where the semi-transmissive portion occupies, so that the resolution of the exposure apparatus in which the mask is used. When the semi-transmissive portion is formed by a smaller fine pattern, there is a problem in that the uniform transmittance distribution in the semi-transmissive portion is deteriorated unless a highly precise fine pattern can be obtained.

For this reason, assuming that the semi-transmissive portion is formed of a semi-transmissive film, for example, a structure as shown in Fig. 12 can be considered.

The gray tone mask 200 shown in FIG. 12A has a structure in which the light shielding portion is formed of a semi-transmissive film and a light shielding film thereon (hereinafter, referred to as conventional structural example A). The gray tone mask of the conventional structural example A can be manufactured by the method shown in FIG. 14 (it calls a conventional manufacturing example A hereafter).

That is, the mask blank 214 in which the translucent film 212 and the light shielding film 213 were formed one by one is prepared first (refer FIG. 14 (a)).

Next, for example, a positive resist for electron beam or laser drawing is applied on the mask blank 214 and baked to form a resist film 215 (see Fig. 14 (b)). Next, drawing is performed using an electron beam drawing machine, a laser drawing machine, or the like. After drawing, this is developed to form a resist pattern 215a on the mask blank (see Fig. 14 (c)).

Next, the light shielding film 213 is etched using the formed resist pattern 215a as a mask, and then the semi-transmissive film 212 is etched. The remaining resist pattern 215a is removed using ashing with oxygen or concentrated sulfuric acid (see Fig. 14 (d)).

Next, the resist is applied to the entire surface again to form a resist film 216 (see Fig. 14E). Then, the second drawing is performed. After drawing, this is developed to form a resist pattern 216b for forming a light shielding film pattern (see Fig. 14 (f)). Next, the light shielding film on the translucent film exposed using the formed resist pattern 216b as a mask is removed by etching. Thereby, the light shielding portion is partitioned from the semi-transmissive portion to form the semi-transmissive portion and the light-shielding portion (see Fig. 14G). The remaining resist pattern is removed using oxygen ashing or the like (see Fig. 14 (h)).

In the conventional manufacturing example A described above, in etching the light shielding film shown in Fig. 14G, it is necessary that the underlying semitransmissive film has resistance to the etching of the light shielding film. For this reason, the light shielding film and the semi-transmissive film need to select a combination of materials having different etching characteristics, and thus there is a problem that the range of material selection is limited.

Next, in the gray tone mask shown in Fig. 12B, the light shielding portion is formed of a light shielding film and a semi-transmissive film thereon (hereinafter referred to as conventional manufacturing example B). The gray tone mask of the conventional manufacture example B can be manufactured by the method shown in FIG. 15 (it calls the following manufacture example B-1 hereafter).

That is, the mask blank 224 in which the light shielding film 213 was formed on the transparent substrate 211 is prepared first (refer FIG. 15 (a)).

On this mask blank 224, for example, a positive resist for laser or electron beam drawing is applied and baked to form a resist film 215. Next, drawing is performed using an electron beam drawing machine, a laser drawing machine, or the like. After drawing, this is developed to form a first resist pattern 215a corresponding to the light transmissive portion sandwiched between the light shielding portion and the light shielding portion on the mask blank (see Fig. 15 (b)).

Next, the light shielding film 213 is wet or dry etched using the formed first resist pattern 215a as a mask to form a pattern 213a corresponding to the light shielding portion (see FIG. 15C). The remaining resist pattern 215a is removed using ashing with oxygen or concentrated sulfuric acid (see Fig. 15 (d)).

Next, a semi-transmissive film 212 is formed over the entire surface (see FIG. 15 (e)). Subsequently, a resist is applied on the translucent film 212 and a resist film 216 for forming a translucent film pattern is formed (see Fig. 15 (f)). Then, the second drawing is performed. After drawing, this is developed and at least a second resist pattern 216a corresponding to the translucent portion is formed (see Fig. 15G).

Next, using the formed resist pattern 216a as a mask, the semi-transmissive film 212 and the light-shielding film 213a in the region to be the light-transmitting part are continuously removed by wet or dry etching, and the semi-transmissive film pattern 212a and the light-shielding film are removed. The pattern 213b is formed. Accordingly, the transflective portion and the light shielding portion are partitioned from the transmissive portion to form the translucent portion, the light shielding portion, and the light transmitting portion. The remaining resist pattern is removed using oxygen ashing or the like (see Fig. 15 (h)).

According to the above-described conventional production example B-1, the semi-transmissive portion is formed directly on the transparent substrate exposing the region corresponding to the semi-transmissive portion, so that when the semi-transmissive portion is formed as in the conventional Structural Example 1, Since only the light shielding film is removed by etching and there is no need to expose the underlying semi-transmissive film, the light-shielding film and the semi-transmissive film may be formed together with a film material having the same or similar etching characteristics as, for example, a chromium / chromium compound. The choice of materials is broadened. However, in forming the light-transmitting portion corresponding to the channel portion, when the light-shielding film and the semi-transmissive film were etched continuously, it was difficult to form a pattern having a good cross-sectional shape of the pattern because the total film thickness of the light-shielding film and the semi-transmissive film was increased. . In particular, when a light shielding film with an antireflection film is used as the light shielding film, the etching rate is different between the lower layer portion and the portion of the antireflection layer. In such a case, it is possible to control the light shielding film material and the etching conditions so that the pattern cross-sectional shape at the time of etching the light shielding film in consideration of the surface antireflection layer is difficult to control in the laminated film with the semi-transmissive film. As a result, there was a problem in that a pattern corresponding to the channel portion with high precision could not be formed, which adversely affected the characteristics of the TFT when used for manufacturing the TFT.

Moreover, as a manufacturing method of the conventional structural example 2, there exists a method shown in FIG. 16 as follows (it is called a conventional structural example B-2 hereafter).

That is, the mask blank 224 in which the light shielding film 213 was formed on the transparent substrate 211 is prepared (refer FIG. 16 (a)).

On this mask blank, the resist film 215 is formed by apply | coating and baking, for example, the positive resist for laser or electron beam drawing. Next, drawing is performed using an electron beam drawing machine, a laser drawing machine, or the like. After drawing, this is developed to form a first resist pattern 215a corresponding to the light shielding portion on the mask blank (see Fig. 16 (b)).

Next, the light shielding film 213 is wet or dry etched using the formed first resist pattern 215a as a mask to form a pattern 213a corresponding to the light shielding portion (see FIG. 16C). The remaining resist pattern 215a is removed using ashing with oxygen, concentrated sulfuric acid, or the like (see Fig. 16 (d)).

Next, a semi-transmissive film 212 is formed over the entire surface (see FIG. 16 (e)). Subsequently, a resist is applied on the translucent film 212 to form a resist film 216 for forming a translucent film pattern (see FIG. 16 (f)). Then, the second drawing is performed. After drawing, this is developed to form at least a second resist pattern 216a corresponding to the semi-transmissive portion (see Fig. 16G).

Next, using the formed resist pattern 216a as a mask, the semi-transmissive film 212 in the region to be the light transmitting portion is removed by wet or dry etching. As a result, the transflective portion is partitioned from the transmissive portion to form the translucent portion and the transmissive portion. The remaining resist pattern 216a is removed using oxygen ashing or the like (see Fig. 16 (h)).

According to the above-described conventional production example B-2, as in the conventional production example B-1, the semitransmissive film and the light shielding film are not continuously etched when forming the transmissive portion corresponding to the channel portion, but only the translucent film is etched. The cross-sectional shape of a pattern can be set as a favorable pattern.

However, in the conventional preparation example B-2, it is necessary to use individual photolithography processes for the formation of the translucent portion and the formation of the light shielding portion. In this manner, when the second drawing is performed, the second drawing is performed by alignment so that the first drawing and the pattern difference do not occur. However, the alignment accuracy is limited and it is difficult to completely eliminate the alignment difference. Therefore, when the semi-transmissive part is used as the semi-transmissive film, there is a problem that a satisfactory pattern may not be obtained due to the difference in alignment between two writings.

It is an enlarged view of the part enclosed with the dotted line of FIG. 12 (B). FIG. 13A illustrates an example of no alignment difference, and FIGS. 13B and 13C illustrate an example in which the transflective portion 203 and the light shielding portion 204 of FIG. 13A cause positional differences. When the semi-transmissive portion causes a positional difference from side to side as in this example, there arises a problem that the width of the transmissive portion 205 corresponding to the channel portion is different from the design value and the characteristics of the TFT substrate change. As described above, there is a problem that a gray tone mask capable of accurately forming a channel portion which is particularly important in TFTs is not obtained.

The present invention has been made in view of the above circumstances and, like the gray tone mask of Japanese Patent Laid-Open No. 2002-261078, is a gray tone mask having a pattern adjacent to one direction in the order of the light transmitting portion, the light shielding portion, and the semi-transmissive portion. It is an object of the present invention to provide a gray tone mask and a method for producing a gray tone mask having good transmittance distribution of the light transmitting portion, good pattern cross-sectional shape of the light blocking portion adjacent to the light transmitting portion, and good pattern accuracy of the light transmitting portion.

In addition, the present invention relates to a gray tone mask of Japanese Laid-Open Patent Publication No. 2002-261078, that is, a light shielding portion formed at opposing portions of a source electrode and a drain electrode of a pattern corresponding to the source electrode and the drain electrode in a thin film transistor substrate, and a source electrode and a drain electrode. A step of manufacturing a thin film transistor substrate having a step of modifying at least a resist pattern formed by the light blocking portion, having a semi-transmissive portion formed in a portion other than the light blocking portion of A gray tone mask used in the present invention, which has a good transmittance distribution of the semi-transmissive portion, a good pattern cross-sectional shape of the light shielding portion adjacent to the transmissive portion corresponding to the channel portion, and a good pattern accuracy of the pattern corresponding to the channel portion. It is an object to provide a method for producing a tone mask and a gray tone mask.

(Configuration 1) A gray tone mask having a pattern consisting of a light blocking portion, a light transmitting portion, and a semi-transmissive portion, wherein the pattern has a pattern adjacent to one direction in the order of the light transmitting portion, the light blocking portion, and the semi-transmissive portion, and A light shielding part is laminated | stacked the light shielding film which forms a light shielding part, and the semi-transmission film | membrane formed in the area | region except the desired margin area | region on the light shielding part side in the adjoining part with the said light-transmitting part on this light shielding film.

(Configuration 2) Light shielding portions formed on opposing portions of the source and drain electrodes of a pattern corresponding to the source electrode and the drain electrode in the thin film transistor substrate, Semi-transmissive portions formed in portions other than the light shielding portions of the source electrode and the drain electrode; A gray tone mask used in a manufacturing process of a thin film transistor substrate having at least a light transmitting portion corresponding to a channel portion adjacent to the light blocking portion, wherein the light blocking portion is a light shielding film forming a light shielding portion, and a portion adjacent to the light transmitting portion on the light shielding film. The semi-transmissive film formed in the area | region except the desired margin area | region on the light-shielding part side in this invention is laminated | stacked.

(Configuration 3) A graytone mask having a pattern consisting of a light shielding portion, a light transmitting portion, and a semi-transmissive portion, and a method of manufacturing a graytone mask having a pattern adjacent to one direction in the order of the light transmitting portion, the light blocking portion, and the semi-transmissive portion. WHEREIN: The process of preparing the mask blank in which the light shielding film was formed on the transparent substrate at least, and drawing and developing a 1st drawing pattern in the 1st resist film for forming a light shielding film pattern, and forming a 1st resist pattern, and In order to form the light shielding part pattern forming process including the process of etching a light shielding film using a resist pattern as a mask, and then forming a semi-transmissive film on the transparent substrate in which the said light shielding part was formed, and then forming a semi-transmissive film pattern A second drawing pattern is drawn and developed on the second resist film formed on the translucent film to form a second resist pattern, and the second resist pattern is formed. And a semi-transmissive film pattern forming step including a step of etching the semi-transmissive film as a mask, wherein the first drawing pattern is a pattern corresponding to the light-shielding portion, and a second drawing pattern is the semi-transmissive portion and the light-shielding portion. It is a pattern corresponding to the area | region except the desired margin area | region on the light shielding part side at least in the adjacent part of a light shielding part and a light transmitting part, The manufacturing method of the gray tone mask characterized by the above-mentioned.

(Configuration 4) Light shielding portions formed on opposing portions of source and drain electrodes of patterns corresponding to source and drain electrodes in thin film transistor substrate, Semi-transmissive portions formed in portions other than light shielding portions of source and drain electrodes; A manufacturing method of a gray tone mask used in a manufacturing process of a thin film transistor substrate having at least a light transmitting portion corresponding to a channel portion adjacent to the light blocking portion, the method comprising: preparing a mask blank on which a light shielding film is formed on a transparent substrate; A light shielding part pattern forming step comprising a step of drawing and developing a first drawing pattern in a first resist film for forming a light shielding film pattern to form a first resist pattern, and etching the light shielding film using the first resist pattern as a mask. And subsequently forming a semi-transmissive film on the transparent substrate on which the light shielding portion is formed, and then semi-transmissive Forming a second resist pattern by drawing and developing a second drawing pattern on the second resist film formed on the translucent film to form a film pattern, and etching the semitransmissive film using the second resist pattern as a mask It has a semi-transmissive film pattern forming process, wherein the first drawing pattern is a pattern corresponding to the light shielding portion, the second drawing pattern is the semi-transmissive portion, at least in the light shielding portion and the light transmitting portion in the light shielding portion It is a pattern corresponding to the area | region except the desired margin area | region on the light-shielding part side of the gray tone mask manufacturing method characterized by the above-mentioned.

(Configuration 5) A graytone mask having a pattern consisting of a light shielding portion, a light transmitting portion, and a semi-transmissive portion, and a method of manufacturing a graytone mask having a pattern adjacent to one direction in the order of the light transmitting portion, the light shielding portion, and the semi-transmissive portion. A method of preparing a mask blank in which at least a translucent film and a light shielding film are laminated on a transparent substrate, and drawing and developing a first drawing pattern in a first resist film for forming a light shielding film pattern to form a first resist pattern. Forming a second light shielding portion pattern forming step including a step of etching the light shielding film using the first resist pattern as a mask; and a second drawing on the second resist film formed on the semitransmissive film to form the semitransmissive film pattern. A semi-transmissive film pattern type including a step of drawing and developing a pattern to form a second resist pattern, and etching the semi-transmissive film using the second resist pattern as a mask. And a first drawing pattern is a pattern corresponding to the light shielding portion, and a second drawing pattern is a desired margin on the side of the light-transmitting portion and at least the light-shielding portion in the light-shielding portion and adjacent to the light-transmitting portion. It is a pattern corresponding to the area | region except an area | region, The manufacturing method of a gray tone mask characterized by the above-mentioned.

(Configuration 6) Light shielding portions formed on opposing portions of source and drain electrodes in patterns corresponding to source and drain electrodes in thin film transistor substrate, Semi-transmissive portions formed in portions other than light shielding portions of source and drain electrodes; A method of manufacturing a gray tone mask for use in a manufacturing process of a thin film transistor substrate having at least a light transmitting portion corresponding to a channel portion adjacent to the light blocking portion, comprising: preparing a mask blank in which a semi-transmissive film and a light shielding film are laminated on a transparent substrate Process to do,

A light shielding part pattern forming process comprising a step of drawing and developing a first drawing pattern in a first resist film for forming a light shielding film pattern to form a first resist pattern, and etching the light shielding film using the first resist pattern as a mask. In order to form a semi-transmissive film pattern, a second drawing pattern is drawn and developed on a second resist film formed on the semi-transmissive film to form a second resist pattern, and the semi-transmissive light is formed using the second resist pattern as a mask. And a semi-transmissive film pattern forming step including a step of etching the film, wherein the first drawing pattern is a pattern corresponding to the light shielding portion, and the second drawing pattern is the semi-transmissive portion, at least the light-shielding portion in the light-shielding portion, and light-transmitting It is a pattern corresponding to the area | region except the desired margin area | region on the light shielding part side in a negative adjacent part, The manufacturing method of the gray tone mask characterized by the above-mentioned.

Hereinafter, the present invention will be described in detail with reference to Examples.

1 is a cross-sectional view showing a pattern near a source electrode and a drain electrode in a TFT substrate of a gray tone mask according to Embodiment 1 of the present invention, and FIG. 2 (a) is an enlarged view of a portion enclosed by a dotted line in FIG.

1 and 2, in the present embodiment, the light shielding film pattern 13a is formed on a region adjacent to the channel portion as an opposing portion of the source electrode and the drain electrode on the transparent substrate 11 such as quartz, and the source The semi-transmissive film pattern 12a is formed in the area | region on the light shielding film and the source electrode and the drain electrode part except the margin area 17 of the said electrode side in the adjoining part of an electrode, a drain electrode, and a channel part. That is, a portion laminated with the semi-transmissive film pattern 12a formed in the area on the light-shielding film except for the light-shielding film pattern 13a and the margin area 17 is a light-shielding portion, and a region in which a semi-transmissive film other than the light-shielding portion is formed is a semi-transmissive portion, a semi-transmissive film A region where neither the 12a nor the light shielding film 13a is formed is a light transmitting portion.

Next, a method of manufacturing the gray tone mask will be described with reference to FIG. 3.

In the present embodiment, first, as shown in FIG. 3 (a), a light shielding film 13 made of, for example, Cr-based material is formed on a large transparent substrate 11 having a main surface of 450 mm x 550 mm in size. The formed mask blank 14 is used.

On this mask blank, the positive resist for laser or electron beam drawing is apply | coated, for example, and it bakes, and the 1st resist film 15 for forming a light shielding film pattern is formed (refer FIG. 3 (b)). Next, drawing is performed using an electron beam drawing machine, a laser drawing machine, or the like. Drawing data (first drawing data) is pattern data corresponding to the light shielding film pattern 13a corresponding to the region adjacent to the channel portion as an opposing portion of the source electrode and the drain electrode shown in FIG. 2. After drawing, this is developed to form a first resist pattern 15a corresponding to the light shielding portion on the mask blank.

In the TFT substrate manufacturing process using the gray tone mask of the present embodiment, the source electrode and the drain electrode are formed on the gate electrode at predetermined intervals, similarly to the gray tone mask of Japanese Patent Laid-Open No. 2002-261078, so that the gate electrode and the source and Since it is necessary to align the drain electrode, it is necessary to set a mark (positioning mark at the time of exposure, a mark for checking position accuracy, etc.) related to alignment with the gate electrode on the mask. In this case, it is important that the channel portion sandwiched between the source electrode and the drain electrode is exactly aligned with the gate electrode, so that the mark having a correlation with the thin film pattern formed on the side of the channel portion of the source electrode and the drain electrode is marked with the pattern of the photomask. It is preferable to set out of the area. In the present invention, the thin film pattern formed on the most channel portion side of the source electrode and the drain electrode is a light shielding film pattern. Therefore, in the present embodiment, the mark is formed in the same manner as the formation of the light shielding film pattern by including the mark related to the alignment with the gate electrode in the drawing data (first drawing data) for forming the light shielding film pattern in the above-described process. In the same manner as in the light shielding film pattern, a mark pattern formed by the light shielding film can be formed.

Next, the light shielding film 13 is wet or dry etched using the formed first resist pattern 15a as a mask to form a pattern 13a corresponding to the light shielding portion (see FIG. 3C). If made of a light-shielding film 13, the Cr-based material, a wet etching, for example, nitric acid, ceric can be used for the ammonium and the etching liquid is diluted by mixing the oxygen salts and the like, dry etching, chlorine, such as Cl ₂ + O ₂ Dry etching gas containing a gas can be used. The remaining resist pattern 15a is removed using ashing with oxygen or concentrated sulfuric acid (see FIG. 3 (d)).

Next, a semi-transmissive film 12 is formed on the entire surface (see FIG. 3 (e)). Subsequently, a resist is applied on the translucent film 12 and a second resist film 16 for forming a translucent film pattern is formed (see FIG. 3 (f)). Then, the second drawing is performed. The drawing data (second drawing data) at this time is pattern data corresponding to the source electrode and the drain electrode except for the margin region 17 on the electrode side in the vicinity of the source electrode and the drain electrode and the channel portion. After drawing, this is developed to form at least the second resist pattern 16a corresponding to the translucent portion (see Fig. 3G). In addition, this margin area is made into the width | variety from the channel part side larger than the assumed alignment difference in consideration of the alignment precision of twice drawing. However, if the margin area is large, a high light reflection by the exposed light shielding film may be considered to be a problem when using the mask, so it is not preferable to make it larger than necessary. Therefore, in the present embodiment, it is preferable to set in the range of 0.1 ~ 1㎛.

Next, the semi-transmissive film 12 of the area | region used as a light transmission part is removed by wet or dry etching using the formed 2nd resist pattern 16a as a mask. As a result, the transflective portion is partitioned from the transmissive portion to form the translucent portion and the transmissive portion. In addition, the remaining resist pattern is removed using oxygen ashing or the like (see FIG. 3 (h)).

As described above, the gray tone mask 10 of the present embodiment shown in Fig. 1 is completed.

2 (b) and 2 (c) show a case in which the drawing by the first drawing pattern and the drawing by the second drawing pattern caused a difference in alignment with respect to the abnormal structure of FIG. 2 (a). As an example, FIG. 2 (b) shows an example in which the second drawing pattern is pushed to the middle right of the drawing with respect to the first drawing pattern, and FIG. 2 (c) shows an example in which the second drawing pattern is pushed to the left in the middle of the drawing with respect to the first drawing pattern. . As shown in these figures, in the gray tone mask in this embodiment, the second drawing data is the source electrode and the drain electrode except for the margin region 17 on the electrode side in the vicinity of the source electrode and the drain electrode and the channel portion. Since the semi-transmissive film pattern 12a is formed by setting a margin area on the channel part side by this, and the alignment difference occurs, the pattern dimension precision corresponding to the channel part is deteriorated. none.

Therefore, according to this embodiment, since an important pattern in TFT characteristics can be formed with high precision, a high quality gray tone mask can be provided.

Moreover, as a material of the light shielding film 13, it is preferable that a high light shielding property is obtained by a thin film, For example, Cr, Si, W, Al etc. are mentioned. In addition, the light shielding film 13 preferably has an antireflection layer made of, for example, an oxide of the metal on the front surface or the front surface and the rear surface thereof, so that the drawing accuracy at the time of laser drawing becomes good. In addition, the light shielding film 13 may be a multilayer film or a composition gradient film whose composition is changed in order to sequentially adjust the etching rate so that the cross-sectional shape by etching is improved. In addition, as the material of the semi-transmissive membrane 12, when the transmittance of the transmissive portion is 100% with a thin film, it is preferable that semi-transmittance of about 50% is obtained. For example, Cr compounds (oxides, nitrides, acids of Cr compounds) are obtained. Nitrides, fluorides, and the like), MoSi, Si, W, Al, and the like. Si, W, Al, etc. are materials with high light-shielding property or semi-translucent also obtained by the film thickness. In addition, since the light shielding part of the mask to be formed is laminated | stacked on the semi-transmissive film 12 and the light-shielding film 13, even if light-shielding film alone lacks light-shielding property, it may be sufficient that a light-shielding property is obtained when laminated | stacked with a semi-transmissive film. In addition, the transmittance here means the transmittance | permeability with respect to the wavelength of the exposure light of the exposure machine for large LCDs using a gray tone mask, for example. The transmittance of the translucent membrane need not be limited to about 50% at all. It is a matter of design to determine the extent to which the translucent portion is transmissive.

The material of the light shielding film 13 and the semi-transmissive film 12 may be the same or similar to each other, but the side-shielding of the light shielding film when the semi-transmissive film is etched and the light shielding film which is the base when the margin region is formed In consideration of the cutting of, it is preferable that the light shielding film is made of a material having resistance during the etching of the translucent film. In addition, in order to prevent the above-mentioned side etching and chipping of the base, an etching stopper layer may be provided before the semi-transmissive film is formed. As the etching stopper layer, for example, SiO ₂ or SOG (Spin on Glass) or the like can be used. These materials have good transmittance and may be left without being removed even if they are inserted into the semi-transmissive portion because their transmission properties are not impaired.

Next, Embodiment 2 of the present invention will be described. In addition, Example 2 is an example which applied this invention to the manufacturing method of the gray tone mask of the structure shown to FIG. 11 (A).

The mask blank 24 used in this embodiment has a light shielding film material and etching selectivity on a large transparent substrate 11 having a main surface of 450 mm x 550 mm, made of quartz or the like as shown in Fig. 4A. The semi-transmissive film 12 made of a branched material and the light shielding film 13 made of, for example, a chromium-based material are sequentially formed.

The mask blank 24 is obtained by sequentially forming the translucent film 12 and the light shielding film 13 on the transparent substrate 11, and the film forming method is a film type such as vapor deposition, sputtering, chemical vapor deposition (CVD), or the like. What is necessary is just to select the method suitable for. There is no restriction | limiting in particular regarding a film thickness, However, It is important to form it in the film thickness optimized so that favorable light-shielding property or translucent property may be obtained.

Next, for example, a positive resist for electron beam or laser drawing is applied on the mask blank 24 and baked to form a first resist film 15 for forming a light shielding film pattern (Fig. 4 (b)). Reference). Next, drawing is performed using an electron beam drawing machine, a laser drawing machine, or the like. Drawing data (first drawing data) is pattern data corresponding to the light shielding film pattern 13a corresponding to the region adjacent to the channel portion as an opposing portion of the source electrode and the drain electrode shown in FIG. 2. After drawing, this is developed to form a first resist pattern 15a corresponding to the light shielding portion on the mask blank (see Fig. 4 (b)).

In addition, about formation of the mark which concerns on alignment with a gate electrode, in the said process, the writing data (1st drawing data) for forming a light shielding film pattern includes the mark which concerns on alignment with a gate electrode, and includes a semi-transmissive film The mark is formed at the same time as the pattern is formed, and in the subsequent step, the mark pattern formed by the semi-transmissive film can be formed similarly to the semi-transmissive film pattern.

Next, the light shielding film 13 is dry-etched using the formed resist pattern 15a as a mask to form a light shielding film pattern 13a corresponding to the light shielding portion (see FIG. 4C). When the light shielding film 13 is made of a Cr-based material, dry etching using chlorine gas can be used. Except for the region corresponding to the light shielding portion, the semi-transmissive film 12 underlying is exposed by etching of the light shielding film 13. The remaining resist pattern 15a is removed using ashing with oxygen or concentrated sulfuric acid (see FIG. 4 (d)).

Next, the resist is applied to the entire surface again to form a second resist film 16 (see Fig. 4E). Then, the second drawing is performed. The drawing data (second drawing data) at this time is pattern data corresponding to the source electrode and the drain electrode except for the margin region 17 on the electrode side in the vicinity of the source electrode and the drain electrode and the channel portion shown in FIG. to be. After drawing, this is developed to form a resist pattern 16a for forming a semi-transmissive film pattern (see Fig. 4 (f)). In addition, the width | variety of this margin area | region is the same as Example 1. FIG.

Next, using the formed resist pattern 16a and the light shielding film pattern 13a as a mask, the semi-transmissive film 12 of the area | region used as a light transmission part is removed by dry etching. In this case, since the light shielding film pattern 13a is resistant to the etching of the semitransmissive film 12, the semitransmissive film 12 is etched along the light shielding film pattern 13a. As a result, the transflective portion is partitioned from the transmissive portion to form the translucent portion and the transmissive portion (see FIG. 4 (g)). The remaining resist pattern is removed using oxygen ashing or the like (see Fig. 4 (h)).

The gray tone mask of this embodiment is completed as mentioned above.

FIG. 5 is an enlarged view of a portion surrounded by the dotted lines in FIGS. 4F and 4G. In the above method for the abnormal structure of FIG. 5A, the drawing by the first drawing pattern and the second drawing pattern are performed. Fig. 5 (b) shows the second drawing pattern right in the center of the drawing with respect to the first drawing pattern, and Fig. 5 (c) shows the second drawing with respect to the first drawing pattern. The drawing pattern is an example of being pushed to the center left of the drawing. As shown in these figures, in the gray tone mask in this embodiment, the second drawing data is the source electrode and the drain electrode except for the margin region 17 on the electrode side in the vicinity of the source electrode and the drain electrode and the channel portion. This is pattern data corresponding to, and accordingly, the margin area is set on the channel portion side and the second resist pattern 16a is formed. Therefore, even if an alignment difference occurs, the pattern dimension precision corresponding to the channel portion is not deteriorated.

FIG. 6 is a diagram showing a case where pattern data corresponding to the source electrode and the drain electrode is used without setting a margin area in the second drawing pattern of the method for comparison. That is, with respect to the abnormal structure of Fig. 6 (a), it is an example assuming a case in which the drawing by the first drawing pattern and the drawing by the second drawing pattern caused a difference in alignment in the above method, and Fig. 6 (b) shows the first With respect to the drawing pattern, the second drawing pattern is pushed to the right in the middle of the drawing, and FIG. 6 (c) shows an example in which the second drawing pattern is pushed to the left in the middle of the drawing with respect to the first drawing pattern.

In the example in which the margin area is not set as shown in these figures, the pattern precision corresponding to the channel portion is deteriorated by the occurrence of alignment difference.

As described above, according to the present embodiment, since a pattern important for TFT characteristics is formed with high precision, a high quality gray tone mask can be provided.

In addition, in the said Example 2, the material similar to Example 1 can be used as a material of the light shielding film 13 and the material of the translucent film 12. However, the combination of the materials of the light shielding film 13 and the semi-transmissive film 12 is different in the etching characteristics of the mutual films, and in the etching environment of one film, the other film needs to be resistant. For example, in the case where the light shielding film 13 is formed of Cr and the translucent film 12 is formed of MoSi, the etching solution in which the Cr light shielding film is dry-etched using chlorine-based gas or mixed with dicerium ammonium nitrate and peroxygen salt is diluted. If wet etching is used, a high etching selectivity can be obtained between the underlying MoSi translucent film, and thus it is possible to remove only the Cr light shielding film by etching with little harm to the MoSi translucent film. Moreover, when the said light shielding film 13 and the translucent film 12 are formed into a film on a board | substrate, it is preferable that adhesiveness is favorable.

In addition, the material of the light shielding film 13 and the translucent film 12 may mutually have the same or similar etching property, and the mask blank which provided the etching stopper layer between the transflective film 13 and the light shielding film 12 can also be used. have. As the etching stopper layer, for example, SiO ₂ or spin on glass (SOG) or the like can be used. Since these materials have good transmittance and do not impair their transmissive properties even if they are inserted into the translucent portion, they can be left without being removed.

In addition, in the above-described embodiment, an example in which the margin area is set only on the channel part side of the light shielding part has been described. As shown in FIG. 7, the margin area 18 is also set for the other parts adjacent to the light shielding part and the light transmitting part. It's okay. By setting the margin area 18, even when an alignment difference occurs in the Y direction, the semi-transmissive film can be prevented from protruding from the light shielding portion.

In addition, in the above embodiment, a gray tone mask for manufacturing a TFT substrate of Japanese Patent Application Laid-Open No. 2002-261078 is exemplified. In the present invention, a gray tone mask having a pattern adjacent to one direction in the order of a light transmitting portion, a light blocking portion, and a semi-light transmitting portion is shown. Applicable to

According to the gray tone mask of the present invention, a gray tone mask having a pattern adjacent in one direction in order of the light transmitting portion, the light blocking portion, and the semi-transmissive portion, and the transmittance distribution of the semi-transmissive portion can be obtained by forming the semi-transmissive portion as a semi-transmissive film. . In addition, since the light shielding portion adjacent to the light transmitting portion is formed by etching only the light shielding film, a pattern having a good cross-sectional shape of the light shielding portion adjacent to the light transmitting portion is obtained. In addition, since the light shielding portion is formed by laminating the light shielding film forming the light shielding portion and a semi-transmissive film formed on the light shielding film in a region excluding a desired margin area on the light shielding portion side adjacent to the light transmitting portion, the pattern precision of the light transmitting portion is A good gray tone mask can be obtained.

Further, according to the gray tone mask of the present invention, the light shielding portion formed in opposing portions of the source electrode and the drain electrode of the pattern corresponding to the source electrode and the drain electrode in the thin film transistor substrate, and the portion other than the light shielding portion of the source electrode and the drain electrode A gray tone mask used in a manufacturing process of a thin film transistor substrate having a semi-transmissive portion formed and a transmissive portion formed in another region including a portion corresponding to a channel portion. You can get it. In addition, since the light shielding portion adjacent to the light transmitting portion is formed by etching only the light shielding film, a pattern having a good cross-sectional shape of the light shielding portion adjacent to the channel portion is obtained. Further, since the light shielding portion is formed so that the light shielding film forming the light shielding portion and the semi-transmissive film formed on the light shielding film in a region other than the desired margin area on the light shielding portion side in the vicinity of the light transmitting portion are laminated. A gray tone mask with good pattern accuracy of the light transmitting portion can be obtained.

Further, according to the manufacturing method of the gray tone mask of the present invention, a gray tone mask having a pattern adjacent in one direction in order of the light transmitting portion, the light blocking portion, and the semi-transmissive portion, and the semi-transmissive portion is formed by forming the semi-transmissive portion as a semi-transmissive film. The transmittance distribution can be obtained. In addition, since the light shielding portion adjacent to the light transmitting portion is formed by etching only the light shielding film, a pattern having a good cross-sectional shape of the light shielding portion adjacent to the light transmitting portion is obtained. Further, the second drawing data for forming the semi-transmissive film pattern may be a pattern corresponding to the semi-transmissive portion and the region except the desired margin region on the light-shielding portion side at least in the light-shielding portion and adjacent portions of the light-shielding portion. A gray tone mask having good pattern accuracy of the light transmitting portion can be produced.

Further, according to the method for manufacturing a gray tone mask, a light shielding portion formed on opposing portions of the source electrode and the drain electrode of a pattern corresponding to the source electrode and the drain electrode in the thin film transistor substrate, and the light shielding portion of the source electrode and the drain electrode A method of manufacturing a gray tone mask used in a manufacturing process of a thin film transistor substrate having a semi-transmissive portion formed in a portion and a transmissive portion formed in another region including a portion corresponding to a channel portion, wherein the semi-transmissive portion is formed by a semi-transmissive film. The transmittance distribution of the light transmitting portion can be obtained. In addition, since the light shielding portion adjacent to the light transmitting portion is formed by etching only the light shielding film, a pattern having a good cross-sectional shape of the light shielding portion adjacent to the channel portion is obtained. Further, the second drawing data for forming the semi-transmissive film pattern may be a pattern corresponding to the semi-transmissive portion and the region except the desired margin region on the light-shielding portion side at least in the light-shielding portion and adjacent portions of the light-shielding portion. A gray tone mask with good pattern precision of the channel portion can be produced.

Claims (6)

In a gray tone mask having a pattern consisting of a light shielding portion, a light transmitting portion, and a semi-light transmitting portion, The pattern has a pattern adjacent in one direction, in order of a light transmitting portion, a light blocking portion, and a semi-light transmitting portion, and the light blocking portion is formed on the light blocking portion on the light blocking film and adjacent to the light transmitting portion on the light blocking portion. A gray tone mask, characterized in that a semi-transmissive film formed in a region excluding a desired margin region is laminated. A light shielding portion formed in opposing portions of the source electrode and the drain electrode of a pattern corresponding to the source electrode and the drain electrode in the thin film transistor substrate, a semi-transmissive portion formed in a portion other than the light shielding portion of the source electrode and the drain electrode, and the light shielding portion; A gray tone mask used in a manufacturing process of a thin film transistor substrate having at least a light transmitting portion corresponding to an adjacent channel portion, And the light shielding film forming the light shielding portion, and a semi-transmissive film formed on the light shielding film in a region excluding a desired margin area on the light shielding portion side adjacent to the light transmitting portion. A gray tone mask having a pattern consisting of a light blocking portion, a light transmitting portion, and a semi-transmissive portion, the method of manufacturing a raytone mask having a pattern adjacent in one direction in order of the light transmitting portion, the light blocking portion, and the semi-transmissive portion, Preparing a mask blank on which a light shielding film is formed, on a transparent substrate; A light shielding part pattern forming step comprising a step of drawing and developing a first drawing pattern in a first resist film for forming a light shielding film pattern to form a first resist pattern, and etching the light shielding film using the first resist pattern as a mask. Wow, Next, forming a translucent film on the transparent substrate on which the light shielding portion is formed, Subsequently, in order to form a semi-transmissive film pattern, a second drawing pattern is drawn and developed on the second resist film formed on the semi-transmissive film to form a second resist pattern, and the second resist pattern is used as a mask. It has a semi-transmissive film pattern forming step comprising the step of etching the light-transmitting film, The first drawing pattern is a pattern corresponding to the light shielding portion, and the second drawing pattern is in a region excluding the semi-transmissive portion and a desired margin area on the light shielding portion side at least in the light shielding portion in the light shielding portion and adjacent to the light transmitting portion. It is a corresponding pattern, The manufacturing method of a gray tone mask characterized by the above-mentioned. A light shielding portion formed in opposing portions of the source electrode and the drain electrode of a pattern corresponding to the source electrode and the drain electrode in the thin film transistor substrate, a semi-transmissive portion formed in a portion other than the light shielding portion of the source electrode and the drain electrode, and the light shielding portion; A manufacturing method of a gray tone mask used in a manufacturing process of a thin film transistor substrate having at least a light transmitting portion corresponding to an adjacent channel portion, Preparing a mask blank on which a light shielding film is formed, on a transparent substrate; A light shielding part pattern forming step comprising a step of drawing and developing a first drawing pattern in a first resist film for forming a light shielding film pattern to form a first resist pattern, and etching the light shielding film using the first resist pattern as a mask. Wow, Forming a translucent film on the transparent substrate on which the light shielding portion is formed; In order to form a semi-transmissive film pattern, a second drawing pattern is drawn and developed on a second resist film formed on the semi-transmissive film to form a second resist pattern, and the semi-transmissive film is formed using the second resist pattern as a mask. It has a semi-transmissive film pattern forming step comprising the step of etching, The first drawing pattern is a pattern corresponding to the light shielding portion, and the second drawing pattern is in a region excluding the semi-transmissive portion and a desired margin area on the light shielding portion side at least in the light shielding portion in the light shielding portion and adjacent to the light transmitting portion. It is a corresponding pattern, The manufacturing method of a gray tone mask characterized by the above-mentioned. A gray tone mask having a pattern consisting of a light blocking portion, a light transmitting portion, and a semi-transmissive portion, the method of manufacturing a gray tone mask having a pattern adjacent in one direction in order of the light transmitting portion, the light blocking portion, and the semi-transmissive portion, Preparing a mask blank in which at least a translucent film and a light shielding film are laminated on a transparent substrate, Forming a first resist pattern by forming and developing a first drawing pattern on the first resist film for forming the light shielding film pattern, and forming a first resist pattern, and etching the light shielding film using the first resist pattern as a mask. Wow, In order to form a semi-transmissive film pattern, a second drawing pattern is drawn and developed on a second resist film formed on the semi-transmissive film to form a second resist pattern, and the semi-transmissive film is etched using the second resist pattern as a mask. It has a semi-transmissive film pattern forming step comprising a step of, The first drawing pattern is a pattern corresponding to the light shielding portion, and the second drawing pattern is in a region excluding the semi-transmissive portion and a desired margin area on the light shielding portion side at least in the light shielding portion in the light shielding portion and adjacent to the light transmitting portion. It is a corresponding pattern, The manufacturing method of a gray tone mask characterized by the above-mentioned. A light shielding portion formed in opposing portions of the source electrode and the drain electrode of a pattern corresponding to the source electrode and the drain electrode in the thin film transistor substrate, a semi-transmissive portion formed in a portion other than the light shielding portion of the source electrode and the drain electrode, and the light shielding portion; A manufacturing method of a gray tone mask used in a manufacturing process of a thin film transistor substrate having at least a light transmitting portion corresponding to an adjacent channel portion, Preparing a mask blank in which at least a translucent film and a light shielding film are laminated on a transparent substrate, Forming a first resist pattern by forming and developing a first drawing pattern on the first resist film for forming the light shielding film pattern, and forming a light shielding part pattern comprising etching the light shielding film using the first resist pattern as a mask Steps, In order to form a semi-transmissive film pattern, a second drawing pattern is drawn and developed on a second resist film formed on the translucent film to form a second resist pattern, and the semi-transmissive film is etched using the second resist pattern as a mask. It has a semi-transmissive film pattern forming step comprising a step of, The first drawing pattern is a pattern corresponding to the light shielding portion, and the second drawing pattern is in a region excluding the semi-transmissive portion and a desired margin area on the light shielding portion side at least in the light shielding portion in the light shielding portion and adjacent to the light transmitting portion. It is a corresponding pattern, The manufacturing method of a gray tone mask characterized by the above-mentioned.

Images