TWI388923B - Defect repairing method for a gray tone mask and gray tone mask - Google Patents

Description

Gray scale mask defect correction method and gray scale mask

The present invention relates to a defect correction method for a graytone mask used in the manufacture of a thin film transistor (hereinafter referred to as TFT) of a liquid crystal display device (hereinafter referred to as LCD), and gray scale light. cover.

An LCD having a TFT is currently rapidly commercialized because it has advantages such as being easy to be thinner and lower in power consumption than a CRT (cathode ray tube). The LCD system has a structure in which a TFT substrate having a structure in which TFTs are arranged on each pixel arranged in a matrix, and a color filter in which a pixel pattern of red, green, and blue are arranged corresponding to each pixel , stacked with a liquid crystal phase. Such an LCD has a large number of manufacturing steps, and the optical TFT substrate is manufactured by using 5 to 6 reticle.

In view of the above circumstances, a method of manufacturing a TFT substrate using four masks has been proposed. In this method, the number of masks used is reduced by a photomask having a light shielding portion, a light transmitting portion, and a gray scale portion (hereinafter referred to as a gray scale mask).

A conventional example of a manufacturing procedure of a TFT substrate using a gray scale mask will be described with reference to FIGS. 1 and 2 .

First, a metal film for a gate electrode is formed on the glass substrate 1. Next, the gate electrode 2 is formed on the glass substrate 1 by performing a photolithography step using a photomask on the metal film for the gate electrode. Thereafter, the gate insulating film 3, the first semiconductor film (a-Si) 4, the second semiconductor film (N+a-Si) 5, the source-drain metal film 6, and the positive-type photoresist film 7 are formed ( Figure 1A).

Next, the photoresist film 7 is exposed and developed using the gray scale mask 100 having the light shielding portion 101, the light transmitting portion 102, and the gray scale portion 103. Thereby, as shown in FIG. 1B, the first photoresist pattern 7A is formed. The first photoresist pattern 7A covers the TFT channel portion formation region, the source-drain formation region, and the data line formation region, and covers the film thickness ratio of the photoresist film forming region of the TFT channel portion. The film thickness of the photoresist film covering the source-drain formation region is thinner.

Further, the source-drain metal film 6 and the second and first semiconductor films 5 and 4 are etched by using the first photoresist pattern 7A as a mask (FIG. 1C).

Next, the photoresist film 7 on which the first photoresist pattern 7A is formed is entirely reduced by ashing using oxygen to remove a thin photoresist film portion covering the TFT channel portion formation region, thereby forming a thin photoresist film portion. The second photoresist pattern 7B (Fig. 2A). Thereafter, the source/drain 6A/6B is formed by etching the source-drain metal film 6 by using the second photoresist pattern 7B as a mask, and then the TFT channel portion forming region is removed by etching. The second semiconductor film 5 (Fig. 2B). Finally, the photoresist film of the remaining second photoresist pattern 7B is peeled off (FIG. 2C).

As shown in FIG. 3, the gray scale mask 100 has light shielding portions 101A and 101B and a light transmission portion 102 corresponding to the source-drain formation region, and has a gray scale portion 103 corresponding to the TFT channel portion formation region. The gray scale portion 103 is a region formed by the light-shielding pattern 103A composed of a fine pattern having a resolution limit of a large LCD exposure machine using the gray scale mask 100. In general, the light shielding portions 101A and 101B and the light shielding pattern 103A are simultaneously formed of the same material such as chromium or a chromium compound. The resolution limit of a large LCD exposure machine using such a gray scale mask is about 3 μm under a stepper exposure machine and about 4 under a mirror projection exposure machine. μ m. Therefore, for example, in FIG. 3, the width of the penetration portion 103B in the gray scale mask portion 103 is less than 3 μm, and the line width of the light shielding pattern 103A is less than 3 μ below the resolution limit of the exposure machine. m.

Specifically, the gray pattern mask portion 103 of the fine pattern type described above is designed such that a fine pattern having a halftone effect between the light shielding portions 101A and 101B and the light transmitting portion 102 is selected as follows. : line and space type, or dot type, or other patterns. Furthermore, when selected as the line and pitch type, it must be considered, for example, how wide is the line width to be designed? What is the ratio of the part that penetrates the light and the part that blocks the light? The overall penetration rate should be set to what extent to complete the design? Wait a lot of factors to complete the design. Moreover, even in the manufacturing process of the gray scale mask, it is necessary to require, for example, the central value management of the line width, and the extremely difficult production technology control such as the line width error management in the mask.

For this reason, a method of forming a semi-transmissive film (halftone film) of a light-transmissive portion is proposed (for example, Patent Document 1: JP-A-2002-189280). The halftone exposure effect can be achieved by using a semi-transmissive film to reduce the amount of exposure. In the case of using a semi-transparent film, it is sufficient to design as long as it is necessary to review the overall transmittance. In the manufacturing process of the gray scale mask, the production of the gray scale mask can be performed by selecting the film type (film material) or film thickness of the semi-transmissive film. Therefore, in the manufacture of the gray scale mask, it is sufficient to control the film thickness of the semi-transmissive film, and it is easier to manage. Further, when the TFT channel portion is formed by the gray scale portion of the gray scale mask, if the semi-transmissive film is used, the patterning can be easily performed by the lithography imaging step, so that the shape of the TFT channel portion is complicated. The shape can also be carried out.

However, in the gray scale mask disclosed in Patent Document 1, when a white defect such as a peeling defect occurs in the gray scale portion composed of the semi-transmissive film, there are problems as described below. When a white defect occurs, the correction method used for the defect correction of the light-shielding film of the general mask is to use a method in which the light-shielding film is buried only in the defect portion, since only the portion in which the light-shielding film is buried becomes low transmittance, and finally There are other types of defects.

On the other hand, a method of embedding a semi-transparent film for correction in a defect portion by controlling the film thickness has also been proposed. However, in the case of using this method, it is difficult to align the position of the semi-transmissive film for correction, and in the case where the defect portion is too small, there is a problem that the semi-transmissive film for correction exceeds the defective portion.

Further, in the gray scale mask, when a black defect due to a light shielding film material or a foreign matter is generated in a gray scale portion composed of a semi-transmissive film, the semi-transparent for correction is embedded in the defective portion. In the case of the film, the same difficulty as described above is also caused.

Further, since the semi-transmissive film must have a characteristic of having an appropriate exposure light transmittance within a predetermined film thickness range, its composition is limited, so that even a laser which is applicable to localized film formation is required. In the CVD apparatus, it is also difficult to control, and the film thickness at the time of embedding the semi-transparent film for correction must be precisely controlled. For example, the film of the same material as the semi-transparent film used in the manufacture of the gray scale mask can be used other materials (materials having different transmittances) when it is not suitable for the local film formation method. ) It is very useful to make bug fixes.

SUMMARY OF THE INVENTION An object of the present invention is to provide a defect correction method for a gray scale mask, which can appropriately correct defects generated in a gray scale portion.

Another object of the present invention is to provide a gray scale reticle whose defects in the gray scale portion have been appropriately corrected.

Still further, another object of the present invention is to provide a gray scale mask having a gray scale portion composed of a fine pattern.

The present invention has been embodied by the following embodiments.

(First Embodiment) A method for correcting a defect of a gray scale mask for forming a photoresist pattern having a film thickness which is different in stages or continuously on a transfer target, and the gray scale mask has a function The step of shielding the light-shielding portion of the exposure light, the light-transmitting portion for allowing the exposure light to penetrate, and the gray-scale portion for reducing the penetration amount of the exposure light, the step comprising: a specific step of the corrected region, the gray-scale portion a step of forming a semi-transparent film to define a defective corrected region in the gray-scale portion; and a step of forming a fine pattern on the corrected region to form a follow-up The step of the fine pattern of the same gray scale effect of the normal gray scale portion in the gray scale portion.

(Second Embodiment) In the method of correcting a defect of the gray scale mask according to the first embodiment, the corrected region is a peeling defect generated in the gray scale portion after the gray scale mask is manufactured. a region, or a detached defect region formed by removing a region containing excess defects formed by a material for forming the light-shielding portion or a foreign matter generated in the gray-scale portion, or The semi-transmissive film for correction is partially formed after the formation of the light-shielding portion or the area of the unnecessary defect formed by the foreign matter generated in the gray-scale portion is removed, and then remains. Fall off the defect area.

(Third Embodiment) In the method of correcting a defect of the gray scale mask according to the first embodiment, the corrected region is a peeling defect generated in the gray scale portion after the gray scale mask is manufactured. a region containing the overlapping portion of the semi-transmissive film which is generated when the semi-transmissive film for correction is partially formed, or is contained in the above-mentioned gray-scale portion The overlapped defect region formed by the formation of the light-shielding portion or the region of the excess defect formed by the foreign matter is removed, and the semi-transmissive film is partially formed by the correction. Part of the area.

(Fourth Embodiment) In the method of correcting a defect of the gray scale mask according to the first or second embodiment, the step of forming the fine pattern further includes a step of forming a light shielding film for correction, which is performed by the gray A light-shielding film for correction is formed in a fine pattern on the region to be corrected which is formed by the detachment defect in the mask portion.

(Fifth Embodiment) In the method for correcting a defect of the gray scale mask according to the first or second embodiment, the step of forming the fine pattern further includes the step of: forming a correction light shielding film, a light-shielding film for correction is formed on the region to be corrected which is formed by the detachment defect in the gray scale mask portion; and the step of processing the micro-pattern is used to obtain the light-shielding film for correction The fine gray-scale effect of the normal gray-scale portion in the gray-scale portion is processed in a fine pattern.

(Sixth Embodiment) In the method of correcting a defect of the gray scale mask according to the fourth or fifth embodiment, the light shielding film for correction is made of the same material as that of the light shielding portion.

(Seventh Embodiment) In the method of correcting a defect of the gray scale mask according to the third embodiment, the step of forming the fine pattern further includes a step of processing in a fine pattern, and the gray scale mask portion is used The overlapping portion of the semi-transmissive film in the corrected region is processed in a fine pattern of the same gray scale effect as that of the normal gray-scale portion in the gray-scale portion.

(Embodiment 8) A method of manufacturing a gray scale mask includes the steps of correcting the defect correction method of the first to third, sixth, and seventh embodiments.

(Ninth embodiment) The present invention provides a gray scale mask for forming a photoresist pattern having a film thickness which is different in stages or continuously on a transfer target, and has a mask for masking exposure light. a light-shielding portion, a light-transmitting portion for allowing exposure light to pass through, and a gray-scale portion for reducing the amount of penetration of the exposure light, wherein the gray-scale portion is formed by a semi-transparent film; There is a corrected region in which the defect has been corrected; the corrected region has a fine pattern in which the same grayscale effect as that of the normal grayscale portion in the grayscale portion is obtained.

(Tenth Embodiment) In the gray scale mask according to the ninth embodiment, the light shielding portion is formed of a light shielding film, and the correction region is made of the same material as the light shielding film. A fine pattern is formed on the film formed.

(11th embodiment) a gray scale mask comprising: a light shielding portion; a light transmitting portion; and a gray scale portion for reducing the penetration amount of the exposure light used when the mask is used; wherein The gray scale portion further includes: a half-transmissive film portion formed of a semi-transparent film formed on the transparent substrate; and a light-shielding fine pattern portion formed of a light-shielding film formed with a fine pattern.

(Twelfth Embodiment) In the gray scale mask of the eleventh embodiment, the pattern of the light-shielding fine pattern portion is formed by regularly arranging unit patterns of the same shape.

(13th embodiment) a gray scale mask comprising: a light shielding portion; a light transmitting portion; and a gray scale portion for reducing the amount of penetration of the exposure light used in the use of the mask; The gray scale portion further includes a semi-transparent fine pattern portion which is formed on the transparent substrate and is composed of a semi-transparent film formed with a fine pattern.

According to a thirteenth embodiment of the present invention, in the gray scale mask of the thirteenth embodiment, the gray scale portion further includes: a semitransparent fine pattern portion which is attached to the transparent substrate and is semitransparent formed with a fine pattern. And a portion of the semi-transmissive film in which the fine pattern is not formed; wherein the film thickness of the semi-transmissive fine pattern portion is thicker than the semi-transmissive film in which the fine pattern is not formed.

(Fifteenth Embodiment) In the gray scale mask of the fourteenth embodiment, the semi-transmissive fine pattern portion further includes a portion in which a semi-transmissive film is laminated.

In a gray scale mask according to any one of the thirteenth to fifteenth aspects, the pattern of the semi-transmissive fine pattern portion is regularly arranged by a unit pattern of the same shape. Composition.

According to the first to seventh embodiments of the present invention, in the gray scale portion, the defective region to be corrected can be obtained in the same manner as the normal gray scale portion in the gray scale portion. The gray scale effect forms a fine pattern to correct the defect, and the corrected region that has been corrected has the same transmittance as the normal gray scale portion in the gray scale portion, so that the gray scale can be appropriately corrected. Defects caused by the steps.

Further, in the gray scale portion, the defect is corrected by forming the fine pattern on the corrected region where the defect is generated. Therefore, for example, the position alignment caused by the correction film being embedded in the peeling defect or the like is complicated. The work can be eliminated, and the above defects can be corrected in a short time and with high precision.

According to the ninth to sixteenth aspects of the present invention, the gradation portion formed by the semi-transmissive film has a corrected region in which the defect has been corrected, and the corrected region has a A fine pattern of the same gray scale effect in the normal gray scale portion in the gray scale portion. Therefore, the above-described corrected region has the same transmittance as the normal gray-scale portion in the gray-scale portion, so that the gray-scale mask in which the defects generated in the gray-scale portion have been appropriately corrected can be provided.

Moreover, the configuration of the gray scale portion may include a semi-transparent film, a light-shielding film in which a fine pattern has been formed, or a semi-transparent film in which a fine pattern has been formed, and the same gray scale effect can be obtained, and the yield is improved. The advantage of the rate.

Further, in the present invention, the local correction of the gray scale portion can be performed by the fine pattern, and since the light transmittance of the corrected portion can be determined in advance by the size or shape of the fine pattern, the gray scale portion is The light transmittance has a large degree of freedom, and an appropriate light-shielding film can be applied depending on the condition of the corrected portion. Therefore, it is easier to control the film formation control conditions such as the film thickness precision, compared to the case where the semi-transmissive film is locally formed.

Hereinafter, several embodiments of the present invention will be described.

[First Embodiment] (Fig. 4A, Fig. 4B, Fig. 5A to Fig. 5C)

4A and 4B are process diagrams showing a first embodiment of a defect correction method using the gray scale mask of the present invention. Fig. 5A shows a gray scale mask corrected by the defect correction method of the gray scale mask of Figs. 4A and 4B. Fig. 5B shows a gray scale mask and a to-be-transferred body at the same time, and Fig. 5C shows a gray scale mask of another form which is different from the gray scale mask shown in Fig. 5B.

The gray scale mask 10 shown in FIGS. 5A to 5C is used to manufacture a thin film transistor (TFT) and a color filter such as a liquid crystal display (LCD), or a plasma display panel (PDP). In short, the gray scale mask 10 is used to form a photoresist pattern 12 having a film thickness different in stages on the transfer target 11 as shown in FIG. 5B. Further, the photoresist pattern is formed in such a manner that the film thickness is continuously different. Further, reference numerals 19A and 19B in Fig. 5B show a film laminated on the light-transmitting substrate 16 in the transfer target body 11.

The gray scale mask 10, specifically, has a light shielding portion 13 for covering the exposure light (the transmittance is substantially 0%) when the gray scale mask 10 is used; allowing the exposure light to be worn by 100%. The light transmissive portion 14 and the gray scale portion 15 which reduces the transmittance of the exposure light to about 20 to 50%. The gray scale portion 15 is formed by forming a light transmissive semi-transmissive film 17 on a light-transmitting substrate 16 such as a glass substrate. Further, the light shielding portion 13 is formed on the light-transmitting substrate 16 and laminated by the semi-transmissive film 17 and the light-shielding light-shielding film 18. The light-shielding portion 13 is formed in the following order: on the light-transmitting substrate 16, in the order of the semi-transmissive film 17 and the light-shielding film 18 (FIG. 5B); or on the light-transmitting substrate 16, The light shielding film 18 and the semi-transmissive film 17 are sequentially formed (FIG. 5C).

The material of the semi-transmissive film 17 may, for example, be a chromium compound, MoSi, Si, W, Al or the like. The chromium compound may be chromium oxide (CrOx), chromium nitride (CrNx), chromium oxynitride (CrOxN), chromium fluoride (CrFx), or the like, or a substance containing carbon or hydrogen in the above compounds. On the other hand, examples of the material of the light shielding film 18 include Cr, Si, W, and Al. The transmittance of the light shielding portion 13 can be set according to conditions such as the semi-transmissive film 17 and the film material and film thickness of the light shielding film 18. Further, the transmittance of the gray scale portion 15 can be set in accordance with conditions such as the film material and film thickness of the semi-transmissive film 17.

When the gray scale mask 10 as described above is used, the exposure light is not penetrated at the light shielding portion 13, and the exposure light is weakened at the gray scale portion 15. As a result, the photoresist film (positive photoresist film) attached to the transfer target 11 has a thick film portion corresponding to the light shielding portion 13, and corresponds to a portion of the film thickness of the gray scale portion 15. It becomes thinner, and the portion corresponding to the light transmitting portion 14 becomes no film, and finally becomes the photoresist pattern 12 (Fig. 5B). In the photoresist pattern 12, the film thickness corresponding to the gray scale portion 15 becomes thinner, that is, the so-called "gray effect".

Next, in the portion where the photoresist pattern 12 has no photoresist film, when the first etching step is performed on, for example, the films 19A and 19B in the transfer target 11, the photoresist pattern 12 is removed by the ash removing step or the like. The thin portion of the resist film is subjected to a second etching step to, for example, the film 19B in the transfer target 11 at the removed portion. Thereby, a gray scale mask 10 can be used to achieve the effect that the conventional mask requires two mask steps to complete, and the number of masks is reduced.

However, in the gray scale portion 15 of the gray scale mask 10 described above, a defect correction method when a peeling defect (white defect) 20 as shown in Fig. 4A occurs is described below.

When the detachment defect 20 is generated in the gray scale portion 15 after the production of the gray scale mask 10, first, the region where the detachment defect 20 is generated is specified as the corrected region 21 (FIG. 4A). Next, in the corrected region 21, a plurality of correction light-shielding films 22 are formed in a fine pattern so that the same gray scale effect as that of the normal gray-scale portion in the gray scale portion 15 can be obtained (FIG. 4B) ).

The correction light shielding film 22 is formed by, for example, a laser CVD apparatus or the like, and arranged in a dot shape with a minimum size that can be formed. In this case, since the shape or position of the correction light shielding film 22 formed in a dot shape is not required to be tight, the laser CVD apparatus does not require a strict position alignment operation. The size or pitch of the correction light shielding film 22 is preferably fixed in advance. As a result, when the plurality of correction light-shielding films 22 are formed in two or more, strict alignment is not required, and workability can be improved.

Further, in this case, the light-shielding film for a correction pattern having a fine pattern shape is preferably formed by regularly arranging unit patterns of the same shape, and the periphery of the individual unit pattern is not adjacent to the gray scale portion and the above The boundary of the shading portion is preferred. This is because it is easier to control the gray scale portion within a certain range of transmittance.

Further, it is preferable that the fine pattern of the correction light-shielding film 22 having the same gray scale effect as that of the normal gray-scale portion in the gray scale portion 15 is formed as follows. That is, the transmittance of the corrected region 21 having the fine pattern is a photoresist film with respect to the photoresist pattern on the transferred body obtained by passing through the normal gray scale portion in the gray scale portion 15. The value is preferably such that a residual film of ±15% or less, more preferably ±10% or less is obtained.

The gray scale mask 10 having the detachment defect in the gray scale portion 15 has the corrected region 21 (Fig. 5A) in which the detachment defect has been corrected as described above. Therefore, the corrected region 21 whose flaw has been corrected becomes the same gray scale effect as that of the normal gray scale portion in the gray scale portion 15, and has a fine pattern-like correction as shown in Fig. 4B. The light shielding film 22 is used.

Since the gray scale mask of the first embodiment is configured as described above, the following effects (1) to (3) can be obtained.

(1) According to the defect correction method of the gray scale mask 10, the normal gray which follows the gray scale portion 15 can be obtained in the gray scale portion 15 on the corrected region 21 where the peeling defect 20 occurs. The correction light-shielding film 22 having a fine pattern is formed by the same gray scale effect in the step portion to correct the defect. After the correction, the corrected region 21 which has been corrected becomes the same transmittance as the normal gray-scale portion in the gray scale portion 15, and the peeling defect generated in the gray scale portion 15 can be appropriately corrected. 20.

(2) In the gray scale portion 15, the cut-off defect 20 is corrected by forming the fine-pattern correction light-shielding film 22 on the corrected region 21 in which the peeling defect 20 has occurred. As a result, for example, a complicated operation such as aligning the position where the correction film is embedded in the detachment defect 20 or the like can be eliminated, and the detachment defect 20 can be corrected in a short time and with high precision.

(3) The gray scale mask 10 has the corrected region 21 in which the peeling defect 20 has been corrected on the gray scale portion 15 formed by the semi-transmissive film 17. Then, the corrected region 21 to be corrected has a fine-patterned correction light-shielding film 22 which can obtain the same gray scale effect as the normal gray-scale portion of the gray scale portion 15. Therefore, the corrected region 21 that has been corrected has the same transmittance as the normal gray-scale portion in the gray-scale portion 15, so that the peeling defect 20 generated in the gray-scale portion 15 can be appropriately provided. Modified grayscale reticle 10.

[Second Embodiment] (Fig. 6A to Fig. 6C)

6A to 6C are process diagrams showing a second embodiment of the defect correction method using the gray scale mask of the present invention. In the second embodiment, the same portions as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted.

In the defect correction method of the gray scale mask of the second embodiment, after the gray scale mask 10 is manufactured, the area of the peeling defect 20 generated in the gray scale portion 15 is specified as the corrected region 21 ( Figure 6A). Next, film formation of the correction light shielding film 23 is performed on the entire region to be corrected 21 by, for example, a laser CVD apparatus (FIG. 6B). After that, the correction light-shielding film 23 is cut into a fine pattern by, for example, a laser repairing device so as to obtain the same gray scale effect as that of the normal gray-scale portion in the gray scale portion 15 (FIG. 6C). . Reference numeral 23A denotes a cut-out processed portion having a fine pattern shape.

Further, it is preferable to perform the cutting process of the fine pattern by the laser repairing device or the like to fix the size and the pitch of the cut portion. Further, the transmittance of the corrected region 21 (corrected region to be corrected) of the fine pattern formed by the correction light-shielding film 23 is also the same as that of the first embodiment (shading having a fine pattern) The transmittance of the corrected region 21 of the film 22 is preferably in the same range.

The gray scale mask 10 shown in FIG. 6A having the peeling defect 20 in the gray scale portion 15 becomes a gray scale as shown in FIG. 6C having the corrected region 21 in which the peeling defect 20 has been corrected as described above. Photomask 10. The corrected region 21 that has been corrected has a fine pattern in which the same gray scale effect as that of the normal gray scale portion in the gray scale portion 15 can be obtained.

Therefore, even in the second embodiment, the same effects as the effects (1) to (3) of the first embodiment described above can be achieved.

[Third embodiment] (Fig. 7A to Fig. 7D)

7A to 7D are process diagrams showing a third embodiment of the defect correction method using the gray scale mask of the present invention. In the third embodiment, the same portions as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted.

In the defect correction method of the gray scale mask of the third embodiment, the material forming the light shielding portion 13 (particularly the material forming the light shielding film 18) generated in the gray scale portion 15 of the gray scale mask 10, Or an unnecessary defect (black defect) 24 (Fig. 7A) composed of a foreign matter is targeted. First, the area containing the excess defect (black defect) 24 is removed by a laser repairing device or the like to form the falling defect 25, and the area in which the falling defect 25 has been formed is specified as the corrected area 26 (FIG. 7B).

Next, the filming of the correction light shielding film 27 is performed by the laser CVD apparatus or the like as a whole in the corrected region 26 (FIG. 7C). After that, the correction light-shielding film 27 is cut into a fine pattern by a laser repairing device or the like so as to obtain the same gray scale effect as that of the normal gray-scale portion in the gray scale portion 15 (FIG. 7D). Reference numeral 27A denotes a cut-out processed portion having a fine pattern shape.

The correction light-shielding film 27 may be the same material as the light-shielding film 18 of the light-shielding portion 13 as in the above-described correction light-shielding film 22, and other materials may be used. Further, as the semi-transmissive film, other semi-transmissive films having different transmittances from the semi-transmissive film 17 may be used. Further, since the fine pattern is cut by a laser repairing device or the like, the size and the pitch of the cut portion can be calculated and fixed in advance, which is preferable. Further, the transmittance of the corrected region 26 (corrected region to be corrected) of the fine pattern formed by the correction light shielding film 27 is also the same as that of the first embodiment (shading having a fine pattern) The transmittance of the corrected region 21 of the film 22 is preferably in the same range.

The gray scale mask 10 having the excess defect (black defect) 24 in the gray scale portion 15 as shown in FIG. 7A is as shown in FIG. 7D (the above-described modified region 26 having the excess defect 24 corrected). The gray scale reticle 10 shown in Fig. 5A). The corrected region 26 that has been corrected has a fine pattern in which the same gray scale effect as that of the normal gray scale portion in the gray scale portion 15 can be obtained.

Therefore, even in the third embodiment, the same effects as the effects (1) to (3) of the first embodiment described above can be achieved.

[Fourth embodiment] (Fig. 8A to Fig. 8C)

8A to 8C are process diagrams showing a fourth embodiment of the defect correction method using the gray scale mask of the present invention. In the fourth embodiment, the same portions as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted.

In the defect correction method of the gray scale mask of the fourth embodiment, first, after the manufacture of the gray scale mask 10, the correction is performed on the area of the peeling defect 20 (Fig. 8A) generated by the gray scale portion 15 Partial film formation was carried out using the semi-transmissive film 28 as shown in Fig. 8B. Then, the semi-transmissive film 17 (Fig. 5B or Fig. 5C) including the normal gray-scale portion of the gray-scale portion 15 and the semi-transparent film for correction are produced when the semi-transmissive film 28 for correction is formed. The region of the overlapping portion 29 of the film 28 is specified as the corrected region 30. Then, the overlapping portion 29 is cut into a fine pattern by a laser repairing device or the like so as to obtain the same gray scale effect as that of the normal gray-scale portion in the gray scale portion 15 (Fig. 8C). Reference numeral 29A denotes a cut-out processed portion having a fine pattern shape.

Further, since the fine pattern is cut by a laser repairing device or the like, the size and the pitch of the cut portion can be calculated and fixed in advance, which is preferable. Further, the transmittance of the corrected region 30 having the fine pattern formed in the overlapping portion 29 of the semi-transmissive film is also the same as that of the first embodiment (the modified light-shielding film 22 having the fine pattern) The penetration rate of 21 is preferably in the same range.

The gray scale mask 10 shown in FIG. 8A having the peeling defect 20 in the gray scale portion 15 is as shown in FIG. 8C (FIG. 5A) having the corrected region 30 in which the peeling defect 20 has been corrected as described above. The gray scale mask 10 is shown. The corrected region 30 that has been corrected has a fine pattern in which the same gray scale effect as that of the normal gray scale portion in the gray scale portion 15 can be obtained.

Therefore, even in the fourth embodiment, the same effects as the effects (1) to (3) of the first embodiment described above can be achieved.

[Fifth Embodiment] (Fig. 9A to Fig. 9E)

Figs. 9A to 9E are diagrams showing the steps of a fifth embodiment of the defect correcting method using the gray scale mask of the present invention. In the fifth embodiment, the same portions as those in the third embodiment (Figs. 7A to 7D) are denoted by the same reference numerals, and their description will be omitted.

In the method of correcting the defect of the gray scale mask of the fifth embodiment, first, the material including the light shielding portion 13 (particularly the material forming the light shielding film 18) or the foreign matter is contained in the same manner as in the third embodiment. The region of the unnecessary defect (black defect) 24 is removed by a laser repairing device or the like to form a peeling defect 25 (Figs. 9A and 9B). Next, the film formation of the correction semi-transmissive film 31 is performed on the area of the peeling defect 25. Then, the semi-transmissive film 17 (Fig. 5B or Fig. 5C) including the normal gray-scale portion of the gray scale portion 15 which is generated when the correction semi-transmissive film 31 is formed is semi-transparent for correction. The overlapping portion 32 of the film 31 and the region of the remaining defect 33 remaining further are specified as the corrected region 34 (Fig. 9C).

Next, the film of the correction light shielding film 35 is formed on the portion of the peeling defect 33 by, for example, a laser CVD apparatus (Fig. 9D). Thereafter, the overlapping portion 32 of the correcting light-shielding film portion 35 and the semi-transmissive film is applied to the same gray scale effect as the normal gray-scale portion in the gray-scale portion 15, and the respective suitable portions are applied. The size and pitch are cut into a fine pattern by a laser repairing device or the like (Fig. 9E). Reference numeral 32A denotes a fine-patterned cut-out portion provided in the overlapping portion 32 of the semi-transmissive film, and reference numeral 35A denotes a cut-out portion in the form of a fine pattern provided in the correction light-shielding film 35.

Further, the correction light shielding film 35 may be made of the same material as the light shielding film 18 of the light shielding portion 13, and other materials may be used. Further, a semi-transparent film for correction can also be used. Further, it is preferable to perform the cutting process of the fine pattern by the laser repairing device or the like, since the size and the pitch of the cut portion can be calculated in advance, and the value of the individual film quality can be fixed. In other words, the transmittance of the corrected region 34 having the fine pattern formed by the overlapping portion 32 of the semi-transmissive film and the correction light-shielding film 35 is also the same as that of the first embodiment (shading having a fine pattern) The transmittance of the corrected region 21 of the film 22 is preferably in the same range.

The gray scale mask 10 shown in FIG. 9A having the excess defect 24 in the gray scale portion 15 is as shown in FIG. 9E (FIG. 5A) having the corrected region 34 in which the excess defect 24 has been corrected as described above. The gray scale mask 10 is shown. The corrected region 34 that has been corrected has a fine pattern in which the same gray scale effect as that of the normal gray scale portion in the gray scale portion 15 can be obtained.

Therefore, even in the fifth embodiment, the same effects as the effects (1) to (3) of the first embodiment described above can be achieved.

The above description has been made only by a few embodiments of the present invention, but the present invention is not limited to the above embodiments.

For example, in each of the above embodiments, the correction light-shielding film 22, 23, 27 or 35 or the correction semi-transmissive film 28 or 31 is formed by a laser CVD apparatus, and a laser is used. The repairing apparatus will be described in the case where the above-described correction film is subjected to a process of cutting a fine pattern. However, FIB (Focused Ion Beam) can also be used for the filming of the above-mentioned correction light-shielding film 22, 23, 27, 35 or the correction semi-transmissive film 28, 31, and the above-mentioned film cutting process. The device is implemented.

That is, as shown in FIG. 10, the FIB device 40 has the following structure: an ion source 41 for generating Ga ⁺ ions, an electromagnetic optical system 42, and an electron gun 43 for neutralizing electrons of Ga ⁺ ions, releasing α A gas gun 49 for etching a gas (iodine gas), and a gas gun 44 for discharging a prene gas. The electromagnetic optical system 42 converts Ga ⁺ ions generated by the ion source 41 into an ion beam 47. A scan amplifier 50 scans the object to be corrected with the ion beam 47.

Then, on the X-Y pedestal 45, the gray-scale reticle 10 carrying the object to be corrected and the X-Y pedestal 45 are moved, and the corrected region 21 of the gray scale reticle 10 described above is (26, 30, 34) Move to the ion beam irradiation area. Next, the corrected region 21 (26, 30, 34) is scanned by the ion beam 47, and the secondary ions (Cr, Si) generated at this time are detected by the action of the secondary ion detector 48 to detect The corrected area 21 (26, 30, 34) is output. The correction light shielding film 22 (23, 27, 35) or the correction half is applied by irradiating the ion beam 47 onto the corrected region 21 (26, 30, 34) of the gray scale mask 10 via the optical system 42. Film formation of the light-transmissive film 28 (31) and cutting of the fine pattern. In addition, the beam diameter of the ion beam is 0.1 μm ψ or less.

When the correction light shielding films 22, 23, 27, 35 or the correction semi-transmissive films 28, 31 are formed, the ion beam 47 is discharged through the optical system 42, and the diene gas is discharged by the gas gun 44. Thereby, the diene gas is brought into contact with the ion beam 47 to carry out polymerization (chemical reaction), and the correction light-shielding film 22, 23, 27, 35 or the semi-transparent film for correction is deposited on the irradiation region of the ion beam 47. 28, 31 film formation.

Further, when the fine pattern is cut out in the corrected regions 21, 26, 30, and 34, the alpha gas (iodine gas) is released by the etching gas gun 49, and is irradiated through the optical system 42 in this state. The ion beam 47 is taken out, and the fine pattern is cut out, and the damage to the light-transmitting substrate 16 of the gray scale mask 10 is further alleviated.

1. . . glass substrate

2. . . Gate electrode

3. . . Gate insulating film

4. . . First semiconductor film (a-Si)

5. . . Second semiconductor film (N+a-Si)

6. . . Source-dipper metal film

6A. . . Source

6B. . . Bungee

7. . . Positive photoresist film

7A. . . First photoresist pattern

7B. . . Second resist pattern

10. . . Gray scale mask

11. . . Transferred body

12. . . Resistive pattern

13. . . Shading

14. . . Translucent part

15. . . Grayscale

16. . . Light transmissive substrate

17. . . Semi-transparent film

18. . . Sunscreen

19A, 19B. . . Laminated film

twenty four. . . Excess defect

21,26,30,34. . . Corrected area

28,31. . . Modified semi-transparent film

29,32. . . Overlapping part

40. . . FIB device

41. . . source of ion

42. . . Electromagnetic system

43. . . Electron gun

44. . . Gas gun

45. . . X-Y pedestal

47. . . Ion beam

49. . . Gas gun for etching

50. . . Scan amplifier

101, 101A, 101B. . . Shading

100. . . Gray scale mask

102. . . Translucent part

103. . . Grayscale

103A. . . Shading pattern

103B. . . Penetration

22,23,27,35. . . Correction mask

20,25,33. . . Shedding defect (white defect)

23A, 27A, 29A, 32A, 35A. . . Fine pattern-like cutting processing section

1A to 1C are views showing a manufacturing step of a conventional TFT substrate using a gray scale mask.

2A to 2C are views showing subsequent steps of the manufacturing steps of Figs. 1A to 1C.

Fig. 3 is a plan view showing a general gray scale mask having a gray scale portion in which a light shielding pattern below the exposure resolution limit of the exposure machine is formed.

4A and 4B are process diagrams showing a first embodiment of a defect correction method using the gray scale mask of the present invention.

5A to 5C are views showing a gray scale mask corrected by the defect correction method of the gray scale mask according to the first embodiment of the present invention, and particularly, FIG. 5A is a plan view showing a gray scale mask, and FIG. 5B is a plan view. At the same time, a side cross-sectional view of the gray scale mask and the transferred body is shown, and FIG. 5C is a side cross-sectional view of another form of gray scale mask different from the gray scale mask shown in FIG. 5B.

6A to 6C are process diagrams showing a second embodiment of the defect correction method using the gray scale mask of the present invention.

7A to 7D are process diagrams showing a third embodiment of the defect correction method using the gray scale mask of the present invention.

8A to 8C are process diagrams showing a fourth embodiment of the defect correction method using the gray scale mask of the present invention.

Figs. 9A to 9E are diagrams showing the steps of a fifth embodiment of the defect correcting method using the gray scale mask of the present invention.

Fig. 10 is a schematic side view showing the structure of a FIB apparatus used in the defect correction method of the gray scale mask of the present invention.

10. . . Gray scale mask

13. . . Shading

14. . . Translucent part

15. . . Grayscale

20. . . Shedding defect

twenty one. . . Corrected area

twenty two. . . Correction mask

Claims (16)

A defect correction method for a gray scale mask for forming a photoresist pattern having a film thickness which is different in stages or continuously on a transfer target, the gray scale mask having a light shielding portion for shielding exposure light a light-transmitting portion for allowing the exposure light to penetrate, and a gray-scale portion for reducing the amount of penetration of the exposure light, characterized by comprising the following steps: a specific step of the corrected region, wherein the gray-scale portion is semi-transparent a step of forming a film to define a defective corrected region in the gray-scale portion; and a step of forming the fine pattern on the corrected region to form a normality in the gray-scale portion The steps of the fine pattern of the gray scale effect of the gray scale portion. The defect correction method of the gray scale mask according to the first aspect of the invention, wherein the modified region is a fall-off defect region generated in the gray scale portion after the gray scale mask is manufactured, or a detached defect region formed by removing a region of excess defects formed by a material for forming the light-shielding portion or a foreign matter generated in the gray scale portion, or containing the region of the gray scale portion The detached defect region formed by the formation of the light-shielding portion or the excess defect region formed by the foreign matter is removed, and the semi-transmissive film for correction is partially formed and then the detached defect region remains. The method for correcting defects of a gray scale mask according to claim 1, wherein the modified region is after the gray scale mask is manufactured, In the area of the detachment defect generated in the gray scale portion, the region containing the overlapping portion of the semi-transmissive film which is generated when the semi-transmissive film for correction is partially formed, or When the semi-transmissive film for correction is partially formed on the detached defect region formed by removing the region of the light-shielding portion formed by the light-shielding portion or the excess defect formed by the foreign matter. The resulting region containing the overlapping portion of the semi-transmissive film. The method for modifying a defect of a gray scale mask according to claim 1, wherein the step of forming the fine pattern further comprises a step of forming a light shielding film for correction, which is caused by a defect in the gray scale mask portion. A light-shielding film for correction is formed in a fine pattern on the corrected region to be formed. The method for modifying a defect of a gray scale mask according to claim 1, wherein the step of forming the fine pattern further comprises the step of: forming a light-shielding film for correction, in the gray-scale mask portion A light-shielding film for correction is formed on the corrected region formed by the peeling defect; and the step of processing in the fine pattern is performed to obtain the normal gray scale in the gray scale portion. Partially identical gray scale effects are processed in a fine pattern. The method for correcting a defect of a gray scale mask according to claim 4, wherein the light shielding film for correction is made of the same material as that of the light shielding portion. The method for correcting a defect of a gray scale mask according to claim 5, wherein the light shielding film for correction is made of the same material as that of the light shielding portion. The method for modifying a defect of a gray scale mask according to claim 3, wherein the step of forming the fine pattern further comprises a step of processing in a fine pattern, wherein the gray-scale mask portion is corrected The overlapping portion of the semi-transmissive film is processed in a fine pattern in which the same gray scale effect as that of the normal gray-scale portion in the gray-scale portion is obtained. A method of manufacturing a gray scale mask, comprising the step of correcting a defect correction method according to any one of claims 1 to 3, 6 to 8. A gray-scale reticle for forming a photoresist pattern having a film thickness which is different in stages or continuously on the object to be transferred, and having a light-shielding portion for shielding exposure light and allowing light to pass through the exposure light And a gray-scale portion for reducing the amount of penetration of the exposure light, wherein the gray-scale portion is formed of a semi-transmissive film, and the modified portion having the defect has been corrected in the gray-scale portion The corrected area is a fine pattern having the same gray scale effect as that of the normal gray scale portion in the gray scale portion. The gray scale mask according to claim 10, wherein the light shielding portion is formed of a light shielding film, and on the modified region, formed on a film formed of the same material as the light shielding film. There are fine patterns. A gray scale mask includes: a light shielding portion; a light transmitting portion; and a gray scale portion for reducing exposure light used when the mask is used The amount of penetration is characterized in that: the gray-scale portion further comprises: a semi-transmissive film portion formed of a semi-transparent film formed on a transparent substrate; and a light-shielding fine pattern portion formed by a light-shielding formed with a fine pattern Made up of membranes. The gray scale mask according to claim 12, wherein the pattern of the light-shielding fine pattern portion is formed by regularly arranging unit patterns of the same shape. A gray-scale reticle includes: a light-shielding portion; a light-transmitting portion; and a gray-scale portion for reducing the penetration amount of the exposure light used when the reticle is used; wherein the gray-scale portion further includes a light transmissive fine pattern portion which is formed on a transparent substrate, is composed of a semi-transparent film formed with a fine pattern, and a portion composed of a semi-transparent film in which a fine pattern is not formed; wherein the half The film thickness of the light-transmissive fine pattern portion is thicker than the semi-transmissive film in which the fine pattern is not formed. A gray scale mask according to claim 14, wherein the semi-transmissive fine pattern portion further includes a portion in which a semi-transmissive film is laminated. The gray scale mask according to claim 14 or 15, wherein the pattern of the semi-transmissive fine pattern portion is formed by regularly arranging unit patterns of the same shape.