JPH0266545A - Method for correcting deficient or defective part of thin film pattern - Google Patents

Abstract

PURPOSE:To easily correct the deficient or defective part with high accuracy and to suppress the generation of a burr part by forming 1st and 2nd specific resist patterns on the surface of a substrate and adhering a thin film to the deficient or defective part of the thin film pattern for correction. CONSTITUTION:A 1st positive type resist film 8 is formed on the surface of the substrate 1, and an extremely small area 8a corresponding to the deficient or defective part 2a is exposed and developed to form the 1st register pattern 10 which has a 1st opening part 9. The 1st resist pattern 10 is denatured into a cured resist pattern 10 and the 2nd positive type resist film 11 is formed on the pattern and 1st opening part 9; and the part 11a' of the 2nd positive type resist film corresponding to the area surrounding the extremely small area is exposed and developed to form the 2nd resist pattern 14 which has a 2nd opening part 13. A thin film 15 is adhered on the 1st and 2nd opening parts 9 and 13 and 2nd resist pattern 14 and the cured resist pattern 10' and 2nd resist pattern 14 are peeled together with the part of the thin film 15. Consequently, the deficient or defective part is easily corrected with high accuracy and the generation of the burr part can be suppressed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applied to photomasks used in the manufacturing process of semiconductor elements, liquid crystal panels, etc., or missing defects in thin film patterns formed on semiconductor substrates such as silicon wafers. on how to fix it.

[Conventional technology]

Hereinafter, a conventional method for repairing missing defects in a thin film pattern will be described using as an example a photomask in which a light-shielding thin film pattern made of chromium is formed on the surface of a glass substrate.

Defects that occur in the light-shielding thin film pattern of a photomask include defects in which part of the pattern is missing (so-called chips), defects in which the pattern is cut midway (so-called disconnections), and pins that occur within the pattern. There are missing defects such as holes. As a method for correcting the part where this missing defect has occurred (missing defect part), for example, Japanese Patent Laid-Open No. 61-5
The lift-off method described in Japanese Patent No. 9732 is adopted.

As shown in FIGS. 2(a) and (1)), a part of the light-shielding thin film pattern 2 made of chromium formed on the lifetime surface -F of the glass substrate 1 of the photomask is missing. When the missing defective part 2a occurs,
As described below, the aforementioned lift-off method is employed to repair the missing defective portion 2a.

Note that FIG. 2(b) is a sectional view taken along line A-A in FIG. 2(a).

That is, first, referring to FIG. 3(a), the missing defective portion 2 is
After applying a positive type photoresist to the surface of the glass substrate 1 having the light-shielding thin film pattern 2 where a has occurred, a positive type photoresist film 3 is formed by baking, and then a resist corresponding to the missing defect portion 2a is applied. Microhead region 3 of membrane 3
a is selectively exposed to ultraviolet light 4.

Next, referring to FIG. 3(b), using a predetermined developer, a positive photoresist It! 3 is developed to form a resist pattern 6 having openings 5.

Next, referring to FIG. 3(C), a chromium thin film 7 is deposited on the opening 5 and the resist pattern 6 by sputtering.

Subsequently, referring to FIG. 3(d), using a predetermined resist stripping solution, the portion of the chromium thin film 7 deposited on the resist pattern 6 is stripped off along with the resist pattern 6, and then,
At this time, the missing defective portion 2a is corrected using the remaining chromium 1117a.

(Problems to be Solved by the Invention) However, when a missing defective portion of a thin film pattern is corrected by the above-described missing defective portion repairing method, the following problems occur.

That is, as described above, after exposing the micro head region 3a of the positive photoresist film 3 corresponding to the missing defective portion 2a to ultraviolet light 4, the resist film 3 is developed to form a resist pattern 6 having openings 5. (Fig. 3(a)
and (b)).

Now, referring to FIG. 4(a), the micro area 3a is exposed to ultraviolet light 4 having a width a of the exposure area, and then the fourth ultraviolet light 4 is exposed.
Referring to Figure (b), when the resist film 3 is developed to form a resist pattern 6 having openings 5, the development progresses from the surface to the bottom surface of the resist film 3. The inner wall surface 6a of the resist pattern 6 is an inclined surface having a predetermined angle θ, and there is a difference in dimension between the upper end and the lower end of the resist pattern 6. Therefore, referring to FIG. 5, the edge (etch) of the chromium thin film 7a remaining and deposited on the missing defect portion 2a through the subsequent steps described above and the edge (etch) of one edge of the light-shielding thin film pattern 2 ( (pattern etching) is shifted in accordance with the above-mentioned dimension difference. Note that the chromium thin film 7a shown in FIG. 5 and FIG.
A thin chromium film deposited only in area a is shown.

As mentioned above, the etch of chrome thin 1!7a and the pattern etch of light-shielding *S pattern 2 are shifted according to the difference in size,
Moreover, if the amount of deviation is large, even if the missing defective portion 2a is repaired by depositing the chromium thin film 7a, it cannot be used as a photomask that requires extremely precise pattern accuracy. It is possible to make the gap smaller by increasing the width a of the exposure area in accordance with the size difference, but this is not practical since it is difficult to predict the size difference. Not.

In view of the above circumstances, the inventor of the present invention conducted studies and found the following facts. That is, first, referring to FIG. 6(a), a positive photoresist 13' thinner than the resist film 3 is formed on the surface of the glass substrate 1, and then the width of the exposure area is adjusted as described above. The micro region 3''a was exposed to the ultraviolet light 4 of a.Next, referring to FIG. 6(b), the resist film 3' was developed to form a resist pattern 6° having an opening 5'. When the pattern 6'
Although the inner wall surface 6°a of the pattern 6' is an inclined surface having the predetermined angle θ, the dimensional difference C between the upper end and the lower end of the pattern 6'
is smaller than the above dimension. Furthermore, this dimensional difference C
becomes smaller (becomes) as the film thickness of the resist 11!3' is increased to M.

Therefore, with reference to FIG. 7, even if the etching of the chromium thin film 7a and the pattern etching of the light-shielding thin film pattern 2 deviate from each other in accordance with the dimensional difference C, the deviation 1 becomes small and the corrected shading sex'? The J film pattern 2 can be kept within an acceptable dimensional accuracy.

However, in this case, the above-mentioned positive photoresist film 3
Because the resist film 3' is thin, pinholes are likely to occur in the resist film 3', and as a result, new defects such as chromium spots (so-called black defects) are created on the photomask in which missing defects have been repaired using the lift-off method. It is more likely to occur.

Therefore, it is not preferable to try to repair the missing defect portion by simply reducing the thickness of the resist film, as this will cause new defects to occur.

By the way, next, referring to FIG. 3(C), a portion of chromium i[7 also adheres to the inclined inner wall surface 6a of the resist pattern 6. Therefore, with reference to FIG. 3(d), when the resist pattern 6 and the portion of the chromium thin film 7 deposited on the pattern 6 are peeled off, the ends of the remaining chromium thin film 7a protrude upward. A paris portion 7b is generated.

When a new photomask (so-called copy mask) is manufactured by using a photomask in which the missing defective part 2a is corrected by the chromium l17a in which the paris part 7b is formed, and includes a step of transferring a pattern by a contact exposure method, Since the crisp portion 7b sinks into the resist film on the copy mask side, defects such as pinholes occur in the copy mask.

The present invention has been made in view of the above-mentioned circumstances, and it is possible to easily correct missing defective parts with high precision, and suppress the occurrence of crisp parts in the corrected missing defective parts. It is an object of the present invention to provide a method for repairing missing defects in a thin film pattern.

[Means to solve the problem]

The present invention has been made to achieve the above object, and provides a method for repairing missing defective parts of a thin film pattern formed on the surface of a substrate by applying a thin film to the missing defective parts of the thin film pattern. After forming a first positive resist film on the surface of the substrate, exposing a minute region of the first positive resist film corresponding to the missing defect portion, and then exposing the first positive resist film to light. developing with a predetermined developing means to form a first resist pattern having a first opening; and performing a treatment on the first resist pattern to make it resistant to the predetermined developing means. The first resist pattern is transformed into a hardened resist pattern, and then a second positive resist film is formed on the first opening and the hardened resist pattern, and a second positive resist film is formed on the first opening and on the hardened resist pattern. A corresponding portion of the second positive resist film is exposed, and then the second positive resist film is developed by the predetermined developing means to form a second resist pattern having a second opening. a step of
a thin film is deposited over the openings of the hardened resist 1-pattern and the second resist pattern;
A method for repairing missing defects in a thin film pattern, comprising the steps of: peeling off the resist pattern along with the thin film portion deposited thereon.

Here, the film thickness of the first positive resist film is desirably thinner than the film thickness of the second positive resist film, and more specifically, the film thickness of the first positive resist film is It is desirable that the thickness of the second positive resist film is 2 to 4 times the thickness of the thin film pattern, and that the thickness of the second positive resist film is 4 times or more the yi thickness of the SS pattern.

[Effect]

Since the cured resist pattern has resistance to the prescribed developing means, it is not removed when the second positive resist pattern is developed by the prescribed developing means.

〔Example〕

An embodiment of the present invention will be described in detail below. In addition, in this example, as shown in FIGS. 2(a) and (b),
A case will be described in which the missing defective portion 2a of the light-shielding thin film pattern 2 made of chromium formed on one main surface of the glass substrate 1 is repaired.

First, referring to FIG. 1(a), a positive photoresist (AZ manufactured by Hoechst Co., Ltd.) is applied to the surface of a glass substrate 1 having a light-shielding thin film pattern 2 (FJ thickness: 800) in which a missing defect portion 2a has occurred. -1350> by a spin code method, and then baked at an ambient temperature of 90°C for 30 minutes to form a first positive photoresist film 8 (film thickness h1: 200°C).
0 people). Next, a minute region 8a of the resist film 8 corresponding to the missing defective portion 2a is selectively exposed to ultraviolet light 4 having a width a of the exposed region.

Next, referring to FIG. 1(b), the first positive photoresist 1lI8 was developed using a predetermined developer (AZ-exclusive developer developed by Hoechst Co., Ltd.) to form a first opening 9. A first resist pattern of 1° is formed.

Next, by baking the ζ first resist pattern 10 at an ambient temperature of 200° C. for 30 minutes, the pattern 10 is transformed into a hardened resist pattern 10' (see FIG. 1(C)) that cannot be removed by the predetermined developer. let

As a result of this baking, the first resist pattern 10 is transformed into a hardened resist pattern 10' that cannot be removed by the predetermined developer, that is, is resistant to the predetermined developer.

Next, referring to FIG. 1(C), the first opening 9,
After applying a positive photoresist (IRAZ-1350, manufactured by Hoechst Co., Ltd.) on the hardened resist pattern 10' by a spin code method, the second positive photoresist film 11 (film Thickness h2: 10,000 people). Next, a portion 11a of the second positive photoresist film corresponding to a region surrounding the minute region 8a is selectively exposed to ultraviolet light 12 having a width d of the exposed region. Note that since the portion 11a of the resist film corresponds to the area surrounding the minute area 8a, the width d of the exposed area is larger than the width a.

Next, referring to FIG. 1(d), the second positive photoresist film 11 is developed using the above-mentioned predetermined developer to form an IC second resist pattern 14 having second openings 13. form. Note that at this time, as described above, the cured resist pattern 10' is resistant to a predetermined developer, so it remains without being removed.

Next, referring to FIG. 1(e), the first opening 9
A chromium film 15 is deposited on the second opening 13 and the second resist 1 to pattern 14 by sputtering.

Subsequently, referring to FIG. 1(f), using a predetermined resist stripping solution (hot concentrated sulfuric acid, liquid temperature 100° C.), the pattern is removed together with the hardened resist pattern 10' and the second resist pattern 14. The portion of the chromium thin film 15 deposited on 10' and 14 is peeled off, and the missing defective portion 2a is repaired using the remaining chromium thin film t5a.

As explained above, according to this embodiment, the first film has a thin film thickness.
After forming a hardened resist pattern 10' from the positive photoresist film 8, a second resist pattern 10' surrounding the pattern 10' is formed.
A resist pattern 14 is formed, and then a chromium thin film 1 is formed.
5 is attached. Therefore, since the film thickness of the first positive photoresist film 8 is thin, the deviation between the etching of the remaining chromium thin film 15a and the pattern etching of the light-shielding thin film pattern 2 is minimized, and the modified light-shielding thin film pattern 2 is can be easily kept within acceptable dimensional accuracy. Further, a second resist pattern 14 is formed using a thick second positive photoresist iii, and a chromium thin film 15 is formed.
After repairing the missing defective part 2a,
New defects such as chrome spots can be prevented from occurring. Furthermore, the area of the inner wall surface of the hardened resist pattern 10' formed from the thin first photoresist film 8 is small, and the second resist pattern 14 surrounding the pattern 10' is formed. Chromium' deposited on each of the patterns 10' and 14? f
The portion of the J film 15 is peeled off and removed well, and as a result, it is possible to significantly suppress the formation of flashing portions at the ends of the remaining chromium thin film 1115a.

The present invention is not limited to the above-described embodiments, but includes modifications and applied examples described below.

First, in the embodiment described above, the case where a chip is repaired as a missing defect portion has been described, but it goes without saying that missing defect portions include wire breaks, pinholes, and the like.

In the above embodiment, the substrate was made of glass, but it may also be made of a semiconductor such as silicon, sapphire, or synthetic resin.

In addition, the thin film pattern was a light-shielding thin film pattern made of chromium in the above example, but in addition to chromium, it may also be made of chromium oxide, chromium carbide, chromium nitride, chromium boride, molybdenum, molybdenum silicide, tungsten, tantalum, titanium, etc. It may be a light-shielding thin film pattern made of a substance, or it may be formed by stacking these light-shielding IIQ patterns. Further, the WI film pattern may be made of a material other than the one having the above-mentioned light-shielding property, such as silicon oxide, aluminum, tin oxide, or a mixture of tin oxide and indium oxide (ITO). Furthermore, it goes without saying that the thickness of the thin film pattern is not limited to the 800 people described in the above embodiment.

As the first and second positive resists, a positive photoresist such as a novolac type other than those mentioned in the above examples, or a positive electron beam resist such as a polyolefin sulfone type or a polymethyl methacrylate resin type may be used. May be adopted.

Note that when a positive electron beam resist is employed, it may be exposed to an electron beam. Further, as a method for applying the positive resist, a spray coating method or the like may be employed in addition to the spin code method.

In addition, as mentioned above, the thickness of the first positive resist film is 2 to 4 times the thickness of the thin film pattern, and the thickness of the second positive resist film is 4 times the thickness of the thin film pattern. The above value is desirable, and by setting the film thickness of each resist film within this range, defects such as chrome spots can be prevented from occurring and missing defective parts can be corrected with high precision.

As a developing means for the first and second positive resist films, in addition to the wet development method using the prescribed developer described in the above example, a prescribed developer corresponding to each type of positive resist film may be used. A wet development method can be employed.

In the above embodiment, when the first resist pattern was processed to be resistant to a predetermined developing means, the first resist pattern was baked, thereby transforming the pattern into a hardened resist pattern. When baking this first resist pattern, it is desirable to set the atmospheric humidity to 200° C. or more and the baking time to 30 minutes or more.

In the above embodiment, the thin film was made of chromium, but in addition to chromium, the thin film may be made of any of the above-mentioned substances necessary for correcting missing defects in the thin film pattern.
The thickness of the film is also appropriately selected to be an appropriate value for correcting the missing defect portion. Furthermore, as a method for forming a thin film, other than the sputtering method, a method such as a vacuum evaporation method, a CVD method, or an ion blating method may be adopted.

In the above embodiments, hot concentrated sulfuric acid was used to cure and remove the second resist pattern, but a dimethylsulfoxy-based or acetone stripping solution may be used for the stripping.

〔Effect of the invention〕

As explained above, according to the method for repairing a missing defect in a thin film pattern of the present invention, the missing defect can be easily corrected with high precision, and a sharp part is generated in the corrected missing defect or recess. This can be suppressed.

[Brief explanation of the drawing]

FIG. 1 is a process cross-sectional view showing an embodiment of the method for repairing a missing defect in a thin film pattern according to the present invention, FIG. 2 is a diagram showing a missing defect that occurs in a light-shielding thin film pattern, and FIG. The figure and the same figure (b) are Δ-A line cross-sectional views in the same figure (a),
FIG. 3 is a process cross-sectional view showing a conventional method for repairing a missing defect in a thin film pattern, and FIGS. 4(a) and 6(a) are cross-sectional views showing a state in which a minute area of a positive photoresist film is exposed. , FIG. 4(b) and FIG. 6(b) are cross-sectional views showing a resist pattern with an opening, and FIGS. 5 and 7 are plan views showing the state of the corrected missing defect portion. 1...Glass substrate, 2...Light-shielding thin film pattern, 2
a... Missing defective part, 4.12... Ultraviolet light, 8...
First positive photoresist 1 - film, 8a... minute region, 9... first opening, 10... first resist pattern, 10'... hardened resist pattern, 11
. . . Second positive photoresist film, 11a . . . Portion of the second positive photoresist film corresponding to the region surrounding the minute region, 13 .
Second resist pattern, 15...Chromium thin film, 15
a...Remaining chromium thin film.

Claims (1)

[Claims] (1) A method for repairing missing defective parts of the thin film pattern by depositing a thin film on the missing defective parts of the thin film pattern formed on the surface of the substrate, the method comprising: depositing a first positive resist film on the surface of the substrate; After the formation, a minute area of the first positive resist film corresponding to the missing defect is exposed to light, and then the first positive resist film is developed by a predetermined developing means to form a first opening. forming a first resist pattern comprising the steps of: performing a treatment on the first resist pattern to make it resistant to the predetermined developing means to transform the first resist pattern into a hardened resist pattern; Next, after forming a second positive resist film on the first opening and the hardened resist pattern, exposing a portion of the second positive resist film corresponding to a region surrounding the micro region, Next, developing the second positive resist film using the predetermined developing means to form a second resist pattern having a second opening; depositing a thin film on a second resist pattern, and then peeling off the cured resist pattern and the second resist pattern together with the portion of the thin film deposited thereon. A method for repairing missing and defective parts of patterns.