JPH11295876A - Multilevel photomask and manufacture of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple multilevel photomask manufacturing method that is substituted for a conventional metallic sputtering method and to reduce the manufacturing costs. SOLUTION: There is one kind or more than one kind of such a area as is optionally provided on a light transmissive substrate, a mask layer which is provided on the light transmissive substrate and has a pattern and an area that is not covered with that mask layer among the light transmissive substrates, comprises plural pieces of exposure areas that contain an ultraviolet light absorption composition and in which ultraviolet light transmittance ranges between 0 to 10% in the exposure areas and constitutes a multilevel pattern of a photomask.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light exposure process technique, and more particularly to a multi-level photomask and a method of manufacturing the same.

[0002]

2. Description of the Related Art The technique of light exposure is already widely used in the process of manufacturing electronic devices. For example,
Printed circuit boards, integrated circuits, flat liquid crystal displays (LC
D) In the manufacturing process of microelectronic devices and the like, various fine circuits and elements are manufactured using light exposure technology. In order to complete a product, it is usually necessary to go through one or more light exposure steps, but one light exposure step involves the application of photoresist, precision counter exposure, development and removal of photoresist. It is necessary to repeat the process many times, and in particular, in the manufacture of an integrated circuit, it is necessary to perform the light exposure process about 10 to 20 times. For this reason,
From the standpoint of reducing production costs and production time, how to save the time and materials required for the light exposure process is the most important point. From this, the idea of a process technology that develops many times with one exposure was born

[0003] The so-called step technology of developing a large number of times by one exposure means that two or more kinds of drawn circuit patterns or element patterns are put together on a single "multi-layer photomask", These two types or two or more types of circuit patterns or element patterns are distinguished by utilizing the difference in transmittance. In the manufacturing process, two or more circuit patterns or element patterns are simultaneously printed on the photoresist layer by a single exposure using the multi-layer photomask. From the difference in transmittance,
On the photoresist layer after exposure, fine circuit patterns or element patterns with various exposure energies are formed.
Since the dissolution rate of the photoresist in the developer depends on the absorbed exposure energy, first develop a circuit pattern or element pattern with the highest absorbed exposure energy to expose and process the processed layer. Can be. When the first processing is completed, a circuit pattern or an element pattern having the second highest exposure energy is developed and processed. In this way, if the development and processing of the exposed and processed layers are repeated in order from the area having the larger exposure amount, it is possible to omit the repetitive operations such as the application of the photoresist, the precise counter exposure and the removal of the photoresist many times.

[0004] IBM's Donis Flagello,
Both names of Andrew Pomerene are "A Si
nagle Exposure Double Dave
lop (SEDD) Process for Sel
f-aligned Lithographic Ap
applications] [Microelectron
ic Engineering 9 (1989) 47-
52], an experiment was conducted by combining a three-layer photomask having three different light transmittances manufactured by a very expensive metal sputtering method and a positive photoresist, and a large number of exposures were performed in one exposure. We have successfully demonstrated the feasibility of developing process technology. This process technique has the greatest advantages that it can reduce the number of operations such as application of a photoresist, precise counter exposure and removal of the photoresist, and can reduce errors caused by the counter exposure. The relative position of the multilayer circuit pattern or element pattern to be manufactured is already accurately manufactured on the multi-level photomask at the time of manufacturing the photomask,
Moreover, in order to distinguish them based on the difference in light transmittance,
After exposure, the circuit pattern or device pattern on the photomask can be completely transferred onto the photoresist layer,
There is no counterpoint problem.

[0005] The most specific application example of the process technique of developing a plurality of times with one exposure is the manufacture of a color filter used in a color liquid crystal display device. Color filters hold the key to determining whether a liquid crystal display can display a bright, lifelike screen. The prior art pigment dispersion method is currently the main technology for manufacturing color filters, but (1) the usage efficiency of the material is not high (about 1% to
(2%), (2) the ability to respond to the enlargement of the substrate is low,
(3) Due to problems such as the use of a high-precision and expensive counter-exposure apparatus many times, the production cost cannot respond to the future situation such as the need for large dimensions and the drop in price. However, improvement of manufacturing technology and cost reduction of related parts are inevitable. For this reason, US Patent Application Publication 564
No. 1595, ED-LITH combines a process technology of developing a large number of patterns with one exposure and a technology of electrodeposition process.
O method was developed to (1) produce large area, (2) simplify process, (3) save material, (4) reduce capital investment,
(5) It is possible to manufacture a color filter having pixels of all shapes and dimensions. A similar technique is found in U.S. Patent Application Publication No. 5,314,769.

[0006] The two core technologies of this process technology are a photoresist that can be developed many times by one exposure and a photomask having a multi-layer light transmittance. IBM's D
onis Flagello and Andrew Pome
ren, both of whom were mentioned in the sentence,
As a positive photoresist which can be developed many times by one exposure, AZ5214 photoresist of Hoechest is used as a photoresist which can be developed twice by one exposure. Also, U.S. Patent Application Publication No. 5,645,970.
Has taken up this type of photoresist technology, which can be developed three or more times at a time.

A conventional method for manufacturing a precision photomask is to apply a photoresist on a glass substrate having a non-translucent metal thin film, expose the photoresist, transfer a required pattern onto the substrate, and finally etch. The metal layer is removed by the method to complete the manufacture of the photomask. This type of photomask is
There are only two types of light transmittance, 100% and 0%. On the other hand, for a multi-level photomask, 6% is between 100% and 0%.
Several layers having various light transmittances such as 0%, 40%, and 20% are provided. However, conventionally, in the production of a multi-layer photomask having various layers of light transmittance, generally, a metal is sputtered on a glass substrate, and the light transmittance is controlled by a method of simultaneously controlling the thickness of a thin metal film to be sputtered. I do. Equipment for metal sputtering is very expensive, and in order to produce patterns with various light transmittances, a number of development steps have to be performed, which causes the cost of this type of mask to be high. .

[0008]

In view of the above problems,
The main object of the present invention is to provide a simple multi-layer photomask manufacturing method that replaces the conventional metal sputtering method, and to reduce the manufacturing cost.

[0009]

To achieve the above-mentioned object,
In order to provide a simple multi-layer photomask manufacturing method and reduce the manufacturing cost, the present invention has developed a new multi-layer photomask manufacturing method. In this new manufacturing method, an exposed layer is formed using a coating containing a composition capable of absorbing ultraviolet light, and the composition and concentration of the ultraviolet light absorbing substance in the exposed layer or the thickness of the exposed layer is changed. Thus, two or more circuit patterns or element patterns combined on one multi-layer photomask are distinguished. The coating containing the ultraviolet light absorbing composition may be a photoresist or an etchable material.

The method for manufacturing a multi-layer photomask according to the present invention comprises the steps of: (a) forming a mask layer having an ultraviolet light transmittance of 0% on a light-transmitting substrate; and (b) forming a pattern of the mask layer. (C) forming a photomask pattern having an ultraviolet light transmittance of 100% and 0%; and (c) applying an exposure layer containing an ultraviolet light absorbing composition on a light transmitting substrate. And (d) designing a pattern of the exposure layer and forming a photomask pattern having an ultraviolet light transmittance of between 0 and 100% on a light-transmitting substrate.

The light-transmitting substrate in step (a) is generally made of quartz glass, and the mask layer is generally made of a metal film, and can be formed by sputtering, CVD, vacuum deposition or spraying.

When a photoresist having a developing function is used as the material for the exposure layer in step (c), a necessary pattern can be created from the exposure layer using a development step in step (d). If an exposure layer material having no photoresist function is used in step (c), step (d)
First, a material for an exposure layer is applied on a substrate, a firing process is performed, a required pattern is manufactured by an etching method in a photoresist process, and the photoresist is finally removed to obtain a required pattern.

In addition, the required transmittance of the ultraviolet light can be obtained by changing the composition and concentration of the ultraviolet light absorbing substance or the thickness of the exposure layer. Here, the ultraviolet light absorbing composition is selected from dyes, pigments, metal particles, and ultraviolet light absorbing agents, and these may be used alone or as a mixture of two or more of these. You may.

The present invention also provides a novel multi-level photomask. This novel photomask is provided with a light-transmitting substrate, on which a light exposure layer having various patterns and ultraviolet light transmittances to be used as a photomask is provided, and the light exposure layer material contains an ultraviolet light absorbing composition. It is a coating film, and may be a photoresist or a coating film that can be etched.
Here, the various ultraviolet light transmittances of the exposure layer are controlled by changing the composition and concentration of the ultraviolet light absorbing composition or the thickness of the exposure layer.

As described above, the multi-layer photomask according to the present invention includes a light-transmitting substrate, a mask layer provided on the light-transmitting substrate and having a pattern, and a mask layer on the light-transmitting substrate. Provided in any area not covered by
It comprises a plurality of exposure areas containing the ultraviolet light absorbing composition, and the above-mentioned exposure areas have an ultraviolet light transmittance of 0 to 100%.
Have one or more kinds of multi-layer patterns for forming a photomask.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS To further clarify the objects, features and advantages of the present invention, some preferred embodiments will be described below.

Example 1 Control of Ultraviolet Light Transmittance by Changing Thickness of Exposure Film Red photoresist (Fuji FilmOlin CR-7001) at different rotation speeds.
Was applied on a transparent glass substrate having a length × width of 320 mm × 400 mm, placed in an oven, baked at 90 ° C. for 10 minutes, and further cured at 230 ° C. for 1 hour. Further, the stock solution of CR-7001 was diluted with an organic solvent. The composition weight ratio of this organic solvent is PGMEA (propylene glycol monomethyl ether acetate): PEAc (propylene glycol monoethyl ether acetate): cyclohexanone = 65: 15: 15. The diluted red photoresist is applied to a glass substrate having a length and width of 320 mm × 400 mm at various rotation speeds, placed in an oven, baked at 90 ° C. for 10 minutes, and then heated for 23 minutes.
Cured for 1 hour at 0 ° C. Table 1 is a table showing the relationship between the thickness of the coating film and the light transmittance in this example. Table 1

Example 2 Control of Ultraviolet Light Transmittance by Changing Concentration of Ultraviolet Light Absorbing Composition in Exposure Layer (1) A photoresist having various concentrations of ultraviolet light absorbing composition is prepared. The composition is as follows. (A) 50 g of an acrylic resin containing 530 mol% of -COOH (36 mol% of methyl methacrylate, 28 mol% of methacrylic acid, 12 mol% of diacetone allylamide,
Hydroxyethyl methacrylate 12 mol%, styrene 1
(B) UV absorber Zapon RED 335 (C.I.
I. Solvent Red 122) 2 g, 3 g or 4 g; (c) 20 g of polyfunctional acrylic monomer [TMPTA (trimethylolpropane triacrylate)]; (d) 120 g of organic solvent (PGMEA: PEAc: cyclohexanone = 65: 15: 15) And (e) initiator ITX (isopropyl thioxanthone) 3
g, Irgacure907 @ 2-methyl-1- [4-
(Methylthio) phenyl] -2-monophorino-propane-1｝ 9 g. (2) The photoresist solution prepared in (1) is 320 m in length × width by a spin coating method (rotation speed: 1000 rpm).
It is applied on a glass substrate of mx 400 mm, placed in an oven, baked at 90 ° C for 10 minutes, and further heated at 230 ° C for 1 minute.
Cured for hours. Table 2 is a table showing the relationship between the thickness of the coating film and the light transmittance in Example 2. Table 2

Example 3 Production of Four-Layer Photomask with Pixels Arranged in Stripes In this embodiment, the transmittance of ultraviolet light is controlled by changing the thickness of the exposure layer, and the pixels are arranged in stripes. The manufactured four-layer photomask was manufactured. (1) A 0.12 μm-thick Cr metal thin film that does not transmit ultraviolet light was formed by a sputtering method on a transparent glass substrate having a length × width of 320 mm × 400 mm. (2) On the Cr metal thin film on the glass substrate of (1), a positive photoresist is further applied by a rotation method (rotation speed: 1000 rpm), and when the application is completed, the resultant is put into an oven and baked at 90 ° C. for 10 minutes. As a result, a photoresist coating film having a thickness of 1.80 μm was obtained. (3) Using a positive photomask 10 having a matrix pattern as shown in FIG. 1, the glass substrate coated with a photoresist thin film is exposed (exposure amount 100 mj /
use cm ^2, 1% aqueous KOH), after development for 90 seconds at room temperature, turn off the water and washed with deionized water and baked for 10 minutes at 120 ° C. in an oven. (4) Cr etching was performed on the substrate for 5 minutes using a CR-7 etching solution of CYANTEK, and after the etching was completed, the substrate was washed away with deionized water. (5) After removing the photoresist and washing, a pattern having pixels with transmittance of ultraviolet light of 100% and 0% was obtained. (6) Red photoresist (Fujifilm CR-70)
01) as an exposure layer, and using an organic solvent to prepare this CR-7
001 was diluted to 82% by weight of the stock solution (the weight composition ratio of this organic solvent was PGMEA: PEAc: cyclohexanone = 65: 15: 15). Then, the diluted photoresist was applied on the glass substrate obtained in (5) by a rotation method (rotation speed: 1000 rpm), and then baked at 90 ° C. for 10 minutes in an oven. (7) Using the photomask 20 having a linear pattern as shown in FIG. 2, a precise counter-point exposure is performed on the glass substrate obtained in (6) (use exposure amount is 200 mj / cm.
² ) In the pixel area, the ultraviolet light transmittance is 40% (λ = 365n).
m) was prepared. Then, Fujifilm C
D-2000 developer was diluted with deionized water to 5
%, Developed at room temperature for 3 minutes, washed with deionized water, drained, and then placed in an oven at 230 ° C for 1 minute.
Cured for hours. (8) Red photoresist (Fujifilm CR-70)
01) as an exposure layer, this CR-7001 was applied on the glass substrate obtained in (7) by a rotation method (rotation speed: 1000 rpm), and then placed in an oven at 90 ° C.
For 10 minutes. (9) Using the photomask 20 having a linear pattern as shown in FIG. 2, perform precise counter-point exposure on the glass substrate obtained in (8) (use exposure amount is 200 mj / cm.
² ) The ultraviolet light transmittance in the pixel area is 20% (λ = 365n)
m) was prepared. Then, Fujifilm C
D-2000 developer was diluted with deionized water to 5
%, Developed at room temperature for 3 minutes, washed with deionized water, drained, and then placed in an oven at 230 ° C for 1 minute.
After curing for a time, the manufacture of the four-level photomask was completed.
FIG. 3 is a view showing the four-layer photomask obtained in this manner.

Embodiment 4: Pixels arranged in a mosaic pattern 4
Manufacture of Hierarchical Photomask In this example, the transmittance of ultraviolet light was controlled by changing the thickness of the exposure layer, and a four-layer photomask in which pixels were arranged in a mosaic pattern was manufactured. (1) A 0.12 μm-thick Cr metal thin film that does not transmit ultraviolet light was formed on a transparent glass substrate having a length × width of 320 mm × 400 mm by a sputtering method. (2) On the Cr metal film on the glass substrate described in (1), a positive photoresist is applied by a rotation method (rotation speed: 1000 rpm).
After baking at 90 ° C. for 10 minutes, the thickness was 1.8.
A 0 μm photoresist coating was obtained. (3) Using a positive photomask 10 having a matrix pattern as shown in FIG. 1, the glass substrate coated with a photoresist thin film is exposed (exposure amount 100 mj /
use cm ^2, 1% aqueous KOH), after then developed for 90 seconds at room temperature, turn off the water and washed with deionized water and baked for 10 minutes at 120 ° C. in an oven. (4) Using a CR-7 etching solution from CYANTEK, the substrate was etched with Cr for 5 minutes. After the etching was completed, the substrate was washed with deionized water. (5) After removing the photoresist and washing, a pattern having pixels with transmittance of ultraviolet light of 100% and 0% was obtained. (6) Red photoresist (Fujifilm CR-70)
01) as an exposure layer, and using an organic solvent to prepare this CR-7
001 was diluted to 82% by weight of the stock solution (the weight composition ratio of this organic solvent was PGMEA: PEAc: cyclohexanone = 65: 15: 15). Then, the diluted photoresist was applied on the glass substrate obtained in (5) by a rotation method (rotation speed: 1000 rpm), and then baked at 90 ° C. for 10 minutes in an oven. (7) Using the photomask 40 having a lattice pattern as shown in FIG. 4, the glass substrate obtained in (6) is subjected to precise counter-point exposure (use exposure amount is 200 mj / c).
m ² ), and an ultraviolet light transmittance of 40% (λ = 365) in the pixel area.
nm). Then, Fuji Film CD-2000 developer was diluted to 5% by weight of the stock solution using deionized water, developed at room temperature for 3 minutes, washed with deionized water, drained, and then placed in an oven. The mixture was cured at 230 ° C. for 1 hour. (8) Red photoresist (Fujifilm CR-70)
01) as an exposure layer, this CR-7001 was applied on the glass substrate obtained in (7) by a rotation method (rotation speed: 1000 rpm), and then placed in an oven at 90 ° C.
For 10 minutes. (9) Using the photomask 40 having a lattice pattern as shown in FIG. 4, the glass substrate obtained in (8) is subjected to precise counter-exposure (the exposure amount used is 200 mj / c).
m ² ), and an ultraviolet light transmittance of 20% (λ = 365) in the pixel area.
nm). Then, Fuji Film CD-2000 developer was diluted to 5% by weight of the stock solution using deionized water, developed at room temperature for 3 minutes, washed with deionized water, drained, and then placed in an oven. This was cured at 230 ° C. for 1 hour to complete the manufacture of a 4-layer photomask. FIG. 5 is a diagram showing the four-layer photomask obtained in this manner.

Example 5: Production of Four-Layer Photomask with Pixels Arranged in Stripes In this example, the transmittance of ultraviolet light was changed by changing the concentration of the ultraviolet light absorbing composition in the exposure layer. A four-layer photomask in which pixels were arranged in a stripe pattern was manufactured. (1) A 0.12 μm-thick Cr metal thin film that does not transmit ultraviolet light was formed on a transparent glass substrate having a length × width of 320 mm × 400 mm by a sputtering method. (2) A positive photoresist is applied on the Cr metal film on the glass substrate described in (1) by a rotation method (rotation speed: 1000 rpm), and when the application is completed, the resultant is put into an oven and baked at 90 ° C. for 10 minutes. As a result, a photoresist coating film having a thickness of 1.80 μm was obtained. (3) Using a positive photomask 10 having a matrix pattern as shown in FIG. 1, the glass substrate coated with a photoresist thin film is exposed (exposure amount 100 mj /
use cm ^2, 1% aqueous KOH), after then developed for 90 seconds at room temperature, turn off the water and washed with deionized water and baked for 10 minutes at 120 ° C. in an oven. (4) Using a CR-7 etching solution from CYANTEK, the substrate was etched with Cr for 5 minutes. After the etching was completed, the substrate was washed with deionized water. (5) After removing the photoresist and washing, a pattern having pixels with transmittance of ultraviolet light of 100% and 0% was obtained. (6) The red photoresist prepared in Example 2 (Zap
on RED (CI Solvent Red 12
2) 335 2.47% by weight) as an exposure layer,
Rotation method (rotation speed 1) on the glass substrate obtained in (5)
000 rpm), put in oven and 90 ℃
For 10 minutes. (7) Using the photomask 20 having a linear pattern as shown in FIG. 2, precision counter-exposure is performed on the glass substrate obtained in (6) (use exposure amount is 200 mj / c).
m ² ), and an ultraviolet light transmittance of 55% (λ = 365) in the pixel area.
nm). Then, the Fuji Film CD-2000 developer was diluted to 5% by weight of the stock solution using deionized water, developed at room temperature for 3 minutes, washed with deionized water, drained, and then placed in an oven. 230 ° C
For 1 hour. (8) The red photoresist prepared in Example 2 (Zap
on RED (CI Solvent Red 12
2) 335 4.82% by weight) as the exposure layer,
The photoresist was applied on the glass substrate obtained in (7) by a rotation method (rotation speed: 1000 rpm), and then baked in an oven at 90 ° C. for 10 minutes. (9) Using the photomask 20 having a linear pattern as shown in FIG. 2, precision counter-exposure is performed on the glass substrate obtained in (8) (use exposure amount is 200 mj / c
m ² ), and 36% ultraviolet light transmittance (λ = 365) in the pixel area.
nm). Then, the Fuji Film CD-2000 developer was diluted to 5% by weight of the stock solution using deionized water, developed at room temperature for 3 minutes, washed with deionized water, drained, and then placed in an oven. This was cured at 230 ° C. for 1 hour to complete the manufacture of a 4-layer photomask. FIG. 3 is a view showing the four-layer photomask obtained in this manner.

Embodiment 6: Pixels arranged in a mosaic pattern 4
Manufacture of Hierarchical Photomask In this example, the transmittance of ultraviolet light was changed by changing the concentration of the ultraviolet light absorbing composition in the exposure layer, and a four-layer photomask in which pixels were arranged in a mosaic pattern was manufactured. (1) A 0.12 μm-thick Cr metal thin film that does not transmit ultraviolet light was formed on a transparent glass substrate having a length × width of 320 mm × 400 mm by a sputtering method. (2) A positive photoresist is applied on the Cr metal film on the glass substrate described in (1) by a rotation method (rotation speed: 1000 rpm), and when the application is completed, the resultant is put into an oven and baked at 90 ° C. for 10 minutes. As a result, a photoresist coating film having a thickness of 1.80 μm was obtained. (3) Using a positive photomask 10 having a matrix pattern as shown in FIG. 1, the glass substrate coated with a photoresist thin film is exposed (exposure amount 100 mj /
use cm ^2, 1% aqueous KOH), after then developed for 90 seconds at room temperature, turn off the water and washed with deionized water and baked for 10 minutes at 120 ° C. in an oven. (4) Using a CR-7 etching solution from CYANTEK, the substrate was etched with Cr for 5 minutes. After the etching was completed, the substrate was washed with deionized water. (5) After removing the photoresist and washing, a pattern having pixels with transmittance of ultraviolet light of 100% and 0% was obtained. (6) The red photoresist prepared in Example 2 (Zap
on RED (CI Solvent Red 12
2) 335 2.47% by weight) as an exposure layer,
Rotation method (rotation speed 1) on the glass substrate obtained in (5)
000 rpm), put in oven and 90 ℃
For 10 minutes. (7) Using the photomask 40 having a lattice pattern as shown in FIG. 4, the glass substrate obtained in (6) is subjected to precise counter-point exposure (use exposure amount is 200 mj / c).
m ² ), and an ultraviolet light transmittance of 55% (λ = 365) in the pixel area.
nm). Then, the Fuji Film CD-2000 developer was diluted to 5% by weight of the stock solution using deionized water, developed at room temperature for 3 minutes, washed with deionized water, drained, and placed in an oven. Cured at ℃ for 1 hour. (8) The red photoresist prepared in Example 2 (Zap
on RED (CI Solvent Red 12
2) 335 4.82% by weight) as the exposure layer,
The photoresist was applied on the glass substrate obtained in (7) by a rotation method (rotation speed: 1000 rpm), and then baked in an oven at 90 ° C. for 10 minutes. (9) Using the photomask 40 having a lattice pattern as shown in FIG. 4, the glass substrate obtained in (8) is subjected to precise counter-exposure (the exposure amount used is 200 mj / c).
m ² ), and 30% ultraviolet light transmittance (λ = 365) in the pixel area.
nm). Then, the Fuji Film CD-2000 developer was diluted to 5% by weight of the stock solution using deionized water, developed at room temperature for 3 minutes, washed with deionized water, drained, and placed in an oven. The composition was cured at 1 ° C. for 1 hour to complete the fabrication of a four-level photomask. FIG. 5 is a diagram showing the four-layer photomask obtained in this manner.

[0023]

The reference numeral 60 in FIG. 6A is a cross-sectional view of the four-level photomask obtained in the embodiment of the present invention. As shown in the figure, a positive photoresist 6 that can be developed many times
When 4 is exposed through the four-layer photomask 60, a latent pattern as shown by a dotted line is formed because the degree of exposure varies from area to area. Thus, after the first development, patterns 64a having various film thicknesses are obtained as shown in FIG. 6B.

Although the preferred embodiments have been disclosed above, they do not limit the scope of the present invention in any way, and general modifications in the technical field can be made without departing from the effects of the present invention. . The manufacturing method of the novel multi-layer photomask of the present invention uses a light exposure process to produce an exposure layer having various patterns and various transmittances of ultraviolet light on a light-transmissive substrate material, and forming the same on a photomask. The necessary transmittance can be obtained by changing either the thickness of the coating film or the concentration of the ultraviolet light absorbing composition.

[Brief description of the drawings]

FIG. 1 is a diagram showing a photomask having a matrix pattern.

FIG. 2 is a diagram showing a photomask having a linear pattern.

FIG. 3 is a diagram illustrating a four-level photomask according to an embodiment of the present invention.

FIG. 4 is a diagram showing a photomask of a check pattern.

FIG. 5 illustrates another four-level photomask according to an embodiment of the present invention.

FIGS. 6a and 6b show changes in the thickness of a film obtained after a first development after a positive photoresist that can be developed many times is exposed through a four-level photomask according to an embodiment of the present invention. FIG.

[Explanation of symbols]

60 Cross-sectional view of four-layer photomask obtained in the embodiment of the present invention 62 Glass substrate 64 Positive photoresist 64a Pattern AB having various thickness

Claims (25)

[Claims] 1. A light-transmissive substrate, a mask layer provided on the light-transmissive substrate and having a pattern, and optionally a region on the light-transmissive substrate that is not covered by the mask layer. And a plurality of exposed areas containing the ultraviolet light absorbing composition, wherein the exposed areas have an ultraviolet light transmittance of 0 to 10
A multi-level photomask in which there is one or more types of areas that are between 0% and constitutes a multi-level pattern of the photomask. 2. The multi-layer photomask according to claim 1, wherein the light-transmitting substrate is made of quartz glass. 3. The multi-layer photomask according to claim 1, wherein the mask layer is made of a metal thin film. 4. The multi-layer photomask according to claim 3, wherein the mask layer is made of a metal thin film of Cr. 5. The multi-level photomask according to claim 1, wherein the material forming the exposed area is a photoresist. 6. The multi-layer photomask according to claim 1, wherein the material forming the exposure area is an etchable material having no photoresist function. 7. The multi-layer photomask according to claim 1, wherein the ultraviolet light absorbing composition is an ultraviolet light absorbing agent. 8. The method according to claim 1, wherein the ultraviolet light absorbing composition comprises a dye, a pigment,
The multi-layer photomask according to claim 1, wherein the photomask is selected from the group consisting of metal particles and an ultraviolet light absorber. 9. The multi-layer photomask according to claim 1, wherein the ultraviolet light transmittance of the exposed area is adjusted by changing the thickness of the exposed area. 10. The multi-layer photomask according to claim 1, wherein the ultraviolet light transmittance of the exposed area is adjusted by changing the concentration of the ultraviolet light absorbing material in the exposed area. . 11. The multi-layer photomask according to claim 1, wherein the ultraviolet light transmittance of the exposed area is adjusted by changing the composition of the ultraviolet light absorbing material in the exposed area. . 12. A step of (a) forming a mask layer having an ultraviolet light transmittance of 0% on a light-transmitting substrate; and (b) designing a pattern of the mask layer so that the ultraviolet light transmittance is 100%. And 0%
Forming a photomask pattern of (c), applying an exposure layer containing an ultraviolet light absorbing composition on the light-transmitting substrate, and (d) designing a pattern of the exposure layer; An ultraviolet light transmittance of 0 to 10 on the light transmitting substrate
Forming a photomask pattern that is between 0%. 13. The method of claim 12, wherein the light transmissive substrate in step (a) is made of quartz glass.
3. The method for manufacturing a multi-level photomask according to item 1. 14. The method of claim 12, wherein the mask layer in step (a) is a metal thin film. 15. The method according to claim 15, wherein the mask layer in step (a) is C
The method for manufacturing a multi-level photomask according to claim 14, wherein the method comprises a metal thin film. 16. The method of claim 12, wherein the exposure layer containing the ultraviolet light absorbing composition in step (c) comprises a photoresist. 17. The method according to claim 12, wherein in the step (d), a pattern of the exposure layer is designed by a light exposure process. 18. The multi-level photolithography according to claim 12, wherein the exposure layer containing the ultraviolet light absorbing composition in step (c) comprises an etchable material having no photoresist function. Manufacturing method of mask. 19. The method according to claim 18, wherein the step (d) designs the pattern of the exposure layer by light exposure and etching. 20. The method according to claim 12, wherein the ultraviolet light absorbing composition is an ultraviolet light absorbing agent. 21. The method of claim 12, wherein the ultraviolet light absorbing composition is selected from the group consisting of a dye, a pigment, metal particles, and an ultraviolet light absorber. . 22. The method of claim 12, wherein in step (c), the ultraviolet light transmittance of the exposed layer is adjusted by changing the thickness of the exposed layer. Law. 23. The method according to claim 12, wherein in step (c), the ultraviolet light transmittance of the exposed layer is adjusted by changing the concentration of the ultraviolet light absorbing composition in the exposed layer.
3. The method for manufacturing a multi-level photomask according to item 1. 24. The method according to claim 12, wherein in step (c), the ultraviolet light transmittance of the exposed layer is adjusted by changing the composition of the ultraviolet light absorbing composition in the exposed layer.
3. The method for manufacturing a multi-level photomask according to item 1. 25. Steps (c) and (d) are repeated,
13. The method of claim 12, wherein a photomask pattern of three or more layers is formed on the light transmitting substrate.