JPH06148869A - Production of phase shift mask - Google Patents

Abstract

PURPOSE:To provide the method for eliminating the generation of dust by cracking and peeling of a coating glass layer generated by calcination of the outer periphery and peripheral parts of the phase shift photomask. CONSTITUTION:This process for production of the phase shift photomask includes a process for coating the surface of a quartz substrate 1 with coating glass, a stage for irradiating photomask pattern regions with energy rays 10 and solidifying the coating glass with which these regions are coated and a stage for etching the coating glass, exclusive of these regions, which is not irradiated with the energy rays 10 and is not solidified by org. solution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
And a method for manufacturing a phase shift photomask having a transparent film for a phase shifter when a fine pattern is formed at a high density.

[0002]

2. Description of the Related Art Conventionally, semiconductor integrated circuits such as IC, LSI and VLSI are coated with a resist layer on a substrate to be processed such as a Si wafer, exposed to a desired pattern by a stepper, and then developed and etched. It is manufactured by repeating what is called a lithography process. A photomask called a reticle used in such a lithography process tends to be required to have a higher density as the semiconductor integrated circuit becomes more complicated and highly integrated.

The line width of the device pattern formed using these reticles is 1 Mbit DRAM.
1.2 μm, for 4M bit DRAM 0.8 μm,
The 16 Mbit DRAM is required to be further miniaturized to 0.5 μm, and various exposure methods are being researched in order to meet such a demand. However, for example, 64M
When it comes to a bit DRAM class device, 0.35μ
A pattern having a line width of m is required, and the conventional stepper exposure method using a reticle has reached the resolution limit of the resist pattern. To overcome this limit, for example, Japanese Patent Publication No. 173744/1983 is proposed. Kosho 62-
There is phase shift lithography that uses a phase shift reticle such as that shown in the '59296 publication. This is a technique for improving the contrast and resolution of a projected image by manipulating the phase of light that passes through a reticle.

The phase shift layer lithography will be briefly described with reference to the drawings. FIG. 4 is a diagram for explaining the principle of the phase shift photomask, and FIG. 5 is a diagram for explaining the principle of the photomask according to the conventional method. Figures 4 (a) and 5 (a) are cross-sectional views of the reticle, and Figures 4 (b) and 5 (b).
Is the light amplitude on the reticle, FIGS. 4 (c) and 5 (c) are the light amplitudes on the wafer, and FIGS. 4 (d) and 5 (d) are the light intensities on the wafer, respectively. A transparent substrate made of quartz or the like (hereinafter referred to as a substrate), 2 a light shielding layer made of chromium or the like (hereinafter referred to as a light shielding layer), 2p a light shielding pattern, 3 a transparent film for phase shifter, 3p a phase shifter pattern, 4 incident light Indicates.

In the conventional method, as shown in FIG. 5A, the light-shielding layer 2 is formed on the substrate 1 to form the light-transmitting portion having a predetermined pattern. As shown in FIG. 4A, a phase shifter pattern 3p made of a transmissive film for inverting the phase by 180 ° is provided on one of the adjacent light transmissive portions on the reticle. Therefore, in the conventional method, the light amplitude on the reticle is in phase as shown in Fig. 5 (b), and the light amplitude on the wafer is also shown in Fig. 5 (c). The above pattern cannot be separated. On the other hand, in the phase shift method in which the phase shifter pattern 3p is provided on one of the adjacent light transmitting parts, the amplitude of the light on the reticle is made to be the opposite phase between the adjacent patterns, as shown in Fig. 4 (b). Therefore, the amplitude of the light on the wafer also has the opposite phase, as shown in Fig. 4 (c). Therefore, the light intensity becomes zero at the boundary of the pattern, and the adjacent patterns can be clearly separated as shown in Fig. 4 (d). Thus, in phase shift lithography, patterns that could not be separated by the conventional method can be separated, which is useful as a means for improving the resolution.

Next, an example of the manufacturing process of the phase shift photomask will be described with reference to FIG. FIG. 6 is a cross-sectional view showing a manufacturing process of a shifter-mounted Levenson-type phase shift photomask. As shown in FIG. 6 (a), an etching stopper layer 6 (an etching stopper layer made of aluminum or the like is formed on a substrate 1 as follows). Etching stopper layer)
Then, as shown in FIG. 6B, the light shielding layer 2 is formed. Next, a resist layer 7 is formed on the light-shielding layer 2, and a predetermined pattern is drawn on the resist layer 7 by a conventional method as shown in FIG. ), A resist pattern 7p is formed.

Next, after performing a heat treatment and a descum treatment as needed, as shown in FIG. 6 (f), the light shielding layer 2 portion exposed from the opening of the resist pattern 7p is etched by an etching gas plasma 9. Dry etching.
As the etching gas, CCl ₄ + O ₂ , CH ₂ Cl
A mixed gas such as ₂ + O ₂ is used (the same material is used for the etching gas plasma for etching the light shielding layer below), and the remaining resist is removed to shield the light, as shown in FIG. 6 (g). A pattern 2p is formed. The formation of the light shielding pattern 2p may be performed by wet etching instead of dry etching by the etching gas plasma 9 (also in the following etching gas plasma etching, the wet method may be used instead of the dry method).

Next, as shown in FIG. 6 (h), a coating glass is spin-coated on the light-shielding layer 2 and then baked to form a transparent film 3 for phase shifter (transparent film for phase shifter made of coating glass or the like). The film is hereinafter referred to as a transparent film for phase shifter). Next, as shown in FIG. 6 (i), a resist layer 17 is formed on the transparent film 3 for phase shifter.
As shown in (j), the resist layer 17 is aligned according to a conventional method, and a predetermined pattern is drawn, developed and rinsed by the ionizing radiation 8 such as an electron beam exposure device, and then the pattern shown in FIG. As shown in FIG.
form p.

Next, after performing a heat treatment and a descum treatment as needed, as shown in FIG. 6 (l), the transparent film 3 for the phase shifter exposed from the opening of the resist pattern 17p is etched by the etching gas plasma. Dry etching is performed by 9 to remove the remaining resist to form a phase shifter pattern 3p as shown in FIG. 6 (m), and the shifter-mounted Levenson type phase shift photomask is completed. As the etching gas, CF ₄ , C ₂ F ₆ , C
HF ₃ , CHF ₃ + O ₂ and a mixed gas thereof are used (the same material is used for the etching gas plasma of the transparent film etching for the phase shifter below).

In addition to the shifter-upper type in which the phase shifter pattern 3p is on the light-shielding pattern 2p as described above, there is also proposed a shifter-downside type phase shift photomask in which the phase shifter pattern 3p is under the light-shielding pattern 2p. ing. The feature of this mask is that the transparent film 3 for the phase shifter can be formed on the flat substrate, so that the variation of the phase shifter pattern 3p in the photomask surface can be reduced.

An example of the manufacturing process of the shifter underlaying type phase shift photomask will be described with reference to FIG. FIG. 7 is a cross-sectional view showing a manufacturing process of a shifter-placed Levenson-type phase shift photomask. First, as shown in FIG. 7 (a), an alumina layer serving as an etching stopper layer 6 is formed on the substrate 1. Next, as shown in FIG. 7 (b), coating glass is spin-coated on the etching stopper layer 6 and then baked to form a transparent film 3 for phase shifter. Next, as shown in FIG. 7C, the light shielding layer 2 is formed on the transparent film 3 for phase shifter. Next, as shown in FIG. 7D, a resist layer 7 is formed on the light shielding layer 2. Next, as shown in FIG. 7 (e), a predetermined pattern is drawn by ionizing radiation 8 such as an electron beam exposure device, developed and rinsed to form a resist pattern 7p as shown in FIG. 7 (f). Form.

Next, after performing heat treatment and descum treatment as needed, as shown in FIG. 7 (g), the portion of the light shielding layer 2 exposed from the opening of the resist pattern 7p is dried by etching gas plasma 9. Etching, Figure 7
As shown in (h), the remaining resist is removed and the light shielding pattern 2p is formed.

Next, as shown in FIG. 7 (i), a resist layer 17 is formed on the light shielding pattern 2p. Next, Fig. 7 (j)
As shown in FIG. 7, a predetermined pattern is drawn by ionizing radiation 8 such as an electron beam exposure device, developed and rinsed, and then the pattern shown in FIG.
As shown in (k), a resist pattern 17p is formed. Next, after performing heat treatment and descum treatment as needed, as shown in FIG. 7L, the transparent film 3 for the phase shifter exposed from the opening of the resist pattern 17p is dry-etched by the etching gas plasma 9. Then
The phase shifter pattern 3p is formed. Next, the remaining resist is removed to complete the shifter-placed Levenson-type phase shift photomask as shown in FIG. 7 (m).

The above is the manufacturing process of the Levenson type phase shift photomask. In addition to these, a halftone type phase shift photomask in which a film having a light transmittance of 10% or more is provided on the upper and lower layers of the phase shifter pattern 3p is also proposed. The feature of this mask is that the number of manufacturing steps is smaller than that of the Levenson type mask in the manufacturing steps.

An example of the manufacturing process of the halftone type phase shift photomask will be described with reference to FIG. FIG. 8 is a cross-sectional view showing the manufacturing process of the halftone type phase shift photomask. First, as shown in FIG. 8 (a), the substrate 1
An alumina layer serving as an etching stopper layer 6 is formed on the top. Next, as shown in FIG. 8 (b), coating glass is spin-coated on the etching stopper layer 6 and then baked to form a transparent film 3 for phase shifter. Next, as shown in FIG. 8 (c), a chromium film serving as the light shielding layer 2 having a light transmittance of 10% is formed on the transparent film 3 for phase shifter. Next, as shown in FIG. 8D, a resist layer 7 is formed on the light shielding layer 2. Next, as shown in FIG. 8 (e), a predetermined pattern is drawn by ionizing radiation 8 such as an electron beam exposure device, developed and rinsed, and as shown in FIG. 8 (f),
A resist pattern 7p is formed.

Next, after performing heat treatment and descum treatment as required, as shown in FIG. 8 (g), the light shielding layer 2 exposed from the opening of the resist pattern 7p is dry-etched by the etching gas plasma 9. Then, Fig. 8 (h)
As shown in, the light shielding pattern 2p is formed. Next, after performing heat treatment and descum treatment as needed,
As shown in FIG. 8 (i), the phase shifter transparent film 3 exposed from the opening of the resist pattern 7p is dry-etched by the etching gas plasma 9 to form the phase shifter pattern 3p. Next, the remaining resist is removed, and the halftone type phase shift photomask is completed as shown in FIG.

[0017]

In the manufacturing process of the phase shift photomask as shown in FIG. 6, FIG. 7 and FIG. 8 above, the coated glass is spin-coated and then baked to form a transparent film for a phase shifter. When forming
The transparent film for the phase shifter on the outer periphery and the peripheral portion of the quartz substrate was peeled off, which caused defects such as dust generation in the photomask. An object of the present invention is to eliminate the above trouble.

[0018]

According to the present invention, the coated glass in the peripheral portion and the peripheral portion on the quartz substrate is removed before spin coating and baking the coated glass in the manufacturing process of the above phase shift photomask. In the method of manufacturing a phase shift photomask, on the substrate 1,
A step of coating the coated glass, a step of irradiating the photomask pattern region with the energy rays 10 to solidify the coated glass in the above-mentioned area, A method of manufacturing a phase shift photomask, comprising a step of etching with an organic solution. The photomask pattern area is an area effective as a photomask except for the outer peripheral portion and the peripheral portion on the quartz substrate. Further, as the above-mentioned energy rays 10, ultraviolet rays and X-rays are used.

The present invention will be described below with reference to the drawings. FIGS. 1, 2 and 3 are cross-sectional views illustrating a manufacturing process to which the present invention is applied to the conventional method of manufacturing the phase shift photomask of FIGS. 6, 7 and 8, respectively.

First, FIG. 1 is a sectional view for explaining an example of a manufacturing process of a shifter-mounted Levenson type phase shift photomask of the present invention. As shown in FIG. 1 (a), an etching stopper layer 6 is formed on the substrate 1, and then, as shown in FIG.
As shown in, the light shielding layer 2 is formed. Next, as shown in FIG. 1 (c), a resist layer 7 is formed on the light shielding layer 2,
As shown in (d), the resist layer 7 is aligned by a conventional method, and a predetermined pattern is drawn with ionizing radiation 8 from an electron beam exposure device or the like, developed, and rinsed, and then, as shown in FIG.
A resist pattern 7p is formed as shown in FIG.

Next, after performing a heat treatment and a descum treatment as needed, as shown in FIG. 1 (f), the light shielding layer 2 portion exposed from the opening of the resist pattern 7p is etched by the etching gas plasma 9. Dry etching.
Then, as shown in FIG. 1 (g), the remaining resist is removed to form a light shielding pattern 2p.

Next, as shown in FIG. 1 (h), coated glass is spin-coated on the light-shielding layer 2 and soft-baked to form a transparent film 3 for a phase shifter. Next, Fig. 1
As shown in (i), the outer periphery and the peripheral portion of the substrate 1 are masked by the light-shielding film 5, and the energy beam 10 is irradiated from above to solidify the transparent film 3 for phase shifter. Then, the portion not irradiated with the energy rays 10 is etched with an organic solvent to obtain the transparent film 3k for the phase shifter in the pattern area, in which the outer periphery and the peripheral portion of the substrate 1 are removed.

Next, as shown in FIG. 1 (k), a resist layer 17 is formed on the transparent film 3k for the phase shifter in the pattern area, and the resist layer 17 is formed by a conventional method as shown in FIG. 1 (l). According to the above, alignment is performed, a predetermined pattern is drawn by the ionizing radiation 8 such as an electron beam exposure device, developed and rinsed to form a resist pattern 17p as shown in FIG. 1 (m).

Next, after performing a heat treatment and a descum treatment as required, as shown in FIG. 1 (n), the transparent film 3k for the phase shifter in the pattern region exposed from the opening of the resist pattern 17p is etched. Dry etching is performed by the gas plasma 9, the remaining resist is removed and the phase shifter pattern 3p is formed as shown in FIG. 1 (o), and the shifter-mounted Levenson type phase shift photomask is completed.

Next, FIG. 2 is a sectional view showing a manufacturing process of a shifter-placed Levenson type phase shift photomask of the present invention. First, as shown in FIG. 2 (a), an alumina layer serving as an etching stopper layer 6 is formed on the substrate 1. Next, as shown in FIG. 2B, a coating glass is spin-coated on the etching stopper layer 6 and soft-baked to form a transparent film 3 for phase shifter. Next, as shown in FIG. 1C, the outer periphery and the peripheral portion of the substrate 1 are masked by the light shielding film 5, and the energy beam 10 is irradiated from above to solidify the transparent film 3 for the phase shifter. Then, the portion not irradiated with the energy ray 10 is etched with an organic solvent to obtain a transparent film 3k for a phase shifter in a pattern region in which the outer periphery and the peripheral portion of the substrate 1 are removed as shown in FIG. 2 (d). Next, as shown in FIG. 2E, the light shielding layer 2 is formed on the transparent film 3k for the phase shifter in the pattern area. Next, as shown in FIG. 2F, a resist layer 7 is formed on the light shielding layer 2. Next, as shown in FIG. 2 (g), alignment is performed according to a conventional method, a predetermined pattern is drawn by ionizing radiation 8 of an electron beam exposure device, etc., developed and rinsed, and then, as shown in FIG. 1 (h). As shown, a resist pattern 7p is formed.

Next, after performing heat treatment and descum treatment as needed, as shown in FIG. 2 (i), the light shielding layer 2 portion exposed from the opening of the resist pattern 7p is dried by etching gas plasma 9. Etching, Figure 1
As shown in (j), the remaining resist is removed and the light shielding pattern 2p is formed.

Next, as shown in FIG. 2K, a resist layer 17 is formed on the light shielding pattern 2p. Next, Fig. 2 (l)
As shown in FIG. 2, a predetermined pattern is drawn by the ionizing radiation 8 such as an electron beam exposure device, developed and rinsed, and then, as shown in FIG.
As shown in (m), a resist pattern 17p is formed. Next, after performing heat treatment and descum treatment as needed, as shown in FIG. 2 (n), the transparent film 3k for the phase shifter in the pattern region exposed from the opening of the resist pattern 17p is etched by the etching gas plasma 9 Dry etching is performed to form a phase shifter pattern 3p. Next, the remaining resist is removed to complete the shifter-placed Levenson-type phase shift photomask of the present invention as shown in FIG. 2 (o).

Next, FIG. 3 is a sectional view showing a manufacturing process of the halftone type phase shift photomask of the present invention. First, as shown in FIG. 3 (a), an alumina layer to be the etching stopper layer 6 is formed on the substrate 1. Next, as shown in FIG. 3 (b), the etching stopper layer 6
The coated glass is spin-coated on top and soft-baked to form the transparent film 3 for the phase shifter. Next, FIG.
As shown in (c), the outer periphery and the peripheral portion of the substrate 1 are masked by the light shielding film 5, and the energy beam 10 is irradiated from above to solidify the transparent film 3 for phase shifter. Then, the portion not irradiated with the energy beam 10 is etched with an organic solvent and baked, and then the substrate 1 is removed as shown in FIG. 3 (d).
A transparent film 3k for a phase shifter in a pattern area of the present invention is obtained by removing the outer periphery and the peripheral portion.

Next, as shown in FIG. 3 (e), a chromium film serving as the light-shielding layer 2 having a light transmittance of 10% is formed on the phase shifter transparent film 3. Next, as shown in FIG. 3F, a resist layer 7 is formed on the light shielding layer 2. Next, as shown in FIG. 3 (g), a predetermined pattern is drawn by ionizing radiation 8 such as an electron beam exposure device, developed, and rinsed.
A resist pattern 7p is formed as shown in FIG.

Next, after performing heat treatment and descum treatment as needed, as shown in FIG. 3 (i), the light shielding layer 2 exposed from the opening of the resist pattern 7p is dry-etched by the etching gas plasma 9. Then, Fig. 3 (j)
As shown in, the light shielding pattern 2p is formed. Next, as shown in FIG. 3 (k), the transparent film 3k for the phase shifter in the pattern area exposed from the opening of the resist pattern 7p is dry-etched by the etching gas plasma 9,
As shown in FIG. 3 (l), a phase shifter pattern 3p is formed. Next, the remaining resist is removed, and the halftone type phase shift photomask of the present invention is completed as shown in FIG.

[0031]

In the present invention, as described above, the outer peripheral portion and peripheral portion coating glass other than the photomask region, which becomes the transparent film for the phase shifter, is removed before firing, so that the portion to be removed may be cracked or peeled. Dust generation can be eliminated and the number of defects in the photomask manufacturing process can be greatly reduced.

[0032]

Example 1 An alumina film to be an etching stopper layer is formed on a quartz substrate. Next, a chromium film is formed as a light shielding layer on the etching stopper layer by a sputtering method. Next, SAL603 (Shipley Co.) resist is spin-coated to a film thickness of about 500 nm. Next, the alignment is performed according to a conventional method, and the SAL is set by an electron beam exposure apparatus.
603 is drawn. Develop, rinse, SAL603
A resist pattern is formed. Next, the chrome film exposed from the opening of the SAL603 resist pattern is removed by CCl ₄
It is removed by reactive plasma etching using + O ₂ , CH ₂ Cl ₂ + O ₂ or the like. Then, the remaining resist is removed by oxygen plasma to obtain a chromium pattern.

Next, Accugla is formed on the chrome pattern.
ss-211S (made by Allied Signal Co.) coated glass is spin-coated. Then, after the soft bake, deep ultraviolet rays are radiated to a portion excluding the peripheral portion and the peripheral portion of the quartz substrate by using a mask aligner, a stepper and the like. next,
Develop with methyl alcohol and rinse with pure water to remove the coated glass on the peripheral and peripheral areas. Then 200 ℃
The transparent film for the phase shifter in the pattern area is formed by firing at ~ 800 ° C.

Next, SAL603 (Shipley Co., Ltd.) resist is spin-coated on the coated glass to a film thickness of about 500 nm. Next, the alignment is performed according to a conventional method, and the SAL is set by an electron beam exposure apparatus.
603 is drawn. Develop, rinse, SAL603
A resist pattern is formed. Next, after performing heat treatment and descum treatment as needed, the transparent film for phase shifter in the pattern area exposed through the opening of the SAL603 resist pattern is CF ₄ , C ₂ F ₆ , CHF ₃ , CF.
It is removed by dry etching using HF ₃ + O ₂ and a mixed gas thereof to form a phase shifter pattern. Next, the remaining resist pattern is removed by ashing with oxygen plasma, and a Levenson type phase shift photomask is completed by placing it on a shifter. Note that the resist can be removed by a wet method, instead of dry etching using oxygen plasma, using a resist-dedicated stripping solution, acid, or the like.

Example 2 An alumina film to be an etching stopper layer is formed on a quartz substrate. Next, Accuglass-211S (allied.
Signal Co., Ltd.) The coated glass is spin-coated.
Then, after the soft bake, deep ultraviolet rays are radiated to a portion excluding the peripheral portion and the peripheral portion of the quartz substrate by using a mask aligner, a stepper and the like. Next, it is developed with methyl alcohol and rinsed with pure water to remove the coated glass on the peripheral portion and the peripheral portion. Then, it is baked at 200 ° C. to 800 ° C. to form a transparent film for a phase shifter in the pattern area.

Next, a chromium film is formed as a light shielding layer on this film by the sputtering method. Next, SAL60
3 (manufactured by Shipley) is spin-coated to a film thickness of about 500 nm. Next, alignment is performed according to a conventional method, and SAL603 is drawn by an electron beam exposure apparatus. Develop, rinse, S
An AL603 resist pattern is formed. Next, SAL
The chromium film exposed from the opening of the 603 resist pattern is removed by reactive plasma etching using CCl ₄ + O ₂ , CH ₂ Cl ₂ + O ₂ or the like. Then, the remaining resist is removed by oxygen plasma to obtain a chromium pattern. Note that the resist can be removed by a wet method, instead of dry etching using oxygen plasma, using a resist-dedicated stripping solution, acid, or the like.

Next, SAL603 is formed on the chrome pattern.
A resist (manufactured by Shipley Co., Ltd.) is spin-coated to a film thickness of about 500 nm. Next, alignment is performed according to a conventional method, and an electron beam exposure apparatus is used to
Drawing of SAL603 is performed. Develop, rinse, SAL
A 603 resist pattern is formed. Next, after performing heat treatment and descum treatment as needed, SAL6
03 The transparent film for the phase shifter in the pattern area exposed from the opening of the resist pattern is CF ₄ , C ₂ F ₆ , and CHF.
By dry etching using ₃ , CHF ₃ + O ₂ and their mixed gas, the remaining resist pattern is ashed and removed by oxygen plasma to complete a Levenson type phase shift photomask placed under a shifter. Note that the resist can be removed by a wet method, instead of dry etching using oxygen plasma, using a resist-dedicated stripping solution, acid, or the like.

Example 3 An alumina film to be an etching stopper layer is formed on a quartz substrate. Next, Accuglass-211S (allied.
Signal Co., Ltd.) The coated glass is spin-coated.
Then, after the soft bake, deep ultraviolet rays are radiated to a portion excluding the peripheral portion and the peripheral portion of the quartz substrate by using a mask aligner, a stepper and the like. Next, it is developed with methyl alcohol and rinsed with pure water to remove the coated glass on the peripheral portion and the peripheral portion. Then, it is baked at 200 ° C. to 800 ° C. to form a transparent film for a phase shifter in the pattern area.

Next, a light transmittance of 1% to 50% is formed on this film.
A chromium film is formed as a light-shielding layer by a sputtering method so that Next, SAL603 (Shipley Co.) resist is spin-coated to a film thickness of about 500 nm. Next, alignment is performed according to a conventional method, and SAL603 is drawn by an electron beam exposure apparatus. After development and rinsing, a SAL603 resist pattern is formed. Next, the chrome film exposed from the opening of the SAL603 resist pattern was removed with CCl ₄ + O ₂ ,
It is removed by reactive plasma etching using CH ₂ Cl ₂ + O ₂ or the like. Then, the remaining resist is removed by oxygen plasma to obtain a chromium pattern. Note that the resist can be removed by a wet method, instead of dry etching using oxygen plasma, using a resist-dedicated stripping solution, acid, or the like.

Next, after performing heat treatment and descum treatment as needed, the transparent film for the phase shifter in the pattern area exposed from the opening of the SAL603 resist pattern is CF ₄ , C ₂ F ₆ , CHF ₃ , CHF. ₃ + O ₂ and a mixed gas of these gases are removed by dry etching, and the remaining resist pattern is removed by ashing with oxygen plasma to complete a halftone type phase shift photomask. Note that the resist can be removed by a wet method, instead of dry etching using oxygen plasma, using a resist-dedicated stripping solution, acid, or the like.

[0041]

According to the method of manufacturing a phase shift photomask of the present invention, after coating the coated glass which becomes the transparent film for the phase shifter, the outer peripheral portion and the peripheral portion on the quartz substrate which cause peeling before firing are peeled off. Since the coated glass is removed, it is possible to eliminate the dust generated by cracking and peeling of the coated glass layer caused by firing, and as a result, the number of defects in the manufacturing process of the phase shift photomask can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating an example of a manufacturing process of a shifter-mounted Levenson-type phase shift photomask of the present invention.

FIG. 2 is a cross-sectional view illustrating an example of a manufacturing process of a shifter-placed Levenson-type phase shift photomask of the present invention.

FIG. 3 is a cross-sectional view illustrating an example of the manufacturing process of the halftone phase shift photomask of the present invention.

FIG. 4 is a diagram illustrating the principle of a phase shift photomask.

FIG. 5 is a diagram illustrating the principle of a photomask according to a conventional method.

FIG. 6 is a cross-sectional view illustrating an example of a manufacturing process of a conventional shifter-mounted Levenson-type phase shift photomask.

FIG. 7 is a cross-sectional view illustrating an example of a manufacturing process of a conventional shifter-placed Levenson-type phase shift photomask.

FIG. 8 is a cross-sectional view illustrating an example of a manufacturing process of a conventional halftone type phase shift photomask.

[Explanation of symbols]

 1 substrate 2 light-shielding layer 2p light-shielding pattern 3 transparent film for phase shifter 3k transparent film for phase shifter in pattern area 3p phase shifter pattern 4 incident light 5 light-shielding film 6 etching stopper layer 7 resist layer 7p resist pattern 8 ionizing radiation 9 etching gas plasma 10 energy ray 17 resist layer 17p resist pattern

Claims (3)

[Claims] 1. A method of manufacturing a phase shift photomask, comprising the steps of coating glass on a substrate (1) and irradiating an energy ray (10) on a photomask pattern area to form the coated glass on the area. A method of manufacturing a phase shift photomask, comprising a step of solidifying and a step of etching a coated glass, which has not been solidified by being irradiated with an energy ray (10) other than the above-mentioned region, with an organic solution. 2. The method of manufacturing a phase shift photomask according to claim 1, wherein the transparent film for phase shifter (3) is formed only in the photomask pattern region. 3. The method for producing a phase shift photomask according to claim 1, wherein ultraviolet rays or X-rays are used as the energy rays (10).