TW201707956A - Phase shift mask blank, method for manufacturing phase shift mask using the same and method for manufacturing display device having an excellent pattern cross-section shape and an excellent CD uniformity - Google Patents

Abstract

The present invention provides a phase shift mask blank. The phase shift mask blank is used in a phase shift mask for a display device having an excellent pattern cross-section shape, an excellent CD (crystal display) uniformity and a tiny pattern. A phase shift film containing chromium series material is arranged on a transparent substrate, and includes: a phase shift layer; a reflectance reduction layer; and a metal layer disposed between the phase shift layer and the reflectance reduction layer, and having an extinction coefficient higher than the extinction coefficient of the reflectance reduction layer in a wavelength band of 350 nm to 436 nm. Furthermore, the phase shift film satisfies specific optical property for serving as a phase shift film to the transmissivity and phase difference of exposure light, and the film surface reflectance of the phase shift film is 10% or less in a wavelength band of 350 nm to 436 nm.

Description

Phase shift mask substrate, method of manufacturing phase offset mask using same, and method of manufacturing display device

The present invention relates to a phase shift mask substrate, a method of manufacturing a phase shift mask using the same, and a method of manufacturing a display device.

In recent years, with the high resolution and high definition of display devices such as FPD (Flat Panel Display), an excellent pattern cross-sectional shape and excellent CD (liquid crystal display) uniformity have been sought. A phase shift mask for a display device having a fine pattern is formed.

Moreover, it is necessary to reduce the manufacturing cost of the phase shift mask by the influence of the low cost of the display device such as FPD. When the previous phase shift mask substrate of the light-shielding film is formed on the phase shift film, the light-shielding film is etched using the resist pattern as a mask to form a light-shielding film pattern, and thereafter, the light-shielding film pattern is formed. The film pattern is etched as a mask to form a phase shift film pattern, and then the resist film pattern is peeled off, and the light-shielding film pattern is peeled off to produce a phase shift film having a phase shift film pattern. Shift cover. On the other hand, when the phase shifting film is not formed with the phase shifting mask base of the light-shielding film, the step of forming the light-shielding film pattern on the phase-shifting film and the peeling step are not required, so that the manufacturing cost can be reduced. .

Corresponding to such a recent situation, it is required to have an excellent pattern cross-sectional shape and excellent CD uniformity and a fine pattern formed using a phase shift mask substrate on which a light-shielding film is not formed on a phase shift film. A phase shift mask for the display device.

For example, Patent Document 1 proposes a method in which two layers are laminated on a transparent substrate. A phase shifting reticle substrate for a display device of a phase shifting film formed of a film. The films constituting the phase shifting film have mutually different compositions, but include materials which can be etched by the same etching solution, and have different etching rates depending on the composition. In Patent Document 1, when the phase shift film is patterned, the etching speed of each film constituting the phase shift film is adjusted to steeply form the slope of the edge portion of the phase shift film pattern.

Further, Patent Document 1 proposes that a transfer pattern including a light-shielding film, a semi-transmissive film, an etching stopper film, and a hard mask film is disposed on the upper or lower portion of the phase inversion film. A phase shift mask substrate for a display device for a functional film of more than one film in a film.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2014-26281

The phase shifting film used in the phase shifting mask for the display device previously proposed does not take into account the laser light used for patterning by the resist film used for forming the phase shift film pattern. Designed by the influence of reflection on the resist film. Therefore, the phase shift film has a film surface reflectance of more than 20% for laser light. As a result, a standing wave is generated in the resist film, the CD uniformity of the resist pattern is deteriorated, and even the CD uniformity of the phase shift film pattern formed by patterning the resist pattern as a mask cannot satisfy the recent years. The situation of the required value.

Accordingly, the present invention has been made in view of the above problems, and an object thereof is to provide a phase shift for reducing a film surface reflectance of light in a wavelength region of 350 nm to 436 nm used as laser drawing light. a phase shift mask substrate for forming a phase shift mask for a display device having an excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern, and a phase shift mask using the same Production method. Further, this issue The purpose of the present invention is to provide a high-resolution, high-definition display device manufacturing method by using a phase shift mask for a display device having an excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern.

The present inventors have made an effort to achieve the above object, and have obtained the following findings: a phase shift film can be formed by at least three layers, and the composition or film thickness of each layer constituting the phase shift film can be designed while making the phase shift The transmittance and phase difference of the film to be exposed to light satisfy the specific optical characteristics required for the phase shift film, and the film surface reflectance of the light in the wavelength region of 350 nm to 436 nm is lowered by the phase shift film.

The present invention has been based on the above findings and has the following constitution.

(Composition 1)

A phase shifting reticle substrate, characterized in that it is provided with a phase shifting film comprising a chrome-based material on a transparent substrate, and the phase shifting film has a phase shifting layer, which mainly has an adjustment for exposure light. a function of transmittance and phase difference; a reflectance reducing layer disposed on an upper side of the phase shifting layer and having a function of lowering a reflectance of light incident from the phase shifting film side; a metal layer Arranging between the phase shifting layer and the reflectance reducing layer, and having an extinction coefficient higher than an extinction coefficient of the reflectance reducing layer in a wavelength region of 350 nm to 436 nm; a laminated structure of the metal layer and the reflectance reducing layer, wherein the phase shifting film has specific optical characteristics with respect to transmittance and phase difference of exposure light, and the phase shifting film is incident on the side opposite to the phase shifting film The film surface reflectance of light is 10% or less in the wavelength region of 350 nm to 436 nm.

(constituent 2)

A phase shift mask substrate characterized in that it is provided with a phase shift film containing a chromium-based material on a transparent substrate, and The phase shifting film has a phase shifting layer mainly having a function of adjusting transmittance and phase difference with respect to exposure light, and a reflectance reducing layer disposed on an upper side of the phase shifting layer and having a function of reducing the reflectance of light incident on the phase shifting film side; the metal layer disposed between the phase shifting layer and the reflectance reducing layer, and having a higher chromium content than the reflectance reducing layer The chromium content; the phase shifting film has a specific optical characteristic for the transmittance and phase difference of the exposure light by the laminated structure of the phase shifting layer, the metal layer, and the reflectance reducing layer, and the phase shift is The film transfer film has a film reflectance of light incident from the side of the phase shift film side of 10% or less in a wavelength region of 350 nm to 436 nm.

(constitution 3)

In the phase shift mask substrate according to the first or second aspect, the film surface reflectance of the phase shift film has a variation range of 5% or less in a wavelength region of 350 nm to 436 nm.

(construction 4)

The phase shift mask substrate according to the first or second aspect, wherein the phase shift film has a film surface reflectance of 13% or less in a wavelength region of 313 nm to 436 nm.

(Constituent 5)

In the phase shift mask substrate according to the fourth aspect, the film surface reflectance of the phase shift film has a variation range of 10% or less in a wavelength region of 313 nm to 436 nm.

(constituent 6)

The phase shift mask substrate according to any one of the first to fifth aspect, wherein the light-shielding film pattern is provided between the transparent substrate and the phase shift film.

(constituent 7)

A method of manufacturing a phase-shifting reticle, comprising the steps of: ???the phase shifting film of the phase shifting reticle substrate according to any one of 1 to 6; Depiction of laser light at any wavelength in the wavelength region of ~436 nm Processing and development processing to form a resist pattern; and etching the phase shift film as a mask to form a phase shift film pattern on the transparent substrate.

(Composition 8)

A method of manufacturing a display device, comprising the steps of: placing a phase shift mask manufactured by the manufacturing method described in the seventh embodiment on a mask stage of an exposure apparatus; and irradiating the phase shift mask The light is exposed, and the phase shift film pattern is transferred to a resist film formed on a substrate of the display device.

(constituent 9)

In the method of manufacturing a display device according to the eighth aspect of the invention, the exposure light is a composite light including light of a plurality of wavelengths selected from a wavelength region of 313 nm to 436 nm.

As described above, the phase shift mask substrate of the present invention is provided on the transparent substrate, and the phase shift film containing the chromium-based material has a phase shift layer, a reflectance reducing layer, and a phase shift layer and a reflectance. a metal layer having a higher extinction coefficient than the reflectance reducing layer in the wavelength region between 350 nm and 436 nm, and the transmittance and phase difference of the phase shift film for the exposure light satisfy the phase shift The specific optical characteristics required for the film, and the film surface reflectance of the phase shift film is 10% or less in the wavelength region of 350 nm to 436 nm. Therefore, the phase shift mask substrate can be used to produce a phase shift mask having an excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern. Further, the phase shift mask can be used to manufacture a high resolution and high definition display device.

Further, another phase shift mask substrate of the present invention is provided on a transparent substrate, and the phase shift film comprising a chromium-based material has a phase shift layer, a reflectance reducing layer, and a phase shift layer and a reflectance. Lowering the chromium between the layers with a higher chromium content than the reflectance lowering layer The metal layer of the content rate, and the transmittance and phase difference of the phase shift film for the exposure light satisfy the specific optical characteristics required for the phase shift film, and the film surface reflectance of the phase shift film is at a wavelength of 350 nm to 436 nm. The area is below 10%. Therefore, the phase shift mask substrate can be used to produce a phase shift mask having an excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern. Further, the phase shift mask can be used to manufacture a high resolution and high definition display device.

10‧‧‧ phase offset mask base

20‧‧‧Transparent substrate

30‧‧‧ phase offset film

31‧‧‧phase offset layer

32‧‧‧Reflectance reduction layer

33‧‧‧metal layer

40‧‧‧ opaque film pattern

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the constitution of a film of a phase shift mask base.

Fig. 2 is a schematic view showing the constitution of other films of the phase shift mask substrate.

Figure 3 is a film surface reflectance spectrum of a phase shifting film of the phase shift mask substrate of Examples 1, 3, and 4.

Fig. 4 is a film surface reflectance spectrum of a phase shift film of the phase shift mask substrate of Comparative Examples 1 and 2.

Fig. 5 is a film surface reflectance spectrum of a phase shift film of the phase shift mask substrate of Comparative Examples 1 and 3.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the following embodiment is one embodiment of the present invention, and the present invention is not limited to the scope. In addition, in the drawings, the same or equivalent portions are denoted by the same reference numerals, and the description thereof is simplified or even omitted.

Embodiment 1.

In the first embodiment, the phase shift mask base will be described.

Fig. 1 is a schematic view showing the film constitution of the phase shift mask substrate 10. The phase shift mask substrate 10 includes a transparent substrate 20 that is transparent to exposure light, and a phase shift film 30 that includes a chromium-based material disposed on the transparent substrate 20. When the transparent substrate 20 is set to have no surface reflection loss, it has a transmittance of 85% or more for the exposure light, and preferably a transmittance of 90% or more. phase The offset film 30 has a phase shift layer 31, a metal layer 33, and a reflectance reducing layer 32 which are sequentially disposed from the transparent substrate 20 side. The phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32 are each formed of a chromium-based material containing chromium (Cr). Therefore, the phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32 can be etched by the same etching solution.

The phase shift layer 31 is disposed on the main surface of the transparent substrate 20. The phase shift layer 31 has a function of adjusting the transmittance and phase difference with respect to the exposure light.

The phase shift layer 31 is formed of a chromium compound containing at least one of chromium (Cr), oxygen (O), and nitrogen (N). Further, the phase shift layer 31 may be formed of a chromium compound containing at least one of chromium (Cr), oxygen (O), and nitrogen (N) and further containing at least one of carbon (C) and fluorine (F). . For example, examples of the material for forming the phase shift layer 31 include CrO, CrN, CrOFCrNF, CrON, CrCO, CrCN, CrOCN, CrFCO, and CrFCON.

The phase shift layer 31 can be formed by sputtering.

The reflectance reducing layer 32 is disposed on the upper side of the phase shift layer 31. The reflectance reducing layer 32 has a function of lowering the reflectance of light incident on the side of the phase shift film 30 (that is, the side of the reflectance reducing layer 32 opposite to the transparent substrate 20 side).

The reflectance reducing layer 32 is formed of a chromium compound containing chromium (Cr) and oxygen (O). Further, the reflectance reducing layer 32 may be formed of a chromium compound containing at least one of chromium (Cr) and oxygen (O) and further containing nitrogen (N), carbon (C), and fluorine (F). For example, examples of the material for forming the reflectance reducing layer 32 include CrO, CrON, CrCO, CrOF, CrOCN, and CrFON.

The reflectance reducing layer 32 can be formed by sputtering.

The metal layer 33 is disposed between the phase shift layer 31 and the reflectance reducing layer 32. The metal layer 33 has a function of adjusting the transmittance to the exposure light, and has a function of lowering the reflectance of the light incident on the side of the phase shift film 30 in combination with the reflectance reducing layer 32.

The metal layer 33 is formed of chromium (Cr) or a chromium compound containing at least one of chromium (Cr), carbon (C), and nitrogen (N). Moreover, the metal layer 33 may also contain chromium (Cr), carbon (C), and nitrogen. It is formed by at least one of (N) and further comprising a chromium compound of at least one of oxygen (O) and fluorine (F). For example, examples of the material for forming the metal layer 33 include Cr, CrC, CrN, CrCN, CrCO, and CrCF.

Since the metal layer 33 is provided, the sheet resistance of the phase shift film is lowered, so that charging of the phase shift mask base and the phase shift mask can be prevented. When the metal layer 33 is not provided, the electricity generated when the phase shift mask substrate and the phase shift mask are moved in and out of the housing does not escape, and the phase shift mask base and the phase shift mask are It stores electricity in the middle, so it is easy to attach foreign matter. Moreover, when the phase shift mask is formed with a small pattern, it is easy to cause the electric self-pattern to enter the pattern, resulting in electrostatic breakdown.

The metal layer 33 can be formed by sputtering.

The metal layer 33 has an extinction coefficient higher than the extinction coefficient of the reflectance reducing layer 32 in the wavelength region of 350 nm to 436 nm. Further, it is preferable that the extinction coefficient higher than the extinction coefficient of the reflectance reducing layer 32 is in the wavelength region of 313 nm to 436 nm.

The difference between the extinction coefficient of the metal layer 33 and the extinction coefficient of the reflectance reducing layer 32 is preferably from 1.5 to 3.5, more preferably from 1.8 to 3.5. When the difference between the extinction coefficients is 1.5 to 3.5, the reflectance in the wavelength region (wavelength region of 350 nm to 436 nm or wavelength region of 313 nm to 436 nm) at the interface between the metal layer 33 and the reflectance reducing layer 32 can be increased, and thus the reflectance is improved. It is preferable to further exert the effect of reducing the reflectance.

Further, the metal layer 33 has an extinction coefficient higher than the extinction coefficient of the phase shift layer 31 in the wavelength region of 350 nm to 436 nm. Further, it is preferable that the extinction coefficient higher than the extinction coefficient of the phase shift layer 31 is in the wavelength region of 313 nm to 436 nm.

The extinction coefficient can be measured using an n&k analyzer, an ellipsometer, or the like.

The metal layer 33 has a chromium (Cr) content (atomic %) higher than the chromium (Cr) content (atomic %) of the reflectance reducing layer 32.

The difference between the Cr content of the metal layer 33 and the Cr content of the reflectance reducing layer 32 is preferably from 10 to 80% by atom, more preferably from 15 to 80% by atom. If the difference in Cr content is 10 to 80 atoms % can increase the reflectance in the above-mentioned wavelength region (wavelength region of 350 nm to 436 nm or wavelength region of 313 nm to 436 nm) at the interface between the metal layer 33 and the reflectance reducing layer 32, so that the reflectance reducing effect can be further exhibited. Therefore, it is preferred. Further, the etching rate of the metal layer 33 can be adjusted by including nitrogen (N), oxygen (O), carbon (C), and fluorine (F) in the chromium (Cr) as a chromium compound. For example, the wet etching rate can be slowed down by including carbon (C) or fluorine (F) in chromium (Cr), and nitrogen (N) or oxygen (O) can be contained in chromium (Cr). Speed up the wet etching process. The etched phase can be shifted by considering the wet etching rate of the phase shift layer 31 and the reflectance reducing layer 32 formed on the metal layer 33, and the chromium compound added with the above element in the chromium. The cross-sectional shape of the film 30 becomes good.

Further, the metal layer 33 has a chromium (Cr) content ratio higher than that of the phase shift layer 31.

The Cr content can be measured using an Oujie electronic spectroscopic device or an X-ray photoelectron spectroscopy device (XPS).

Each of the phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32 preferably has a refractive index of 2.0 or more in a wavelength region of 350 nm to 436 nm. When the refractive index of 2.0 or more is obtained, the film thickness of the phase shift film 30 required to obtain desired optical characteristics (transmittance and phase difference) can be made thin. Therefore, the phase shift mask produced by using the phase shift mask substrate 10 including the phase shift film 30 can have a phase shift film pattern having an excellent pattern cross-sectional shape and excellent CD uniformity.

The refractive index can be measured using an n&k analyzer or an ellipsometer.

The phase shift film 30 has specific optical characteristics with respect to the transmittance and phase difference of the exposure light by the laminated structure of the phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32.

The transmittance of the phase shift film 30 to the exposure light satisfies the value required as the phase shift film 30. The transmittance of the phase shift film 30 is preferably 1% to 20%, more preferably 3% to 10%, with respect to light of a specific wavelength (hereinafter referred to as a representative wavelength) included in the exposure light. That is, the exposure light is a composite light of light having a wavelength range of 313 nm or more and 436 nm or less. In the case, the phase shift film 30 has the above-described transmittance for light of a representative wavelength included in the wavelength range. For example, when the exposure light is a composite light including an i-line, an h-line, and a g-line, the phase shift film 30 has the above-described transmittance for any of the i-line, the h-line, and the g-line.

The phase difference of the phase shift film 30 with respect to the exposure light satisfies the value required as the phase shift film 30. The phase difference of the phase shift film 30 is preferably from 160 to 200, more preferably from 170 to 190, with respect to the light of the representative wavelength included in the exposure light. By this property, the phase of the light of the representative wavelength included in the exposure light can be changed by 160° to 200°. Therefore, a phase difference of 160 to 200° is generated between the light of the representative wavelength transmitted through the phase shift film 30 and the light of the representative wavelength transmitted only through the transparent substrate 20. That is, in the case where the exposure light is a composite light including light in a wavelength range of 313 nm or more and 436 nm or less, the phase shift film 30 has the above-described phase difference with respect to light of a representative wavelength included in the wavelength range. For example, when the exposure light is a composite light including an i line, an h line, and a g line, the phase shift film 30 has the above-described phase difference for any of the i line, the h line, and the g line.

The transmittance and phase difference of the phase shift film 30 can be controlled by adjusting the composition and thickness of each of the phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32 constituting the phase shift film 30. Therefore, in this embodiment, the composition and thickness of each of the phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32 are adjusted such that the transmittance and the phase difference of the phase shift film 30 have the specific optical characteristics described above. . Furthermore, the transmittance of the phase shift film 30 is mainly affected by the composition and thickness of the phase shift layer 31 and the metal layer 33. The refractive index of the phase shift film 30 is mainly affected by the composition and thickness of the phase shift layer 31.

The transmittance and the phase difference can be measured using a phase shift amount measuring device or the like.

The phase shift film 30 has a film surface reflectance of light incident from the side of the phase shift film 30 of 10% or less in a wavelength region of 350 nm to 436 nm. Further, it is preferably 13% or less in a wavelength region of 313 nm to 436 nm. In other words, it is preferable that the phase shift film 30 has a film surface reflectance of light incident from the side of the phase shift film 30 of 10% or less in a wavelength region of 350 nm to 436 nm, and even if the wavelength region is expanded to 313 nm to 436 nm. It is 13% or less. Phase shift When the film surface reflectance of the film 30 is 10% or less in the wavelength region of 350 nm to 436 nm, the film surface reflectance of the laser light is lowered, so that a phase shift mask having excellent CD uniformity can be formed. Further, when the film surface reflectance of the phase shift film 30 is 13% or less in the wavelength region of 313 nm to 436 nm, the film surface reflectance of the exposure light is lowered, so that the pattern formed in the phase shift mask is turned At the time of printing, blurring (flashing) of the transfer pattern due to reflected light from the substrate of the display device can be prevented.

The fluctuation range of the film surface reflectance of the phase shift film 30 is preferably 9% or less in the wavelength region of 350 nm to 436 nm, and more preferably 8.5% or less. Further, it is preferably 12.5% or less, more preferably 12%, in the wavelength region of 313 nm to 436 nm. In other words, it is preferable that the fluctuation range of the film surface reflectance of the phase shift film 30 is 9% or less in the wavelength region of 350 nm to 436 nm, and further preferably 8.5% or less, and it is preferable to expand the wavelength region to 313 nm. ~436nm is also 12.5% or less, and further 12% or less.

The film reflectance of the phase shift film 30 and its fluctuation range can be performed by the refractive index, the extinction coefficient, and the thickness of each of the phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32 constituting the phase shift film 30. Adjust and control. The extinction coefficient and the refractive index can be controlled by adjusting the composition. Therefore, in the embodiment, the phase shift layer 31 is adjusted such that the film surface reflectance of the phase shift film 30 and the fluctuation range thereof have the specific physical properties described above. The composition and thickness of each of the metal layer 33 and the reflectance reducing layer 32. Furthermore, the film reflectance of the phase shift film 30 and its fluctuation range are mainly affected by the composition and thickness of each of the metal layer 33 and the reflectance reducing layer 32.

The film surface reflectance can be measured using a spectrophotometer or the like. The fluctuation range of the film surface reflectance can be obtained from the difference between the maximum reflectance and the minimum reflectance in the wavelength region of 350 nm to 436 nm or 313 nm to 436 nm.

The phase shift layer 31 may be a case of including a single film having a uniform composition, a case of including a plurality of films having different compositions, or a case of including a single film which continuously changes in the thickness direction. The metal layer 33 and the reflectance reducing layer 32 are also the same.

2 is a schematic view showing the constitution of other films of the phase shift mask substrate 10. As shown in Figure 2 The phase shift mask substrate 10 may be a light-shielding film pattern 40 provided between the transparent substrate 20 and the phase shift film 30.

When the phase shift mask substrate 10 is provided with the light-shielding film pattern 40, the light-shielding film pattern 40 is disposed on the main surface of the transparent substrate 20. The light-shielding film pattern 40 has a function of blocking transmission of exposure light.

The material forming the light-shielding film pattern 40 is not particularly limited as long as it has a function of blocking the transmission of the exposure light. For example, a chromium-based material can be cited. Examples of the chromium-based material include chromium (Cr) or a chromium compound containing at least one of chromium (Cr), carbon (C), and nitrogen (N). Further, a chromium compound containing at least one of chromium (Cr), oxygen (O), and fluorine (F) or at least one of chromium (Cr), carbon (C), and nitrogen (N) may be cited and further included a chromium compound of at least one of oxygen (O) and fluorine (F). For example, examples of the material for forming the light-shielding film pattern 40 include Cr, CrC, CrN, and CrCN.

The light-shielding film pattern 40 can be formed by patterning a light-shielding film formed by sputtering.

In the portion in which the phase shift film 30 and the light-shielding film pattern 40 are laminated, the optical density with respect to the exposure light is preferably 3 or more, and more preferably 3.5 or more.

The optical density can be measured using a spectrophotometer or an OD (Optical Densitometer).

The light-shielding film pattern 40 may be a single film including a uniform composition, a case where a plurality of films having different compositions are included, or a case where a single film having a composition continuously changing in the thickness direction may be included.

Furthermore, the phase shift mask substrate 10 may also be provided with a resist film on the phase shift film 30.

Next, a method of manufacturing the phase shift mask substrate 10 of the embodiment will be described. The phase shift mask substrate 10 can be fabricated by performing the following preparation steps and phase offset film forming steps.

Hereinafter, each step will be described in detail.

1. Preparation steps

In the preparation step, first, the transparent substrate 20 is prepared. The material of the transparent substrate 20 is not particularly limited as long as it is a material that is translucent to the exposure light used. For example, synthetic quartz glass, soda lime glass, and alkali-free glass are mentioned.

When the phase shift mask substrate 10 having the light-shielding film pattern 40 is produced, a light-shielding film containing a chromium-based material is formed on the transparent substrate 20 by sputtering, for example. Thereafter, a resist pattern is formed on the light-shielding film, and the light-shielding film is etched using the resist pattern as a mask to form the light-shielding film pattern 40. Thereafter, the resist pattern is peeled off.

2. Phase shift film formation step

In the phase shift film forming step, a phase shift film 30 containing a chromium-based material is formed on the transparent substrate 20 by sputtering. Here, when the light-shielding film pattern 40 is formed on the transparent substrate 20, the phase-shift film 30 is formed so as to cover the light-shielding film pattern 40.

The phase shift film 30 is formed by forming a phase shifting layer 31 on the main surface of the transparent substrate 20, forming a metal layer 33 on the phase shift layer 31, and forming a reflectance reducing layer 32 on the metal layer 33. form.

The film formation of the phase shift layer 31 is performed using a sputtering target containing a chromium or chromium compound, for example, in a sputtering gas atmosphere containing a mixed gas of an inert gas and an active gas, the inert gas containing a gas selected from the group consisting of helium and neon. At least one of a group consisting of argon gas, helium gas and helium gas, the active gas comprising a gas selected from the group consisting of oxygen, nitrogen, nitrogen monoxide gas, nitrogen dioxide gas, carbon dioxide gas, hydrocarbon gas, and fluorine gas. At least one of the groups. Examples of the hydrocarbon-based gas include methane gas, butane gas, propane gas, and styrene gas.

Similarly, the film formation of the metal layer 33 uses a sputtering target containing a chromium or chromium compound, for example, inert to contain at least one selected from the group consisting of helium, neon, argon, xenon, and xenon. Gas is sprayed under a gas atmosphere, or contains inert gas and Performing a mixed gas of a reactive gas under a sputtering gas atmosphere, the inert gas comprising at least one selected from the group consisting of helium, neon, argon, neon, and xenon, the reactive gas comprising selected from the group consisting of oxygen and nitrogen. At least one of a group consisting of nitric oxide gas, nitrogen dioxide gas, carbon dioxide gas, hydrocarbon gas, and fluorine gas. Examples of the hydrocarbon-based gas include methane gas, butane gas, propane gas, and styrene gas.

Similarly, the film formation of the reflectance reducing layer 32 is performed using a sputtering target containing a chromium or chromium compound, for example, in a sputtering gas atmosphere containing a mixed gas of an inert gas and an active gas, the inert gas containing a gas selected from the group consisting of helium gas. At least one of a group consisting of helium, argon, helium and neon, the active gas comprising a gas selected from the group consisting of oxygen, nitrogen, nitrogen monoxide, nitrogen dioxide, carbon dioxide gas, hydrocarbon gas, fluorine gas At least one of the group consisting of. Examples of the hydrocarbon-based gas include methane gas, butane gas, propane gas, and styrene gas.

When the phase shifting layer 31, the metal layer 33, and the reflectance reducing layer 32 are formed, the composition and thickness of the phase shifting layer 31, the metal layer 33, and the reflectance reducing layer 32 are the transmittance of the phase shifting film 30. The phase difference has the specific optical characteristics described above, and the film surface reflectance of the phase shift film 30 and the fluctuation range thereof have the specific physical properties described above. The composition of each of the phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32 can be controlled by the composition of the sputtering gas, the flow rate, and the like. The thickness of each of the phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32 can be controlled by sputtering power, sputtering time, and the like. Further, when the sputtering apparatus is a continuous sputtering apparatus, the thickness of each of the phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32 can be controlled by the substrate transfer speed.

In the case where the phase shift layer 31 includes a uniform single film, the film forming process is performed only once without changing the composition and flow rate of the sputtering gas. In the case where the phase shift layer 31 includes a plurality of films having different compositions, the film forming process is performed plural times by changing the composition and flow rate of the sputtering gas during each film forming process. When the phase shifting layer 31 includes a single film which continuously changes in the thickness direction, the composition of the sputtering gas is formed on one side. And the flow rate change is performed only once in the above film forming process. The film formation of the metal layer 33 and the film formation of the reflectance reducing layer 32 are also the same. The sputtering power applied to the sputtering target can be reduced in the case of performing a plurality of film forming processes.

The phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32 are preferably continuously formed using a continuous sputtering apparatus without being exposed to the atmosphere by taking the transparent substrate 20 out of the apparatus. The film formation can be continuously performed without taking out the device, thereby preventing surface oxidation or surface carbonization of the accidental layers. Unexpected surface oxidation or surface carbonization of each layer exists to cause laser light for use in drawing a resist film formed on the phase shift film 30, or to transfer a phase shift film pattern to a substrate formed on a display device The reflectance of the exposure light used in the resist film changes, and the etching rate of the oxidized portion or the carbonized portion changes.

Further, in the case of manufacturing the phase shift mask substrate 10 having a resist film, a resist film is formed on the phase shift film.

The phase shift mask substrate 10 of the first embodiment is provided on the transparent substrate 20, and the phase shift film 30 containing a chromium-based material has a phase shift layer 31, a reflectance reducing layer 32, and a phase shift layer. 31 and the reflectance reducing layer 32 have a metal layer 33 having a higher extinction coefficient than the extinction coefficient of the reflectance reducing layer 32 in a wavelength region of 350 nm to 436 nm, and on the one hand, the phase shifting film 30 is for exposure light. The transmittance and the phase difference satisfy the specific optical characteristics required for the phase shift film 30. On the other hand, the film reflectance of the phase shift film 30 is 10% or less in the wavelength region of 350 nm to 436 nm. Therefore, the phase shift mask substrate 10 can be used to produce a phase shift mask having an excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern.

Further, the phase shift mask substrate 10 of the first embodiment is provided on the transparent substrate 20, and the phase shift film 30 containing a chromium-based material has a phase shift layer 31, a reflectance reducing layer 32, and a phase shift. The metal layer 33 between the shift layer 31 and the reflectance reducing layer 32 has a chromium content higher than that of the reflectance reducing layer 32, and on the one hand, the phase shift film 30 is exposed. The light transmittance and the phase difference satisfy the specific optical characteristics required for the phase shift film 30. On the other hand, the film surface reflectance of the phase shift film 30 is 10% or less in the wavelength region of 350 nm to 436 nm. Therefore, the phase shift mask substrate 10 can be used to produce a phase shift mask having an excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern.

Embodiment 2.

In the second embodiment, a method of manufacturing a phase shift mask will be described. The phase shift mask substrate can be fabricated by performing the following resist pattern forming step and phase shift film pattern forming step.

Hereinafter, each step will be described in detail.

1. Resist film pattern forming step

In the resist pattern forming step, first, a resist film is formed on the phase shift film 30 of the phase shift mask substrate 10 of the first embodiment. In the case where the phase shift mask substrate 10 is provided with a resist film on the phase shift film 30, the formation of the resist film is not performed. The resist film material used is not particularly limited. It suffices that it is a laser light having a wavelength selected from any wavelength range of 350 nm to 436 nm which will be described later. Further, the resist film may be either a positive type or a negative type.

Thereafter, a specific pattern is drawn on the resist film using laser light having any one of wavelengths selected from the wavelength range of 350 nm to 436 nm. As the pattern drawn on the resist film, a line and gap pattern or a contact hole pattern can be cited.

Thereafter, the resist film is developed with a specific developer to form a resist pattern on the phase shift film 30.

2. Phase shift film patterning step

In the phase shift film pattern forming step, first, the phase shift film 30 is etched using the resist pattern as a mask to form a phase shift film pattern. Each of the phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32 constituting the phase shift film 30 is formed of a chromium-based material containing chromium (Cr). Therefore, the phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32 can be the same The etching medium (etching solution, etching gas) is etched. The etching medium (etching solution, etching gas) for etching the phase shift film 30 is not particularly limited as long as it can selectively etch the phase shift film 30. Specifically, an etching solution containing cerium ammonium nitrate and perchloric acid or an etching gas containing a mixed gas of chlorine gas and oxygen gas may be mentioned.

Thereafter, the resist pattern is peeled off using a resist stripping solution or by ashing.

According to the method of manufacturing a phase shift mask of the second embodiment, it is possible to manufacture a phase shift mask having an excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern.

Embodiment 3.

In the third embodiment, a method of manufacturing a display device will be described. The display device can be manufactured by performing the following photomask mounting step and pattern transfer step.

Hereinafter, each step will be described in detail.

Loading step

In the placing step, the phase shift mask manufactured in the second embodiment is placed on the mask stage of the exposure apparatus. Here, the phase shift mask is disposed to face the resist film formed on the substrate of the display device with a projection optical system that is exposed to the exposure device.

2. Pattern transfer step

The pattern transfer step irradiates the phase shift mask with the exposure light, and transfers the phase shift film pattern to the resist film formed on the substrate of the display device. The exposure light is a composite light including light of a plurality of wavelengths selected from a wavelength region of 313 nm to 436 nm, or a monochromatic light selected by cutting off a certain wavelength region from a wavelength region of 313 nm to 436 nm by a filter or the like. For example, the exposure light includes a composite light of an i-line, an h-line, and a g-line, or a mixed light including a j-ray, an i-line, an h-line, and a g-line, or a monochromatic light of an i-line. When composite light is used as the exposure light, the exposure light intensity can be increased and the throughput can be increased, so that the manufacturing cost of the display device can be reduced.

According to the method of manufacturing the display device of the third embodiment, high resolution can be produced, High-definition display device.

[Examples]

Hereinafter, the present invention will be further specifically described based on examples and comparative examples. Furthermore, the following examples are illustrative of the invention and are not intended to limit the invention.

The phase shift mask substrates of Examples 1 to 4 and Comparative Examples 1 to 3 were provided with a transparent substrate and a phase shift film containing a chromium-based material disposed on the transparent substrate. As the transparent substrate, a synthetic quartz glass substrate having a size of 800 mm × 920 mm and a thickness of 10 mm was used.

3 is a graph showing the film surface reflectance spectrum of the phase shifting film of the phase shift mask substrate of Examples 1, 3, and 4, and FIG. 4 is a graph showing the phase shift of the phase shift mask substrate of Comparative Examples 1 and 2. The film surface reflectance spectrum of the film, and Fig. 5 shows the film surface reflectance spectrum of the phase shift film of the phase shift mask base of Comparative Examples 1 and 3.

Hereinafter, Examples 1 to 4 and Comparative Examples 1 to 3 will be described in detail.

Example 1.

The phase shift film of the phase shift mask substrate of Example 1 includes a phase shift layer (CrOCN, film thickness: 89 nm), a metal layer (CrC, film thickness: 10 nm), and a reduced reflectance, which are sequentially disposed from the transparent substrate side. Layer (CrOCN, film thickness 30 nm).

The phase shift layer (CrOCN) has a refractive index of 2.44 and an extinction coefficient of 0.71 at a wavelength of 313 nm, a refractive index of 2.51 at a wavelength of 350 nm, an extinction coefficient of 0.59, a refractive index of 2.52 at a wavelength of 365 nm, and an extinction coefficient of 0.55. The refractive index at a wavelength of 413 nm was 2.54 and the extinction coefficient was 0.44, the refractive index at a wavelength of 436 nm was 2.54, and the extinction coefficient was 0.40.

The metal layer (CrC) has a refractive index of 2.14 and an extinction coefficient of 2.61 at a wavelength of 313 nm, a refractive index of 2.24 at a wavelength of 350 nm, an extinction coefficient of 2.85, a refractive index of 2.29 at a wavelength of 365 nm, an extinction coefficient of 2.94, and a wavelength of 413 nm. The refractive index was 2.52 and the extinction coefficient was 3.20. The refractive index at the wavelength of 436 nm was 2.65 and the extinction coefficient was 3.3.

Refractive index reduction layer (CrOCN) has a refractive index of 2.46 and extinction at a wavelength of 313 nm The coefficient is 0.47, the refractive index at wavelength 350nm is 2.47 and the extinction coefficient is 0.37, the refractive index at wavelength 365nm is 2.47 and the extinction coefficient is 0.33, the refractive index at wavelength 413nm is 2.43 and the extinction coefficient is 0.23, and the wavelength is 436nm. The refractive index was 2.41 and the extinction coefficient was 0.20.

Further, the refractive index and extinction coefficient of the phase shifting layer were measured using n&k Analyzer 1280 (trade name) manufactured by N&K Technology. The measurement of the refractive index and the extinction coefficient of the phase shifting layer was carried out on a synthetic quartz glass substrate on a sample obtained by film formation under the same conditions as those of the phase shifting layer shown below. The measurement of the refractive index and the extinction coefficient of the metal layer, and the measurement of the refractive index and the extinction coefficient of the reflectance reducing layer were also performed in the same manner. Further, the measurements were carried out in the same manner in Examples 2 to 4 and Comparative Examples 1 to 3.

The Cr content of the phase shift layer (CrOCN) was 32 atom%, the Cr content of the metal layer (CrC) was 46 atom%, and the Cr content of the reflectance lower layer (CrOCN) was 28 atom%.

In addition, the Cr content rate was measured using a SAM670 type scanning type Auger electronic spectroscopic device (trade name) manufactured by ULVAC-PHI Corporation. The measurements were also carried out in the same manner in Examples 2 to 4 and Comparative Examples 1 to 3.

The phase shift film has a transmittance of 5.98% and a phase difference of 178.66° for light of 365 nm by the above three-layer structure.

In addition, the transmittance and the phase difference were measured using MPM-100 (trade name) manufactured by Lasertec Corporation of Japan. The measurements were also carried out in the same manner in Examples 2 to 4 and Comparative Examples 1 to 3.

The film surface reflectance of the phase shift film is 12.0% in the wavelength of 313 nm, 8.3% in 350 nm, 7.3% in the wavelength of 365 nm, and 6.6% in the wavelength of 405 nm, and is in the wavelength of 413 nm. 6.6%, 6.8% at a wavelength of 436 nm. Further, the fluctuation range of the film surface reflectance of the phase shift film was 1.7% in the wavelength region of 350 nm to 436 nm, 0.7% in the wavelength region of 365 nm to 436 nm, and 5.5% in the wavelength region of 313 nm to 436 nm.

Curve a in Fig. 3 shows the film surface reflectance spectrum of the phase shift film of the phase shift mask substrate of Example 1.

In addition, the film surface reflectance was measured using SolidSpec-3700 (trade name) manufactured by Shimadzu Corporation. The measurements were also carried out in the same manner in Examples 2 to 4 and Comparative Examples 1 to 3.

The sheet resistance of the phase shift film was 508 Ω/□. Therefore, the phase shift mask substrate of Embodiment 1 can prevent charging.

In addition, the sheet resistance was measured using K-705RM (trade name) manufactured by Kyowa Rigaku Corporation. The measurements were also carried out in the same manner in Examples 2 to 4 and Comparative Examples 1 to 3.

The phase shift mask substrate of Example 1 was fabricated by the following method.

First, a synthetic quartz glass substrate as a transparent substrate is prepared. The two main surfaces of the transparent substrate are mirror-polished. The two main surfaces of the transparent substrates prepared in Examples 2 to 4 and Comparative Examples 1 to 3 were also mirror-polished in the same manner.

Thereafter, the transparent substrate is carried into a continuous sputtering apparatus. A sputtering chamber is provided in the continuous sputtering apparatus.

Thereafter, a sputtering power of 2.7 kW was applied to the chromium target disposed in the sputtering chamber, and a mixed gas of Ar gas, N ₂ gas, and CO ₂ gas was introduced into the sputtering chamber and transported at a speed of 200 mm/min. Substrate. When the transparent substrate passes through the vicinity of the chromium target, a phase shift layer containing a thickness of 89 nm of CrOCN is formed on the main surface of the transparent substrate. Here, the mixed gas system was introduced into the sputtering chamber such that Ar became a flow rate of 35 sccm, N ₂ became a flow rate of 35 sccm, and CO ₂ became a flow rate of 14.5 sccm.

Thereafter, a sputtering power of 0.4 kW was applied to the chromium target, and a mixed gas of Ar gas and CH ₄ gas (a mixed gas containing CH ₄ gas in an Ar gas at a concentration of 8%) was introduced at a flow rate of 100 sccm. The transparent substrate was transported at a speed of 400 mm/min to the sputtering chamber. When the transparent substrate passes through the vicinity of the chromium target, a metal layer containing a film thickness of 10 nm of CrC is formed on the phase shift layer.

Thereafter, a sputtering power of 2.0 kW was applied to the chromium target, and a mixed gas of Ar gas and N ₂ gas and CO ₂ gas was introduced into the sputtering chamber, and the transparent substrate was conveyed at a speed of 200 mm/min. When the transparent substrate passes through the vicinity of the chromium target, a reflectance-reducing layer containing CrOCN having a film thickness of 30 nm is formed on the metal layer. Here, the mixed gas system was introduced into the sputtering chamber such that Ar became a flow rate of 35 sccm, N ₂ became a flow rate of 35 sccm, and CO ₂ became a flow rate of 18.2 sccm.

Thereafter, a transparent substrate including a phase shifting layer (CrOCN, film thickness: 89 nm), a metal layer (CrC, film thickness: 10 nm), and a reflectance reducing layer (CrOCN, film thickness: 30 nm) is formed. The continuous sputtering apparatus is taken out and washed.

Furthermore, the film formation of the phase-shift layer, the film formation of the metal layer, and the film formation of the reflectance-reducing layer are continuously performed in the continuous sputtering apparatus without removing the transparent substrate to the continuous sputtering. Exposure to the atmosphere is caused outside the device.

Using the phase shift mask substrate described above, a phase shift mask was fabricated by the following method.

First, a resist film containing a positive photoresist of a novolac type is formed on the phase shift film of the phase shift mask substrate.

Thereafter, laser light having a wavelength of 413 nm was used by a laser drawing machine to draw a specific pattern on the resist film.

Thereafter, the resist film is developed with a specific developer to form a resist pattern on the phase shift film.

Thereafter, the phase shift film is etched using the resist pattern as a mask to form a phase shift film pattern. Each of the phase shifting layer, the metal layer, and the reflectance reducing layer constituting the phase shifting film is formed of a chromium-based material containing chromium (Cr). Therefore, the phase shift layer, the metal layer, and the reflectance reducing layer can be etched by the same etching solution. Here, as an etching solution for etching the phase shift film, an etching solution containing cerium ammonium nitrate and perchloric acid is used.

Thereafter, the resist film pattern was peeled off using a resist stripper.

Phase offset film pattern of a phase shift mask fabricated using the phase shift mask substrate described above The cross section is caused by corrosion in the metal layer located at the central portion in the film thickness direction of the phase shift film pattern, but does not affect the characteristics of the mask.

In addition, the phase shift film pattern profile of the phase shift mask was observed using an electron microscope (JSM7401F (trade name) manufactured by JEOL Ltd.). The measurements were also carried out in the same manner in Examples 2 to 4 and Comparative Examples 1 to 3.

The CD unevenness of the phase shift film pattern of the phase shift mask manufactured using the phase shift mask substrate described above was relatively good and was 70 nm. The CD unevenness is an offset width from the target line and gap pattern (width of the line pattern: 2.0 μm, width of the gap pattern: 2.0 μm).

Further, the CD unevenness of the phase shift film pattern of the phase shift mask was measured using SIR8000 manufactured by Seiko Instruments Nano Technologies. The measurements were also carried out in the same manner in Examples 2 to 4 and Comparative Examples 1 to 3.

The phase shift mask has excellent pattern cross-sectional shape and excellent CD uniformity, and the phase shift film pattern has low film surface reflectance for exposure light, so the phase shift mask can be used to produce high resolution. And high-definition display device.

Further, the phase shift mask can be manufactured by using a phase shift mask substrate having a phase shift film having a small sheet resistance, so that even when a small pattern is formed, electricity does not easily enter the pattern from the pattern. Therefore, it is not easy to cause electrostatic damage.

Example 2.

The phase shifting film of the phase shift mask substrate of Example 2 includes a phase shift layer (CrOCN, film thickness: 89 nm), a metal layer (CrC, film thickness: 20 nm), and a reduced reflectance, which are sequentially disposed from the transparent substrate side. Layer (CrOCN, film thickness 30 nm). Only the metal layer is different from the phase shift mask substrate of Example 1.

The values of the refractive index and the extinction coefficient of the phase shift layer (CrOCN) are the same as in the first embodiment.

The metal layer (CrC) has a refractive index of 2.09 at a wavelength of 313 nm and an extinction coefficient of 2.05, a refractive index of 2.08 at a wavelength of 350 nm, an extinction coefficient of 2.18, and a folding at a wavelength of 365 nm. The emission rate was 2.08 and the extinction coefficient was 2.24. The refractive index at the wavelength of 413 nm was 2.11 and the extinction coefficient was 2.45. The refractive index at the wavelength of 436 nm was 2.15 and the extinction coefficient was 2.55.

The values of the refractive index and the extinction coefficient of the reflectance reducing layer (CrOCN) were the same as in the first embodiment.

The Cr content ratio of the phase shift layer (CrOCN) and the reflectance reduction layer (CrOCN) is the same as in the first embodiment. The Cr content of the metal layer (CrC) was 43 atom%.

The phase shift film has a transmittance of 5.78% and a phase difference of 177.02° with respect to light of 365 nm by the above three-layer structure.

The phase shift film film surface reflectance is 12.0% in the wavelength of 313 nm, 8.4% in 350 nm, 8.4% in the wavelength of 365 nm, 8.2% in the wavelength of 405 nm, and 8.4% in the wavelength of 413 nm. , 8.7% at a wavelength of 436 nm. Further, the fluctuation range of the phase shift film surface reflectance was 1.0% in the wavelength region of 350 nm to 436 nm, 0.6% in the wavelength region of 365 nm to 436 nm, and 3.8% in the wavelength region of 313 nm to 436 nm.

The sheet resistance of the phase shift film was 560 Ω/□. Therefore, the phase shift mask substrate of Embodiment 2 can prevent charging.

When Example 2 based on the deposition of the metal layer, is applied to the chromium target of sputter plating 0.33kW power, one surface of the mixed gas of Ar gas and of the CH ₄ gas (Ar gas in a concentration of 15% of the CH ₄ gas mixture containing The gas was introduced into the sputtering chamber at a flow rate of 100 sccm, and the transparent substrate was conveyed at a speed of 400 mm/min. When the transparent substrate passes through the vicinity of the chromium target, a metal layer containing a film thickness of 20 nm of CrC is formed on the phase shift layer. Otherwise, the phase shift mask substrate of Example 2 was fabricated by the same method as in Example 1.

A phase shift mask was produced by the same method as in Example 1 using the phase shift mask substrate described above.

The phase offset film pattern of the phase shift mask fabricated using the phase shift mask substrate described above is perpendicular to the cross section and no corrosion occurs in the metal layer.

The CD unevenness of the phase shift film pattern of the phase shift mask manufactured using the phase shift mask substrate described above was relatively good and was 50 nm.

The phase shift mask has excellent pattern cross-sectional shape and excellent CD uniformity, and the phase shift film pattern has low film surface reflectance for exposure light, so the phase shift mask can be used to produce high resolution. And high-definition display device.

Further, the phase shift mask can be manufactured by using a phase shift mask substrate having a phase shift film having a small sheet resistance, so that even when a small pattern is formed, electricity does not easily enter the pattern from the pattern. Therefore, it is not easy to cause electrostatic damage.

Example 3.

The phase shifting film of the phase shift mask substrate of Embodiment 3 includes a phase shift layer (CrOCN, film thickness: 89 nm), a metal layer (CrCN, film thickness: 22 nm), and a reflectance which are sequentially arranged from the transparent substrate side. The layer was lowered (CrOCN, film thickness: 30 nm). Only the metal layer is different from the phase shift mask substrate of Example 1.

The values of the refractive index and the extinction coefficient of the phase shift layer (CrOCN) are the same as in the first embodiment.

The metal layer (CrCN) has a refractive index of 2.07 and an extinction coefficient of 2.14 at a wavelength of 313 nm, a refractive index of 2.12 at a wavelength of 350 nm, an extinction coefficient of 2.28, a refractive index of 2.14 at a wavelength of 365 nm, an extinction coefficient of 2.35, and a wavelength of 413 nm. The refractive index was 2.26 and the extinction coefficient was 2.55. The refractive index at the wavelength of 436 nm was 2.33 and the extinction coefficient was 2.64.

The values of the refractive index and the extinction coefficient of the reflectance reducing layer (CrOCN) were the same as in the first embodiment.

The Cr content ratio of the phase shift layer (CrOCN) and the reflectance reduction layer (CrOCN) is the same as in the first embodiment. The Cr content of the metal layer (CrCN) was 40 atom%.

The phase shift film has a transmittance of 6.00% and a phase difference of 176.78° for light of 365 nm by the above three-layer structure.

The phase shift film film surface reflectance is 13.0% in the wavelength of 313 nm, in 350 nm It is 9.5%, 8.4% in the wavelength of 365 nm, 7.6% in the wavelength of 405 nm, 7.6% in the wavelength of 413 nm, and 7.6% in the wavelength of 436 nm. Further, the fluctuation range of the phase shift film surface reflectance was 1.9% in the wavelength region of 350 nm to 436 nm, 0.8% in the wavelength region of 365 nm to 436 nm, and 5.6% in the wavelength region of 313 nm to 436 nm.

Curve b in Fig. 3 shows the film surface reflectance spectrum of the phase shifting film of the phase shift mask substrate of Example 3.

The sheet resistance of the phase shift film was 800 Ω/□. Therefore, the phase shift mask substrate of Embodiment 3 can prevent charging.

In the third embodiment, when a metal layer is formed, a sputtering gas of 0.42 kW is applied to the chromium target, and a mixed gas of Ar gas and CH ₄ gas and N ₂ gas is introduced into the sputtering chamber while being 400 mm/min. Transfer the transparent substrate at a speed. When the transparent substrate passes through the vicinity of the chromium target, a metal layer containing a thickness of 22 nm of CrCN is formed on the phase shift layer. Here, the mixed gas system is introduced into the sputtering method in such a manner that a mixed gas of Ar gas and CH ₄ gas (a mixed gas containing CH ₄ gas in an Ar gas at a concentration of 8%) becomes 100 sccm, and N ₂ becomes a flow rate of 30 sccm. indoor. Otherwise, the phase shift mask substrate of Example 3 was fabricated by the same method as in Example 1.

A phase shift mask was produced by the same method as in Example 1 using the phase shift mask substrate described above.

The phase shift film pattern profile of the phase shift mask manufactured using the phase shift mask substrate described above generates some corrosion in the metal layer located in the central portion of the phase shift film pattern in the film thickness direction, but does not affect The extent of the reticle characteristics.

The CD unevenness of the phase shift film pattern of the phase shift mask manufactured using the phase shift mask substrate described above was relatively good and was 75 nm.

The phase shift mask has excellent pattern cross-sectional shape and excellent CD uniformity, and the phase shift film pattern has low film surface reflectance to the exposed light, so the above phase can be used. The offset mask creates a high resolution and high definition display device.

Further, the phase shift mask can be manufactured by using a phase shift mask substrate having a phase shift film having a small sheet resistance, so that even when a small pattern is formed, electricity does not easily enter the pattern from the pattern. Therefore, it is not easy to cause electrostatic damage.

Example 4.

The phase shifting film of the phase shifting mask substrate of Example 4 includes a phase shifting layer (CrOCN, film thickness: 91.5 nm), a metal layer (CrC, film thickness: 10 nm), and a reflection which are sequentially disposed from the transparent substrate side. Rate reduction layer (CrOCN, film thickness 28 nm).

The values of the refractive index and the extinction coefficient of each of the phase shift layer (CrOCN), the metal layer (CrN), and the reflectance lowering layer (CrOCN) are the same as those in the first embodiment.

The Cr content of each of the phase shift layer (CrOCN), the metal layer (CrN), and the reflectance reduction layer (CrOCN) is the same as that of the first embodiment.

The phase shift film has a transmittance of 5.55% for light of 365 nm and a phase difference of 182.30° by the above three-layer structure.

The phase shift film surface reflectance is 12.3% in the wavelength of 313 nm, 9.2% in 350 nm, 8.5% in the wavelength of 365 nm, 8.3% in the wavelength of 405 nm, and 8.5 in the wavelength of 413 nm. % is 8.8% at a wavelength of 436 nm. Further, the fluctuation range of the phase shift film surface reflectance was 1.0% in the wavelength region of 350 nm to 436 nm, 0.6% in the wavelength region of 365 nm to 436 nm, and 4.2% in the wavelength region of 313 nm to 436 nm.

Curve c in Fig. 3 shows the film surface reflectance spectrum of the phase shift film of the phase shift mask substrate of Example 4.

The sheet resistance of the phase shift film was 510 Ω/□. Therefore, the phase shift mask substrate of Embodiment 4 can prevent charging.

In the fourth embodiment, the transparent substrate was transported at a speed of 205 mm/min when the phase-shifting layer was formed. At the time of film formation of the metal layer, a mixed gas of Ar gas and CH ₄ gas (a mixed gas containing CH ₄ gas at a concentration of 15% in Ar gas) was introduced into the sputtering chamber at a flow rate of 200 sccm. At the time of film formation of the reflectance-reducing layer, the transparent substrate was conveyed at a speed of 215 mm/min. Otherwise, the phase shift mask substrate of Example 4 was fabricated by the same method as in Example 1.

A phase shift mask was produced by the same method as in Example 1 using the phase shift mask substrate described above.

The phase offset film pattern profile of the phase shift mask manufactured using the phase shift mask substrate described above is slightly corroded in the metal layer located in the central portion of the phase shift film pattern in the film thickness direction, but Does not affect the extent of the reticle characteristics.

The CD unevenness of the phase shift film pattern of the phase shift mask manufactured using the phase shift mask substrate described above was relatively good and was 55 nm.

The phase shift mask has an excellent pattern cross-sectional shape and excellent CD uniformity, and has a low film surface reflectance for exposure light, so that the phase shift mask can be used to produce a high resolution and high definition display. Device.

Further, the phase shift mask can be manufactured by using a phase shift mask substrate having a phase shift film having a small sheet resistance, so that even when a small pattern is formed, electricity does not easily enter the pattern from the pattern. Therefore, it is not easy to cause electrostatic damage.

Comparative Example 1.

The phase shift film of the phase shift mask substrate of Comparative Example 1 contained only the phase shift layer (CrOCN, film thickness 122 nm). The phase shift mask substrate of Comparative Example 1 is different from the phase shift mask substrate of the embodiment in that the phase shift film does not have a metal layer and a reflectance reducing layer.

The phase shift layer (CrOCN) has a refractive index of 2.36 and an extinction coefficient of 0.74 at a wavelength of 313 nm, a refractive index of 2.43 at a wavelength of 350 nm, an extinction coefficient of 0.66, a refractive index of 2.45 at a wavelength of 365 nm, and an extinction coefficient of 0.62. The refractive index at a wavelength of 413 nm was 2.49 and the extinction coefficient was 0.53, the refractive index at a wavelength of 436 nm was 2.50, and the extinction coefficient was 0.49.

The phase shift layer (CrOCN) has a Cr content of 32 atom%.

The phase shift film has a transmittance of 5.20% for light of 365 nm and a phase difference of 179.60° by the above-described one-layer structure.

The phase shift film surface reflectance is 19.9% in the wavelength of 313 nm, 20.3% in 350 nm, 20.7% in the wavelength of 365 nm, 22.0% in the wavelength of 405 nm, and 22.1 in the wavelength of 413 nm. % is 22.2% in the wavelength of 436 nm. Further, the fluctuation range of the phase shift film surface reflectance was 1.9% in the wavelength region of 350 nm to 436 nm, 1.6% in the wavelength region of 365 nm to 436 nm, and 2.4% in the wavelength region of 313 nm to 436 nm.

The curve d in Figs. 4 and 5 indicates the film surface reflectance spectrum of the phase shift film of the phase shift mask substrate of Comparative Example 1.

The sheet resistance of the phase shift film cannot be measured (∞). Therefore, the phase shift mask substrate of Comparative Example 1 is more likely to cause charging than the phase shift mask substrate of the embodiment.

The phase shift mask substrate of Comparative Example 1 was produced by the following method.

First, a synthetic quartz glass substrate as a transparent substrate is prepared.

Thereafter, the transparent substrate is carried into the continuous sputtering apparatus.

Thereafter, a sputtering power of 3.5 kW was applied to the chromium target placed in the sputtering chamber, and a mixed gas of Ar gas and N ₂ gas and CO ₂ gas was introduced into the sputtering chamber, and the substrate was transported at a speed of 200 mm/min. Substrate. When the transparent substrate passes through the vicinity of the chromium target, a phase shift layer containing a thickness of 122 nm of CrOCN is formed on the main surface of the transparent substrate. Here, the mixed gas system was introduced into the sputtering chamber such that Ar became 46 sccm, N ₂ became 46 sccm, and CO _{2 was at} a flow rate of 18.5 sccm.

Thereafter, a transparent substrate on which a phase shift film including a phase shift layer (CrOCN, film thickness: 122 nm) was formed was taken out from the continuous sputtering apparatus and washed.

A phase shift mask was produced by the same method as in Example 1 using the phase shift mask substrate described above.

The phase offset film pattern profile of the phase shift mask fabricated using the phase shift mask substrate described above is vertical.

The CD of the phase shift film pattern of the phase shift mask manufactured using the phase shift mask substrate described above is not 90 nm, and the phase shift mask of the display device for high resolution and high definition is not achieved. The level of requirements.

Although the phase shift mask has an excellent pattern cross-sectional shape, since the CD unevenness is large, and the phase shift film pattern has a high reflectance to the exposed light, the phase shift mask cannot be used. A high resolution and high definition display device is manufactured.

Further, the phase shift mask can be manufactured by using a phase shift mask substrate having a phase shift film having a large sheet resistance, so that even when a small pattern is formed, electricity easily enters the pattern from the pattern. Therefore, it is easy to cause electrostatic damage.

Comparative Example 2.

The phase shift film of the phase shift mask substrate of Comparative Example 2 includes a phase shift layer (CrOCN, film thickness: 113.4 nm) and a reflectance reduction layer (CrOCN, film thickness: 7 nm) which are sequentially arranged from the transparent substrate side. . The phase shift mask substrate of Comparative Example 2 differs from the phase shift mask substrate of the embodiment in that the phase shift film does not have a metal layer.

The phase shift layer (CrOCN) has a refractive index of 2.37 and an extinction coefficient of 0.72 at a wavelength of 313 nm, a refractive index of 2.45 at a wavelength of 350 nm, an extinction coefficient of 0.64, a refractive index of 2.48 at a wavelength of 365 nm, and an extinction coefficient of 0.60. The refractive index at a wavelength of 413 nm was 2.52 and the extinction coefficient was 0.48, the refractive index at a wavelength of 436 nm was 2.53, and the extinction coefficient was 0.44.

The reflectance reduction layer (CrOCN) has a refractive index of 2.24 and an extinction coefficient of 0.36 at a wavelength of 313 nm, a refractive index of 2.20 at a wavelength of 350 nm, an extinction coefficient of 0.28, a refractive index of 2.18 at a wavelength of 365 nm, and an extinction coefficient of 0.26. The refractive index at a wavelength of 413 nm was 2.13 and the extinction coefficient was 0.20, the refractive index at a wavelength of 436 nm was 2.11, and the extinction coefficient was 0.17.

The Cr content of the phase shift layer (CrOCN) was 33 atom%, and the Cr content of the reflectance lower layer (CrOCN) was 26 atom%.

The phase shift film has a transmittance of 8.40% and a phase difference of 172.50° with respect to light of 365 nm by the above two-layer structure.

The phase shift film surface reflectance is 16.2% in the wavelength of 313 nm, 17.9% in 350 nm, 18.9% in the wavelength of 365 nm, 20.4% in the wavelength of 405 nm, and 20.4 in the wavelength of 413 nm. % is 19.7% in the wavelength of 436 nm. Further, the fluctuation range of the phase shift film surface reflectance was 2.5% in the wavelength region of 350 nm to 436 nm, 1.5% in the wavelength region of 365 nm to 436 nm, and 4.2% in the wavelength region of 313 nm to 436 nm.

The curve e in Fig. 4 indicates the film surface reflectance spectrum of the phase shift film of the phase shift mask substrate of Comparative Example 2.

The sheet resistance of the phase shift film cannot be measured (∞). Therefore, the phase shift mask substrate of Comparative Example 2 is more likely to cause charging than the phase shift mask substrate of the embodiment.

The phase shift mask substrate of Comparative Example 2 was produced by the following method.

First, a synthetic quartz glass substrate as a transparent substrate is prepared.

Thereafter, the transparent substrate is carried into the continuous sputtering apparatus.

Thereafter, a sputtering gas having a sputtering power of 3.4 kW was applied to the chromium target placed in the sputtering chamber, and a mixed gas of Ar gas, N ₂ gas, and CO ₂ gas was introduced into the sputtering chamber, and the substrate was transported at a speed of 200 mm/min. Substrate. When the transparent substrate passes through the vicinity of the chromium target, a phase shift layer containing a thickness of 113.4 nm of CrOCN is formed on the main surface of the transparent substrate. Here, the mixed gas system was introduced into the sputtering chamber such that Ar became 35 sccm, N ₂ became 35 sccm, and CO ₂ became a flow rate of 19.8 sccm.

Thereafter, a sputtering gas of 0.5 kW was applied to the chromium target placed in the sputtering chamber, and a mixed gas of Ar gas, N ₂ gas, and CO ₂ gas was introduced into the sputtering chamber, and the substrate was transported at a speed of 200 mm/min. Substrate. When the transparent substrate passes through the vicinity of the chromium target, a reflectance-reducing layer containing CrOCN having a thickness of 7 nm is formed on the phase shift layer. Here, the mixed gas system was introduced into the sputtering chamber such that Ar became 35 sccm, N ₂ became 35 sccm, and CO ₂ became a flow rate of 19.8 sccm.

Thereafter, a transparent substrate on which a phase shift film including a phase shift layer (CrOCN, film thickness: 113.4 nm) and a reflectance-reducing layer (CrOCN, film 7 nm) was formed was taken out from the continuous sputtering apparatus and washed.

Further, the film formation of the phase shifting layer and the film formation of the reflectance reducing layer are continuously performed in the continuous sputtering apparatus without exposing the transparent substrate to the atmosphere outside the continuous sputtering apparatus.

A phase shift mask was produced by the same method as in Example 1 using the phase shift mask substrate described above.

The phase shift film pattern profile of the phase shift mask manufactured using the phase shift mask substrate described above is formed in a shape in which an etching solution is immersed in the interface with the resist film.

The CD of the phase shift film pattern of the phase shift mask manufactured by using the phase shift mask substrate described above is not 200 nm, and the phase shift mask of the display device for high resolution and high definition is not achieved. The level of requirements.

The phase shift mask is formed in a cross-sectional shape of the pattern which is immersed at the interface with the resist film, and the CD unevenness is large. Further, the phase shift film pattern has a high film surface reflectance for the exposed light, and thus cannot be A high-resolution and high-definition display device is manufactured using the phase shift mask described above.

Further, the phase shift mask can be manufactured by using a phase shift mask substrate having a phase shift film having a large sheet resistance, so that even when a small pattern is formed, electricity easily enters the pattern from the pattern. Therefore, it is easy to cause electrostatic damage.

Comparative Example 3.

The phase shift film of the phase shift mask substrate of Comparative Example 3 includes a phase shift layer (CrOCN, film thickness 113.4 nm) and a first reflectance lowering layer which are sequentially arranged from the transparent substrate side. (CrOCN, film thickness: 7 nm) and second reflectance-reducing layer (CrOCN, film thickness: 13.6 nm). The phase shift film of the phase shift mask substrate of Comparative Example 3 corresponds to the second reflectance reducing layer (CrOCN) provided on the reflectance reducing layer of the phase shift mask substrate of Comparative Example 2.

The values of the refractive index and the extinction coefficient of the phase shift layer (CrOCN) are the same as those of the phase shift layer (CrOCN) of Comparative Example 2.

The values of the refractive index and the extinction coefficient of the first reflectance reducing layer (CrOCN) are the same as those of the reflectance reducing layer (CrOCN) of Comparative Example 2.

The second reflectance reducing layer (CrOCN) has a refractive index of 2.41 and an extinction coefficient of 0.41 at a wavelength of 313 nm, a refractive index of 2.40 at a wavelength of 350 nm, an extinction coefficient of 0.32, a refractive index of 2.39 at a wavelength of 365 nm, and an extinction coefficient of 0.29, a refractive index of 2.35 at a wavelength of 413 nm and an extinction coefficient of 0.21, a refractive index of 2.33 at a wavelength of 436 nm and an extinction coefficient of 0.19.

The Cr content of the phase shift layer (CrOCN) and the first reflectance lowering layer (CrOCN) is the same as the Cr content of the phase shift layer (CrOCN) and the reflectance lowering layer (CrOCN) of Comparative Example 2. The Cr content of the second reflectance reducing layer (CrOCN) was 29 atom%.

The phase shift film has a transmittance of 8.00% and a phase difference of 190.00° for light of 365 nm by the above three-layer structure.

The phase shift film surface reflectance is 12.9% in the wavelength of 313 nm, 12.2% in 350 nm, 12.8% in the wavelength of 365 nm, 15.7% in the wavelength of 405 nm, and 16.3 in the wavelength of 413 nm. %, 17.5% at a wavelength of 436 nm. Further, the fluctuation range of the phase shift film surface reflectance was 5.2% in the wavelength region of 350 nm to 436 nm, 4.6% in the wavelength region of 365 nm to 436 nm, and 5.4% in the wavelength region of 313 nm to 436 nm.

The curve f in Fig. 5 indicates the film surface reflectance spectrum of the phase shift film of the phase shift mask substrate of Comparative Example 3.

The sheet resistance of the phase shift film cannot be measured (∞). Therefore, the phase shift light of Comparative Example 3 The cover substrate is more likely to cause charging than the phase offset mask substrate of the embodiment.

In Comparative Example 3, after the film formation of the reflectance-reducing layer of Comparative Example 2, a mixed gas of Ar gas, N ₂ gas, and CO ₂ gas was applied while applying a sputtering power of 1.0 kW to the chromium target placed in the sputtering chamber. The transparent substrate was conveyed at a speed of 200 mm/min while being introduced into the sputtering chamber. When the transparent substrate passes through the vicinity of the chromium target, a second reflectance-reducing layer containing CrOCN having a film thickness of 13.6 nm is formed on the first reflectance-reducing layer. Here, the mixed gas system was introduced into the sputtering chamber such that Ar became 35 sccm, N ₂ became 35 sccm, and CO ₂ became a flow rate of 19.8 sccm. Otherwise, the phase shift mask substrate of Comparative Example 3 was produced by the same method as Comparative Example 2.

A phase shift mask was produced by the same method as in Example 1 using the phase shift mask substrate described above.

The phase shift film pattern of the phase shift mask manufactured using the phase shift mask substrate described above is perpendicular to the cross section, but is formed in a shape in which an etching solution is immersed at the interface with the resist film.

The CD of the phase shift film pattern of the phase shift mask manufactured using the phase shift mask substrate described above is not 180 nm, and the phase shift mask of the display device for high resolution and high definition is not achieved. The level of requirements.

The phase shift mask is formed in a cross-sectional shape of the pattern which is immersed at the interface with the resist film, and the CD unevenness is large. Further, the phase shift film pattern has a high film surface reflectance for the exposed light, and thus cannot be A high-resolution and high-definition display device is manufactured using the phase shift mask described above.

Further, the phase shift mask can be manufactured by using a phase shift mask substrate having a phase shift film having a large sheet resistance, so that even when a small pattern is formed, electricity easily enters the pattern from the pattern. Therefore, it is easy to cause electrostatic damage.

As described above, the present invention has been described in detail based on the embodiments and examples, but the present invention is not limited thereto. It will be apparent to those skilled in the art that changes or modifications can be made within the technical spirit of the invention.

10‧‧‧ phase offset mask base

20‧‧‧Transparent substrate

30‧‧‧ phase offset film

31‧‧‧phase offset layer

32‧‧‧Reflectance reduction layer

33‧‧‧metal layer

Claims (9)

A phase shifting reticle substrate, characterized in that it is provided with a phase shifting film comprising a chrome-based material on a transparent substrate, and the phase shifting film has a phase shifting layer, which mainly has an adjustment for exposure light. a function of transmittance and phase difference; a reflectance reducing layer disposed on an upper side of the phase shifting layer and having a function of lowering a reflectance of light incident from the phase shifting film side; and a metal layer; Arranging between the phase shifting layer and the reflectance reducing layer, and having an extinction coefficient higher than an extinction coefficient of the reflectance reducing layer in a wavelength region of 350 nm to 436 nm; a layered structure of the layer, the metal layer, and the reflectance reducing layer, wherein the phase shifting film has specific optical characteristics with respect to transmittance and phase difference of exposure light, and the phase shifting film is incident on the side opposite to the phase shifting film The film surface reflectance of the light is 10% or less in the wavelength region of 350 nm to 436 nm. A phase shifting reticle substrate, characterized in that it is provided with a phase shifting film comprising a chrome-based material on a transparent substrate, and the phase shifting film has a phase shifting layer, which mainly has an adjustment for exposure light. a function of transmittance and phase difference; a reflectance reducing layer disposed on an upper side of the phase shifting layer and having a function of lowering a reflectance of light incident from the phase shifting film side; and a metal layer; And being disposed between the phase shifting layer and the reflectance reducing layer, and having a chromium content higher than a chromium content of the reflectance reducing layer; and the phase shifting layer, the metal layer, and the a laminated structure of a reflectance reducing layer having a specific optical characteristic for transmittance and phase difference of exposure light, and a film surface reflectance of the phase shifting film for light incident from the phase shifting film side It is 10% or less in the wavelength region of 350 nm to 436 nm. The phase shift mask substrate according to claim 1 or 2, wherein a variation range of a film surface reflectance of the phase shift film is 5% or less in a wavelength region of 350 nm to 436 nm. The phase shift mask substrate of claim 1 or 2, wherein the phase shift film has a film surface reflectance of 13% or less in a wavelength region of 313 nm to 436 nm. The phase shift mask substrate of claim 4, wherein the film surface reflectance of the phase shift film has a variation range of 10% or less in a wavelength region of 313 nm to 436 nm. The phase shift mask substrate according to any one of claims 1 to 2, wherein a light-shielding film pattern is provided between the transparent substrate and the phase shift film. A method of manufacturing a phase-shifting reticle, comprising the steps of: applying the phase shifting film of the phase shifting mask substrate according to any one of claims 1 to 6 to a phase shifting film having a thickness selected from the group consisting of 350 nm Forming and processing a laser light of any wavelength in a wavelength region of ~436 nm to form a resist pattern; and etching the phase shift film as a mask on the transparent film A phase shift film pattern is formed thereon. A manufacturing method of a display device, comprising the steps of: placing a phase shift mask manufactured by the manufacturing method of claim 7 on a mask stage of an exposure apparatus; and shifting the phase shift mask The exposure light is irradiated, and the phase shift film pattern is transferred to a resist film formed on a substrate of the display device. The method of manufacturing a display device according to claim 8, wherein the exposure light is a composite light including light of a plurality of wavelengths selected from a wavelength region of 313 nm to 436 nm.