KR20170009722A - A phase shift mask blank and a method for manufacturing phase shift mask using the same, and a method for manufacturing the display device - Google Patents

Abstract

Provided is a phase shift mask blank having an excellent cross-sectional pattern shape and CD uniformity, used to form a phase shift mask for a display device having micropatterns formed. A phase shift film containing a chromium-based material is installed on a transparent substrate, and comprises a phase shift layer, a reflectivity reducing layer, and a metal layer installed between the phase shift layer and the reflectivity reducing layer. The metal layer has an extinction coefficient higher than the extinction coefficient of the reflectivity reducing layer in a wavelength region of 350-436 nm. The transmittance and phase difference of the phase shift film with respect to exposed light satisfy prescribed optical characteristics required as a phase shift film. The emulsion side reflectivity of the phase shift film is less than or equal to 10% in a wavelength region of 350-436 nm.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase shift mask blank, a method of manufacturing a phase shift mask using the phase shift mask blank, a method of manufacturing a phase shift mask using the phase shift mask blank,

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

In recent years, there has been a demand for a phase shift mask for a display in which fine patterns are formed, with high resolution and high definition of display devices such as FPD (Flat Panel Display), excellent pattern cross-sectional shapes and excellent CD uniformity .

In addition, there is a need to reduce the manufacturing cost of the phase shift mask under the influence of the lower cost of display devices such as FPDs. In the conventional phase shift mask blank in which the light shielding film is formed on the phase shift film, the light shielding film is etched using the resist film pattern as a mask to form a light shielding film pattern. Thereafter, The film is etched to form a phase shift film pattern. Thereafter, the resist film pattern is peeled off and the light shielding film pattern is peeled off to produce a phase shift mask having a phase shift film pattern. On the other hand, in the case of a phase shift mask blank in which no light shielding film is formed on the phase shift film, the step of forming the light shielding film pattern on the phase shift film and the peeling step are not necessary, and the manufacturing cost can be reduced.

In response to such a recent situation, there is proposed a method for manufacturing a display device having a fine pattern, which has excellent pattern cross-sectional shape and excellent CD uniformity, which is produced by using a phase shift mask blank in which no light shielding film is formed on the phase shift film A phase shift mask is required.

For example, Patent Document 1 proposes a phase shift mask blank for a display device having a phase shift film having a structure in which two or more thin films are laminated on a transparent substrate. The thin films constituting the phase shift film have different compositions but all contain an etchable material by the same etching solution and have different etching rates with different compositions. In Patent Document 1, the etching speed of each thin film constituting the phase shift film is adjusted so that the edge inclination of the edge portion of the phase shift film pattern is hardly formed at the time of patterning the phase shift film.

Further, in Patent Document 1, a phase for a display device in which a functional film including a light-shielding film, a semitransmissive film, an etching stopper film, and a hard mask film as well as one or more films required for a transfer pattern is disposed on or under the phase reversal film A shift mask blank is also proposed.

Japanese Patent Application Laid-Open No. 2014-26281

The phase shift film used in the conventionally proposed phase shift mask for a display is designed in consideration of the influence on the resist film due to the reflection of the laser imaging light used for patterning the resist film used for forming the phase shift film pattern It is not. As a result, the film surface reflectance of the phase shift film to the laser imaging light exceeds 20%. As a result, standing waves are generated in the resist film, deteriorating the CD uniformity of the resist film pattern, and furthermore, the CD uniformity of the phase shift film pattern formed by patterning using the resist film pattern as a mask, May not be satisfied.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a phase shift film in which film surface reflectance for light in a wavelength range of 350 nm to 436 nm used as laser imaging light is reduced, A phase shift mask blank having excellent CD uniformity and used for forming a phase shift mask for a display in which a fine pattern is formed, and a method for manufacturing a phase shift mask using the same. It is another object of the present invention to provide a method for manufacturing a high-definition and high-precision display device by using a phase shift mask for a display device having a fine pattern section and a good pattern cross-sectional shape and excellent CD uniformity.

The inventors of the present invention have studied extensively in order to achieve the above object, and have found that the phase shift film is composed of at least three layers and the composition and the film thickness of each layer constituting the phase shift film are designed so that the transmittance of the phase shift film to the exposure light and It has been found that the film surface reflectance of the phase shift film with respect to the light in the wavelength range of 350 nm to 436 nm can be reduced while satisfying the predetermined optical characteristics required as the phase shift film.

The present invention is based on this finding, and has the following configuration.

(Configuration 1)

A phase shift mask blank comprising a phase shift film including a chromium-based material on a transparent substrate,

The phase shift film is mainly composed of a phase shift layer having a function of adjusting transmittance and phase difference with respect to exposure light and a function disposed on the phase shift layer to reduce the reflectance of light incident from the phase shift film side And a metal layer disposed between the phase shift layer and the reflectance reducing layer and having a thinning coefficient higher than an extinction coefficient of the reflectance reducing layer in a wavelength region of 350 nm to 436 nm,

The laminate structure of the phase shift layer, the metal layer, and the reflectance reducing layer may have a structure in which the transmittance and phase difference of the phase shift film with respect to the exposure light have predetermined optical characteristics, Wherein the film surface reflectance of the phase shift film is 10% or less in a wavelength range of 350 nm to 436 nm.

(Composition 2)

A phase shift mask blank comprising a phase shift film including a chromium-based material on a transparent substrate,

The phase shift film is mainly composed of a phase shift layer having a function of adjusting transmittance and phase difference with respect to exposure light and a function disposed on the phase shift layer to reduce the reflectance of light incident from the phase shift film side And a metal layer disposed between the phase shift layer and the reflectance reducing layer and having a chromium content higher than that of the reflectance reducing layer,

The laminate structure of the phase shift layer, the metal layer, and the reflectance reducing layer may have a structure in which the transmittance and phase difference of the phase shift film with respect to the exposure light have predetermined optical characteristics, Wherein the film surface reflectance of the phase shift film is 10% or less in a wavelength range of 350 nm to 436 nm.

(Composition 3)

Wherein the fluctuation range of the film surface reflectance of the phase shift film is 5% or less in a wavelength range of 350 nm to 436 nm.

(Composition 4)

The phase shift mask blank according to the constitution 1 or 2, wherein the film surface reflectance of the phase shift film is 13% or less in a wavelength range of 313 nm to 436 nm.

(Composition 5)

Wherein the fluctuation range of the film surface reflectance of the phase shift film is 10% or less in a wavelength range of 313 nm to 436 nm.

(Composition 6)

A phase shift mask blank according to any one of Structures 1 to 5, characterized in that a light shielding film pattern is provided between the transparent substrate and the phase shift film.

(Composition 7)

By the imaging process and the development process using the laser light having any one wavelength selected from the wavelength range of 350 nm to 436 nm on the phase shift film of the phase shift mask blank described in any one of the constitutions 1 to 6, A step of forming a resist film pattern,

A step of forming a phase shift film pattern on the transparent substrate by etching the phase shift film using the resist film pattern as a mask

And a step of forming the phase shift mask.

(Composition 8)

A step of mounting the phase shift mask manufactured by the manufacturing method described in Configuration 7 on a mask stage of an exposure apparatus,

A step of irradiating the phase shift mask with exposure light and transferring the phase shift film pattern to a resist film formed on the display device substrate

The method comprising the steps of:

(Composition 9)

Wherein the exposure light is composite light containing light of a plurality of wavelengths selected in a wavelength range of 313 nm to 436 nm.

As described above, the phase shift mask blank according to the present invention is a phase shift mask blank comprising a phase shift layer including a chromium-based material provided on a transparent substrate, a phase shift layer formed between the phase shift layer and the reflectance reduction layer, Has a metal layer having an extinction coefficient higher than the extinction coefficient of the reflectance reducing layer in the wavelength region of 350 nm to 436 nm and has a predetermined optical characteristic required for the phase shift film as the transmittance and the phase difference of the phase shift film with respect to the exposure light And the film surface reflectance of the phase shift film is 10% or less in the wavelength range of 350 nm to 436 nm. This makes it possible to manufacture a phase shift mask having fine pattern cross-sections and excellent CD uniformity using the phase shift mask blank. Further, by using this phase shift mask, a high-resolution, high-precision display device can be manufactured.

According to another aspect of the present invention, there is provided a phase shift mask blank comprising a phase shift film including a chromium-based material provided on a transparent substrate, wherein the phase shift film includes a phase shift layer, a reflectance reduction layer, And has a chromium content higher than the chromium content of the abatement layer. It is preferable that the transmittance and phase difference of the phase shift film with respect to the exposure light satisfy predetermined optical characteristics required as the phase shift film, And 10% or less in the wavelength region of 436 nm to 436 nm. This makes it possible to manufacture a phase shift mask having fine pattern cross-sections and excellent CD uniformity using the phase shift mask blank. Further, by using this phase shift mask, a high-resolution, high-precision display device can be manufactured.

1 is a schematic diagram showing the film structure of a phase shift mask blank.
2 is a schematic diagram showing another film structure of the phase shift mask blank.
3 is a film surface reflectance spectrum of the phase shift film of the phase shift mask blank of Examples 1, 3 and 4. FIG.
4 is a film surface reflectance spectrum of the phase shift film of the phase shift mask blank of Comparative Examples 1 and 2.
5 is a film surface reflectance spectrum of the phase shift film of the phase shift mask blank of Comparative Examples 1 and 3.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are one form of embodying the present invention, and the present invention is not limited thereto. In the drawings, the same or equivalent parts are denoted by the same reference numerals, and the description thereof may be simplified or omitted.

Embodiment 1

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

1 is a schematic diagram showing the film structure of the phase shift mask blank 10. The phase shift mask blank 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. The transparent substrate 20 has a transmittance of 85% or more, preferably 90% or more, with respect to the exposure light when there is no surface reflection loss. The phase shift film 30 has a phase shift layer 31, a metal layer 33 and a reflectance reducing layer 32 which are arranged in this order from the transparent substrate 20 side. Each of the phase shift layer 31, the metal layer 33 and the reflectance reducing layer 32 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 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 transmittance and phase difference with respect to exposure light.

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

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 reducing the reflectance for light incident from the side of the phase shift film 30 (that is, the side opposite to the side of the transparent substrate 20 of the reflectance reducing layer 32).

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

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 of the exposure light and a function of reducing the reflectance of light incident from 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) and carbon (C) and nitrogen (N). The metal layer 33 is made of chromium (Cr), at least one of carbon (C) and nitrogen (N), and further contains at least one of oxygen (O) and fluorine Or may be formed of a compound. For example, Cr, CrC, CrN, CrCN, CrCO, and CrCF may be used as the material for forming the metal layer 33. [

By providing the metal layer 33, the sheet resistance of the phase shift film is lowered, so that it is possible to prevent the phase shift mask blank and charge-up of the phase shift mask. When the metal layer 33 is not provided, electricity is accumulated in the phase shift mask blank and the phase shift mask without leakage of electricity generated when the phase shift mask blank and the phase shift mask are removed from the case. Easy. Further, when a small pattern is formed in the phase shift mask, electricity is emitted from the pattern to the pattern, and electrostatic breakdown is apt to occur.

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. In addition, it is preferable to have an extinction coefficient higher than the extinction coefficient of the reflectance reducing layer 32 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 1.5 to 3.5, and more preferably 1.8 to 3.5. (The wavelength range of 350 nm to 436 nm, or the wavelength range of 313 nm to 436 nm) of the interface between the metal layer 33 and the reflectance reducing layer 32, the difference in the extinction coefficient is in the range of 1.5 to 3.5. It is preferable that the reflectance reduction effect is further exhibited.

In addition, 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. In addition, it is preferable to have an extinction coefficient higher than the extinction coefficient of the phase shift layer 31 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 reduction 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 10 to 80 atomic%, more preferably 15 to 80 atomic%. (A wavelength range of 350 nm to 436 nm, or a wavelength range of 313 nm to 436 nm) at the interface between the metal layer 33 and the reflectance reducing layer 32, if the difference in the Cr content is 10 to 80 atomic% It is possible to increase the reflectance in the reflector, and thus the reflectance reduction effect can be further exerted. The etching rate of the metal layer 33 can be adjusted by adding nitrogen (N), oxygen (O), carbon (C), and fluorine (F) to chromium (Cr) to form a chromium compound. For example, by containing carbon (C) or fluorine (F) in chromium (Cr), the wet etching rate can be slowed and by containing nitrogen (N) or oxygen (O) The etching rate can be increased. The chromium compound to which the above-described element is added in consideration of the wet etching rate with respect to the phase shift layer 31 and the reflectance reduction layer 32 formed above and below the metal layer 33 can be obtained, The cross-sectional shape of the film 30 can be improved.

The metal layer 33 has a chromium (Cr) content higher than that of the chrome (Cr) content in the phase shift layer 31.

The Cr content can be measured using an Auger electron spectroscopy apparatus or an X-ray photoelectron spectroscopy apparatus (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. If the refractive index is 2.0 or more, the film thickness of the phase shift film 30 necessary for obtaining desired optical characteristics (transmittance and phase difference) can be reduced. Therefore, the phase shift mask fabricated using the phase shift mask blank 10 having the phase shift film 30 can have a phase shift film pattern having excellent pattern cross-sectional shape and excellent CD uniformity.

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

The transmittance and the phase difference of the phase shift film 30 with respect to the exposure light have predetermined optical characteristics 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 with respect to the exposure light satisfies the required value as the phase shift film 30. The transmittance of the phase shift film 30 is preferably from 1% to 20%, more preferably from 3% to 10%, with respect to light of a predetermined wavelength included in the exposure light (hereinafter referred to as representative wavelength) %to be. That is, when the exposure light is composite light including light in a wavelength range of 313 nm to 436 nm, the phase shift film 30 has the transmittance described above for the light of the representative wavelength included in the wavelength range. For example, when the exposure light is composite light including i-line, h-line and g-line, the phase shift film 30 has the transmittance described above for any one of i-line, h-line and g-line.

The phase difference of the phase shift film 30 with respect to the exposure light satisfies the required value as the phase shift film 30. [ The phase difference of the phase shift film 30 is preferably 160 占 to 200 占 and more preferably 170 占 to 190 占 with respect to light having a typical wavelength included in the exposure light. With this property, the phase of the light of the representative wavelength included in the exposure light can be changed to 160 ° to 200 °. This causes a phase difference of 160 to 200 degrees 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, when the exposure light is composite light including light in a wavelength range of 313 nm to 436 nm, the phase shift film 30 has the above-described phase difference with respect to the light of the representative wavelength included in the wavelength range. For example, when the exposure light is composite light including i-line, h-line and g-line, the phase shift film 30 has the above-described phase difference with respect to any one of i-line, h-line and g-line.

The transmittance and the phase difference of the phase shift film 30 are controlled by adjusting the composition and thickness of each of the phase shift layer 31, the metal layer 33 and the reflectance reduction layer 32 constituting the phase shift film 30 can do. The metal layer 33 and the reflectance reducing layer 32 are formed so that the transmittance and the phase difference of the phase shift film 30 have the predetermined optical characteristics as described above. Composition and thickness are adjusted. The transmittance of the phase shift film 30 is mainly influenced 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 influenced by the composition and the thickness of the phase shift layer 31.

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

The film surface reflectance of the phase shift film 30 with respect to the light incident from the side of the phase shift film 30 is 10% or less in the wavelength range of 350 nm to 436 nm. Further, it is preferably 13% or less in the wavelength range of 313 nm to 436 nm. That is, the film surface reflectance of the phase shift film 30 with respect to the light incident from the side of the phase shift film 30 is 10% or less in the wavelength range of 350 nm to 436 nm, and the wavelength range is 313 nm to 436 nm It is preferably 13% or less. When the film surface reflectance of the phase shift film 30 is 10% or less in the wavelength range of 350 nm to 436 nm, the film surface reflectance for the laser imaging light is reduced, so that a phase shift mask having excellent CD uniformity can be formed have. When the film surface reflectance of the phase shift film 30 is 13% or less in the wavelength range of 313 nm to 436 nm, the film surface reflectance for exposure light is reduced. Therefore, when the pattern formed on the phase shift mask is transferred It is possible to prevent blur (flare) of the transfer pattern caused by the reflected light from the display device substrate.

The fluctuation range of the film surface reflectance of the phase shift film 30 is preferably 9% or less, more preferably 8.5% or less in the wavelength range of 350 nm to 436 nm. Further, in a wavelength range of 313 nm to 436 nm, it is preferably 12.5% or less, more preferably 12%. That is, the fluctuation range of the film surface reflectance of the phase shift film 30 is preferably 9% or less, more preferably 8.5% or less in the wavelength range of 350 nm to 436 nm, and preferably 12.5 Or less, more preferably 12% or less.

The film surface reflectance and the fluctuation width of the phase shift film 30 are set so that the refractive index and the extinction coefficient of each of the phase shift layer 31, the metal layer 33 and the reflectance reducing layer 32 constituting the phase shift film 30, It can be controlled by adjusting the thickness. Since the extinction coefficient and the refractive index can be controlled by adjusting the composition, in this embodiment, the phase shift layer 30, the metal layer 31, (33) and the reflectance reducing layer (32) are adjusted. The film surface reflectance and the variation range of the phase shift film 30 are mainly influenced by the composition and thickness of the metal layer 33 and the reflectance reducing layer 32, respectively.

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

The phase shift layer 31 may contain a single film having a uniform composition, may include a plurality of films having different compositions, or may include a single film in which the composition continuously varies in the thickness direction . The same applies to the metal layer 33 and the reflectance reducing layer 32.

2 is a schematic diagram showing another film structure of the phase shift mask blank 10. As shown in Fig. 2, the phase shift mask blank 10 may be provided with a light shielding film pattern 40 between the transparent substrate 20 and the phase shift film 30.

When the phase shift mask blank 10 has 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 the transmission of the exposure light.

The material forming the light-shielding film pattern 40 is not particularly limited as long as it is a material having a function of blocking the transmission of exposure light. For example, a chromium-based material. As the chromium-based material, chromium (Cr) or a chromium compound containing at least one of chromium (Cr), carbon (C) and nitrogen (N) can be given. (Cr), at least one of chromium (Cr), carbon (C), and nitrogen (N), or a chromium compound containing at least one of oxygen And a chromium compound further containing at least one of oxygen (O) and fluorine (F). For example, Cr, CrC, CrN and CrCN can be given as materials for forming the light shielding film pattern 40. [

The light shielding film pattern 40 can be formed by patterning the light shielding film formed by sputtering by etching.

In the portion where the phase shift film 30 and the light shielding film pattern 40 are laminated, the optical density 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, an OD meter or the like.

The light-shielding film pattern 40 may include a single film having a uniform composition, or may include a plurality of films having different compositions, or may include a single film in which the composition continuously changes in the thickness direction .

The phase shift mask blank 10 may be provided with a resist film on the phase shift film 30.

Next, a manufacturing method of the phase shift mask blank 10 of this embodiment will be described. The phase shift mask blank 10 is manufactured by performing the following preparation step and phase shift film formation step.

Hereinafter, each step will be described in detail.

1. Preparation process

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 having translucency to the exposure light to be used. For example, synthetic quartz glass, soda lime glass, and alkali-free glass can be mentioned.

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

2. Phase shift film forming process

In the phase shift film forming step, a phase shift film 30 including 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 the phase shift layer 31 on the main surface of the transparent substrate 20 and forming the metal layer 33 on the phase shift layer 31, Is formed by depositing a reduction layer (32).

The phase shift layer 31 is formed by using a sputtering target containing chromium or a chromium compound and at least one selected from the group consisting of helium gas, neon gas, argon gas, krypton gas and xenon gas And a mixed gas of an inert gas containing at least one selected from the group consisting of an oxygen gas, a nitrogen gas, a nitrogen monoxide gas, a nitrogen dioxide gas, a carbon dioxide gas, a hydrocarbon gas and a fluorine gas, It is done in atmosphere. 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 may be performed by using a sputtering target containing chromium or a chromium compound, and at least one selected from the group consisting of helium gas, neon gas, argon gas, krypton gas and xenon gas An inert gas containing at least one species selected from the group consisting of a helium gas, a neon gas, an argon gas, a krypton gas, and a xenon gas and an inert gas containing an oxygen gas, a nitrogen gas, Is carried out in a sputter gas atmosphere containing a mixed gas of an active gas containing at least one species selected from the group consisting of nitrogen 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.

Likewise, the film of the reflectance reducing layer 32 can be formed by using a sputtering target containing chromium or a chromium compound and at least one selected from the group consisting of helium gas, neon gas, argon gas, krypton gas and xenon gas A mixed gas of an inert gas containing a species and an active gas containing at least one species selected from the group consisting of an oxygen gas, a nitrogen gas, a nitrogen monoxide gas, a nitrogen dioxide gas, a carbon dioxide gas, a hydrocarbon gas and a fluorine gas In a sputter gas atmosphere. Examples of the hydrocarbon-based gas include methane gas, butane gas, propane gas and styrene gas.

The compositions and thicknesses of the phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32 in the phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32 are , The transmittance and the phase difference of the phase shift film 30 have the above-described predetermined optical characteristics, and the film surface reflectance and the fluctuation width of the phase shift film 30 are adjusted to have the above-mentioned predetermined physical properties. The compositions of the phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32 can be controlled by the composition of the sputter gas, the flow rate, and the like. The thicknesses 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. When the sputtering apparatus is an in-line sputtering apparatus, the thicknesses of the phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32 can be controlled by the transporting speed of the substrate.

In the case where the phase shift layer 31 includes a single film having a uniform composition, the above-described film formation process is performed only once without changing the composition and the flow rate of the sputter gas. When the phase shift layer 31 includes a plurality of films having different compositions, the above-described film formation process is repeated a plurality of times by changing the composition and flow rate of the sputter gas for each film formation process. In the case where the phase shift layer 31 includes a single film whose composition continuously changes in the thickness direction, the above-described film formation process is performed only once while changing the composition and the flow rate of the sputter gas. The same applies to the film formation of the metal layer 33 and the film formation of the reflectance reducing layer 32. When the film forming process is performed a plurality of times, the sputtering power applied to the sputtering target can be reduced.

The phase shift layer 31, the metal layer 33 and the reflectance reducing layer 32 are formed by continuously removing the transparent substrate 20 from the apparatus by using an in-line sputtering apparatus without exposure to the atmosphere . By continuously forming the film without taking it out of the apparatus, surface oxidation and surface carbonization of each unintended layer can be prevented. Unintended surface oxidation or surface carbonization of each layer may be caused by a laser beam used when drawing a resist film formed on the phase shift film 30 or a laser beam used when transferring a phase shift film pattern onto a resist film formed on a display device substrate There is a fear that the reflectance for the light is changed or the etching rate of the oxidized portion or the carbonized portion is changed.

In the case of manufacturing the phase shift mask blank 10 having a resist film, a resist film is then formed on the phase shift film.

The phase shift mask blank 10 of Embodiment 1 has a structure in which a phase shift film 30 including a chromium-based material provided on a transparent substrate 20 is formed on the phase shift layer 31 and the reflectance reducing layer 32 The metal layer 33 having a lower extinction coefficient than the extinction coefficient of the reflectance reducing layer 32 in the wavelength region of 350 nm to 436 nm provided between the phase shift layer 31 and the reflectance reducing layer 32, And the transmissivity and phase difference of the phase shift film 30 with respect to the exposure light satisfy the predetermined optical characteristics required as the phase shift film 30 and the film surface reflectance of the phase shift film 30 is in the range of 350 nm to 436 nm In the wavelength region of 10% or less. This makes it possible to manufacture a phase shift mask having fine pattern cross-sections and excellent CD uniformity using the phase shift mask blank 10.

The phase shift mask blank 10 of the first embodiment is characterized in that the phase shift film 30 including a chromium-based material provided on the transparent substrate 20 has a phase shift layer 31 and a reflectance reduction layer 32 And a metal layer 33 provided between the phase shift layer 31 and the reflectance reducing layer 32 and having a chromium content higher than the chromium content of the reflectance reducing layer 32. The phase shift of the phase shift layer 31, The film surface reflectance of the phase shift film 30 is 10% or less in the wavelength range of 350 nm to 436 nm while the transmittance and the retardation of the film 30 satisfy predetermined optical characteristics required for the phase shift film 30 . This makes it possible to manufacture a phase shift mask having fine pattern cross-sections and excellent CD uniformity using the phase shift mask blank 10.

Embodiment 2

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

Hereinafter, each step will be described in detail.

1. Step of forming a resist film pattern

In the resist film pattern forming process, first, a resist film is formed on the phase shift film 30 of the phase shift mask blank 10 of the first embodiment. However, when the phase shift mask blank 10 is provided with the resist film on the phase shift film 30, the formation of the resist film is not performed. The resist film material to be used is not particularly limited. As long as it is sensitive to laser light having any wavelength selected in a wavelength range of 350 nm to 436 nm which will be described later. The resist film may be either a positive type or a negative type.

Thereafter, a prescribed pattern is drawn on the resist film by using laser light having any one wavelength selected from the wavelength range of 350 nm to 436 nm. As a pattern to be drawn on the resist film, a line-and-space pattern or a hole pattern can be mentioned.

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

2. Phase shift film pattern forming process

In the phase shift film pattern forming step, the phase shift film 30 is first etched using the resist film 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 etched by the same etching medium (etching solution, etching gas). 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 an ammonium ceric nitrate and perchloric acid or an etching gas containing a mixed gas of chlorine gas and oxygen gas can be used.

Thereafter, the resist film pattern is peeled off by using a resist stripper or by ashing.

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

Embodiment 3

In Embodiment 3, a manufacturing method of a display device will be described. The display device is manufactured by performing the following mask loading step and pattern transfer step.

Hereinafter, each step will be described in detail.

1. Loading process

In the stacking step, the phase shift mask manufactured in the second embodiment is mounted on the mask stage of the exposure apparatus. Here, the phase shift mask is arranged to face the resist film formed on the display device substrate through the projection optical system of the exposure apparatus.

2. Pattern transfer process

In the pattern transfer process, the phase shift mask is irradiated with exposure light, and the phase shift film pattern is transferred onto the resist film formed on the display device substrate. The exposure light is a composite light containing light of a plurality of wavelengths selected from a wavelength range of 313 nm to 436 nm or a monochromatic light which is selected by cutting a wavelength region from a wavelength region of 313 nm to 436 nm by a filter or the like. For example, the exposure light is composite light including i-line, h-line and g-line, mixed light including j-line, i-line, h-line and g-line, or monochromatic light of i-line. When the 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 manufacturing method of the display device of the third embodiment, a high-resolution, high-precision display device can be manufactured.

[Example]

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

The phase shift mask blank of Examples 1 to 4 and Comparative Examples 1 to 3 includes a transparent substrate and a phase shift film including a chromium-based material disposed on the transparent substrate. As the transparent substrate, a synthetic quartz glass substrate having a size of 800 mm x 920 mm and a thickness of 10 mm was used.

FIG. 3 shows the film surface reflectance spectrum of the phase shift film of the phase shift mask blank of Examples 1, 3 and 4, FIG. 4 shows the film surface reflectance spectrum of the phase shift film of the phase shift mask blank of Comparative Examples 1 and 2, Shows the film surface reflectance spectrum of the phase shift film of the phase shift mask blank of Comparative Examples 1 and 3.

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

Example 1

The phase shift film in the phase shift mask blank of Example 1 was composed of a phase shift layer (CrOCN, film thickness: 89 nm), a metal layer (CrC, film thickness: 10 nm) (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 and 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, A refractive index of 2.54 and a extinction coefficient of 0.44 at a wavelength of 413 nm, a refractive index of 2.54 and a extinction coefficient of 0.40 at a wavelength of 436 nm.

The metal layer (CrC) had 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 and an extinction coefficient of 2.85, a refractive index of 2.29 at a wavelength of 365 nm and an extinction coefficient of 2.94, A refractive index of 2.52 and an extinction coefficient of 3.20 at 413 nm, a refractive index of 2.65 at a wavelength of 436 nm, and an extinction coefficient of 3.3.

The reflectance reducing layer (CrOCN) has a refractive index of 2.46 and an extinction coefficient of 0.47 at a wavelength of 313 nm, a refractive index of 2.47 at a wavelength of 350 nm and an extinction coefficient of 0.37, a refractive index of 2.47 at a wavelength of 365 nm and an extinction coefficient of 0.33, A refractive index of 2.43 and an extinction coefficient of 0.23 at a wavelength of 413 nm, a refractive index of 2.41 at a wavelength of 436 nm, and an extinction coefficient of 0.20.

The refractive index and the extinction coefficient of the phase shift layer were measured using n & k Analyzer 1280 (trade name) manufactured by n & k Technology. The refractive index and the extinction coefficient of the phase shift layer were measured on a synthetic quartz glass substrate under the same conditions as the film formation conditions of the phase shift layer described below. 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 performed in the same manner. In Examples 2 to 4 and Comparative Examples 1 to 3, the same measurements were made.

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

Further, the Cr content was measured using SAM 670-type scanning electron microscope (trade name) manufactured by ULVAC PASA CORPORATION. The same measurements were carried out in Examples 2 to 4 and Comparative Examples 1 to 3 as well.

The phase shift film had a transmittance of 5.98% and a phase difference of 178.66 占 with respect to light of 365 nm by the three-layer structure described above.

The transmittance and the retardation were measured using MPM-100 (trade name) manufactured by Lasertec, Japan. The same measurements were carried out in Examples 2 to 4 and Comparative Examples 1 to 3 as well.

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

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

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

The sheet resistance of the phase shift film was 508? / ?. As a result, the phase shift mask blank of Embodiment 1 can prevent charge-up.

Further, the sheet resistance was measured using K-705RM (trade name) manufactured by Kyowari Chemical Co., Ltd. The same measurements were carried out in Examples 2 to 4 and Comparative Examples 1 to 3 as well.

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

First, a synthetic quartz glass substrate which is a transparent substrate was prepared. The positive major surface of the transparent substrate is mirror-polished. The both main surfaces of the transparent substrates prepared in Examples 2 to 4 and Comparative Examples 1 to 3 were mirror-polished as well.

Thereafter, the transparent substrate was transferred into an in-line sputtering apparatus. A sputtering chamber is provided in the in-line type sputtering apparatus.

Thereafter, a sputtering power of 2.7 kW was applied to the chromium target disposed in the sputter chamber, and a mixed gas of Ar gas, N ₂ gas and CO ₂ gas was introduced into the sputter chamber, and the transparent substrate was heated at a rate of 200 mm / And returned. A phase shift layer having a film thickness of 89 nm including CrOCN was formed on the main surface of the transparent substrate when the transparent substrate passed the vicinity of the chromium target. Here, the mixed gas was introduced into the sputter chamber at a flow rate of 35 sccm for Ar, 35 sccm for N ₂ , and 14.5 sccm for CO ₂ .

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 at a concentration of 8% in Ar gas) was supplied at a flow rate of 100 sccm, The transparent substrate was transported at a rate of 400 mm / min. When the transparent substrate passed around the chromium target, a metal layer having a film thickness of 10 nm containing CrC was formed on the phase shift layer.

Thereafter, 2.0 kW of sputter power was applied to the chromium target, and the transparent substrate was transported at a rate of 200 mm / min while a mixed gas of Ar gas, N ₂ gas and CO ₂ gas was introduced into the sputter chamber. When the transparent substrate passed around the chromium target, a reflectance reducing layer having a film thickness of 30 nm including CrOCN was formed on the metal layer. Here, the mixed gas was introduced into the sputter chamber so that the flow rate of Ar was 35 sccm, N ₂ was 35 sccm, and CO ₂ was 18.2 sccm.

Thereafter, a transparent substrate on which a phase shift film composed of a phase shift layer (CrOCN, film thickness 89 nm), a metal layer (CrC, film thickness 10 nm) and a reflectance reducing layer (CrOCN Removed from the apparatus, and cleaned.

The formation of the phase shift layer, the formation of the metal layer, and the formation of the reflectance reducing layer were continuously performed in an in-line sputtering apparatus without exposing the transparent substrate to the outside of the in-line sputtering apparatus.

Using the phase shift mask blank described above, a phase shift mask was produced by the following method.

First, a resist film containing a positive type novolac photoresist was formed on the phase shift film of the above-mentioned phase shift mask blank.

Thereafter, a predetermined pattern was drawn on the resist film by using a laser beam with a wavelength of 413 nm by a laser imaging device.

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

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

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

The phase shift mask pattern cross section of the phase shift mask produced by using the phase shift mask blank described above has a slight shift in the metal layer located at the center of the phase shift film pattern in the film thickness direction, There was no impact.

The cross section of the phase shift film pattern of the phase shift mask was observed using an electron microscope (JSM7401F (trade name) manufactured by Nihon Denshiku Co., Ltd.). The same measurements were carried out in Examples 2 to 4 and Comparative Examples 1 to 3 as well.

The CD deviation of the phase shift film pattern of the phase shift mask manufactured using the phase shift mask blank described above was 70 nm and was good. The CD deviation is a shift width from a target line and space pattern (width of line pattern: 2.0 mu m, width of space pattern: 2.0 mu m).

The CD deviation of the phase shift film pattern of the phase shift mask was measured using SIR8000 manufactured by Seiko Instruments Nanotechnology. The same measurements were carried out in Examples 2 to 4 and Comparative Examples 1 to 3 as well.

The above-mentioned phase shift mask has excellent pattern cross-sectional shape and excellent CD uniformity and also has a low film-surface reflectance of the phase shift film pattern with respect to exposure light. Therefore, by using the phase shift mask described above, . ≪ / RTI >

Further, since this phase shift mask is manufactured using a phase shift mask blank having a phase shift film with a small sheet resistance, it is difficult for electric discharge to occur from the pattern to the pattern even when a small pattern is formed, .

Example 2

The phase shift film in the phase shift mask blank of Example 2 is composed of a phase shift layer (CrOCN, film thickness 89 nm), a metal layer (CrC, film thickness 20 nm), and a reflectance reducing layer (CrOCN, film thickness 30 nm). Only the metal layer is different from the phase shift mask blank of the first embodiment.

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

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

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

The Cr content ratios of the phase shift layer (CrOCN) and the reflectance reducing layer (CrOCN) are the same as those in the first embodiment. The Cr content of the metal layer (CrC) was 43 atom%.

The phase shift film had a transmittance of 5.78% and a phase difference of 179.02 DEG with respect to light of 365 nm by the three-layer structure described above.

The phase shift film had a film surface reflectance of 12.0% at a wavelength of 313 nm, 8.4% at 350 nm, 8.4% at a wavelength of 365 nm, and 8.2% at a wavelength of 405 nm, And 8.4% at a wavelength of 436 nm. The phase shift film had a variation width of the film surface reflectance of 1.0% in the wavelength range of 350 nm to 436 nm, 0.6% in the wavelength range of 365 nm to 436 nm, and a wavelength range of 313 nm to 436 nm , It was 3.8%.

The sheet resistance of the phase shift film was 560? / ?. As a result, the phase shift mask blank of the second embodiment can prevent charge-up.

In Example 2, a sputtering power of 0.33 kW was applied to a chromium target at the time of film formation of a metal layer, and a mixed gas of an Ar gas and a CH ₄ gas (a mixed gas containing CH ₄ gas at a concentration of 15% Gas) was introduced into the sputter chamber at a flow rate of 100 sccm, and the transparent substrate was transported at a rate of 400 mm / min. When the transparent substrate passed through the vicinity of the chromium target, a metal layer having a film thickness of 20 nm containing CrC was formed on the phase shift layer. In other respects, the phase shift mask blank of Example 2 was produced in the same manner as in Example 1.

Using the phase shift mask blank described above, a phase shift mask was produced in the same manner as in Example 1. [

The cross section of the phase shift film pattern of the phase shift mask manufactured using the phase shift mask blank described above was vertical and no electroless was generated in the metal layer.

The CD deviation of the phase shift film pattern of the phase shift mask manufactured using the phase shift mask blank described above was 50 nm, which was good.

The above-mentioned phase shift mask has excellent pattern cross-sectional shape and excellent CD uniformity and also has a low film-surface reflectance of the phase shift film pattern with respect to exposure light. Therefore, by using the phase shift mask described above, . ≪ / RTI >

Further, since this phase shift mask is manufactured using a phase shift mask blank having a phase shift film with a small sheet resistance, it is difficult for electric discharge to occur from the pattern to the pattern even when a small pattern is formed, .

Example 3

The phase shift film in the phase shift mask blank of Example 3 is composed of a phase shift layer (CrOCN, film thickness: 89 nm), a metal layer (CrCN, film thickness: 22 nm) (CrOCN, film thickness 30 nm). Only the metal layer is different from the phase shift mask blank of the first embodiment.

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

The metal layer (CrCN) had 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 and an extinction coefficient of 2.28, a refractive index of 2.14 at a wavelength of 365 nm and an extinction coefficient of 2.35, A refractive index of 2.26 and an extinction coefficient of 2.55 at 413 nm, a refractive index of 2.33 at a wavelength of 436 nm, and an extinction coefficient of 2.64.

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

The Cr content ratios of the phase shift layer (CrOCN) and the reflectance reducing layer (CrOCN) are the same as those in the first embodiment. The Cr content of the metal layer (CrCN) was 40 atomic%.

The phase shift film had a transmittance of 6.00% and a phase difference of 176.78 占 with respect to light of 365 nm by the three-layer structure described above.

The phase shift film had a film surface reflectance of 13.0% at a wavelength of 313 nm, 9.5% at 350 nm, 8.4% at a wavelength of 365 nm, and 7.6% at a wavelength of 405 nm, And 7.6% at a wavelength of 436 nm. The phase shift film had a fluctuation range of the film surface reflectance of 1.9% in the wavelength range of 350 nm to 436 nm, 0.8% in the wavelength range of 365 nm to 436 nm, and a wavelength range of 313 nm to 436 nm Was 5.6%.

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

The sheet resistance of the phase shift film was 800 OMEGA / square. As a result, the phase shift mask blank of Embodiment 3 can prevent charge-up.

In Example 3, a sputtering power of 0.42 kW was applied to a chromium target at the time of forming a metal layer, and a mixed gas of Ar gas, CH ₄ gas, and N ₂ gas was introduced into the sputter chamber, To transport the transparent substrate. A metal layer having a film thickness of 22 nm including CrCN was formed on the phase shift layer when the transparent substrate passed around the chromium target. Here, the mixed gas was introduced into the sputtering chamber so that a mixed gas of Ar gas and CH ₄ gas (a mixed gas containing CH ₄ gas at a concentration of 8% in Ar gas) of 100 sccm and N ₂ at a flow rate of 30 sccm . In other respects, the phase shift mask blank of Example 3 was produced in the same manner as in Example 1.

Using the phase shift mask blank described above, a phase shift mask was produced in the same manner as in Example 1. [

The phase shift mask pattern cross section of the phase shift mask produced by using the phase shift mask blank described above has a slight shift in the metal layer located at the center of the phase shift film pattern in the film thickness direction, There was no impact.

The CD deviation of the phase shift film pattern of the phase shift mask produced using the above-mentioned phase shift mask blank was 75 nm, which was good.

The above-mentioned phase shift mask has excellent pattern cross-sectional shape and excellent CD uniformity and also has a low film-surface reflectance of the phase shift film pattern with respect to exposure light. Therefore, by using the phase shift mask described above, . ≪ / RTI >

Further, since this phase shift mask is manufactured using a phase shift mask blank having a phase shift film with a small sheet resistance, it is difficult for electric discharge to occur from the pattern to the pattern even when a small pattern is formed, .

Example 4

The phase shift film in the phase shift mask blank of Example 4 was composed of a phase shift layer (CrOCN, film thickness 91.5 nm), a metal layer (CrC, film thickness 10 nm) and a reflectance reducing 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 reducing layer (CrOCN) are the same as those in Example 1.

The Cr content ratios of the phase shift layer (CrOCN), the metal layer (CrN), and the reflectance reducing layer (CrOCN) were the same as those in Example 1.

The phase shift film had a transmittance of 5.55% and a phase difference of 182.30 ° with respect to light of 365 nm by the three-layer structure described above.

The phase shift film had a film surface reflectance of 12.3% at a wavelength of 313 nm, 9.2% at 350 nm, 8.5% at a wavelength of 365 nm, and 8.3% at a wavelength of 405 nm, And 8.5% at a wavelength of 436 nm, and 8.8% at a wavelength of 436 nm. The phase shift film had a variation width of the film surface reflectance of 1.0% in the wavelength range of 350 nm to 436 nm, 0.6% in the wavelength range of 365 nm to 436 nm, and a wavelength range of 313 nm to 436 nm Was 4.2%.

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

The sheet resistance of the phase shift film was 510 OMEGA / & squ &. As a result, the phase shift mask blank of the fourth embodiment can prevent charge-up.

In Example 4, the transparent substrate was transported at a rate of 205 mm / min when forming the phase shift layer. During the 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 sputter chamber at a flow rate of 200 sccm. At the time of forming the reflectance reducing layer, the transparent substrate was transported at a rate of 215 mm / min. In other respects, the phase shift mask blank of Example 4 was produced in the same manner as in Example 1.

Using the phase shift mask blank described above, a phase shift mask was produced in the same manner as in Example 1. [

The phase shift mask pattern cross section of the phase shift mask produced using the above-mentioned phase shift mask blank has a slight electric field in the metal layer located at the center in the film thickness direction of the phase shift film pattern. There was no impact.

The CD deviation of the phase shift film pattern of the phase shift mask manufactured using the phase shift mask blank described above was 55 nm and was good.

The above-mentioned phase shift mask has excellent pattern cross-sectional shape and excellent CD uniformity and also has a low film-surface reflectance with respect to exposure light, so that a high-resolution, high-precision display device can be manufactured using the above-mentioned phase shift mask .

Further, since this phase shift mask is manufactured using a phase shift mask blank having a phase shift film with a small sheet resistance, it is difficult for electric discharge to occur from the pattern to the pattern even when a small pattern is formed, .

Comparative Example 1

The phase shift film in the phase shift mask blank of Comparative Example 1 is composed only of the phase shift layer (CrOCN, film thickness 122 nm). The phase shift mask blank of Comparative Example 1 is different from the phase shift mask blank of the embodiment in that the phase shift film is not provided with the metal layer and the 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 and 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, A refractive index of 2.49 and a extinction coefficient of 0.53 at a wavelength of 413 nm, a refractive index of 2.50 at a wavelength of 436 nm, and an extinction coefficient of 0.49.

The Cr content of the phase shift layer (CrOCN) was 32 atomic%.

The phase shift film had a transmittance of 5.20% and a phase difference of 179.60 占 with respect to light of 365 nm by the single-layer structure described above.

The phase shift film had a film surface reflectance of 19.9% at a wavelength of 313 nm, 20.3% at 350 nm, 20.7% at a wavelength of 365 nm, and 22.0% at a wavelength of 405 nm, , And 22.2% at a wavelength of 436 nm. The phase shift film had a variation width of the film surface reflectance of 1.9% in the wavelength range of 350 nm to 436 nm, 1.6% in the wavelength range of 365 nm to 436 nm, and a wavelength range of 313 nm to 436 nm , It was 2.4%.

4 and 5, the curve d represents the film surface reflectance spectrum of the phase shift film of the phase shift mask blank of Comparative Example 1. [

The sheet resistance of the phase shift film was unmeasurable (?). As a result, the phase shift mask blank of Comparative Example 1 is more likely to cause charge-up as compared with the phase shift mask blank of the embodiment.

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

First, a synthetic quartz glass substrate which is a transparent substrate was prepared.

Thereafter, the transparent substrate was transferred into an in-line sputtering apparatus.

Thereafter, sputtering power of 3.5 kW was applied to the chromium target disposed in the sputter chamber, and a mixed gas of Ar gas, N ₂ gas and CO ₂ gas was introduced into the sputter chamber, and the transparent substrate was sputtered at a rate of 200 mm / And returned. A phase shift layer having a film thickness of 122 nm including CrOCN was formed on the main surface of the transparent substrate when the transparent substrate passed around the chromium target. Here, the mixed gas was introduced into the sputtering chamber so that the flow rate of Ar was 46 sccm, N ₂ was 46 sccm, and CO ₂ was 18.5 sccm.

Thereafter, the transparent substrate on which the phase shift film composed of the phase shift layer (CrOCN, film thickness: 122 nm) was formed was taken out from the inline type sputtering apparatus and cleaned.

Using the phase shift mask blank described above, a phase shift mask was produced in the same manner as in Example 1. [

The phase shift film pattern section of the phase shift mask manufactured using the phase shift mask blank described above was vertical.

The CD deviation of the phase shift mask pattern of the phase shift mask fabricated using the phase shift mask blank described above was 90 nm and did not reach the level required for the phase shift mask used for manufacturing high resolution, high precision display devices.

The phase shift mask described above has an excellent pattern cross-sectional shape. However, since the CD deviation is large and the film surface reflectance of the phase shift film pattern with respect to exposure light is high, the phase shift mask described above can be used for high- The device could not be manufactured.

Further, since this phase shift mask is manufactured using a phase shift mask blank having a phase shift film having a large sheet resistance, when a small pattern is formed, electricity is likely to be emitted from the pattern to the pattern, and electrostatic destruction tends to occur .

Comparative Example 2

The phase shift film in the phase shift mask blank of Comparative Example 2 is composed of a phase shift layer (CrOCN, film thickness 113.4 nm) and a reflectance reducing layer (CrOCN, film thickness 7 nm) arranged in this order from the transparent substrate side . The phase shift mask blank of Comparative Example 2 is different from the phase shift mask blank 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 and 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, A refractive index of 2.52 and an extinction coefficient of 0.48 at a wavelength of 413 nm, a refractive index of 2.53 at a wavelength of 436 nm, and an extinction coefficient of 0.44.

The reflectance reducing 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 and 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, A refractive index of 2.13 and a extinction coefficient of 0.20 at a wavelength of 413 nm, a refractive index of 2.11 and a extinction coefficient of 0.17 at a wavelength of 436 nm.

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

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

The phase shift film had a film surface reflectance of 16.2% at a wavelength of 313 nm and 17.9% at 350 nm, 18.9% at a wavelength of 365 nm, and 20.4% at a wavelength of 405 nm, 20.4%, and 19.7% at a wavelength of 436 nm. The phase shift film had a variation width of the film surface reflectance of 2.5% in a wavelength range of 350 nm to 436 nm, 1.5% in a wavelength range of 365 nm to 436 nm, and a wavelength range of 313 nm to 436 nm Was 4.2%.

Curve e in FIG. 4 shows the film surface reflectance spectrum of the phase shift film of the phase shift mask blank of Comparative Example 2.

The sheet resistance of the phase shift film was unmeasurable (?). As a result, the phase shift mask blank of Comparative Example 2 is more likely to cause charge-up as compared with the phase shift mask blank of the embodiment.

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

First, a synthetic quartz glass substrate which is a transparent substrate was prepared.

Thereafter, the transparent substrate was transferred into an in-line sputtering apparatus.

Thereafter, sputtering power of 3.4 kW was applied to the chromium target disposed in the sputter chamber, and a mixed gas of Ar gas, N ₂ gas and CO ₂ gas was introduced into the sputter chamber, and the transparent substrate was sputtered at a rate of 200 mm / And returned. A phase shift layer having a film thickness of 113.4 nm containing CrOCN was formed on the main surface of the transparent substrate when the transparent substrate passed around the chromium target. Here, the mixed gas was introduced into the sputter chamber so that the flow rate of Ar was 35 sccm, N ₂ was 35 sccm, and CO ₂ was 19.8 sccm.

Thereafter, a sputtering power of 0.5 kW was applied to the chromium target disposed in the sputter chamber, and a mixed gas of Ar gas, N ₂ gas and CO ₂ gas was introduced into the sputter chamber, and the transparent substrate was heated at a rate of 200 mm / And returned. When the transparent substrate passed through the chromium target, a 7 nm-thick reflectance reducing layer containing CrOCN was formed on the phase shift layer. Here, the mixed gas was introduced into the sputter chamber so that the flow rate of Ar was 35 sccm, N ₂ was 35 sccm, and CO ₂ was 19.8 sccm.

Thereafter, the transparent substrate on which the phase shift film composed of the phase shift layer (CrOCN, film thickness 113.4 nm) and the reflectance reducing layer (CrOCN, film 7 nm) was formed was taken out from the inline type sputtering apparatus and cleaned.

The film formation of the phase shift layer and the film formation of the reflectance reduction layer were continuously performed in an in-line sputtering apparatus without taking the transparent substrate out of the in-line sputtering apparatus and exposing it to the atmosphere.

Using the phase shift mask blank described above, a phase shift mask was produced in the same manner as in Example 1. [

The phase shift mask pattern section of the phase shift mask manufactured using the phase shift mask blank described above had a shape in which the etching solution penetrated the interface of the resist film.

The CD deviation of the phase shift mask pattern of the phase shift mask fabricated using the phase shift mask blank described above was 200 nm and did not reach the level required for the phase shift mask used for manufacturing a high resolution, high precision display device.

Since the phase shift mask described above has a pattern cross-sectional shape in which penetration into the interface of the resist film occurs and the CD deviation is large and the phase shift film pattern with respect to the exposure light has a high reflectance on the film surface, A high-resolution, high-precision display device could not be manufactured.

Further, since this phase shift mask is manufactured using a phase shift mask blank having a phase shift film having a large sheet resistance, when a small pattern is formed, electricity is likely to be emitted from the pattern to the pattern, and electrostatic destruction tends to occur .

Comparative Example 3

The phase shift film in the phase shift mask blank of Comparative Example 3 had a phase shift layer (CrOCN, thickness: 113.4 nm) and a first reflectance reduction layer (CrOCN, film thickness 7 nm) arranged in this order from the transparent substrate side And a second reflectance reducing layer (CrOCN, film thickness 13.6 nm). The phase shift film in the phase shift mask blank of Comparative Example 3 corresponds to the case where the second reflectance reducing layer (CrOCN) is provided on the reflectance reducing layer in the phase shift mask blank of Comparative Example 2.

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

The refractive index and the extinction coefficient of the first reflectance reducing layer (CrOCN) are the same as the refractive index and the extinction coefficient of the reflectance reducing layer (CrOCN) of the second comparative example.

The second reflectance reducing layer (CrOCN) had 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 and 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 and a extinction coefficient of 0.21 at a wavelength of 413 nm, 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 reducing layer (CrOCN) is the same as the Cr content of the phase shift layer (CrOCN) and the reflectance reducing layer (CrOCN) of Comparative Example 2. The Cr content of the second reflectance reducing layer (CrOCN) was 29 atomic%.

The phase shift film had a transmittance of 8.00% and a phase difference of 190.00 ° with respect to light of 365 nm by the three-layer structure described above.

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

The curve f in FIG. 5 represents the film surface reflectance spectrum of the phase shift film of the phase shift mask blank of Comparative Example 3.

The sheet resistance of the phase shift film was unmeasurable (?). As a result, the phase shift mask blank of Comparative Example 3 is more likely to cause charge-up as compared with the phase shift mask blank of the embodiment.

In Comparative Example 3, after the formation of the reflectance reducing layer in Comparative Example 2, a sputtering power of 1.0 kW was applied to a chromium target disposed in the sputter chamber, and a mixed gas of Ar gas, N ₂ gas, and CO ₂ gas was sputtered The transparent substrate was transported at a speed of 200 mm / min while being introduced into the chamber. When the transparent substrate passed through the chromium target, a second reflectance reducing layer having a film thickness of 13.6 nm containing CrOCN was formed on the first reflectance reducing layer. Here, the mixed gas was introduced into the sputter chamber so that the flow rate of Ar was 35 sccm, N ₂ was 35 sccm, and CO ₂ was 19.8 sccm. In other respects, the phase shift mask blank of Comparative Example 3 was produced by the same method as that of Comparative Example 2.

Using the phase shift mask blank described above, a phase shift mask was produced in the same manner as in Example 1. [

Although the phase shift mask pattern cross section of the phase shift mask manufactured using the above-mentioned phase shift mask blank was vertical, the etching solution had penetrated into the interface of the resist film.

The CD deviation of the phase shift mask pattern of the phase shift mask fabricated using the phase shift mask blank described above was 180 nm and did not reach the level required for the phase shift mask used for manufacturing a high resolution, high-precision display device.

Since the phase shift mask described above has a pattern cross-sectional shape in which penetration into the interface of the resist film occurs and the CD deviation is large and the film surface reflectance of the phase shift film pattern with respect to exposure light is high, A high-resolution, high-precision display device could not be manufactured.

Further, since this phase shift mask is manufactured using a phase shift mask blank having a phase shift film having a large sheet resistance, when a small pattern is formed, electricity is likely to be emitted from the pattern to the pattern, and electrostatic destruction tends to occur .

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

10: Phase shift mask blank
20: transparent substrate
30: phase shift film
31: phase shift layer
32: reflectance reduction layer
33: metal layer
40: Shading film formation pattern

Claims (9)

A phase shift mask blank comprising a phase shift film including a chromium-based material on a transparent substrate,
The phase shift film is mainly composed of a phase shift layer having a function of adjusting transmittance and phase difference with respect to exposure light and a function disposed on the phase shift layer to reduce the reflectance of light incident from the phase shift film side And a metal layer disposed between the phase shift layer and the reflectance reducing layer and having a thinning coefficient higher than an extinction coefficient of the reflectance reducing layer in a wavelength region of 350 nm to 436 nm,
The laminate structure of the phase shift layer, the metal layer, and the reflectance reducing layer may have a structure in which the transmittance and phase difference of the phase shift film with respect to the exposure light have predetermined optical characteristics, Wherein the film surface reflectance of the phase shift film is 10% or less in a wavelength range of 350 nm to 436 nm. A phase shift mask blank comprising a phase shift film including a chromium-based material on a transparent substrate,
The phase shift film is mainly composed of a phase shift layer having a function of adjusting transmittance and phase difference with respect to exposure light and a function disposed on the phase shift layer to reduce the reflectance of light incident from the phase shift film side And a metal layer disposed between the phase shift layer and the reflectance reducing layer and having a chromium content higher than that of the reflectance reducing layer,
The laminate structure of the phase shift layer, the metal layer, and the reflectance reducing layer may have a structure in which the transmittance and phase difference of the phase shift film with respect to the exposure light have predetermined optical characteristics, Wherein the film surface reflectance of the phase shift film is 10% or less in a wavelength range of 350 nm to 436 nm. 3. The method according to claim 1 or 2,
Wherein the fluctuation range of the film surface reflectance of the phase shift film is 5% or less in a wavelength range of 350 nm to 436 nm. 3. The method according to claim 1 or 2,
Wherein a film surface reflectance of the phase shift film is 13% or less in a wavelength range of 313 nm to 436 nm. 5. The method of claim 4,
Wherein the fluctuation range of the film surface reflectance of the phase shift film is 10% or less in a wavelength range of 313 nm to 436 nm. 3. The method according to claim 1 or 2,
And a light shielding film pattern is provided between the transparent substrate and the phase shift film. A method for manufacturing a phase shift mask blank according to claim 1 or 2, wherein the phase shift film is formed by a drawing process and a development process using laser light having a wavelength selected from 350 nm to 436 nm in a wavelength range, A step of forming a film pattern,
A step of forming a phase shift film pattern on the transparent substrate by etching the phase shift film using the resist film pattern as a mask
And a step of forming the phase shift mask. A step of mounting the phase shift mask manufactured by the manufacturing method according to claim 7 on a mask stage of an exposure apparatus,
A step of irradiating the phase shift mask with exposure light and transferring the phase shift film pattern to a resist film formed on the display device substrate
The method comprising the steps of: 9. The method of claim 8,
Wherein the exposure light is composite light including light of a plurality of wavelengths selected in a wavelength range of 313 nm to 436 nm.

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