KR102548886B1 - Phase shift mask blank and method for manufacturing phase shift mask using the same, and method for manufacturing display device - Google Patents

Abstract

A phase shift mask blank used for formation of a phase shift mask for a display device having an excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern formed thereon and having good transfer accuracy is provided. A phase shift film is provided on a transparent substrate, the phase shift film contains a metal-based material or a metal silicide-based material, and the phase shift film is disposed between the phase shift layer and the reflectance reduction layer disposed above the phase shift layer. An intermediate layer is provided, and the intermediate layer is a metal-based material having a higher metal content than the metal content of the reflectance-reducing layer or a metal silicide-based material having a higher total content of metal and silicon than the reflectance-reducing layer, and the film surface reflectance of the phase shift film is It is 15% or less in the wavelength range of 350 nm - 436 nm, and the back surface reflectance of the phase shift film with respect to light incident from the transparent substrate side is 20% or less in the wavelength range of 365 nm - 436 nm.

Description

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

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

In recent years, with the high resolution and high precision of display devices such as FPD (Flat Panel Display), a phase shift mask for display devices having an excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern formed thereon is required. there is.

Moreover, under the influence of price reduction of display devices, such as FPD, reduction of the manufacturing cost of a phase shift mask is required. In the case of a conventional phase shift mask blank in which a 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, and then phase The shift film is etched to form a phase shift film pattern, then the resist film pattern is peeled off, and the light-shielding film pattern is further peeled off to manufacture 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 a light-shielding film is not formed on the phase shift film, the formation process and the peeling process of the light-shielding film pattern on the phase shift film become unnecessary, and manufacturing cost can be reduced.

In response to such a recent situation, a display in which a fine pattern is formed with an excellent pattern cross-sectional shape and excellent CD uniformity, produced using a phase shift mask blank on which a light-shielding film is not formed on the phase shift film. Phase shift masks for devices are in demand.

For example, in patent document 1, the phase shift mask blank for display apparatuses provided with the phase shift film of the structure in which the thin film of two or more layers was laminated|stacked on the transparent substrate is proposed. Although each thin film which comprises this phase shift film has a mutually different composition, all contain the substance which can be etched by the same etchant, and have a different etching rate when a composition differs. In patent document 1, the etching rate of each thin film which comprises a phase shift film is adjusted so that the cross-sectional inclination of the edge part of a phase shift film pattern may be formed steeply at the time of patterning of a phase shift film.

Further, in Patent Document 1, a functional film including one or more of the films required for a transfer pattern, including a light blocking film, a semi-transmissive film, an etch stop film, and a hard mask film, is disposed above or below the phase shift film for a display device. A phase shift mask blank of , has also been proposed.

Japanese Unexamined Patent Publication No. 2014-26281

A phase shift film used in a conventionally proposed phase shift mask for a display device is designed in consideration of the effect on the resist film due to the reflection of laser drawing light used in patterning the resist film used to form the phase shift film pattern. It is not done. For this reason, the film surface reflectance of the phase shift film with respect to laser drawing light will exceed 20 %. As a result, a standing wave is generated in the resist film, and as a result, the CD uniformity of the resist film pattern deteriorates, and by extension, the CD uniformity of the phase shift film pattern formed by patterning using the resist film pattern as a mask, In recent years, there are cases where the required value cannot be satisfied.

In addition, phase shift films used in conventionally proposed phase shift masks for display devices are not designed in consideration of the influence of reflection with the optical system of the exposure machine and reflection with the pellicle or display substrate adhered to the phase shift mask. not. For this reason, when the pattern formed on the phase shift mask is transferred using the phase shift mask for the display device, blurring (flare) of the transferred pattern due to reflected light from the display device substrate occurs, resulting in transfer accuracy. There is a problem of deterioration or a risk of generating a CD error of a transferred pattern transferred to a display device substrate.

For this reason, the present invention was made in view of the above-mentioned problems, and the film surface reflectance for light in the wavelength range of 350 nm to 436 nm used as laser drawing light and the wavelength range of 365 nm to 436 nm used as exposure light A phase used 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 formed and having good transfer accuracy by providing a phase shift film in which the back surface reflectance for light is reduced. It is an object to provide a shift mask blank and a manufacturing method of a phase shift mask using the same. In addition, by using a phase shift mask for a display device having an excellent pattern cross-sectional shape and excellent CD uniformity, a fine pattern is formed and the transfer accuracy is good, a high-resolution, high-precision display device without CD errors can be obtained. It aims at providing a manufacturing method.

In order to achieve the above-mentioned object, the present inventors intensively examine, configure the phase shift film with at least three layers, and devise the composition and film thickness of each layer constituting the phase shift film, thereby determining the transmittance of the phase shift film to exposure light and While the phase difference satisfies the prescribed optical characteristics required as a phase shift film, the film surface reflectance of the phase shift film to light in the wavelength range of 350 nm to 436 nm and the back surface reflectance to light in the wavelength range of 365 nm to 436 nm can be reduced. I have come to the knowledge that it is possible.

This invention was made based on this knowledge, and has the following structures.

(Configuration 1)

As a phase shift mask blank provided with a phase shift film on a transparent substrate,

The phase shift film contains a metallic material containing one or more types of metal and at least one selected from oxygen, nitrogen and carbon, or one or more types of metal and silicon and at least one selected from oxygen, nitrogen and carbon. It includes at least one of metal silicide-based materials that

The phase shift film includes a phase shift layer mainly having a function of adjusting the transmittance of exposure light and a phase difference, and a function of reducing the reflectance of light incident from the phase shift film side disposed above the phase shift layer. It has a reflectance reduction layer mainly having and an intermediate layer disposed between the phase shift layer and the reflectance reduction layer,

The intermediate layer is a metal-based material having a metal content higher than that of the reflectance reducing layer, or a metal having a total content higher than the metal content of the reflectance reducing layer or the total content of metal and silicon of the reflectance reducing layer. It is a silicide-based material,

The phase shift layer, the intermediate layer, and the reflectance reduction layer have a laminated structure in which transmittance and phase difference of the phase shift film to exposure light have predetermined optical characteristics,

The film surface reflectance of the phase shift film to light incident from the phase shift film side is 15% or less in a wavelength range of 350 nm to 436 nm, and the back surface reflectance of the phase shift film to light incident from the transparent substrate side A phase shift mask blank characterized in that this is 20% or less in the wavelength range of 365 nm to 436 nm.

(Configuration 2)

The phase shift mask blank according to configuration 1, wherein the phase shift film contains a material that can be etched with the same etchant.

(Configuration 3)

The phase shift mask blank according to configuration 1 or 2, wherein the metal is chromium.

(Configuration 4)

The phase shift layer and the reflectance reduction layer contain a chromium-based material containing chromium, oxygen, and nitrogen, and chromium is 30 to 70 atomic%, oxygen is 20 to 60 atomic%, and nitrogen is 0.4 to 30 atomic%. , The content of nitrogen contained in the phase shift layer is equal to or greater than the content of nitrogen contained in the reflectance reduction layer, and the content of oxygen contained in the reflectance reduction layer is included in the phase shift layer higher than the oxygen content.

The middle layer contains chromium and carbon, and the chromium content is 55 to 90 atomic %, and the carbon content is 10 to 45 atomic %, and the chromium content contained in the middle layer is the phase shift layer and the reflectance reducing layer. The phase shift mask blank according to configuration 3, characterized in that the chromium content is higher than the chromium content included in .

(Configuration 5)

The phase shift layer includes chromium mononitride or dichromium nitride,

The phase shift mask blank according to configuration 3 or 4, wherein the reflectance reduction layer contains chromium (III) oxide in which chromium and oxygen are bonded.

(Configuration 6)

The intermediate layer includes a chromium-based material further containing oxygen,

The phase shift mask blank according to any one of configurations 3 to 5, wherein the phase shift layer, the intermediate layer, and the reflectance reduction layer contain chromium (III) oxide in which chromium and oxygen are bonded.

(Configuration 7)

Configuration 1, wherein the phase shift layer contains a metal silicide-based material containing at least one of oxygen and nitrogen, and the reflectance reducing layer contains a metal-based material containing at least one of oxygen and nitrogen. Or the phase shift mask blank described in 2.

(Configuration 8)

The phase shift mask blank according to configuration 7, wherein the metal silicide-based material is a molybdenum silicide-based material, a zirconium silicide-based material, a titanium silicide-based material, or a molybdenum zirconium silicide-based material.

(Configuration 9)

The phase shift mask blank according to Configuration 1, wherein one or two of the phase shift layer, the intermediate layer, and the reflectance reducing layer contain a material having etching selectivity with other layers.

(Configuration 10)

Configuration 9, wherein the phase shift layer and the intermediate layer contain a material containing a chromium-based material, and the reflectance reducing layer contains a metal-based material having etching selectivity with the phase shift layer and the intermediate layer. The phase shift mask blank described in.

(Configuration 11)

The phase shift mask blank according to configuration 10, characterized in that the reflectance reduction layer contains titanium and a titanium-based material containing any one of oxygen and nitrogen.

(Configuration 12)

The phase shift mask blank according to any one of configurations 1 to 11, comprising a light-shielding film pattern between the transparent substrate and the phase shift film.

(Configuration 13)

The phase shift mask blank according to configuration 12, wherein the back surface reflectance of the light-shielding film pattern to light incident from the transparent substrate side is 20% or less in a wavelength range of 365 nm to 436 nm.

(Configuration 14)

The phase shift mask according to any one of Configurations 1 to 11, wherein a light-shielding film is provided on the phase shift film, and the film surface reflectance of the light-shielding film is 15% or less in a wavelength range of 350 nm to 436 nm. blank.

(composition 15)

Forming a resist film on the phase shift film of the phase shift mask blank according to any one of configurations 1 to 8, 12, and 13, and forming a resist film pattern on the resist film by a drawing process and a development process; ,

A method for manufacturing a phase shift mask comprising a step of etching the phase shift film using the resist film pattern as a mask to form a phase shift film pattern on the transparent substrate.

(Configuration 16)

Forming a resist film on the phase shift film of the phase shift mask blank according to any one of configurations 9 to 13, and forming a resist film pattern on the resist film by a drawing process using a laser beam and a development process; ,

etching the reflectance reducing layer using the resist film pattern as a mask to form a reflectance reducing layer pattern;

A method for manufacturing a phase shift mask comprising a step of forming a phase shift film pattern on the transparent substrate by etching the intermediate layer and the phase shift layer using the reflectance reducing layer pattern as a mask.

(Configuration 17)

A step of forming a resist film on the light-shielding film of the phase shift mask blank according to configuration 14, and forming a resist film pattern on the resist film by a drawing process and a development process;

etching the light-shielding film using the resist film pattern as a mask to form a light-shielding film pattern on the phase shift film;

A method for manufacturing a phase shift mask comprising a step of forming a phase shift film pattern on the transparent substrate by etching the phase shift film using the light-shielding film pattern as a mask.

(composition 18)

A step of loading the phase shift mask obtained by the method for manufacturing a phase shift mask according to any one of configurations 15 to 17 on a mask stage of an exposure apparatus;

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

(composition 19)

The method for manufacturing a display device according to Configuration 18, wherein the exposure light is composite light containing light of a plurality of wavelengths selected from 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 provided with a phase shift film on a transparent substrate, and the phase shift film is at least one selected from one or more types of metal, oxygen, nitrogen, and carbon. At least one of a metal-based material containing one or a metal silicide-based material containing at least one metal, silicon, and at least one selected from oxygen, nitrogen, and carbon, wherein the phase shift film is exposed to exposure light. A phase shift layer mainly having a function of adjusting the transmittance and phase difference to the phase shift layer, and a reflectance reducing layer disposed above the phase shift layer and mainly having a function of reducing the reflectance of light incident from the phase shift film side; An intermediate layer disposed between the phase shift layer and the reflectance reducing layer, wherein the intermediate layer is a metal-based material having a higher metal content than the metal content of the reflectance reducing layer, or the metal content of the reflectance reducing layer or the metal content of the reflectance reducing layer. It is a metal silicide-based material having a higher total content rate than the total content rate of metal and silicon in the reflectance reducing layer, and the phase shift layer, the intermediate layer, and the reflectance reducing layer have a laminated structure, so that the transmittance of the phase shift film to exposure light The phase difference has a predetermined optical characteristic, the film surface reflectance of the phase shift film with respect to light incident from the phase shift film side is 15% or less in the wavelength range of 350 nm to 436 nm, and is incident from the transparent substrate side. The back surface reflectance of the said phase shift film with respect to light is 20 % or less in the wavelength range of 365 nm - 436 nm. For this reason, using this phase shift mask blank, it is possible to manufacture a phase shift mask having an excellent pattern cross-sectional shape and excellent CD uniformity, having a fine pattern formed thereon, and having good transfer accuracy. Further, using this phase shift mask, it is possible to manufacture a high-resolution, high-precision display device that does not generate a CD error.

1 is a schematic diagram showing the film configuration of a phase shift mask blank.
Fig. 2 is a schematic diagram showing another film configuration of a phase shift mask blank.
Fig. 3 is a schematic diagram showing another film configuration of a phase shift mask blank.
4 is a film surface reflectance spectrum of a phase shift film of a phase shift mask blank in Examples 1 and 2 and Comparative Example 1;
Fig. 5 is a back surface reflectance spectrum of a phase shift film of a phase shift mask blank in Examples 1 and 2 and Comparative Example 1;
Fig. 6 is a graph showing results of compositional analysis in the depth direction of the phase shift film of the phase shift mask blank in Example 1;

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail, referring drawings. In addition, the following embodiment is one form at the time of actualizing this invention, and it does not limit this invention within the scope. Note that, in the drawings, the same or equivalent parts are given the same reference numerals, and the description thereof may be simplified or omitted.

Embodiment 1 (Embodiment 1-1, 1-2, 1-3).

In Embodiment 1, a phase shift mask blank is described.

1 is a schematic diagram showing a film configuration of a phase shift mask blank 10 in Embodiment 1-1. The phase shift mask blank 10 includes a transparent substrate 20 that is transparent to exposure light, and a phase shift film 30 disposed on the transparent substrate 20 . The transparent substrate 20 has a transmittance of 85% or more, preferably 90% or more, to exposure light when it is assumed that there is no surface reflection loss.

The phase shift film 30 is a metal-based material containing at least one metal and at least one selected from oxygen, nitrogen, and carbon, or at least one selected from one or more metals, silicon, and oxygen, nitrogen, and carbon. A metal silicide-based material containing

Examples of the metal contained in the metallic material include transition metals such as chromium (Cr), Zr (zirconium), molybdenum (Mo), tantalum (Ta), tungsten (W), and titanium (Ti), typical metals such as aluminum (Al) can be heard

Examples of the metal silicide-based material include nitrides of metal silicides, oxides of metal silicides, oxynitrides of metal silicides, carbonized nitrides of metal silicides, oxidized carbides of metal silicides, and oxidized carbonized nitrides of metal silicides. Examples of the metal contained in the metal silicide-based material include the above-described transition metals and typical metals.

The phase shift film 30 has the phase shift layer 31, the metal layer 33 which is an intermediate|middle layer, and the reflectance reduction layer 32 from the transparent substrate 20 side.

The phase shift film 30 may constitute all of the phase shift layer 31, the reflectance reduction layer 32, and the metal layer 33 with a metal-based material, as described in detail in Examples (Examples 1, 2), any one or two layers of the phase shift layer 31, the reflectance reduction layer 32, and the metal layer 33 are composed of a metal-based material, and the other layer is composed of a metal silicide-based material It may be (Example 3).

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 mainly adjusting the transmittance and phase difference with respect to exposure light. The phase shift layer 31 is a layer having the thickest film thickness compared to the film thicknesses of the reflectance reduction layer 32 and the metal layer 33 in the phase shift film 30 . In addition, the content rate of each element which comprises the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 mentioned later is set as the value measured by X-ray photoelectron spectroscopy (XPS, ESCA).

The phase shift layer 31 includes a metal-based material or a metal-silicide-based material.

When the entire phase shift film 30 includes a chromium (Cr)-based material, the phase shift layer 31 includes a chromium-based material containing chromium (Cr), oxygen (O), and nitrogen (N), The average content of each element is preferably 30 to 70 atomic% for chromium, 20 to 60 atomic% for oxygen, and 0.4 to 30 atomic% for nitrogen. In addition, the phase shift layer 31 contains a chromium nitride in which chromium and nitrogen are bonded as a bonding state (chemical state) of components constituting the phase shift layer 31, and in particular, chromium mononitride (CrN) or 2 nitride It is preferable to include chromium (Cr ₂ N). In addition, the phase shift layer 31 may have a chromium-type material containing at least 1 sort(s) of carbon (C) and fluorine (F). For example, as a material which forms the phase shift layer 31, CrON, CrOCN, and CrFCON are mentioned.

In addition, when molybdenum (Mo), zirconium (Zr), or titanium (Ti) is contained in the metal of the metal silicide-based material constituting the phase shift film 30, the phase shift layer 31 is molybdenum (Mo), A molybdenum silicide-based material containing silicon (Si), nitrogen (N) and/or oxygen (O), or a material containing zirconium (Zr), silicon (Si), nitrogen (N) and/or oxygen (O) It includes a zirconium silicide-based material or a titanium silicide-based material containing titanium (Ti), silicon (Si), nitrogen (N) and/or oxygen (O). In the case of molybdenum silicide-based materials, the average content of each element is 5 to 20 atomic% for molybdenum (Mo), 15 to 45 atomic% for silicon (Si), 0 to 75 atomic% for nitrogen (N), and 0 to 75 atomic% for oxygen (O ) is preferably 0 to 45 atomic%. In the case of the zirconium silicide-based material, the average content of each element is 5 to 35 atomic% for zirconium (Zr), 5 to 45 atomic% for silicon (Si), 0 to 70 atomic% for nitrogen (N), and 0 to 70 atomic% for oxygen. It is preferable that (O) is 0-70 atomic%. In the case of the titanium silicide-based material, the average content of each element is titanium (Ti) 5 to 30 atomic%, silicon (Si) 10 to 45 atomic%, nitrogen (N) 0 to 70 atomic%, oxygen It is preferable that (O) is 0-60 atomic%. Moreover, the phase shift layer 31 may have a molybdenum silicide-type material containing carbon (C), or a zirconium silicide-type material containing carbon (C).

The phase shift layer 31 can be formed by sputtering.

The reflectance reduction layer 32 is disposed above the phase shift layer 31 . The reflectance reduction layer 32 mainly has a function of reducing the reflectance of light incident from the phase shift film 30 side (ie, the side opposite to the transparent substrate 20 side of the reflectance reduction layer 32). The reflectance reduction layer 32 reduces the reflectance of the phase shift film 30 by the interference effect of the reflection by the interface between the metal layer 33 and the reflectance reduction layer 32 and the reflection by the surface of the reflectance reduction layer 32 . It is a layer whose film thickness is adjusted in order to reduce it.

The reflectivity reducing layer 32 includes a metal-based material or a metal silicide-based material.

When the entire phase shift film 30 includes a chromium (Cr)-based material, the reflectance reduction layer 32 includes a chromium-based material containing chromium (Cr), oxygen (O), and nitrogen (N), The average content of each element is 30 to 70 atomic% for chromium, 20 to 60 atomic% for oxygen, and 0.4 to 30 atomic% for nitrogen. In addition, the reflectance reducing layer 32 is a combined state (chemical state) of components constituting the reflectance reducing layer 32, and includes chromium oxide in which chromium and oxygen are combined, and in particular, chromium (III) oxide (Cr ₂ O ₃ ) is preferred. In addition, the reflectance reduction layer 32 may include a chromium-based material containing at least one of carbon (C) and fluorine (F). For example, as a material forming the reflectance reduction layer 32, CrON, CrOCN, and CrFON are mentioned. In this case, the effect of reducing the reflectance with respect to light incident from the phase shift film side (the surface side of the reflectance reducing layer 32) and the viewpoint of forming an excellent pattern cross-sectional shape by wet etching as a whole of the phase shift film 30 , the average content of nitrogen (N) contained in the phase shift layer 31 is equal to or greater than the average content of nitrogen (N) contained in the reflectance reduction layer 32, and the reflectance reduction layer 32 ) The average content rate of oxygen (O) contained in the phase shift layer 31 is set as more than the average content rate of oxygen (O) contained in the state. In addition, the average content of oxygen (O) contained in the reflectance reduction layer 32 is at least 1 at% or more, preferably 5 at% or more, than the average content of oxygen (O) contained in the phase shift layer 31. It is preferable to increase it from the point of the effect of reducing the film surface reflectance.

In addition, when molybdenum (Mo), zirconium (Zr), or titanium (Ti) is contained in the metal of the metal silicide-based material constituting the phase shift film 30, the reflectance reduction layer 32 is composed of titanium (Ti) and nitrogen. It includes a titanium-based material containing (N) and oxygen (O) or a titanium-based material containing titanium (Ti) and oxygen (O), and the average content of each element is 15 to 45 for titanium (Ti). It is preferable that atomic %, nitrogen (N) is 20-50 atomic %, and oxygen (O) is 15-65 atomic %. In addition, in the case of a metal silicide-based material constituting the phase shift film 30, the reflectance reduction layer 32 is a molybdenum silicide-based material containing molybdenum (Mo), silicon (Si), nitrogen (N), and oxygen (O). Material, molybdenum silicide-based material containing molybdenum (Mo), silicon (Si), and oxygen (O), zirconium silicide-based material containing zirconium (Zr), silicon (Si), nitrogen (N), and oxygen (O) A zirconium silicide-based material containing zirconium (Zr), silicon (Si), and oxygen (O), a titanium silicide-based material containing titanium (Ti), silicon (Si), nitrogen (N), and oxygen (O), A titanium silicide-based material containing titanium (Ti), silicon (Si), and oxygen (O) may be included, but in order to ensure adhesion to a resist film (not shown) formed on the surface, HMDS (hexamethyldisilazane) It is preferable to perform surface treatment, such as.

The reflectance reduction layer 32 can be formed by sputtering.

The metal layer 33 is disposed between the phase shift layer 31 and the reflectance reduction layer 32 . The metal layer 33 has a function of adjusting the transmittance of exposure light and, in combination with the reflectance reduction layer 32, has a function of reducing the reflectance of light incident from the phase shift film 30 side. . Moreover, it has the function of reducing the reflectance with respect to the light incident from the transparent substrate 20 side, combining with a phase shift layer.

The metal layer 33 is a metal-based material having an average metal content higher than the average metal content of the reflectance reducing layer 32, or a total amount higher than the total average content of metal and silicon in the reflectance reducing layer 32. and a metal silicide-based material having an average content rate.

When the entire phase shift film 30 contains a chromium (Cr)-based material, or the metal of the metal silicide-based material constituting the phase shift film 30 contains molybdenum (Mo), zirconium (Zr), or titanium (Ti) ) is included, the metal layer 33 contains chromium (Cr) and carbon (C), and the average content of each element is 55 to 90 atomic % of chromium (Cr) and carbon (C). The content rate is 10 to 45 atomic%, and the average content rate of chromium contained in the metal layer 33 is larger than the average content rate of chromium contained in the phase shift layer 31 and the reflectance reduction layer 32 . When the entire phase shift film 30 is etched with the same etchant, it is possible to suppress the cross-sectional shape of the metal layer 33 from becoming tapered by setting the average content of carbon (C) to 10 atomic% or more. Further, by setting the average content of carbon (C) in the metal layer 33 to 45 atomic% or less, it is possible to suppress the cross-sectional shape of the metal layer 33 from becoming tapered. By setting the average content of carbon (C) in the metal layer 33 within the above appropriate range, a pattern can be formed in the metal layer 33 by an appropriate mask process. In addition, the metal layer 33 may further contain a chromium-based material containing at least one of nitrogen (N), oxygen (O), and fluorine (F). For example, as a material forming the metal layer 33, CrC, CrCN, CrCO, CrCF, and CrCON are mentioned. Among them, it is preferable that the metal layer 33 is made of a chromium-based material containing chromium (Cr), carbon (C), and oxygen (O). And, as a bonding state (chemical state) of components constituting the phase shift layer 31, the reflectance reduction layer 32, and the metal layer 33, from the viewpoint of obtaining an excellent pattern cross-sectional shape by wet etching, all of these It is more preferred to include chromium(III) oxide (Cr ₂ O ₃ ) in the layer.

In addition, when titanium (Ti) is included in the metal of the metal-based material constituting the phase shift film 30 and molybdenum (Mo), zirconium (Zr), or titanium (Ti) is included in the metal of the metal silicide-based material. , The metal layer 33 is a molybdenum silicide-based material containing molybdenum (Mo), silicon (Si), carbon (C) and / or nitrogen (N), zirconium (Zr), and silicon (Si) , a zirconium silicide-based material containing carbon (C) and / or nitrogen (N), or a titanium silicide-based material containing titanium (Ti) and silicon (Si), carbon (C) and / or nitrogen (N) includes In the case of the molybdenum silicide-based material, the average content of each element is 5 to 20 at% for molybdenum (Mo), 15 to 70 at% for silicon (Si), 0 to 20 at% for carbon (C), and 0 to 20 at% for nitrogen (N ) is preferably 0 to 30 atomic%. In addition, in the case of zirconium silicide-based materials, the average content of each element is 5 to 35 atomic% for zirconium (Zr), 5 to 70 atomic% for silicon (Si), 0 to 20 atomic% for carbon (C), and nitrogen. It is preferable that (N) is 0-20 atom%. In the case of the titanium silicide-based material, the average content of each element is 5 to 35 atomic% for titanium (Ti), 5 to 70 atomic% for silicon (Si), 0 to 20 atomic% for carbon (C), and nitrogen. It is preferable that (N) is 0-20 atom%. The average content rate of molybdenum silicide contained in the metal layer 33, the average content rate of zirconium silicide, and the average content rate of titanium silicide are the average content rate of molybdenum silicide contained in the phase shift layer 31 and the reflectance reduction layer 32, zirconium The average content rate of silicide is greater than the average content rate of titanium silicide. Further, the metal layer 33 may be a molybdenum silicide-based material, a zirconium silicide-based material, or a titanium silicide-based material containing at least one of carbon (C), nitrogen (N) and oxygen (O). For example, examples of the material forming the metal layer 33 include MoSiC, MoSiN, MoSiCN, MoSiCO, MoSiCON, ZrSiC, ZrSiN, ZrSiCN, ZrSiCO, ZrSiCON, TiSiC, TiSiN, TiSiCN, TiSiCO, and TiSiCON.

Since the sheet resistance of the phase shift film 30 decreases by providing the metal layer 33, charge-up of a phase shift mask blank and a phase shift mask can be prevented. When the metal layer 33 is not provided, electricity generated when the phase shift mask blank and the phase shift mask are taken out of the case does not escape and the electricity accumulates in the phase shift mask blank and the phase shift mask. easy to attach In addition, when a small pattern is formed on the phase shift mask, electricity bounces from the pattern to the pattern, and electrostatic destruction is likely to occur.

The metal layer 33 can be formed by sputtering.

The metal layer 33 preferably has a higher extinction coefficient than that of the reflectance reducing layer 32 in the wavelength range of 350 nm to 436 nm. In the wavelength range of 313 nm to 436 nm, it is preferable to have a higher extinction coefficient than the extinction coefficient of the reflectance reducing layer 32 .

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, more preferably 1.8 to 3.5. If the difference in extinction coefficient is 1.5 to 3.5, in the above wavelength range (wavelength range of 350 nm to 436 nm or wavelength range of 313 nm to 436 nm) at the interface between the metal layer 33 and the reflectance reduction layer 32 Since the reflectance of can be increased, since the effect of reducing the reflectance is more exhibited, it is preferable.

Moreover, it is preferable that the metal layer 33 has a higher extinction coefficient than the extinction coefficient of the phase shift layer 31 in the wavelength range of 350 nm - 436 nm. Moreover, it is preferable to have a higher extinction coefficient than the extinction coefficient of the phase shift layer 31 in the wavelength range of 313 nm - 436 nm.

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

When the metal layer 33 and the reflectance reducing layer 32 contain a chromium-based material, the metal layer 33 contains chromium (Cr) higher than the average content (atomic %) of chromium (Cr) in the reflectance reducing layer 32. It has an average content rate (atomic %).

The difference between the average Cr content of the metal layer 33 and the average Cr content of the reflectance reducing layer 32 is preferably 10 to 80 atomic%, more preferably 15 to 80 atomic%. When the difference in average content of Cr is 10 to 80 atomic percent, the above wavelength range (wavelength range of 350 nm to 436 nm or wavelength range of 313 nm to 436 nm) at the interface between the metal layer 33 and the reflectance reducing layer 32 Since the reflectance in can be increased, since the reflectance reduction effect is exhibited more, it is preferable. The etching rate of the metal layer 33 can be adjusted by making chromium (Cr) contain nitrogen (N), oxygen (O), carbon (C), and fluorine (F) to form a chromium-based material. For example, by containing carbon (C) or fluorine (F) in chromium (Cr), the wet etching rate can be reduced, and by containing nitrogen (N) or oxygen (O) in chromium (Cr), the wet etching rate can be reduced. Etch speed can be increased. Considering the wet etching rate of the phase shift layer 31 and the reflectance reduction layer 32 formed above and below the metal layer 33, the phase after etching is made of a chromium-based material in which the above-mentioned elements are added to chromium. The cross-sectional shape of the shift film 30 can be improved.

In addition, the metal layer 33 has an average content of chromium (Cr) higher than the average content of chromium (Cr) of the phase shift layer 31 .

It is preferable that each of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 has a refractive index of 2.0 or more in a wavelength range of 350 nm to 436 nm. When it has a refractive index of 2.0 or more, the film thickness of the phase shift film 30 required to obtain desired optical characteristics (transmittance and phase difference) can be reduced. Therefore, a phase shift mask produced using the phase shift mask blank 10 provided with the phase shift film 30 can have a phase shift film pattern having an excellent pattern cross-sectional shape and excellent CD uniformity.

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

Due to the laminated structure of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32, the transmittance of the phase shift film 30 to exposure light and the phase difference have predetermined optical characteristics.

In the phase shift film 30, any of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 may contain a material that can be etched with the same etchant, and the phase shift layer 31, the metal One or two of the layer 33 and the reflectance reduction layer 32 may contain a material having etching selectivity with the other layers.

The transmittance of the phase shift film 30 with respect to exposure light satisfies a value required as the phase shift film 30 . The transmittance of the phase shift film 30 is preferably 1% to 70%, more preferably 2% to 60% with respect to light of a predetermined wavelength included in exposure light (hereinafter referred to as representative wavelength). , more preferably 3% to 50%. That is, when the exposure light is composite light containing light in a wavelength range of 313 nm or more and 436 nm or less, the phase shift film 30 has the above-described transmittance with respect to light of a representative wavelength included in the wavelength range. For example, when the exposure light is composite light including j-line (wavelength: 313 nm), i-line (wavelength: 365 nm), h-line (wavelength: 405 nm), and g-line (wavelength: 436 nm), the phase The shift film 30 has the above-described transmittance with respect to any one of j-line, i-line, h-line and g-line.

The phase difference of the phase shift film 30 with respect to exposure light satisfies the value required as the phase shift film 30 . The phase difference of the phase shift film 30 is preferably 160° to 200°, and more preferably 170° to 190° with respect to light of a representative wavelength included in the exposure light. Due to this property, the phase of the light of the representative wavelength included in the exposure light can be changed by 160° to 200°. For this reason, a phase difference of 160 to 200° occurs between light of a representative wavelength transmitted through the phase shift film 30 and light of a representative wavelength transmitted only through the transparent substrate 20 . That is, when the exposure light is composite light containing 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 composite light including j-line, i-line, h-line, and g-line, the phase shift film 30 is the above-mentioned one of the j-line, i-line, h-line, and g-line. have a phase difference.

The transmittance and phase difference of the phase shift film 30 are controlled by adjusting the respective composition and thickness of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 constituting the phase shift film 30. can do. For this reason, in this embodiment, each of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 so that the transmittance and phase difference of the phase shift film 30 may have the above-mentioned predetermined optical characteristics. Composition and thickness are adjusted. In addition, 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 .

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

The film surface reflectance of the phase shift film 30 with respect to the light incident from the phase shift film 30 side is 15% or less in the wavelength range of 350 nm - 436 nm. Moreover, it is preferable that it is 22.5 % or less in the wavelength range of 313 nm - 436 nm. That is, the film surface reflectance of the phase shift film 30 to light incident from the phase shift film 30 side is 15% or less in the wavelength range of 350 nm to 436 nm, and the wavelength range is 313 nm to 436 nm. Even if it is enlarged, it is preferable that it is 22% or less. When the film surface reflectance of the phase shift film 30 is 15% or less in the wavelength range of 350 nm to 436 nm, the film surface reflectance with respect to laser writing light is reduced, so that a phase shift mask having excellent CD uniformity can be formed. there is. In addition, when the film surface reflectance of the phase shift film 30 is 22.5% or less in the wavelength range of 313 nm to 436 nm, the film surface reflectance with respect to exposure light is reduced, so when transferring the pattern formed on the phase shift mask , Fading (flare) of the transfer pattern caused by reflected light from the display device substrate can be prevented. The film surface reflectance of the phase shift film 30 is preferably 20% or less, more preferably 15% or less in 313 nm to 436 nm.

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

The back surface reflectance of the phase shift film 30 with respect to the light incident from the transparent substrate 20 side is 20% or less in the wavelength range of 365 nm - 436 nm. Moreover, it is preferable that it is 20 % or less also in the wavelength range of 313 nm - 436 nm. Since the back surface reflectance of the phase shift film 30 to exposure light is reduced by making the back surface reflectance of the phase shift film 30 into the said range, when transferring the pattern formed on the phase shift mask, the optical system of an exposure machine and Deterioration in transfer accuracy due to reflected light can be suppressed. In addition to the requirements for the back surface reflectance of the phase shift film 30, if the film surface reflectance of the phase shift film 30 is 20% or less in the wavelength range of 350 nm to 436 nm, reflection with the optical system of the exposure machine and phase shift mask Since the influence of the reflection of the pellicle adhered to the display device substrate can be reduced, the transfer accuracy is improved, and a phase shift mask that prevents CD errors in the transferred pattern transferred to the display device substrate can be formed.

The fluctuation width of the back surface reflectance of the phase shift film 30 is preferably 18% or less in the wavelength range of 365 nm to 436 nm, more preferably 16% or less. In the wavelength range of 313 nm to 436 nm, it is preferably 18% or less, more preferably 16% or less. That is, the fluctuation range of the film surface reflectance of the phase shift film 30 is 9% or less in the wavelength range of 350 nm to 436 nm, and preferably 8.5% or less, and the wavelength range is 12.5% in the 313 nm to 436 nm range. % or less, preferably 12% or less.

The film surface reflectance of the phase shift film 30, the back surface reflectance, and their variation width are the respective refractive indices of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 constituting the phase shift film 30, It can be controlled by adjusting the extinction coefficient and thickness. Since the extinction coefficient and the refractive index can be controlled by adjusting the composition, in this embodiment, the phase shift layer 31 is such that the film surface reflectance and the back surface reflectance of the phase shift film 30 and their fluctuation width have the above-described predetermined physical properties. , The composition and thickness of each of the metal layer 33 and the reflectance reduction layer 32 are adjusted. In addition, the film surface reflectance of the phase shift film 30, the back surface reflectance, and their fluctuation range are mainly influenced by the respective composition and thickness of the metal layer 33 and the reflectance reduction layer 32.

The film surface reflectance and the back surface reflectance can be measured using a spectrophotometer or the like. The fluctuation range of the film surface reflectance 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 include a single film having a uniform composition, may include a plurality of films having different compositions, or may include a single film whose composition continuously changes in the thickness direction. The same applies to the metal layer 33 and the reflectance reduction layer 32 .

In addition, at the interface between the phase shift layer 31 and the metal layer 33 and the interface between the metal layer 33 and the reflectance reduction layer 32, each phase shift layer 31, the metal layer 33, the reflectance reduction layer Each element constituting (32) may have a composition gradient region where the composition gradient is continuous.

2 is a schematic diagram showing another film configuration of the phase shift mask blank 10 in Embodiment 1-2. As shown in FIG. 2 , the phase shift mask blank 10 may be equipped with a light-shielding film pattern 40 between the transparent substrate 20 and the phase shift film 30 . The phase shift film 30 in Embodiment 1-2 is the same as Embodiment 1-1, and description is abbreviate|omitted.

When the phase shift mask blank 10 has the light-blocking film pattern 40, the light-blocking film pattern 40 is disposed on the main surface of the transparent substrate 20. The light blocking 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 transmission of exposure light. If necessary, a back surface reflectance reducing layer 41 for reducing the back surface reflectance of the light blocking film pattern 40 to the light incident from the transparent substrate 20 side of the light blocking film pattern 40 on the transparent substrate 20 side. ) may be formed. In this case, the light-blocking film pattern 40 has a configuration including a back surface reflectance reducing layer 41 from the side of the transparent substrate 20 and a light-blocking layer 42 having a function of blocking transmission of exposure light. For example, as a material of the light-blocking film pattern, metal-based materials such as chromium-based materials and metal silicide-based materials are exemplified. Examples of the chromium-based material include chromium (Cr) or a chromium-based material containing chromium (Cr) and at least one of carbon (C) and nitrogen (N). In addition, a chromium-based material containing at least one of chromium (Cr), oxygen (O) and fluorine (F), or at least one of chromium (Cr), carbon (C) and nitrogen (N) and a chromium-based material further containing at least one of oxygen (O) and fluorine (F). For example, as a material forming the light-blocking film pattern 40, Cr, CrC, CrN, CrCN, CrO, CrON, CrCO, and CrCON can be cited.

Examples of the metal silicide-based material include metal silicides, nitrides of metal silicides, oxides of metal silicides, oxynitrides of metal silicides, carbonized nitrides of metal silicides, oxidized carbides of metal silicides, and oxidized carbonized nitrides of metal silicides. Examples of the metal contained in the metal silicide-based material include the above-described transition metals and typical metals.

In addition, when the light-shielding film pattern 40 includes the back reflectance reducing layer 41, the back reflectance reducing layer 41 preferably has a characteristic of being 20% or less in the wavelength range of 365 nm to 436 nm. . Further, the back surface reflectance reducing layer 41 preferably has a characteristic of being 20% or less in the wavelength range of 313 nm to 436 nm.

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

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

Optical density can be measured using a spectrophotometer or an OD meter.

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

The material of the light-shielding film pattern 40 may be a material having etching selectivity with respect to the phase shift film 30 (the phase shift layer 31, the metal layer 33, and the reflectance reducing layer 32), and the etching selectivity It may be made of a material that does not have

Next, FIG. 3 is a schematic diagram showing another film configuration of the phase shift mask blank 10 in Embodiment 1-3. As shown in FIG. 3 , the phase shift mask blank 10 may include a transparent substrate 20 , a phase shift film 30 , and a light-shielding film 45 . The light-blocking film 45 may include a single film with a uniform composition, a plurality of films with different compositions, or a single film whose composition continuously changes in the thickness direction. The phase shift film 30 in Embodiment 1-3 is the same as Embodiment 1-1, and description is abbreviate|omitted. In addition, the material forming the light-blocking film 45 is not particularly limited as long as it is a material having a function of blocking transmission of exposure light. If necessary, a surface reflectance reducing layer 47 for reducing the film surface reflectance of the light blocking film 45 with respect to light incident on the surface side of the light blocking film 45 may be formed. In this case, the light-blocking film 45 has a structure including a light-blocking layer 46 having a function of blocking transmission of exposure light from the phase shift film 30 side and a surface reflectance reducing layer 47 . For example, as the material of the light-blocking film 45, the same material as that of the above-described light-blocking film pattern 40 can be used. In addition, when the light-shielding film 45 includes the surface reflectance reducing layer 47, it is preferable that the surface reflectance reducing layer 47 has a characteristic of being 20% or less in the wavelength range of 365 nm to 436 nm. Further, the surface reflectance reducing layer 47 preferably has a characteristic of being 22.5% or less in the wavelength range of 313 nm to 436 nm. In addition, the light shielding layer 46 and the surface reflectance reduction layer 47 may each be a single layer, or at least one of them may have a plurality of laminated structures.

The light blocking film 45 can be formed by sputtering.

In Embodiment 1-3, the material of the light-shielding film 45 has etching selectivity with respect to the phase shift film 30 (the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32). It may be a material or a material having no etching selectivity. Considering the manufacturing process of the phase shift mask, the material of the light-shielding film 45 is preferably a material having etching selectivity with respect to the phase shift film 30 .

Further, in the phase shift mask blank 10 of Embodiment 1-2 or Embodiment 1-3, between the phase shift film 30 and the light-shielding film pattern 40, the phase shift film 30 and Between the light-blocking films 45, another functional film may be formed on the light-blocking film 45. Examples of the functional film include an etching stop film and an etching mask film.

The phase shift mask blank 10 of Embodiment 1-1 or Embodiment 1-2 may have a resist film on the phase shift film 30, and the phase shift mask blank 10 of Embodiment 1-3 ) may be provided with a resist film on the light blocking film 45 .

Next, the manufacturing method of the phase shift mask blank 10 of Embodiment 1-1 mentioned above and 1-2 is demonstrated. The phase shift mask blank 10 is manufactured by performing the following preparation process and phase shift film formation process.

Hereinafter, each process is demonstrated in detail.

1. Preparation process

In the preparation process, 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 transmits exposure light to be used. For example, synthetic quartz glass, soda-lime glass, and non-alkali glass are mentioned.

When manufacturing the phase shift mask blank 10 provided with the light-shielding film pattern 40 of Embodiment 1-2, after that, by the sputtering method on the transparent substrate 20, for example, a chromium-type material is included. to form a light-shielding film that Thereafter, a resist film pattern is formed on the light-blocking film, and the light-blocking film is etched using the resist film pattern as a mask to form the light-blocking film pattern 40 . After that, the resist film pattern is peeled off. In the case where the light-shielding film pattern 40 has a function of reducing the back surface reflectance for light incident from the transparent substrate 20 side, chromium and oxygen, for example, are added onto the transparent substrate 20 by a sputtering method. A back surface reflectance reducing layer 41 containing chromium oxide and a light blocking layer 42 of a chromium-based material containing chromium are formed on the back surface reflectance reducing layer 41 to form a light blocking film. Thereafter, a resist film pattern is formed on the light-blocking film, and the light-blocking film is etched using the resist film pattern as a mask to form the light-blocking film pattern 40 . Thereafter, the resist film pattern is peeled off to obtain a light-shielding film pattern 40 on the transparent substrate 20 .

2. Phase shift film formation process

In the phase shift film formation step, the phase shift film 30 containing a metal-based material or a metal silicide-based material is formed on the transparent substrate 20 by a sputtering method. Here, when the light-shielding film pattern 40 is formed on the transparent substrate 20, the phase shift film 30 is formed so that the light-shielding film pattern 40 may be covered.

The phase shift film 30 forms a film of the phase shift layer 31 on the main surface of the transparent substrate 20, forms a film of the metal layer 33 on the phase shift layer 31, and on the metal layer 33 It is formed by forming the reflectance reduction layer 32 into a film. Below, the case where the phase shift film 30 is formed from a chromium-type material is demonstrated. In addition, also when forming the phase shift film 30 with another metal type material or metal silicide type material, it can form by the sputtering method similarly by adjusting the sputtering target material and sputtering atmosphere.

Film formation of the phase shift layer 31 uses a sputtering target containing chromium or a chromium-based material, for example, at least one selected from the group consisting of helium gas, neon gas, argon gas, krypton gas, and xenon gas. A sputter comprising a mixed gas of an inert gas containing and an active gas containing at least one selected from the group consisting of oxygen gas, nitrogen gas, nitrogen monoxide gas, nitrogen dioxide gas, carbon dioxide gas, hydrocarbon gas, and fluorine gas. carried out in a gas atmosphere. As hydrocarbon-type gas, methane gas, butane gas, propane gas, styrene gas etc. are mentioned, for example. As the sputtering target, other than chromium metal, chromium-based materials such as chromium oxide, chromium nitride, chromium oxynitride, and chromium oxynitride carbide can be used.

Similarly, the film formation of the metal layer 33 uses a sputter target containing chromium or a chromium-based material, for example, at least one selected from the group consisting of helium gas, neon gas, argon gas, krypton gas, and xenon gas. A sputter gas atmosphere containing an inert gas containing species, or an inert gas containing at least one selected from the group consisting of helium gas, neon gas, argon gas, krypton gas, and xenon gas, oxygen gas, nitrogen gas , nitrogen monoxide gas, nitrogen dioxide gas, carbon dioxide gas, hydrocarbon-based gas, and a sputtering gas atmosphere containing a mixed gas of an active gas containing at least one selected from the group consisting of fluorine-based gas. As hydrocarbon-type gas, methane gas, butane gas, propane gas, styrene gas etc. are mentioned, for example. As the sputter target, other than chromium metal, chromium-based materials such as chromium oxide, chromium nitride, chromium oxynitride, and chromium oxynitride carbide can be used.

Similarly, at least one selected from the group consisting of helium gas, neon gas, argon gas, krypton gas, and xenon gas is used to form the reflectance reducing layer 32 using a sputter target containing chromium or a chromium-based material. A mixed gas of an inert gas containing at least one gas and an active gas containing at least one selected from the group consisting of oxygen gas, nitrogen gas, nitrogen monoxide gas, nitrogen dioxide gas, carbon dioxide gas, hydrocarbon gas, and fluorine gas. is performed in a sputter gas atmosphere. As hydrocarbon-type gas, methane gas, butane gas, propane gas, styrene gas etc. are mentioned, for example. As the sputter target, other than chromium metal, chromium-based materials such as chromium oxide, chromium nitride, chromium oxynitride, and chromium oxynitride carbide can be used.

When the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 are formed, the respective composition and thickness of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 are Adjust the transmittance and phase difference of the phase shift film 30 to have the above-described predetermined optical characteristics, and the film surface reflectance and back surface reflectance of the phase shift film 30 and their fluctuation range to have the above-described predetermined physical properties and optical characteristics do. Each composition of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 can be controlled by the composition and flow rate of the sputtering gas. Each thickness of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 can be controlled by sputtering power, sputtering time, and the like. Moreover, when a sputtering apparatus is an in-line sputtering apparatus, each thickness of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 can be controlled also by the conveyance speed of a board|substrate.

When the phase shift layer 31 includes a single film with a uniform composition or a plurality of films, the film formation process described above is performed only once or a plurality of times without changing the composition and flow rate of the sputtering gas.

When the phase shift layer 31 includes a plurality of films having different compositions, the above-described film formation process is performed multiple times by changing the composition and flow rate of the sputtering gas for each film formation process, or multiple times by changing the material and composition of the sputtering target. , or a combination thereof is performed plural times.

For example, when the phase shift layer 31 includes a single film whose composition continuously changes in the thickness direction, the film formation process described above is performed only once while changing the composition and flow rate of the sputtering gas. The same applies to the film formation of the metal layer 33 and the film formation of the reflectance reduction layer 32 . When the film formation process is performed a plurality of times, the sputtering power applied to the sputtering target can be reduced. Even when the composition of at least one of the metal layer 33 and the reflectance reduction layer 32 is different from that of the phase shift layer 31, if the different composition is a composition of a non-metal such as C, N, O, the film forming process described above , It is possible to form a film by changing the composition and flow rate of the sputtering gas for each film formation process. In addition, when a different composition is a metal (Cr, Si, Zr), a change of a target is required. In this case, a plurality of targets having different compositions are installed in advance, and the position of the target to be discharged is changed according to the target composition.

The phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 are continuously formed using an in-line sputtering device, without exposing the transparent substrate 20 to the outside of the device and exposing it to the atmosphere. desirable. By continuously forming a film without taking it out of the apparatus, it is possible to prevent unintentional surface oxidation and surface carbonization of each layer. Unintended surface oxidation or surface carbonization of each layer is used when transferring a phase shift film pattern to a resist film formed on a laser beam or display device substrate used when drawing a resist film formed on the phase shift film 30 There is a possibility of changing the reflectance of the exposure light to be applied, and also changing the etching rate of the oxidized portion or the carbonized portion.

Moreover, when manufacturing the phase shift mask blank 10 provided with a resist film, a resist film is formed next on a phase shift film.

In the phase shift mask blank 10 of this Embodiment 1-1, the phase shift film 30 containing a metal-based material or metal silicide-based material formed on a transparent substrate 20 comprises a phase shift layer 31 and a reflectance It has a metal layer 33 having an average chromium content higher than the average chromium content of the reduction layer 32, and the average chromium content of the reduction layer 32 formed between the phase shift layer 31 and the reflectance reduction layer 32, While the transmittance and phase difference of the phase shift film 30 to exposure light satisfy the prescribed optical characteristics required as the phase shift film 30, the film surface reflectance of the phase shift film 30 is in the wavelength range of 350 nm to 436 nm. is 15% or less, and the back surface reflectance of the phase shift film 30 is 20% or less in the wavelength range of 365 nm to 436 nm. For this reason, using this phase shift mask blank 10, it is possible to manufacture a phase shift mask having an excellent pattern cross-section shape and excellent CD uniformity, a fine pattern is formed, and the transfer accuracy becomes good.

Next, the manufacturing method of the phase shift mask blank 10 in Embodiment 1-3 is demonstrated. The manufacturing method of the phase shift mask blank 10 of Embodiment 1-3 explained above is the above-mentioned "1. Preparation process”, “2. Phase shift film formation process" is the same, so description is abbreviate|omitted, and the light-shielding film formation process is demonstrated below.

3. Light-shielding film formation process

In the light-shielding film formation step, the light-shielding film 45 made of a metal or metal silicide-based material is formed on the phase shift film 30 by a sputtering method.

The light-blocking film 45 is formed by forming a light-blocking layer 46 on the phase shift film 30 and, if necessary, a surface reflectance reducing layer 47 on the light-blocking layer 46 . In the following, a case where the phase shift film 30 is made of a metal silicide-based material and the light-shielding film 45 is made of a chromium-based material will be described. In addition, when the phase shift film 30 is a metal-based material (for example, a chromium-based material), when the light-shielding film 45 is formed of a metal silicide-based material, the phase shift film 30 and the light-shielding film ( When 45) is a metal-based material (eg, a chromium-based material), between the phase shift film 30 and the light-shielding film 45 is formed of a material having etching selectivity (eg, a metal silicide-based material). Even in the case, it can form by the sputtering method similarly by adjusting the sputtering target material and sputtering atmosphere.

The film formation of the light shielding layer 46 is carried out by using a sputter target containing chromium or a chromium-based material, for example, at least one selected from the group consisting of helium gas, neon gas, argon gas, krypton gas, and xenon gas. A sputter gas containing a mixed gas of an active gas containing at least one selected from the group consisting of oxygen gas, nitrogen gas, nitrogen monoxide gas, nitrogen dioxide gas, carbon dioxide gas, hydrocarbon-based gas, and fluorine-based gas. done in the atmosphere As hydrocarbon-type gas, methane gas, butane gas, propane gas, styrene gas etc. are mentioned, for example. As the sputtering target, in addition to chromium metal, chromium-based materials such as chromium oxide, chromium nitride, chromium carbide, chromium oxynitride, chromium oxide carbide, chromium nitride carbide, and chromium oxynitride carbide can be used.

Similarly, the film formation of the surface reflectance reducing layer 47 is performed using a sputter target containing chromium or a chromium-based material, for example, 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 at least one gas and an active gas containing at least one selected from the group consisting of oxygen gas, nitrogen gas, nitrogen monoxide gas, nitrogen dioxide gas, carbon dioxide gas, hydrocarbon gas, and fluorine gas It is performed in a sputter gas atmosphere containing As hydrocarbon-type gas, methane gas, butane gas, propane gas, styrene gas etc. are mentioned, for example. As the sputtering target, in addition to chromium metal, chromium-based materials such as chromium oxide, chromium nitride, chromium carbide, chromium oxynitride, chromium oxide carbide, chromium nitride carbide, and chromium oxynitride carbide can be used.

When forming the light-blocking layer 46 and the surface reflectance-reducing layer 47, the respective composition and thickness of the light-blocking layer 46 and the surface reflectance-reducing layer 47 depend on the optical density and surface reflectance of the light-blocking film 45. In addition, the above-mentioned predetermined physical properties and optical characteristics (in the combination of the phase shift film 30 and the light-shielding film 45, the optical density is 3.0 or more, and the film surface reflectance of the light-shielding film 45 is 350 nm to 436 nm 15% or less in the wavelength region of . The respective compositions of the light blocking layer 46 and the surface reflectance reducing layer 47 of the light blocking film 45 can be controlled by the composition and flow rate of the sputtering gas. The respective thicknesses of the light shielding layer 46 and the surface reflectance reducing layer 47 can be controlled by sputtering power, sputtering time, and the like. In the case where the sputtering device is an inline type sputtering device, the respective thicknesses of the light shielding layer 46 and the surface reflectance reducing layer 47 can be controlled also by the transport speed of the substrate.

Embodiment 2 (Embodiment 2-1, 2-2).

Embodiment 2 demonstrates the manufacturing method of a phase shift mask. Embodiment 2-1 is a manufacturing method of a phase shift mask using the phase shift mask blank of Embodiments 1-1 and 1-2. Embodiment 2-2 is a manufacturing method of a phase shift mask using the phase shift mask blank of Embodiment 1-3. The manufacturing method of the phase shift mask of Embodiment 2-1 uses the phase shift mask blanks of Embodiments 1-1 and 1-2, and the process of forming the following resist film pattern (resist film pattern formation process) and phase It has the process of forming a shift film pattern (phase shift film pattern formation process), and the manufacturing method of the phase shift mask of Embodiment 2-2 uses the phase shift mask blank of Embodiment 1-3, the following resist film It has a pattern formation process, a process of forming a light-shielding film pattern (light-shielding film pattern formation process), and a phase shift film pattern formation process.

Hereinafter, each process is demonstrated in detail.

Manufacturing method of the phase shift mask of Embodiment 2-1

1. Resist film pattern formation process

In the resist film pattern formation step, first, a resist film is formed on the phase shift film 30 of the phase shift mask blank 10 of Embodiments 1-1 and 1-2. However, when the phase shift mask blank 10 is a thing equipped with a resist film on the phase shift film 30, formation of a resist film is not performed. The resist film material to be used is not particularly limited. What is necessary is just to be sensitive to the laser beam which has a certain wavelength selected from the wavelength range of 350 nm - 436 nm mentioned later. In addition, the resist film may be of either a positive type or a negative type.

After that, a predetermined pattern is drawn on the resist film using a laser beam having a certain wavelength selected from a wavelength range of 350 nm to 436 nm. As a pattern to be drawn on the resist film, a line and space pattern and a hole pattern are exemplified.

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

2. Phase shift film pattern formation process

In the phase shift film pattern formation step, first, the phase shift film 30 is 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 reduction layer 32 constituting the phase shift film 30 is etched with an etching medium (etching solution, etching gas) for etching the phase shift film 30. It is not particularly limited as long as it can be etched. For example, when each of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 constituting the phase shift film 30 contains a chromium-based material containing chromium (Cr). , an etching solution containing ceric ammonium nitrate and perchloric acid, or an etching gas containing a mixed gas of chlorine gas and oxygen gas. In addition, when each of the phase shift layer 31 constituting the phase shift film 30, the metal layer 33, and the reflectance reduction layer 32 contains a metal silicide-based material, hydrofluoric acid, hydrofluoric acid and An etching solution comprising at least one fluorine compound selected from ammonium hydrogen fluoride and at least one oxidizing agent selected from hydrogen peroxide, nitric acid and sulfuric acid, or containing hydrogen peroxide and ammonium fluoride and at least one oxidizing agent selected from phosphoric acid, sulfuric acid and nitric acid Etching solutions, fluorine-containing gases such as CF ₄ gas, CHF ₃ gas, and SF ₆ gas, and etching gases obtained by mixing these gases with O ₂ gas are exemplified.

After that, the resist film pattern is stripped using a resist stripper or by ashing.

In addition, when one or two layers of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 contain a material having etching selectivity with other layers, the etching medium is changed depending on the layer. , the desired etching can be performed.

According to the manufacturing method of the phase shift mask of this Embodiment 2-1, the phase shift mask which has an excellent pattern cross-section shape and excellent CD uniformity, the fine pattern is formed, and the transfer precision becomes favorable can be manufactured.

Manufacturing method of the phase shift mask of Embodiment 2-2

1. First resist film pattern formation process

In the 1st resist film pattern formation process, first, a resist film is formed on the light-shielding film 45 of the phase shift mask blank 10 of Embodiment 1-3. However, when the phase shift mask blank 10 is a thing equipped with a resist film on the light-shielding film 45, formation of a resist film is not performed. The resist film material to be used is not particularly limited. What is necessary is just to be sensitive to the laser beam which has a certain wavelength selected from the wavelength range of 350 nm - 436 nm mentioned later. In addition, the resist film may be of either a positive type or a negative type.

After that, a predetermined pattern is drawn on the resist film using a laser beam having a certain wavelength selected from a wavelength range of 350 nm to 436 nm. As a pattern to be drawn on the resist film, a line and space pattern and a hole pattern are exemplified.

After that, the resist film is developed with a predetermined developer, and a first resist film pattern is formed on the light blocking film 45 .

2. Mask pattern formation process for phase shift film pattern formation (first light-shielding film pattern formation process)

In the mask pattern forming step, the light-shielding film 45 is etched using the first resist film pattern as a mask to form a mask pattern for phase shift film pattern formation. The etching medium (etching solution, etching gas) for etching the light-blocking film 45 is particularly limited as long as it can etch each of the light-blocking layer 46 and the surface reflectance reducing layer 47 constituting the light-blocking film 45. It doesn't work. For example, when each of the light blocking layer 46 and the surface reflectance reducing layer 47 constituting the light blocking film 45 includes a chromium-based material containing chromium (Cr), ceric ammonium nitrate and An etching solution containing perchloric acid and an etching gas containing a mixed gas of chlorine gas and oxygen gas are exemplified. Further, when each of the light blocking layer 46 and the surface reflectance reducing layer 47 constituting the light blocking film 45 includes a metal silicide-based material, at least one selected from hydrofluoric acid, hydrosilicic acid and ammonium bifluoride. An etching solution containing a fluorine compound of and at least one oxidizing agent selected from hydrogen peroxide, nitric acid, and sulfuric acid, or an etching solution containing hydrogen peroxide, ammonium fluoride, and at least one oxidizing agent selected from phosphoric acid, sulfuric acid, and nitric acid, or CF ₄ gas , fluorine-based gases such as CHF ₃ gas and SF ₆ gas, and etching gases obtained by mixing these gases with O ₂ gas.

After that, the resist film pattern is stripped using a resist stripper or by ashing.

3. Phase shift film pattern formation process

In the phase shift film pattern forming step, the phase shift film 30 is etched using the above-described mask pattern (first light-shielding 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 reduction layer 32 constituting the phase shift film 30 is etched with an etching medium (etching solution, etching gas) for etching the phase shift film 30. It is not particularly limited as long as it can be etched. About the etching medium, it is the same as that of Embodiment 2-1, and description is abbreviate|omitted.

4. Second resist film pattern formation process

The second resist film pattern forming step is for forming a predetermined light-shielding film pattern on the phase shift film pattern, and is a step of forming the second resist film pattern on the first light-shielding film pattern (mask pattern described above). A resist film is formed so as to cover the phase shift film pattern and the first light-shielding film pattern obtained in the above process.

After that, a predetermined pattern is drawn on the resist film using a laser beam having a certain wavelength selected from a wavelength range of 350 nm to 436 nm. As a pattern to be drawn on the resist film, a line and space pattern and a hole pattern are exemplified.

Thereafter, the resist film is developed with a predetermined developing solution to form a second resist film pattern on the first light-shielding film pattern.

5. Light-shielding film pattern formation process

Using the second resist film pattern as a mask, the first light-shielding film pattern is etched to form a light-shielding film pattern on the phase shift film pattern. Since the etching medium (etching solution, etching gas) for etching the first light-blocking film pattern is the same as the etching medium for etching the light-blocking film 45 described above, a description thereof is omitted.

After that, the second resist film pattern is stripped using a resist stripping solution or by ashing.

According to the manufacturing method of the phase shift mask of this Embodiment 2-2, it is a phase shift mask in which a light-shielding film pattern is formed on the phase shift film pattern, and has an excellent pattern cross-sectional shape and excellent CD uniformity, and a fine pattern is formed. A phase shift mask with good transfer accuracy can be manufactured.

Embodiment 3.

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

Hereinafter, each process is demonstrated in detail.

1. Loading process

In the loading step, the phase shift mask manufactured in Embodiments 2-1 and 2-2 is loaded on the mask stage of the exposure apparatus. Here, the phase shift mask is disposed so as to face the resist film formed on the display device substrate through the projection optical system of the exposure device.

2. Pattern transfer process

In the pattern transfer step, exposure light is applied to the phase shift mask to transfer the phase shift film pattern to the resist film formed on the display device substrate. Exposure light is composite light containing light of a plurality of wavelengths selected from a wavelength range of 313 nm to 436 nm, or monochromatic light selected by cutting a certain wavelength range from a wavelength range of 313 nm to 436 nm with 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 i-line monochromatic light. If the composite light is used as the exposure light, the exposure light intensity can be increased to improve the throughput, so that the manufacturing cost of the display device can be reduced.

In addition, since it is a phase shift mask in which the back surface reflectance of the phase shift film is 20% or less in the wavelength range of 365 to 436 nm, the influence of reflection on the exposure device side can be suppressed, and the resist film formed on the display device substrate It is possible to perform high-precision pattern transfer. Further, in a phase shift mask in which the film surface reflectance of the phase shift film is 22.5% or less in the wavelength range of 313 nm to 436 nm, blurring (flare) of the transfer pattern caused by reflected light from the display device substrate side can be prevented. Moreover, high-precision pattern transfer can be performed with respect to the resist film formed on the display device substrate.

The phase shift mask manufactured by the phase shift mask blank of Embodiment 1 and the phase shift mask manufacturing method of Embodiment 2 described above is preferably used as a phase shift mask blank and a phase shift mask for projection exposure of equal magnification exposure. . In particular, it is preferable to use it in an exposure environment of projection exposure of equal exposure exposure having a numerical aperture (NA) of 0.06 to 0.15.

According to the manufacturing method of the display device of Embodiment 3, it is possible to manufacture a high-resolution, high-precision display device that does not generate a CD error.

[Example]

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples. In addition, the following Example is an example of this invention, and it does not limit this invention.

The phase shift mask blanks of Examples 1 to 5 and Comparative Example 1 include a transparent substrate and a phase shift film disposed on the transparent substrate. As a transparent substrate, a synthetic quartz glass substrate having a size of 800 mm x 920 mm and a thickness of 10 mm was used.

Hereinafter, Examples 1 to 5 and Comparative Example 1 will be described in detail.

Example 1.

The phase shift film in the phase shift mask blank of Example 1 includes a phase shift layer, a metal layer, and a reflectance reduction layer arranged sequentially from the transparent substrate side, and the interface between the phase shift layer and the metal layer, the metal layer A composition gradient region is formed at the interface between the reflectance reduction layer and the reflectance reduction layer (see Fig. 6).

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

First, a synthetic quartz glass substrate as a transparent substrate was prepared. Both principal surfaces of the transparent substrate are mirror-polished. Both principal surfaces of the transparent substrates prepared in Examples 2 to 5 and Comparative Example 1 were similarly mirror-polished.

Next, the transparent substrate was loaded into an in-line sputtering device. A sputter room is installed in the in-line type sputtering device.

Next, sputtering power of 2.7 kW was applied to the chrome target arranged in the sputter chamber, and a mixed gas of Ar gas, N ₂ gas, CO ₂ gas, and O ₂ gas was introduced into the sputter chamber at a speed of 200 mm/min. The transparent substrate was conveyed. Here, the mixed gas was introduced into the sputter chamber at flow rates of 35 sccm for Ar, 35 sccm for N ₂ , 13 sccm for CO ₂ , and 10 sccm for O ₂ . When the transparent substrate passed near the chromium target, a phase shift layer containing a chromium-based material (CrCON) containing Cr, C, O, and N was formed on the transparent substrate.

Next, a sputtering power of 0.6 kW was applied to the chrome target, and a mixed gas of Ar gas and CH ₄ gas (a mixed gas in which the Ar gas contained CH ₄ gas at a concentration of 4%) was introduced into the sputter chamber, The transparent substrate was transported at a speed of 400 mm/min. When the transparent substrate passed near the chromium target, a metal layer containing a chromium-based material (CrC) containing Cr and C was formed on the phase shift layer.

Next, a sputtering power of 3.3 kW was applied to the chrome target, and the transparent substrate was transported at a rate of 400 mm/min while introducing a mixed gas of Ar gas, N ₂ gas, CO ₂ gas, and O ₂ gas into the sputter chamber. made it When the transparent substrate passed near the chromium target, a reflectance reducing layer containing chromium-based material (CrCON) containing Cr, C, O, and N was formed on the metal layer. Here, the mixed gas was introduced into the sputter chamber at flow rates of 35 sccm for Ar, 35 sccm for N ₂ , 13 sccm for CO ₂ , and 9 sccm for O ₂ .

Next, the transparent substrate on which the phase shift film containing the phase shift layer, the metal layer, and the reflectance reduction layer was formed was taken out from the inline type sputtering apparatus, and cleaning was performed.

In addition, film formation of a phase shift layer, film formation of a metal layer, and film formation of a reflectance reduction layer were performed continuously in an inline sputtering apparatus without exposing to the air by taking out a transparent substrate to the outside of an inline sputtering apparatus.

Since the phase shift film including the phase shift layer, the metal layer, and the reflectance reduction layer of Example 1 was formed with an in-line sputtering apparatus, the interface between the phase shift layer and the metal layer and the interface between the metal layer and the reflectance reduction layer were respectively A composition gradient region in which elements constituting the layer are continuously compositionally inclined is formed.

About the phase shift film of Example 1, the result of measuring the composition in the depth direction by X-ray photoelectron spectroscopy (ESCA) is shown in FIG.

The phase shift layer contains a chromium-based material containing chromium (Cr), oxygen (O), nitrogen (N), and carbon (C), and the average content of each element is Cr: 49.8 atomic%, O: They were 40.0 atomic%, N: 8.2 atomic%, and C: 2.0 atomic%. In addition, the metal layer contains a chromium-based material containing chromium (Cr), carbon (C), and oxygen (O), and the average content of each element is Cr: 69.9 atomic%, C: 22.7 atomic%, It was O: 7.4 atomic %. In addition, the reflectance reduction layer contains a chromium-based material containing chromium (Cr), oxygen (O), nitrogen (N), and carbon (C), and the average content of each element is Cr: 48.5 atomic%; They were O: 47.4 atomic%, N: 3.7 atomic%, and C: 0.4 atomic%. Further, between the phase shift layer and the metal layer and between the metal layer and the reflectance reduction layer, there was a composition gradient region in which each element continuously decreased or increased.

In addition, the bonding state (chemical state) of the elements was evaluated from the spectrum of Cr, O, and N in each layer. As a result, it was confirmed that the phase shift layer mainly contained chromium mononitride (CrN) and that chromium (III) oxide (Cr ₂ O ₃ ) was present.

In addition, it was confirmed that the bonding state (chemical state) of the elements constituting the metal layer mainly contained chromium (Cr), and that chromium (III) oxide (Cr ₂ O ₃ ) was present.

In addition, the bonding state (chemical state) of the elements constituting the reflectance reducing layer mainly includes chromium (III) oxide (Cr ₂ O ₃ ), and chromium mononitride (CrN) and chromium nitride (Cr ₂ N) exist. I could confirm what I was doing.

The phase shift film had the transmittance|permeability with respect to 365 nm light of 4.9% and phase difference of 187 degrees by the above-mentioned 3-layer structure.

In addition, transmittance and retardation were measured using MPM-100 (trade name) manufactured by Lasertech Co., Ltd. Measurements were made in the same manner in Examples 2 to 5 and Comparative Example 1.

Curve a in FIG. 4 shows the film surface reflectance spectrum of the phase shift film of the phase shift mask blank of Example 1. Curve a in FIG. 5 shows the back surface reflectance spectrum of the phase shift film of the phase shift mask blank of Example 1.

4, the phase shift film has a film surface reflectance of 13.3% at a wavelength of 313 nm, 9.6% at a wavelength of 350 nm, 8.3% at a wavelength of 365 nm, and 7.1% at a wavelength of 405 nm. %, 7.3% at a wavelength of 413 nm, and 8.1% at a wavelength of 436 nm. Further, the phase shift film has a fluctuation range of film surface reflectance of 2.5% in the wavelength range of 350 nm to 436 nm, 1.2% in the wavelength range of 365 nm to 436 nm, and a wavelength range of 313 nm to 436 nm. , it was 6.2%.

As shown in FIG. 5 , the phase shift film has a back surface reflectance of 9.7% at a wavelength of 313 nm, 8.8% at a wavelength of 350 nm, 9.0% at a wavelength of 365 nm, and 12.3% at a wavelength of 405 nm. %, 13.2% at a wavelength of 413 nm, and 16.1% at a wavelength of 436 nm. In addition, the phase shift film has a fluctuation range of film surface reflectance of 7.3% in the wavelength range of 350 nm to 436 nm, 7.1% in the wavelength range of 365 nm to 436 nm, and a wavelength range of 313 nm to 436 nm. , it was 7.3%.

Thus, the film surface reflectance of the phase shift film is 15% or less in the wavelength range of 350 nm to 436 nm, and the back surface reflectance of the phase shift film is 20% or less in the wavelength range of 365 nm to 436 nm. Therefore, using this phase shift mask blank, it is possible to manufacture a phase shift mask having an excellent pattern cross-section shape and excellent CD uniformity, a fine pattern is formed, and the transfer accuracy is good.

In addition, the film surface reflectance and the back surface reflectance were measured using SolidSpec-3700 (trade name) manufactured by Shimadzu Corporation. Measurements were made in the same manner in Examples 2 to 5 and Comparative Example 1.

A phase shift mask was manufactured by the following method using the phase shift mask blank described above.

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

Thereafter, a predetermined pattern was drawn on the resist film using a laser beam having a wavelength of 413 nm by a laser drawing machine.

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

After that, 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, metal layer, and reflectance reduction layer constituting the phase shift film is formed from a chromium-based material containing chromium (Cr). For this reason, a phase shift layer, a metal layer, and a reflectance reduction layer can be etched with the same etching solution. Here, as an etching solution for etching the phase shift film, an etching solution containing ceric ammonium nitrate and perchloric acid was used.

After that, the resist film pattern was stripped using a resist stripper.

In the cross section of the phase shift film pattern of the phase shift mask manufactured using the phase shift mask blank described above, slight erosion occurred in the metal layer located in the central portion of the phase shift film pattern in the film thickness direction, but the mask characteristics were not affected. It was to the extent that it would not give.

In addition, the phase shift film pattern cross section of the phase shift mask was observed using the electron microscope (JSM7401F (brand name) by Nippon Electronics Co., Ltd.). Measurements were made in the same manner in Examples 2 to 3 and Comparative Example 1.

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

In addition, CD fluctuation of the phase shift film pattern of a phase shift mask was measured using SIR8000 by the Seiko Instruments Nanotechnology company. Measurements were made in the same manner in Examples 2 to 5 and Comparative Example 1.

The phase shift mask described above has an excellent pattern cross-sectional shape, excellent CD uniformity, and good transfer accuracy, and has low reflectance and back surface reflectance of the phase shift film pattern with respect to exposure light, and the back surface reflectance of the phase shift film pattern is also Since it is low, when a display device was manufactured using the phase shift mask described above, it was possible to manufacture a high-resolution and high-precision display device in which CD errors did not occur. In addition, the pattern transfer process using the phase shift mask in the manufacturing process of the display device is projection exposure of equal exposure with a numerical aperture (NA) of 0.1, and exposure light is j-line, i-line, h-line, and g-line. It was set as the composite light containing.

Example 2.

The phase shift film in the phase shift mask blank of Example 2 contains the phase shift layer, the metal layer, and the reflectance reduction layer arrange|positioned sequentially from the transparent substrate side.

Each layer of the phase shift layer in the phase shift mask blank of Example 2, the metal layer, and the reflectance reduction layer was formed into a film according to the following film-forming conditions.

The phase shift layer is a mixed gas, Ar is 35 sccm, N ₂ is 35 sccm, CO ₂ is 100 sccm, and O ₂ is introduced into the sputter chamber at a flow rate of 35 sccm, in the same manner as in Example 1, on a transparent substrate A phase shift layer containing a chromium-based material (CrON) containing Cr, O, and N was formed into a film.

Next, the metal layer is the same as in Example 1 except that the sputtering power of 0.5 kW was applied to the chrome target arranged in the sputter chamber, and a chromium-based material (CrC) containing Cr and C was applied on the phase shift layer. A metal layer was formed.

Next, the reflectance reducing layer was a metal mixture in the same manner as in Example 1, except that the gas mixture was introduced into the sputter chamber so that Ar was 35 sccm, N ₂ was 35 sccm, CO ₂ was 100 sccm, and O ₂ was 35 sccm. On the layer, a reflectance reducing layer containing a chromium-based material (CrON) containing Cr, O, and N was formed.

Regarding the phase shift film of Example 2, as a result of measuring the composition in the depth direction by X-ray photoelectron spectroscopy (ESCA), the phase shift layer mainly contains chromium (Cr), oxygen (O), and nitrogen (N). A chromium-based material was included, and the average content of each element was Cr: 45.5 atomic%, O: 53.8 atomic%, N: 0.6 atomic%, and C: 0.1 atomic%. In addition, the metal layer contains a chromium-based material containing chromium (Cr), carbon (C), and oxygen (O), and the average content of each element is Cr: 74.7 atomic%, C: 15.8 atomic%, O: 8.8 atomic%, N: 0.7 atomic%. In addition, the reflectance reduction layer mainly contains a chromium-based material containing chromium (Cr), oxygen (O), and nitrogen (N), and the average content of each element is Cr: 44.4 atomic %, O: 55.0 atomic %. %, N: 0.5 atomic%, C: 0.1 atomic%. Further, between the phase shift layer and the metal layer and between the metal layer and the reflectance reduction layer, there was a composition gradient region in which each element continuously decreased or increased.

In addition, the bonding state (chemical state) of the elements was evaluated from the spectrum of Cr, O, and N in each layer. As a result, it can be confirmed that the phase shift layer mainly contains dichromium nitride (Cr ₂ N), and also contains chromium (III) oxide (Cr ₂ O ₃ ) and chromium (VI) oxide (CrO ₃ ). there was.

In addition, it was confirmed that the bonding state (chemical state) of the elements constituting the metal layer mainly contained chromium (Cr), and that chromium (III) oxide (Cr ₂ O ₃ ) was present.

In addition, it was confirmed that the bonding state (chemical state) of elements constituting the reflectance reducing layer mainly contained chromium (III) oxide (Cr ₂ O ₃ ).

The phase shift film had the transmittance|permeability with respect to 365 nm light of 4.9%, and phase difference 187 degrees with the above-mentioned 3-layer structure.

Curve b in FIG. 4 shows the film surface reflectance spectrum of the phase shift film of the phase shift mask blank of Example 2. Curve b in FIG. 5 shows the back surface reflectance spectrum of the phase shift film of the phase shift mask blank of Example 2.

4, the phase shift film has a film surface reflectance of 21% at a wavelength of 313 nm, 14.7% at a wavelength of 350 nm, 12.8% at a wavelength of 365 nm, and 10.2% at a wavelength of 405 nm. %, 9.8% at a wavelength of 413 nm, and 9.0% at a wavelength of 436 nm. In addition, the phase shift film has a fluctuation range of film surface reflectance of 5.7% in the wavelength range of 350 nm to 436 nm, 3.8% in the wavelength range of 365 nm to 436 nm, and a wavelength range of 313 nm to 436 nm. , it was 12.0%.

As shown in FIG. 5 , the phase shift film has a back surface reflectance of 7.5% at a wavelength of 313 nm, 8.3% at a wavelength of 350 nm, 9.8% at a wavelength of 365 nm, and 14.9% at a wavelength of 405 nm. %, 15.9% at a wavelength of 413 nm, and 18.2% at a wavelength of 436 nm. Further, the phase shift film has a variation range of film surface reflectance of 9.9% in the wavelength range of 350 nm to 436 nm, 8.3% in the wavelength range of 365 nm to 436 nm, and a wavelength range of 313 nm to 436 nm. , it was 11.0%.

Thus, the film surface reflectance of the phase shift film is 15% or less in the wavelength range of 350 nm to 436 nm, and the back surface reflectance of the phase shift film is 20% or less in the wavelength range of 365 nm to 436 nm. Therefore, using this phase shift mask blank, it is possible to manufacture a phase shift mask having an excellent pattern cross-section shape and excellent CD uniformity, a fine pattern is formed, and the transfer accuracy is good.

In addition, the film surface reflectance and the back surface reflectance were measured using SolidSpec-3700 (trade name) manufactured by Shimadzu Corporation.

A phase shift mask was manufactured using the phase shift mask blank of Example 2 similarly to the above-mentioned example. The CD variation (CD uniformity) of the phase shift film pattern of the obtained phase shift mask was 65 nm, which was good. The CD variation (CD uniformity) is the deviation width from the target line and space pattern (line pattern width: 2.0 µm, space pattern width: 2.0 µm).

Since the phase shift mask described above has an excellent pattern cross-sectional shape, excellent CD uniformity, and good transfer accuracy, and the film surface reflectance of the phase shift film pattern with respect to exposure light is low, and the back surface reflectance of the phase shift film pattern is also low, When a display device was manufactured using the phase shift mask described above, it was possible to manufacture a high-resolution and high-precision display device free of CD errors. In addition, the pattern transfer process using the phase shift mask in the manufacturing process of the display device is projection exposure of equal exposure with a numerical aperture (NA) of 0.1, and exposure light is j-line, i-line, h-line, and g-line. It was set as the composite light containing.

Example 3.

The phase shift film in the phase shift mask blank of Example 3 contains a phase shift layer, a metal layer, and a reflectance reduction layer arranged sequentially from the transparent substrate side. In the phase shift mask blank of Example 3, the phase shift layer and the metal layer (intermediate layer) contained a molybdenum silicide-based material, and the reflectance reducing layer contained a titanium-based material having etching selectivity with the phase shift layer and the metal layer. .

The phase shift layer in the phase shift mask blank of Example 3, the metal layer, and the reflectance reduction layer were formed into a film according to the following film-forming conditions.

The phase shift layer is formed by applying a sputtering power of 6.0 kW to a molybdenum silicide target (Mo:Si=1:4), introducing Ar gas, O ₂ gas, and N ₂ gas into the sputter chamber, and Mo and Mo on the transparent substrate. A phase shift layer (film thickness: 100 nm) containing a molybdenum silicide-based material (MoSiON) containing Si, O, and N was formed into a film. Here, Ar gas was introduced into the sputter chamber at a flow rate of 50 sccm, O ₂ gas at 40 sccm, and N ₂ gas at a flow rate of 50 sccm.

The metal layer (intermediate layer) is composed of Mo, Si and N on a transparent substrate while applying a sputtering power of 1.5 kW to (Mo:Si=1:4) and introducing Ar gas and N ₂ gas into the sputter chamber. A metal layer (intermediate layer) (film thickness: 30 nm) containing a molybdenum silicide-based material (MoSiN) was formed into a film. Here, Ar gas was introduced into the sputter chamber at a flow rate of 60 sccm and N ₂ gas at a flow rate of 40 sccm.

The reflectance reduction layer is a titanium-based material containing Ti, O, and N on the metal layer while applying sputtering power of 2.0 kW to the titanium target and introducing Ar gas, O ₂ gas, and N ₂ gas into the sputter chamber ( A reflectance reducing layer (film thickness: 60 nm) containing TiON) was formed. Here, Ar gas was introduced into the sputter chamber at a flow rate of 100 sccm, O ₂ gas at 60 sccm, and N ₂ gas at a flow rate of 60 sccm.

Regarding the phase shift film of Example 3, as a result of measuring the composition in the depth direction by X-ray photoelectron spectroscopy (ESCA), the phase shift layer was Mo: 10 atomic%, Si: 40 atomic%, O: 25 atomic%, N: 25 at%, metal layer (intermediate layer) Mo: 15 at%, Si: 60 at%, N: 25 at%, reflectance reducing layer Ti: 50.5 at%, O: 40.5 at%, N: 9.0 at% was %. Further, between the phase shift layer and the metal layer and between the metal layer and the reflectance reduction layer, there was a composition gradient region in which each element continuously decreased or increased.

The phase shift film had a transmittance of 6.60% for light of 365 nm and a phase difference of 183.3° due to the three-layer structure described above.

The phase shift film has a film surface reflectance of 7.60% at a wavelength of 313 nm, 0.79% at a wavelength of 350 nm, 0.05% at a wavelength of 365 nm, 4.34% at a wavelength of 405 nm, and 4.34% at a wavelength of 413 nm. 5.53%, and 8.74% at a wavelength of 436 nm. Further, the phase shift film has a variation range of the film surface reflectance of 8.69% in the wavelength range of 350 nm to 436 nm, 8.69% in the wavelength range of 365 nm to 436 nm, and a wavelength range of 313 nm to 436 nm. , it was 8.69%.

The phase shift film has a back surface reflectance of 12.52% at a wavelength of 313 nm, 15.87% at 350 nm, 17.36% at a wavelength of 365 nm, 19.17% at a wavelength of 405 nm, and 19.17% at a wavelength of 413 nm. 19.07%, and 18.10% at a wavelength of 436 nm. In addition, the phase shift film has a fluctuation range of film surface reflectance of 3.30% in the wavelength range of 350 nm to 436 nm, 1.81% in the wavelength range of 365 nm to 436 nm, and a wavelength range of 313 nm to 436 nm. , it was 6.65%.

Thus, the film surface reflectance of the phase shift film is 15% or less in the wavelength range of 350 nm to 436 nm, and the back surface reflectance of the phase shift film is 20% or less in the wavelength range of 365 nm to 436 nm. Therefore, using this phase shift mask blank, it is possible to manufacture a phase shift mask having an excellent pattern cross-section shape and excellent CD uniformity, a fine pattern is formed, and the transfer accuracy is good.

In addition, the film surface reflectance and the back surface reflectance were measured using SolidSpec-3700 (trade name) manufactured by Shimadzu Corporation.

A resist film pattern was formed on the phase shift film by the same method as in Example 1 using the phase shift mask blank described above. Then, using the resist film pattern as a mask, the reflectance reducing layer containing a titanium-based material was wet etched with an etchant obtained by diluting a mixed solution of ammonium bifluoride and hydrogen peroxide with pure water to form a pattern on the reflectance reducing layer. Furthermore, the phase shift layer and metal layer containing a molybdenum silicide type material were wet-etched with the etchant which diluted the mixed solution of ammonium hydrogen fluoride and hydrogen peroxide with pure water, and the phase shift layer and the metal layer were patterned. In addition, the resist film pattern remaining on the reflectance reducing layer was also removed by this wet etching. In this way, a phase shift mask was manufactured by forming a phase shift film pattern in the phase shift layer, the metal layer, and the reflectance reduction layer.

The CD variation (CD uniformity) of the phase shift film pattern of the obtained phase shift mask was 58.0 nm, which was good. The CD variation (CD uniformity) is the deviation width from the target line and space pattern (line pattern width: 2.0 µm, space pattern width: 2.0 µm).

Since the phase shift mask described above has an excellent pattern cross-sectional shape, excellent CD uniformity, and good transfer accuracy, and also has a low film surface reflectance of the phase shift film pattern to exposure light, a display device was manufactured, and the phase shift mask described above was manufactured. Using the mask, it was possible to manufacture a high-resolution, high-precision display device free of CD errors. In addition, the pattern transfer process using the phase shift mask in the manufacturing process of the display device is projection exposure of equal exposure with a numerical aperture (NA) of 0.1, and exposure light is j-line, i-line, h-line, and g-line. It was set as the composite light containing.

In addition, in this phase shift mask, since the phase shift layer and the metal layer (intermediate layer) contain a molybdenum silicide-based material and the reflectance reduction layer contains a titanium-based material, adhesion to the resist film can be improved. , which is advantageous for fine pattern formation.

Comparative Example 1.

The phase shift film in the phase shift mask blank of Comparative Example 1 contains only the phase shift layer (CrOCN, film thickness 122 nm). The phase shift mask blank of Comparative Example 1 differs from the phase shift mask blank of the above-mentioned example in that the phase shift film does not include a metal layer and a reflectance reduction layer.

The phase shift layer in the phase shift mask blank of the comparative example 1 was formed into a film according to the following film-forming conditions.

The phase shift layer is transparent at a rate of 200 mm/min while applying sputtering power of 3.5 kW to a chrome target disposed in the sputter chamber and introducing a mixed gas of Ar gas, N ₂ gas, and CO ₂ gas into the sputter chamber. The substrate was conveyed. When the transparent substrate passed near the chromium target, a 122 nm-thick phase shift layer containing CrOCN was formed on the main surface of the transparent substrate. Here, the mixed gas was introduced into the sputter chamber at flow rates of 46 sccm for Ar, 32 sccm for N ₂ , and 18.5 sccm for CO ₂ .

For the phase shift film of Comparative Example 1, the composition in the depth direction was measured by X-ray photoelectron spectroscopy (ESCA). The phase shift film was uniform in the depth direction, and was Cr: 44 atomic%, C: 8 atomic%, O: 30 atomic%, and N: 18 atomic%.

The phase shift film had a transmittance of 4.5% with respect to light of 365 nm and a phase difference of 181° by the one-layer structure described above.

Curve c in FIG. 4 shows the film surface reflectance spectrum of the phase shift film of the phase shift mask blank of Comparative Example 1. Curve c in FIG. 5 shows the back surface reflectance spectrum of the phase shift film of the phase shift mask blank of Comparative Example 1.

4, the phase shift film has a film surface reflectance of 21.0% at a wavelength of 313 nm, 23.9% at a wavelength of 350 nm, 24.0% at a wavelength of 365 nm, and 25.1% at a wavelength of 405 nm. %, 25.3% at a wavelength of 413 nm, and 26.0% at a wavelength of 436 nm. Further, the phase shift film has a variation range of film surface reflectance of 2.1% in the wavelength range of 350 nm to 436 nm, 2.0% in the wavelength range of 365 nm to 436 nm, and a wavelength range of 313 nm to 436 nm. , it was 12.0%.

As shown in FIG. 5 , the back surface reflectance of the phase shift film is 7.5% at a wavelength of 313 nm, 17.1% at a wavelength of 350 nm, 17.9% at a wavelength of 365 nm, and 19.9% at a wavelength of 405 nm. %, 20.2% at a wavelength of 413 nm, and 20.3% at a wavelength of 436 nm. In addition, the phase shift film has a fluctuation range of film surface reflectance of 3.2% in the wavelength range of 350 nm to 436 nm, 2.4% in the wavelength range of 365 nm to 436 nm, and a wavelength range of 313 nm to 436 nm. , it was 11.0%.

A phase shift mask was manufactured by the method similar to Example 1 using the phase shift mask blank mentioned above.

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.

The CD variation of the phase shift film pattern of the phase shift mask produced using the phase shift mask blank described above is 90 nm, and has not reached a level required for a phase shift mask used for manufacturing a high-resolution, high-precision display device.

Although the phase shift mask described above has an excellent pattern cross-sectional shape, since the film surface reflectance of the phase shift film exceeds 15% in the wavelength range of 350 nm to 436 nm, CD fluctuation is large (CD uniformity is poor, ), and since the film surface reflectance of the phase shift film pattern with respect to exposure light is high and the back surface reflectance of the phase shift film pattern is also higher than that of the examples, using the above-described phase shift mask, CD errors do not occur, high resolution , it was not possible to manufacture a high-precision display device. In addition, the pattern transfer process using the phase shift mask in the manufacturing process of the display device is projection exposure of equal exposure with a numerical aperture (NA) of 0.1, and exposure light is j-line, i-line, h-line, and g-line. It was set as the composite light containing.

Example 4.

The phase shift mask blank of Example 4 is a phase shift mask blank in which a light-shielding film was formed on the phase shift film of Example 3.

After forming a phase shift film on a transparent substrate similarly to Example 3 mentioned above, the light-shielding film was formed into a film according to the following film-forming conditions. The light-shielding film has a structure including a light-shielding layer and a surface reflectance reduction layer from the phase shift film side, the light-shielding layer is a laminated structure of a lower light-shielding layer and an upper light-shielding layer, and the surface reflectance reduction layer is a first surface reflectance reduction layer. layer and the second surface reflectance reducing layer.

In the lower light shielding layer, sputtering power of 1.5 kW is applied to a chrome target placed in the sputtering chamber, and the transparent substrate is conveyed at a conveyance speed of 400 mm/min while a mixed gas of Ar gas and N ₂ gas is introduced into the sputtering chamber. Thus, a lower light shielding layer containing CrN containing Cr and N was formed. Further, the mixed gas was introduced into the sputtering chamber so that the flow rate of Ar was 65 sccm and N ₂ was 15 sccm.

Next, a sputtering power of 8.5 kW was applied to a chrome target disposed in the sputtering chamber on the lower light shielding layer, and Ar/CH ₄ (4.9%) gas, which is a mixed gas of Ar gas and CH ₄ gas, was introduced into the sputtering chamber. While doing so, the transparent substrate was conveyed at a conveyance speed of 400 mm/min, and an upper light shielding layer containing CrC containing Cr and C was formed. Further, Ar/CH ₄ (4.9%) as a mixed gas was introduced into the sputter chamber at a flow rate of 31 sccm.

Next, a sputtering power of 1.5 kW was applied to the chrome target disposed in the sputter chamber on the upper light-shielding layer, and Ar/CH ₄ (5.5%) gas, which is a mixed gas of Ar gas and CH ₄ gas, and N ₂ gas and While a mixed gas of O ₂ gas was introduced into the sputter chamber, the transparent substrate was conveyed at a conveyance speed of 400 mm/min, and a first surface reflectance reducing layer containing CrCON containing Cr, C, O, and N was formed. . In addition, the mixed gas was introduced into the sputter chamber at a flow rate of 31 sccm for Ar/CH ₄ (5.5%), 8 sccm for N ₂ , and 3 sccm for O ₂ .

Finally, a sputtering power of 1.95 kW was applied to the chrome target placed in the sputter chamber on the first surface reflectance reducing layer, and Ar/CH ₄ (5.5%) gas, which is a mixed gas of Ar gas and CH ₄ gas, and N _{The second} surface reflectance reducing layer containing CrCON containing Cr, C, O, and N by conveying a transparent substrate at a conveyance speed of 400 mm/min while introducing a mixed gas of 2 gas and O ₂ gas into the sputter chamber. was formed into a film to obtain a phase shift mask blank. In addition, the mixed gas was introduced into the sputter chamber at a flow rate of 31 sccm for Ar/CH ₄ (5.5%), 8 sccm for N ₂ , and 3 sccm for O ₂ .

The film surface reflectance of the light-shielding film of the phase shift mask blank in which the phase shift film and the light-shielding film were formed on the transparent substrate was 17.2% at a wavelength of 313 nm, 12.1% at a wavelength of 350 nm, and 11.0% at a wavelength of 365 nm, 405 It was 8.2% at the wavelength of nm, 7.5% at the wavelength of 413 nm, and 8.4% at the wavelength of 436 nm. Moreover, the optical density of 365 nm in the laminated film of a phase shift film and a light-shielding film was 4.0 or more. In addition, the back surface reflectance of the phase shift film in this phase shift mask blank is 12.5% at a wavelength of 313 nm, 17.4% at a wavelength of 365 nm, and 19.2% at a wavelength of 405 nm, at a wavelength of 436 nm. was 18.1%.

Thus, the film surface reflectance of the phase shift film is 15% or less in the wavelength range of 350 nm to 436 nm, and the film surface reflectance of the light-shielding film is 15% or less in the wavelength range of 350 nm to 436 nm. , Since the back surface reflectance of the phase shift film is 20% or less in the wavelength range of 365 nm to 436 nm, a fine pattern is formed with an excellent pattern cross-sectional shape and excellent CD uniformity using this phase shift mask blank. Thus, a phase shift mask having good transfer accuracy can be manufactured.

A phase shift mask was manufactured by the following method using the phase shift mask blank described above. First, a first resist film pattern was formed on the light blocking film. Then, using the first resist film pattern as a mask, the light-shielding film was wet-etched with an etchant containing ceric ammonium nitrate and perchloric acid to form a mask pattern including the light-shielding film pattern on the phase shift film.

Next, using the mask pattern as a mask, the phase shift film was wet-etched with an etchant obtained by diluting a mixed solution of ammonium bifluoride and hydrogen peroxide with pure water to form a phase shift film pattern. In addition, the resist film pattern remaining on the mask pattern was also removed by this wet etching solution.

Next, in order to form a light-shielding film pattern at the center of the above-described phase shift film pattern, a resist film is formed on the above-described mask pattern and the phase shift film pattern, and a second resist film pattern is formed on the mask pattern in the same manner as above did Then, using the second resist film pattern as a mask, the light-shielding film is wet-etched with an etchant containing ceric ammonium nitrate and perchloric acid to form a light-shielding film pattern in the central portion on the phase shift film, and finally, a resist stripper is applied. was used to peel off the resist film pattern to prepare a phase shift mask.

The CD variation (CD uniformity) of the phase shift film pattern of this obtained phase shift mask was 57.0 nm, which was good. The CD variation (CD uniformity) is the deviation width from the target line and space pattern (line pattern width: 2.0 µm, space pattern width: 2.0 µm).

The phase shift mask described above has an excellent pattern cross-sectional shape, excellent CD uniformity, and good transfer accuracy, and has low film surface reflectance of the phase shift film pattern and light-shielding film pattern with respect to exposure light, and the back surface reflectance of the phase shift film pattern Since the phase shift mask was also low, when a display device was manufactured using the phase shift mask described above, it was possible to manufacture a high-resolution and high-precision display device free of CD errors. In addition, the pattern transfer process using the phase shift mask in the manufacturing process of the display device is projection exposure of equal exposure with a numerical aperture (NA) of 0.1, and exposure light is j-line, i-line, h-line, and g-line. It was set as the composite light containing.

Example 5.

The phase shift mask blank of Example 5 is a phase shift mask blank in which a phase shift film was formed on a light-shielding film pattern including a laminated film of a back surface reflectance reduction layer and a light-shielding layer on a transparent substrate.

The rear surface reflectance reduction layer and the light shielding layer in the light-shielding film pattern described above are formed by forming a light-shielding film and patterning according to the following film formation conditions.

The back surface reflectance reduction layer is formed by applying a sputtering power of 4.0 kW to a chrome target disposed in the sputter chamber, and introducing a mixed gas of Ar gas, N ₂ gas, and O ₂ gas into the sputter chamber at a transport speed of 350 mm/min. The transparent substrate was transported in the , and a back surface reflectance reducing layer containing CrON containing Cr, O, and N was formed. Further, Ar was introduced into the sputter chamber at a flow rate of 100 sccm, N ₂ at 45 sccm, and O ₂ at a flow rate of 25 sccm.

Next, a sputtering power of 5.0 kW was applied to the chrome target disposed in the sputtering chamber on the back surface reflectance reducing layer, and a mixed gas of Ar gas and N ₂ gas was introduced into the sputtering chamber at a transport speed of 200 mm/min. The transparent substrate was transported in , and a light shielding layer containing CrN containing Cr and N was formed into a film. Further, Ar was introduced into the sputter chamber at a flow rate of 130 sccm and N ₂ at a flow rate of 30 sccm.

As described above, the back surface reflectance of the light-shielding film comprising the laminated film of the back surface reflectance reduction layer and the light-blocking layer formed on the transparent substrate was 10.4% at a wavelength of 313 nm, 6.2% at a wavelength of 365 nm, and 405 nm. It was 4.7% in the wavelength and 4.8% in the wavelength of 436 nm.

And, by patterning the above-described light-shielding film by etching, a light-shielding film pattern was formed on the transparent substrate.

Next, the phase shift film of Example 1 was formed on the light-shielding film pattern to prepare a phase shift mask blank. The film surface reflectance of the phase shift film of this phase shift mask blank has the same optical properties as in Example 1, and the film surface reflectance is 13.3% at a wavelength of 313 nm, 9.6% at 350 nm, and 365 nm. It was 8.3% at a wavelength, 7.1% at a wavelength of 405 nm, 7.3% at a wavelength of 413 nm, and 8.1% at a wavelength of 436 nm. Further, the phase shift film has a fluctuation range of film surface reflectance of 2.5% in the wavelength range of 350 nm to 436 nm, 1.2% in the wavelength range of 365 nm to 436 nm, and a wavelength range of 313 nm to 436 nm. , it was 6.2%. In addition, the back surface reflectance of the phase shift film in which the light-shielding film pattern is not formed has the same optical characteristics as in Example 1, and the back surface reflectance is 9.7% at a wavelength of 313 nm and 8.8% at 350 nm, It was 9.0% at a wavelength of 365 nm, 12.3% at a wavelength of 405 nm, 13.2% at a wavelength of 413 nm, and 16.1% at a wavelength of 436 nm. In addition, the phase shift film has a fluctuation range of film surface reflectance of 7.3% in the wavelength range of 350 nm to 436 nm, 7.1% in the wavelength range of 365 nm to 436 nm, and a wavelength range of 313 nm to 436 nm. , it was 7.3%.

Thus, the film surface reflectance of the phase shift film is 15% or less in the wavelength range of 350 nm to 436 nm, and the back surface reflectance of the light-shielding film pattern is 15% or less in the wavelength range of 350 nm to 436 nm. Since the back surface reflectance of the shift film is 20% or less in the wavelength range of 365 nm to 436 nm, using this phase shift mask blank, a fine pattern is formed with excellent pattern cross-section shape and excellent CD uniformity, and transfer A phase shift mask with good accuracy can be manufactured.

Further, similarly to Example 1 described above, a phase shift mask was manufactured using this phase shift mask blank. As a result, the CD variation (CD uniformity) of the phase shift film pattern was as good as 70 nm.

The phase shift mask described above has an excellent pattern cross-sectional shape, excellent CD uniformity, and good transfer accuracy, and has low reflectance and back surface reflectance of the phase shift film pattern with respect to exposure light, and the back surface reflectance of the phase shift film pattern is also Since it is low, when a display device was manufactured using the phase shift mask described above, it was possible to manufacture a high-resolution and high-precision display device in which CD errors did not occur. In addition, the pattern transfer process using the phase shift mask in the manufacturing process of the display device is projection exposure of equal exposure with a numerical aperture (NA) of 0.1, and exposure light is j-line, i-line, h-line, and g-line. It was set as the composite light containing.

As mentioned above, although this invention was demonstrated in detail based on embodiment and Example, this invention is not limited to this. It is clear that modifications and improvements within the technical spirit of the present invention are possible for those skilled in the art.

10: phase shift mask blank
20: transparent substrate
30: phase shift film
31: phase shift layer
32: reflectance reduction layer
33: metal layer
40: light blocking film pattern
41: back surface reflectance reduction layer
42: light blocking layer
45: light blocking film
46: light blocking layer
47: surface reflectance reducing layer

Claims (15)

As a phase shift mask blank provided with a phase shift film on a transparent substrate,
The phase shift film contains a metallic material containing one or more types of metal and at least one selected from oxygen, nitrogen and carbon, or one or more types of metal and silicon and at least one selected from oxygen, nitrogen and carbon. It includes at least one of metal silicide-based materials that
The phase shift film includes a phase shift layer mainly having a function of adjusting the transmittance of exposure light and a phase difference, and a function of reducing the reflectance of light incident from the phase shift film side disposed above the phase shift layer. It has a reflectance reduction layer mainly having and an intermediate layer disposed between the phase shift layer and the reflectance reduction layer,
The intermediate layer is a metal-based material having a metal content higher than that of the reflectance reducing layer, or a metal having a total content higher than the metal content of the reflectance reducing layer or the total content of metal and silicon of the reflectance reducing layer. It is a silicide-based material,
The phase shift layer, the intermediate layer, and the reflectance reduction layer have a laminated structure in which transmittance and phase difference of the phase shift film to exposure light have predetermined optical characteristics,
The film surface reflectance of the phase shift film to light incident from the phase shift film side is 22.5% or less in the wavelength range of 313 nm to 436 nm, and the back surface reflectance of the phase shift film to light incident from the transparent substrate side. A phase shift mask blank characterized in that this is 20% or less in the wavelength range of 313 nm to 436 nm. As a phase shift mask blank provided with a phase shift film on a transparent substrate,
The phase shift film contains a metallic material containing one or more types of metal and at least one selected from oxygen, nitrogen and carbon, or one or more types of metal and silicon and at least one selected from oxygen, nitrogen and carbon. It includes at least one of metal silicide-based materials that
The phase shift film includes a phase shift layer mainly having a function of adjusting the transmittance of exposure light and a phase difference, and a function of reducing the reflectance of light incident from the phase shift film side disposed above the phase shift layer. It has a reflectance reduction layer mainly having and an intermediate layer disposed between the phase shift layer and the reflectance reduction layer,
The intermediate layer is a metal-based material having a metal content higher than that of the reflectance reducing layer, or a metal having a total content higher than the metal content of the reflectance reducing layer or the total content of metal and silicon of the reflectance reducing layer. It is a silicide-based material,
The phase shift layer, the intermediate layer, and the reflectance reduction layer have a laminated structure in which transmittance and phase difference of the phase shift film to exposure light have predetermined optical characteristics,
The film surface reflectance of the phase shift film to light incident from the phase shift film side is 22.5% or less in the wavelength range of 313 nm to 436 nm, and the back surface reflectance of the phase shift film to light incident from the transparent substrate side. A phase shift mask blank characterized in that this is 20% or less in the wavelength range of 365 nm to 436 nm. According to claim 1 or 2,
A phase shift mask blank characterized in that the fluctuation range of the film surface reflectance of the phase shift film is 12.5% or less in a wavelength range of 313 nm to 436 nm. According to claim 1 or 2,
A phase shift mask blank characterized in that the fluctuation width of the back surface reflectance of the phase shift film is 18% or less in a wavelength range of 313 nm to 436 nm. According to claim 1 or 2,
The phase shift mask blank, characterized in that the phase shift film contains a material that can be etched with the same etchant. According to claim 1 or 2,
The metal silicide-based material constituting the phase shift film is any of a nitride of a metal silicide, an oxide of a metal silicide, an oxynitride of a metal silicide, a carbonized nitride of a metal silicide, an oxidized carbide of a metal silicide, and an oxidized carbonized nitride of a metal silicide Phase shift mask blank, characterized in that. According to claim 6,
The phase shift mask blank, characterized in that the metal silicide-based material is a molybdenum silicide-based material, a zirconium silicide-based material, a titanium silicide-based material, or a molybdenum zirconium silicide-based material. According to claim 1 or 2,
The metal contained in the metal-based material constituting the phase shift film is any one of chromium (Cr), zirconium (Zr), molybdenum (Mo), tantalum (Ta), tungsten (W), titanium (Ti), and aluminum (Al). Phase shift mask blank, characterized in that the. According to claim 1 or 2,
A phase shift mask blank comprising a light-shielding film on the phase shift film, wherein the light-shielding film has a film surface reflectance of 15% or less in a wavelength range of 350 nm to 436 nm. A step of forming a resist film on the phase shift film of the phase shift mask blank according to claim 1 or 2, and forming a resist film pattern on the resist film by a drawing process and a development process;
A method for manufacturing a phase shift mask comprising a step of etching the phase shift film using the resist film pattern as a mask to form a phase shift film pattern on the transparent substrate. A step of forming a resist film on the light-shielding film of the phase shift mask blank according to claim 9, and forming a resist film pattern on the resist film by a drawing process and a development process;
etching the light-shielding film using the resist film pattern as a mask to form a light-shielding film pattern on the phase shift film;
A method for manufacturing a phase shift mask comprising a step of forming a phase shift film pattern on the transparent substrate by etching the phase shift film using the light-shielding film pattern as a mask. A step of loading the phase shift mask obtained by the method for manufacturing a phase shift mask according to claim 10 on a mask stage of an exposure apparatus;
A method for manufacturing a display device comprising a step of irradiating the phase shift mask with exposure light and transferring the phase shift film pattern to a resist film formed on a display device substrate. A step of loading the phase shift mask obtained by the method for manufacturing a phase shift mask according to claim 11 on a mask stage of an exposure apparatus;
A method for manufacturing a display device comprising a step of irradiating the phase shift mask with exposure light and transferring the phase shift film pattern to a resist film formed on a display device substrate. According to claim 12,
The method for manufacturing a display device according to claim 1 , wherein the exposure light is composite light including light of a plurality of wavelengths selected from a wavelength range of 313 nm to 436 nm. According to claim 13,
The method for manufacturing a display device according to claim 1 , wherein the exposure light is composite light including light of a plurality of wavelengths selected from a wavelength range of 313 nm to 436 nm.

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