TWI645246B - Phase shift mask blank and its manufacturing method, and method for manufacturing phase shift mask - Google Patents

Abstract

The invention provides a phase-shifting mask substrate capable of patterning a phase-shifting film into a cross-sectional shape that can fully exert a phase-shifting effect by wet etching, and a method for manufacturing the same, and a phase-shifting film that can fully exert a phase-shifting effect Manufacturing method of patterned phase shift mask.

The phase shift mask base 1 has a structure in which a phase shift film 3 containing metal, silicon, oxygen, and / or nitrogen is formed on a transparent substrate 2. The phase shift film 3 has a main layer 3a and an outermost layer 3b including the same material. The refractive index at the wavelength of 365 nm of the upper part of the main layer on the outermost surface layer 3b side is smaller than the refractive index of the wavelength of 365 nm at the lower part of the main layer on the transparent substrate 2 side.

Description

Phase-shifting mask base and manufacturing method thereof, and manufacturing method of phase-shifting mask

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

Currently, as a method used for a liquid crystal display device, there is a VA (Vertical alignment) method or an IPS (In Plane Switching) method. By these methods, a liquid crystal display device with high definition, high speed display performance, and wide viewing angle is sought. In liquid crystal display devices employing these methods, pixel electrodes are formed by using lines and gap patterns of transparent conductive films, thereby improving response speed and viewing angle. Recently, the further improvement of the self-response speed and the viewing angle, or the improvement of the light utilization efficiency of the liquid crystal display device, that is, from the viewpoint of the low power consumption of the liquid crystal display device or the improvement of the contrast, the miniaturization of the distance between the line and the gap pattern is required . For example, it is desirable to narrow the gap width (the total of the line width L and the gap width S) from the line to the gap pattern from 6 μm to 5 μm, and then from 5 μm to 4 μm. In this case, it is often the case that at least one of the line width L and the gap width S does not reach 3 μm. For example, there are many cases where L <3 μm, or L ≦ 2 μm, or S <3 μm, or S ≦ 2 μm.

In addition, it is used in the manufacture of liquid crystal display devices or organic EL (Electroluminescence). In a light emitting) display device, elements such as transistors are formed by laminating a plurality of conductive films or insulating films that have been patterned as necessary. At this time, it is often the case that the photolithography step is used for the patterning of each film of the stacked layers. For example, thin film transistors ("TFTs") used in such display devices have a structure in which contact holes formed in a passivation film (insulating layer) of a plurality of patterns constituting the TFT penetrate the insulation. Layer, and is electrically connected to the connection portion located on the lower layer side. At this time, if the patterns on the upper layer side and the lower layer side are not accurately positioned and the shape of the contact hole is not reliably formed, accurate operation of the display device cannot be guaranteed. Further, here, it is necessary to improve the display performance and increase the integration of the element pattern, so that miniaturization of the pattern is required. That is, the diameter of the hole pattern must also be less than 3 μm. For example, it is considered that a hole pattern having a diameter of 2.5 μm or less and a diameter of 2.0 μm or less is required. In the near future, it is also desired to form a pattern having a diameter of 1.5 μm or less.

In view of such a background, for example, a photomask for manufacturing a display device that can respond to the miniaturization of a line and gap pattern or a contact hole is desired.

When the miniaturization of line and gap patterns or contact holes is realized, in the previous photomask, the resolution limit of the exposure machine used for display device manufacturing is 3 μm, so it is necessary to have a process margin without sufficient process margin. Production of products with minimum line widths close to the analytical limit. Therefore, there is a problem that the defective rate of the display device becomes high.

For example, in a case where a mask having a hole pattern for forming a contact hole is used and transferred to a transferee, a hole pattern having a diameter exceeding 3 μm can be transferred using a previous mask. However, it is very difficult to transfer a hole pattern having a diameter of 3 μm or less, especially a hole pattern having a diameter of 2.5 μm or less. In order to transfer a hole pattern having a diameter of 2.5 μm or less, for example, conversion to an exposure machine having a high NA (numerical aperture) is also considered, but a large investment is required.

Therefore, in order to improve the resolution to correspond to the miniaturization of line and gap patterns or contact holes, for example, a phase shift mask has attracted attention as a mask for manufacturing a display device.

Recently, a chrome-based phase shift has been developed as a mask for the manufacture of liquid crystal display devices. Phase shift mask for film.

Patent Document 1 describes a halftone type phase shift mask including a transparent substrate, a light-shielding layer formed on the transparent substrate, and a phase-shift layer formed around the light-shielding layer, which can be 300 nm to 500 nm. Any of the light in the following wavelength regions has a phase difference of 180 degrees and contains a chromium oxynitride-based material. The phase shift mask is manufactured by patterning a light shielding layer on a transparent substrate, forming a phase shift layer on the transparent substrate by covering the light shielding layer, and forming a resist on the phase shift layer. Layer, a resist pattern is formed by exposing and developing the resist layer, and using the resist pattern as an etching mask to pattern the phase shift layer.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2011-13283

The present inventors have intensively studied a phase shift mask provided with a chromium-based phase shift film. As a result, it was found that when the resist pattern is used as a mask and the chromium-based phase shift film is patterned by wet etching, the wet etching solution penetrates into the resist film and the chromium-based phase shift film. Interface, and the interface portion is etched faster. The cross-sectional shape of the edge portion of the formed chromium-based phase-shifting film pattern is inclined to form a tapered shape of a skirt.

In the case where the cross-sectional shape of the edge portion of the chromium phase shift film pattern is a cone shape, as the film thickness of the edge portion of the chromium phase shift film pattern decreases, the phase shift effect decreases. Therefore, the phase shift effect cannot be fully exerted. In addition, the penetration of the wet etching solution into the interface between the resist film and the chromium-based phase shift film is due to poor adhesion between the chromium-based phase shift film and the resist film. Therefore, it is difficult to strictly control the cross-sectional shape of the edge portion of the chromium-based phase shift film pattern, and it is very difficult to control the line width (critical dimension, CD).

Furthermore, the present inventors have made The method of verticalizing the cross-sectional shape of the edge part has been studied intensively. A method has been developed so that the film composition (for example, nitrogen content) of the phase shift film is inclined and the etching rate in the thickness direction is changed, and additives (for example, Al, Ga) are added to the phase shift film to control the etching time. Method. However, in these methods, it is very difficult to achieve uniformity of the transmittance of the entire area of the phase shift mask.

Therefore, the present invention was made in view of the above-mentioned problems, and an object thereof is to provide a phase shift mask substrate capable of patterning a phase shift film into a cross-sectional shape capable of fully exerting a phase shift effect by wet etching, and a manufacturing method thereof Method, and method for manufacturing a phase-shifting mask having a phase-shifting film pattern capable of fully exerting a phase-shifting effect.

(Composition 1)

A phase shift mask substrate, characterized in that it forms a phase shift film containing metal, silicon and oxygen and / or nitrogen on a transparent substrate, and the phase shift film has a main layer and an outermost layer containing the same material. The refractive index at the wavelength of 365 nm of the upper part of the main layer on the surface layer side is smaller than the refractive index of the lower part of the main layer on the transparent substrate side at the wavelength of 365 nm.

(Composition 2)

For example, the phase-shift mask substrate of 1 is characterized in that the difference (△ n) between the refractive index of the lower part of the main layer at a wavelength of 365 nm and the refractive index of the upper part of the main layer at a wavelength of 365 nm is -0.01 or less.

(Composition 3)

For example, the phase shift mask substrate of 1 is characterized in that the difference (Δn) between the refractive index of the lower part of the main layer at a wavelength of 365 nm and the refractive index of the upper part of the main layer at a wavelength of 365 nm is -0.10 or less.

(Composition 4)

The phase shift mask base of any one of constitutions 1 to 3, characterized in that: The refractive index of the upper part of the main layer at a wavelength of 365 nm is 2.50 or more.

(Composition 5)

The phase shift mask substrate according to any one of the constitutions 1 to 4, wherein an etching mask film is formed on the phase shift film.

(Composition 6)

For example, the phase-shift mask substrate of 5 is characterized in that the etching mask film has a light-shielding film, and the light-shielding film has a light-shielding function.

(Composition 7)

For example, the phase-shifting mask base of constitution 5 or constitution 6 is characterized in that the etching mask film is made of a material containing chromium.

(Composition 8)

The phase shift mask substrate according to any one of the constitutions 1 to 7, wherein the phase shift mask substrate is used to make an original version of the phase shift mask by wet etching.

(Composition 9)

A method for manufacturing a phase shift mask substrate, characterized in that: a phase shift film containing metal, silicon, oxygen, and / or nitrogen is formed on a transparent substrate by a sputtering method using a continuous sputtering device, And a film forming step of forming the phase shift film having a main layer and an outermost layer containing the same material on the transparent substrate, the film forming step is to use a metal silicide sputtering target containing metal and silicon to convert an active gas It is supplied in such a way that it becomes an environment containing the above-mentioned active gas more in the second half of the film formation than in the first half of the film formation, and by reactive sputtering using a mixed gas containing an inert gas and the above-mentioned active gas. get on.

(Composition 10)

For example, the manufacturing method of the phase shift mask substrate constituting 9 is characterized in that the phase shift film is oxidized and supplied by supplying the transparent substrate near the sputtering target from the transport direction of the transparent substrate on the downstream side with respect to the sputtering target. And / or nitriding active gas, which becomes a The environment in which the first half of the film contains more active gas.

(Composition 11)

For example, the manufacturing method of the phase shift mask base of 9 is characterized in that the refractive index at the wavelength of 365 nm of the upper part of the main layer on the most surface layer side is smaller than that of the lower part of the main layer on the transparent substrate side Adjust the flow rate of the active gas with a refractive index of 365 nm.

(Composition 12)

For example, the manufacturing method of the phase shift mask base according to any one of constitutions 9 to 11, wherein the refractive index at a wavelength of 365 nm of the lower part of the main layer on the transparent substrate side is relative to that on the outermost surface side. The flow rate of the active gas is adjusted so that the difference in the refractive index (Δn) at the wavelength of 365 nm in the upper part of the main layer becomes -0.01 or less.

(Composition 13)

For example, the manufacturing method of the phase shift mask base according to any one of constitutions 9 to 11, wherein the refractive index at a wavelength of 365 nm of the lower part of the main layer on the transparent substrate side is relative to that on the outermost surface side. The refractive index difference (Δn) at a wavelength of 365 nm in the upper part of the main layer is adjusted to be -0.10 or less, and the flow rate of the active gas is adjusted.

(Composition 14)

For example, the method for manufacturing a phase shift mask substrate according to any one of the constitutions 9 to 13, is characterized in that, after the film forming step of forming the phase shift film, a method of forming an etching mask film on the phase shift film is provided. Membrane step.

(Composition 15)

A method of manufacturing a phase shift mask using a phase shift mask substrate such as any one of 1 to 8 or a phase shift mask substrate manufactured by a manufacturing method such as any one of 9 to 14 The phase shift film is patterned by wet etching to produce a phase shift mask.

The phase shift mask substrate according to the present invention is formed with a metal silicide-based material. Phase shift film. The phase shift film has a main layer and an outermost layer substantially containing the same material. The refractive index of the upper part of the main layer on the outermost surface side has a refractive index at a wavelength of 365 nm, which is smaller than the refractive index of the lower part of the main layer on the transparent substrate side. rate. The phase-shifting mask base structured in this way can pattern the phase-shifting film into a cross-sectional shape that can fully exert the phase-shifting effect by wet etching. Since the phase shift mask substrate can make a cross-sectional shape of an edge portion of a phase shift film pattern obtained by patterning the phase shift film into a cross-sectional shape that can fully exert a phase shift effect, it can be formed to include improved resolution, An original plate for manufacturing a phase shift mask having a phase shift film pattern with good CD characteristics.

In addition, the method for manufacturing a phase-shifting mask substrate according to the present invention includes forming a main layer containing a metal silicide-based material on a transparent substrate by a sputtering method using a continuous sputtering device, and having a main layer containing the same material, and The film forming step of the phase shift film of the outermost layer. This film forming step uses a sputtering target containing a metal and silicon, and uses an active gas having a component that slows down the wet etching rate of the phase shift film to become the second half of the phase shift film and the first half of the film. It is supplied in an environment richer in the above-mentioned active gas, and is performed by reactive sputtering using a mixed gas containing the above-mentioned inert gas and the above-mentioned active gas. By such a manufacturing method, a phase shift mask substrate capable of patterning (etching) a phase shift film into a cross-sectional shape capable of fully exerting a phase shift effect can be manufactured. Since the cross-sectional shape of the edge portion of the phase shift film pattern can be a cross-sectional shape that can fully exert the effect of phase shift, a phase shift mask that can be patterned into a phase shift film pattern with improved resolution and good CD characteristics can be manufactured. Substrate.

In addition, according to the method of manufacturing a phase shift mask of the present invention, the phase shift mask is manufactured using the phase shift mask substrate described above. Therefore, a phase shift mask having a phase shift film pattern capable of fully exerting a phase shift effect can be manufactured. Since the phase shift film pattern can fully exert a phase shift effect, a phase shift mask having a phase shift film pattern with improved resolution and good CD characteristics can be manufactured. The phase shift mask can correspond to the miniaturization of line and gap patterns or contact holes.

1‧‧‧Phase shift mask base

2‧‧‧ transparent substrate

3‧‧‧ phase shift film

3a‧‧‧Main floor

3b‧‧‧ surface layer

3'‧‧‧ phase shift film pattern

4‧‧‧ light-shielding film

4'‧‧‧Light-shielding film pattern

5‧‧‧resist film

5'‧‧‧ resist film pattern

10‧‧‧Phase shift mask substrate

11‧‧‧Sputtering device

13‧‧‧The first sputtering target

14‧‧‧Second sputtering target

15‧‧‧The third sputtering target

16‧‧‧The fourth sputtering target

21‧‧‧ auxiliary line

22‧‧‧ auxiliary line

23‧‧‧ side

24‧‧‧ auxiliary line

26‧‧‧Top and side contact

27‧‧‧ the position of the side of the position where the height of 2/3 of the film thickness drops from the upper surface

30‧‧‧Phase shift mask

50‧‧‧Phase shift mask

55'‧‧‧ resist film pattern

BU‧‧‧ buffer chamber

GA11‧‧‧The first gas inlet

GA12‧‧‧Second gas introduction port

GA21‧‧‧The third gas inlet

GA22‧‧‧The fourth gas inlet

GA31‧‧‧The fifth gas inlet

GA32‧‧‧No. 6 gas inlet

GA41‧‧‧7th gas inlet

GA42‧‧‧8th gas inlet

LL‧‧‧ moved into the chamber

S‧‧‧ Arrow

SP1‧‧‧The first sputtering chamber

SP2‧‧‧Second Sputtering Chamber

ULL‧‧‧ moved out of the chamber

θ‧‧‧ section angle

FIG. 1 is a cross-sectional view showing the structure of a phase shift mask base according to the first embodiment of the present invention. Illustration.

FIG. 2 is a schematic view showing a continuous sputtering apparatus capable of forming a film on a phase-shift mask substrate.

Fig. 3 is a cross-sectional view showing the structure of a phase shift mask base according to a second embodiment of the present invention.

4 (a) to (e) are cross-sectional views showing each step of a method for manufacturing a phase shift mask according to Embodiment 3 of the present invention.

5 (a) to (h) are sectional views showing each step of a method for manufacturing a phase shift mask according to Embodiment 4 of the present invention.

FIG. 6 is a graph showing a refractive index at a wavelength of 190 nm to 1000 nm of an upper part of a main layer and a lower part of the main layer of the phase shift film of the phase shift mask substrate of Example 1. FIG.

FIG. 7 is a graph showing the refractive index at the wavelength of 190 nm to 1000 nm of the main layer upper part and the lower part of the main layer of the phase shift film of the phase shift mask base of Comparative Example 1. FIG.

8 is a cross-sectional photograph showing a cross-sectional shape of an edge portion of a phase shift film pattern in Example 1. FIG.

9 is a cross-sectional photograph showing a cross-sectional shape of an edge portion of a phase shift film pattern of Comparative Example 1. FIG.

FIG. 10 is a cross-sectional view for explaining a cross-sectional angle of a cross section of an edge portion of a phase shift film pattern of a phase shift mask.

FIG. 11 is a graph showing the refractive index of the upper part of the main layer and the lower part of the main layer of the phase shift film of the phase shift mask substrate of Example 3 at a wavelength of 190 nm to 1000 nm.

FIG. 12 is a sectional photograph showing a sectional shape of an edge portion of a phase shift film pattern in Example 3. FIG.

FIG. 13 is a graph showing the refractive index of the main layer upper part and the lower part of the main layer of the phase shift film of the phase shift mask substrate of Example 4 at a wavelength of 190 nm to 1000 nm.

14 is a cross section showing a cross-sectional shape of an edge portion of a phase shift film pattern in Example 4 photo.

FIG. 15 is a graph showing the relationship between the difference in refractive index (Δn) at the lower part of the main layer of the phase shift film 3 at a wavelength of 365 nm with respect to the upper part of the main layer at a wavelength of 365 nm (Δn) and the section angle of the pattern section of the phase shift film. Illustration.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. It should be noted that the following embodiment is an embodiment when the present invention is embodied, and the present invention is not limited to this range.

<Embodiment 1>

In the first embodiment, a phase shift mask substrate for manufacturing a display device and a manufacturing method thereof will be described.

FIG. 1 is a cross-sectional view showing the structure of a phase-shifting mask substrate according to Embodiment 1 of the present invention, and FIG. 2 is a schematic view showing a continuous sputtering apparatus capable of forming a film for the phase-shifting mask substrate.

As shown in FIG. 1, the phase shift mask base 1 of Embodiment 1 has a structure in which a phase shift film 3 containing a metal silicide-based material is laminated on a transparent substrate 2.

The manufacturing method of the phase shift mask substrate 1 of the first embodiment thus constituted includes a preparation step that prepares a transparent substrate, and a film formation step (hereinafter, there may be a case called a phase shift film formation step), which is performed by sputtering A phase shift film is formed on the main surface of the transparent substrate.

Hereinafter, each step will be described in detail.

1. Preparation steps

First, a transparent substrate 2 is prepared.

The material of the transparent substrate 2 is not particularly limited as long as it is a material that is transparent to the light used for the exposure. Examples include synthetic quartz glass, soda lime glass, and alkali-free glass.

2. Phase shift film formation steps

Next, as shown in FIG. 1, a phase shift film 3 containing a metal silicide-based material is formed on the transparent substrate 2 by a sputtering method using a continuous sputtering apparatus.

In detail, a film-forming step is performed in which an inert gas is supplied downstream of the transparent substrate 2 near the sputtering target in the transport direction of the sputtering target using a sputtering target containing metal and silicon and applying sputtering power. With an active gas that oxidizes and / or nitrides the phase shift film, a phase shift film 3 containing metal, silicon, oxygen, and / or nitrogen is formed by reactive sputtering using a mixed gas containing an inert gas and an active gas.

Here, it does not matter whether the inert gas and the active gas supplied from the downstream side with respect to the sputtering target are mixed before being supplied. For example, either an inert gas and an active gas may be mixed in advance and the mixed gas may be supplied from a gas introduction port at a specific flow rate, or a specific flow of inert gas and active gas may be supplied from a dedicated gas introduction port, respectively.

Then, instead of exposing the phase shift film 3 to the atmosphere, the step of exposing the phase shift film 3 to a gaseous environment containing a component that slows down the wet etching rate of the phase shift film 3 may be continuously performed after the film formation step. .

The phase shift film 3 has a property (phase shift effect) that changes the phase of the exposed light. Due to this property, a specific phase difference occurs between the light exposed through the phase shift film 3 and the light exposed through the transparent substrate 2 only. In the case where the exposed light is a composite light including light in a wavelength range of 300 nm to 500 nm, the phase shift film 3 is formed so as to generate a specific phase difference with respect to light having a representative wavelength. For example, when the exposed light is a composite light including i-rays, h-rays, and g-rays, the phase shift film 3 is configured to generate a phase difference of 180 degrees with respect to any of the i-rays, h-rays, and g-rays. form. In order to exert the phase shift effect, for example, the phase difference of the i-ray phase shift film 3 is set to a range of 180 degrees ± 10 degrees, and preferably set to approximately 180 degrees. The transmittance of the phase shift film 3 is preferably 1% or more and 20% or less of a representative wavelength of any of i-rays, h-rays, and g-rays. It is particularly preferred that the transmittance of the phase shift film 3 at a representative wavelength of any of i-rays, h-rays, and g-rays is preferably 3% or more and 10% or less.

The metal silicide-based material constituting the phase shift film 3 may include metal and silicon as long as it has a specific transmittance and phase difference with respect to the exposed light, and may further include other elements. The other elements may be elements that can control the refractive index (n) and extinction coefficient (k) of the exposed light, and are selected from at least one element selected from oxygen (O) and nitrogen (N). As other elements, carbon (C) and fluorine (F) may be contained. Examples include metal silicide oxides, metal silicide oxide nitrides, metal silicide nitrides, metal silicide carbide nitrides, metal silicide oxide carbides, and metal silicide carbide oxide nitrides. Wait. In addition, from the viewpoint of pattern controllability using wet etching, the metal silicide-based material constituting the phase shift film 3 preferably contains metal, silicon, and a component that slows down the wet etching rate of the phase shift film 3. material. Examples of the component that slows down the wet etching rate of the phase shift film 3 include nitrogen (N) and carbon (C). Examples of the metal include transition metals such as molybdenum (Mo), tantalum (Ta), tungsten (W), titanium (Ti), and zirconium (Zr). Examples of the metal silicide-based material constituting the phase shift film 3 include a metal silicide nitride, a metal silicide oxide nitride, a metal silicide oxide carbide, a metal silicide carbide carbide, and a metal silicide. Carbonized oxide nitride. Specifically, molybdenum silicide (MoSi) nitride, tantalum silicide (TaSi) nitride, tungsten silicide (WSi) nitride, titanium silicide (TiSi) nitride, zirconium silicide ( ZrSi) nitride, molybdenum silicide oxide nitride, tantalum silicide oxide nitride, tungsten silicide oxide nitride, titanium silicide oxide nitride, zirconium silicide oxide nitride, molybdenum silicide Carbide oxide, Carbide oxide of tantalum silicide, Carbide oxide of titanium silicide, Carbide oxide of tungsten silicide, Carbide oxide of zirconium silicide, Carbide nitride of molybdenum silicide, Nitrogen carbide of tantalum silicide Carbide, titanium silicide carbide nitride, zirconium silicide carbide nitride, tungsten silicide carbide nitride, molybdenum silicide carbide oxide nitride, tantalum silicide carbide oxide nitride, titanium silicide carbide oxidation Carbide oxide nitrides of nitrides, tungsten silicides, and carbide oxide nitrides of zirconium silicides.

When the material constituting the phase shift film 3 is metal, silicon, or nitrogen, its composition is self-phase Expected phase difference (180 ° ± 20 °) for light exposure, transmittance (1% to 20%), wet etching characteristics (cross-section shape of CD pattern 3 or CD unevenness), chemical resistance Sexual perspective. The ratio of metal to silicon is preferably metal: silicon = 1: 1 to 1: 9. The content of nitrogen is preferably 25 atomic% or more and 55 atomic% or less, and more preferably 30 atomic% or more and 50 atomic% or less.

The film-forming step of the phase shift film 3 is performed using a sputtering target containing metal and silicon in a sputtering gas environment containing a gas having components capable of controlling the refractive index (n) and extinction coefficient (k) of the light to be exposed. . The sputtering gas environment includes an inert gas and an active gas that oxidizes and / or nitrides the phase shift film. Examples of the active gas include oxygen (O ₂ ), carbon monoxide (CO), carbon dioxide (CO ₂ ), nitrogen (N ₂ ), nitrogen monoxide (NO), nitrogen dioxide (NO ₂ ), and monoxide Dinitrogen gas (N ₂ O), hydrocarbon-based gas (CH ₄ etc.), fluorocarbon-based gas (CF ₄ etc.), fluorine-nitride-based gas (NF ₃ etc.), and the like. In addition, from the viewpoint of utilizing the pattern controllability of the wet etching, it is preferable to use a sputtering target including metal and silicon to form the film for the phase shift film 3. The slow component gas is sputtered in a gas environment. As a component which slows down the wet etching rate of the phase shift film 3, as mentioned above, nitrogen (N) and carbon (C) are mentioned, for example. Examples of the gas having a component that slows down the wet etching rate of the phase shift film 3 include nitrogen gas, nitrogen monoxide gas, nitrogen dioxide gas, nitrogen monoxide gas, carbon monoxide gas, carbon dioxide gas, and hydrocarbon-based gas (CH ₄ etc.), reactive gas such as fluorocarbon-based gas (CF ₄ etc.), fluorine nitride-based gas (NF ₃ etc.). Examples of the inert gas include helium, neon, argon, krypton, and xenon. The sputtering gas environment includes, for example, a mixed gas of an inert gas and an active gas. The inert gas contains at least one selected from the group consisting of helium, neon, argon, krypton, and xenon. The active gas contains At least one of a group of nitrogen monoxide gas and nitrogen dioxide gas.

It is also possible to perform an exposure step after forming the phase shift film 3, that is, to expose the phase shift film 3 to an exposure gas containing a gas having a component that slows down the wet etching rate of the phase shift film 3. surroundings. As a component which slows down the wet-etching speed of the phase shift film 3, as mentioned above, nitrogen (N) is mentioned, for example. Examples of the gas having a component that slows down the wet etching rate of the phase shift film 3 include an active gas such as nitrogen. In the gas environment for exposure, as the inert gas, helium, neon, argon, krypton, xenon, and the like may be included. In the case where the exposure gas environment includes a mixed gas environment of nitrogen and an inert gas, the ratio of nitrogen to the inert gas (nitrogen / inert gas) is 20% or more, and preferably 30% or more.

The method of obtaining the desired optical characteristics (phase difference) of the film thickness of the phase shift film 3 is appropriately adjusted in a range of 80 nm to 140 nm.

Generally speaking, as shown in FIG. 1, the phase shift film 3 has the same material: a main layer 3 a; and a topmost layer 3b, which is oxidized from the surface of the main layer 3a to the depth by surface oxidation after film formation. Direction formed. The main layer 3a shows a characteristic that the composition ratio of each element in the depth direction of the film is substantially uniform (at least, it can be said to be substantially uniform in the analysis result by X-ray photoelectron spectroscopy), and the phase shift of the phase shift effect of the phase shift film 3 is exhibited The body region of the membrane 3. When the etching mask film 4 is formed immediately after the phase shift film 3 is formed, or when the etching mask film 4 is continuously formed in a vacuum after the phase shift film 3 is formed, it is not The outermost surface layer 3b is formed between the phase shift film 3 and the etching mask film 4, and the phase shift film 3 is composed of only the main layer 3a.

The phase shift film 3 may be any of a single-layer film and a laminated film. In the case where the phase shift film 3 is composed of a laminated film, it is preferable to make the composition and the composition ratio uniform between the interfaces of the respective layers, and to fix the etching rate during wet etching, for example, to prevent so-called The occurrence of dissolution. In the case of a laminated film, it is preferable that the film-forming step of the phase-shift film 3 is performed a plurality of times under the same film-forming conditions. The plurality of film formation steps are preferably performed continuously in the same continuous sputtering apparatus. In the case where a plurality of film formation steps are performed continuously, for example, a continuous sputtering apparatus described below is used. Furthermore, in the case where a plurality of film-forming steps are performed, the sputtering power applied to the sputtering target can be reduced when the phase-shift film 3 is formed.

The film thickness of the outermost surface layer 3b is, for example, preferably from 0.1 nm to 10 nm, but is not limited to this range.

With the above-described step of forming the phase shift film, the refractive index at the wavelength of 365 nm of the upper portion (hereinafter, referred to as the upper portion of the main layer) of the main layer 3a of the phase shift film 3 can be made smaller than that of the main layer The refractive index of the lower part of the layer 3a on the transparent substrate 2 side (hereinafter, referred to as the lower part of the main layer) at a wavelength of 365 nm. The phase shift film 3 having such a configuration can be used to have a cross-sectional shape that can fully exhibit the phase effect by patterning by wet etching.

The refractive index of the upper part of the main layer at a wavelength of 365 nm is preferably 2.50 or more. Furthermore, the difference (Δn) between the refractive index of the lower part of the main layer at a wavelength of 365 nm and the refractive index of the upper part of the main layer at a wavelength of 365 nm is preferably -0.01 or less, more preferably -0.10 or less. When the difference in refractive index (Δn) at a wavelength of 365 nm exceeds -0.01, there is a possibility that it is difficult to form a cross-sectional shape to the extent that the phase effect can be exhibited by patterning the phase shift film 3 of the wet etching. (If it is -0.10 or less, a substantially vertical cross-sectional shape can be obtained).

Furthermore, by the above-mentioned phase shift film forming step, the wavelength is not limited to 365 nm. For example, even in the range of 190 nm to 1000 nm, the refractive index of the upper part of the main layer at the measurement wavelength can be made smaller than that of the lower part of the main layer. (Refer to Fig. 6, Fig. 11 and Fig. 13 below).

In the main layer 3a of the phase shift film 3, as described above, the composition ratio of each element in the film depth direction is substantially uniform. Here, the composition ratio of each element in the film depth direction is substantially uniform, which means that the center value of the content of each element in the film depth direction of the phase shift film 3 obtained under the film forming conditions in the above film forming step is used as a reference. , And the content of each element of the main layer 3a converges within a range of a specific fluctuation range with respect to the center content. For example, it is set to ± 2.5 atomic% with respect to the center content of each element of metal, silicon, nitrogen, and oxygen.

In addition, the composition ratio of each element in the film depth direction of the main layer 3a of the phase shift film 3 is substantially uniform, and the film formation step may not be used for the purpose of providing stepwise or continuous composition changes in the film thickness direction. This is achieved by forming the phase shift film 3 when the operation of changing the supply method or supply amount of the sputtering source material or the sputtering gas is performed.

Such a phase shift film forming step can be performed using, for example, the continuous sputtering apparatus 11 shown in FIG. 2. get on.

The sputtering apparatus 11 is a continuous type, and includes five chambers including a carry-in chamber LL, a first sputtering chamber SP1, a buffer chamber BU, a second sputtering chamber SP2, and a carry-out chamber ULL. The five chambers are sequentially and sequentially arranged.

The transparent substrate 2 mounted on a tray (not shown) can be carried into the chamber LL, the first sputtering chamber SP1, the buffer chamber BU, and the second sputtering chamber SP2 in the direction of the arrow S at a specific transfer speed. , And the order of removal of the chamber ULL. In addition, the transparent substrate 2 mounted on a tray (not shown) can be moved out of the chamber ULL, the second sputtering chamber SP2, the buffer chamber BU, and the first sputtering chamber SP1 in the direction opposite to the arrow S. And the order of returning into the chamber LL.

The space between the carry-in chamber LL and the first sputtering chamber SP1 and the space between the second sputtering chamber SP2 and the carry-out chamber ULL are separated by a partition plate. The carry-in chamber LL and the carry-out chamber ULL can be separated from the outside of the sputtering apparatus 11 by a partition plate.

The carry-in chamber LL, the buffer chamber BU, and the carry-out chamber ULL are connected to an exhaust device (not shown) that performs exhaust.

In the first sputtering chamber SP1, a first sputtering target 13 including metal and silicon, which is used to form a phase shift film 3, is disposed on the side of the carry-in chamber LL, and a transparent substrate 2 near the first sputtering target 13 is provided. A first gas introduction port GA11 is disposed upstream of the first sputtering target 13 in the conveying direction shown by the arrow S, and a second gas introduction is disposed downstream of the first sputtering target 13.口 GA12. In the first sputtering chamber SP1, a second sputtering target 14 including a metal and silicon for forming a phase shift film 3 is disposed on the buffer chamber BU side, and a transparent substrate 2 near the second sputtering target 14 is disposed. A third gas introduction port GA21 is disposed upstream of the second sputtering target 14 in the conveying direction shown by the arrow S, and a fourth gas position is disposed downstream of the second sputtering target 14 Gas inlet GA22.

Here, the distance between the first sputtering target 13 and the second gas introduction port GA12 on the downstream side is set to be wider than the distance between the first sputtering target 13 and the first gas introduction port GA11 on the upstream side. This department This is because, as will be described below, the sputtering gas environment is changed by providing a distance between the sputtering target and the downstream gas introduction port. Similarly, the distance between the second sputtering target 14 and the fourth gas introduction port GA22 on the downstream side is set to be wider than the distance between the second sputtering target 14 and the third gas introduction port GA21 on the upstream side.

Furthermore, in the first sputtering chamber SP1, it is preferable that the distance between the sputtering target and the gas introduction port on the downstream side is set to, for example, 15 cm or more and 50 cm or less, and the distance between the sputtering target and the gas introduction port on the upstream side is, for example, preferably It is set to 1 cm or more and 5 cm or less.

In the second sputtering chamber SP2, a third sputtering target 15 containing metal and silicon for forming a phase shift film 3 is disposed on the buffer chamber BU side, and a transparent substrate 2 near the third sputtering target 15 is placed there. A fifth gas introduction port GA31 is disposed upstream of the third sputtering target 15 in the conveying direction shown by the arrow S, and a sixth gas introduction is disposed downstream of the third sputtering target 15.口 GA32. In the second sputtering chamber SP2, a fourth sputtering target 16 including metal and silicon, which is used to form a phase shift film 3, is disposed on the ULL side of the carry-out chamber, and a transparent substrate 2 near the fourth sputtering target 16 is arranged. A seventh gas introduction port GA41 is disposed upstream of the fourth sputtering target 16 in the conveying direction indicated by the arrow S, and an eighth gas position is disposed downstream of the fourth sputtering target 16. Gas inlet GA42.

Here, as in the first sputtering chamber SP1, the distance between the third sputtering target 15 and the sixth gas introduction port GA32 on the downstream side is set to be longer than the third sputtering target 15 and the fifth gas introduction port on the upstream side. The interval of GA31 is wider. Similarly, the distance between the fourth sputtering target 16 and the downstream eighth gas introduction port GA42 is set to be wider than the distance between the fourth sputtering target 16 and the upstream seventh gas introduction port GA41.

In addition, in the second sputtering chamber SP2, as in the first sputtering chamber SP1, it is preferable that the interval between the sputtering target and the gas introduction port on the downstream side be set to, for example, 15 cm to 50 cm. The distance between the target and the gas introduction port on the upstream side is set to, for example, 1 cm to 5 cm.

In FIG. 2, the first sputtering target 13, the second sputtering target 14, the third sputtering target 15, and the fourth The sputtering target 16 is indicated by hatching.

Here, a case where the phase shift film 3 (a single film formation) composed of a single-layer film is formed will be described.

First, the transparent substrate 2 mounted on a tray (not shown) is carried into the carry-in chamber LL of the sputtering apparatus 11.

Next, after the inside of the sputtering device 11 is set to a specific vacuum degree, for example, from the second gas introduction port GA12 on the downstream side of the first sputtering target 13, the sputtering gas at a specific flow rate includes an inert gas and an active gas. The form of the mixed gas of the gas is introduced into the first sputtering chamber SP1, and a specific sputtering power is applied to the first sputtering target 13. The application of the sputtering power and the introduction of the sputtering gas are continued until the transparent substrate 2 is transferred to the unloading chamber ULL.

By supplying the sputtering gas from the downstream side, the presence of an inert gas having a relatively long flight distance on the upstream side of the chamber (a part remote from the second gas introduction port GA12) becomes high, and therefore it can be considered as the inert gas. Inert gas-rich sputtering gas environment with more gas content than specified content. In addition, it is considered that the sputtering gas environment has a tendency to decrease the content of the inert gas to a specific content (the effect of the difference in flight distance gradually disappears) as it moves from the upstream side to the downstream side, and is close to the second The position of the gas introduction port GA12 becomes a sputtering gas environment containing a specific content of an inert gas and an active gas. That is, in the film formation of the phase shift film, an environment rich in active gas is formed in the second half of the film formation compared with the first half of the film formation.

The "supply sputtering gas from the downstream side" is not only supplied from the downstream side with respect to the sputtering target (it must be only the downstream side), but may be supplied from both the upstream and downstream sides, for example. As a result, as long as "the formation of the phase shift film, an environment rich in (more contained) active gas in the second half of the film formation than in the first half of the film formation" can be achieved (ie, since the The supply of sputtering gas system on the downstream side of the plating target refers to one of the specific methods used to achieve the above-mentioned "enriched active gas (more active gas) in the second half of film formation". If other methods can be used to achieve "Yucheng The second half of the membrane is rich in active gas (more active gas) ").

Then, the transparent substrate 2 mounted on a tray (not shown) is transported at a specific speed, It is carried in the direction of the arrow S in the order of the carrying-in chamber LL, the first sputtering chamber SP1, the buffer chamber BU, the second sputtering chamber SP2, and the carrying-out chamber ULL. When the transparent substrate 2 passes near the first sputtering target 13 of the first sputtering chamber SP1, the main surface of the transparent substrate 2 is formed on the main surface of the transparent substrate 2 by reactive sputtering with a specific thickness to form substantially the same metal silicide. It is a phase shift film 3 (including the outermost surface layer formed by oxidation after film formation), which is a single-layer film. The film formation of such a phase shift film 3 is performed in the above-mentioned sputtering gas environment. Therefore, the film formation in the lower part of the main layer of the phase shift film 3 is on the upstream side of the chamber, and is mainly performed in a sputtering gas environment rich in inert gas (more inert gas). On the downstream side, it is mainly carried out in a sputtering gas environment containing a specific content of an inert gas and an active gas. It is considered that the film formation of the main layer 3a of the phase shift film 3 is performed by the reactive sputtering in such a sputtering gas environment around the second half of the film formation when the transparent substrate 2 passes downstream. In addition, the phase shift film 3 was measured with a spectroscopic ellipsometer under simulated conditions in which an oxide film was formed on the outermost surface and the main layer was a gradient film (Graded Layer) having a refractive index gradient, using a spectroscopic ellipsometer. As a result of the refractive index of the shift film 3, the refractive index of the upper part of the main layer at a wavelength of 365 nm is smaller than the refractive index of the lower part of the main layer at a wavelength of 365 nm. By making the phase shift film 3 thus formed, that is, by making the refractive index of the upper part of the main layer of the phase shift film 3 at a wavelength of 365 nm smaller than the refractive index of the lower part of the main layer at a wavelength of 365 nm, the wet etching can be performed. The cross-sectional shape of the etched cross section of the edge portion of the phase shift film pattern 3 'obtained by patterning is a vertical cross-sectional shape or a nearly vertical cross-sectional shape that can fully exert the phase shift effect.

On the other hand, when a sputtering gas is supplied from a first gas introduction port GA11 disposed on the upstream side of the first sputtering target 13 to form a phase shift film, a specific content is included from the upstream side to the downstream side. The sputtering gas environment of inert gas and active gas, it can be considered that the main layer of the phase shift film is from the first half of the film formation before the transparent substrate 2 passes above the first sputtering target 13 to the second half of the film formation after the pass. Film formation. As a result, when a film is formed under the condition that a sputtering gas is supplied from the upstream, if an oxide film is formed on the outermost surface of the phase shift film 3 and the main layer is an inclined film (a film having a refractive index gradient) Under the simulation conditions, by If the refractive index of the phase shift film 3 is measured by a spectroscopic ellipsometer, the refractive index at the wavelength of 365nm rises from the lower part of the autonomous layer to the upper part of the main layer. Therefore, the refractive index of the upper part of the main layer at a wavelength of 365nm is greater than that of the lower part of the main layer at a wavelength of 365nm. The refractive index. The cross-sectional shape of the etched section of the edge portion of the phase shift film pattern obtained by patterning the phase shift film thus formed by wet etching is tapered.

In addition, in the film formation of the phase shift film 3, a state in which a main valve (not shown) of an exhaust device (not shown) connected to the buffer chamber BU is closed and the exhaust is stopped may be set. In addition, the transparent substrate 2 may be transported without causing the sputtering gas to flow into the second sputtering chamber SP2 with the main valve (not shown) closed.

Furthermore, instead of the first sputtering target 13 described above, the second sputtering target 14 may be used to form the phase shift film 3 composed of a single-layer film. In this case, a sputter gas of a specific flow rate is introduced into the first sputtering chamber SP1 from the fourth gas introduction port GA22 on the downstream side of the second sputtering target 14, and a specific gas is applied to the second sputtering target 14. Sputtering power. Alternatively, instead of the first sputtering target 13 or the second sputtering target 14 of the first sputtering chamber SP1, the third sputtering target 15 or the fourth sputtering target 16 of the second sputtering chamber SP2 may be used. The film formation of the phase shift film 3 which consists of a single-layer film is performed. In this case, a 6th gas introduction port GA32 (or 8th gas introduction port GA42) downstream of the 3rd sputtering target 15 (or 4th sputtering target 16) introduces a sputter gas of a specific flow rate to the 3rd sputtering target 15 (or 4th sputtering target 16). 2 sputtering chamber SP2, and a specific sputtering power is applied to the third sputtering target 15 (or the fourth sputtering target 16).

The case where the phase shift film 3 (film formation multiple times) which consists of a laminated film is formed is demonstrated.

In this case, there are the following film formation methods: The first film formation method repeats the transportation in the direction of the arrow S of the transparent substrate 2 and the transportation in the direction opposite to the arrow S, and each time the transportation in the direction of the arrow S, the The metal silicide-based single-layer film constituting a part of the phase-shifting film 3 is sequentially laminated to form the phase-shifting film 3; the second film forming method is to use the first 1 At least two of the sputtering target 13 to the fourth sputtering target 16 are formed by sequentially stacking a metal silicide-based single-layer film constituting a part of the phase shift film 3 to form a phase shift film 3; and a third film forming method It is a combination of the first film forming method and the second film forming method. Film formation methods It is appropriately selected according to the number of layers of the phase shift film 3.

In addition, in these film forming methods, similar to the film formation of the phase shift film 3 composed of a single-layer film, when the transparent substrate 2 is transported in the direction of the arrow S, a sputtering gas having a specific flow rate is used in The film-forming sputtering target is supplied downstream to perform film formation of the phase shift film 3.

In the first film forming method, for example, the following procedure is followed.

The single-layer film formed as described above is used as the first layer of the metal silicide-based single-layer film constituting a part of the phase shift film 3, and then the transparent substrate 2 is sequentially removed from the cavity in the direction opposite to the arrow S The chamber ULL is returned to the carry-in chamber LL, and the second layer of the metal silicide-based single-layer film constituting a part of the phase shift film 3 is performed again in the same manner as the film formation of the first-layer metal silicide-based single-layer film. Film formation.

The same applies to the case of forming the metal silicide-based single-layer film after the third layer, which constitutes a part of the phase shift film 3.

By using the film-forming step of the first film-forming method, a multilayer film composed of two or more layers including the same metal silicide-based material having a specific film thickness on the main surface of the transparent substrate 2 is formed. Formed phase shift film 3.

In the second film forming method, for example, the following procedure is followed.

First, the transparent substrate 2 is carried into the carry-in chamber LL of the sputtering apparatus 11.

Next, after the inside of the sputtering device 11 is set to a specific vacuum degree, a sputtering gas of a specific flow rate is introduced into the first sputtering chamber SP1 from the second gas introduction port GA12 on the downstream side of the first sputtering target 13. From the sixth gas introduction port GA32 downstream of the third sputtering target 15, a sputtering gas having the same composition as the sputtering gas introduced into the first sputtering chamber SP1 is introduced into the second sputtering at a specific flow rate. In the chamber SP2, specific sputtering power is applied to the first sputtering target 13 and the third sputtering target 15, respectively. The application of the sputtering power and the introduction of the sputtering gas are continued until the transparent substrate 2 is transferred to the unloading chamber ULL.

Then, the transparent substrate 2 is sequentially transported from the carry-in chamber LL to the carry-out chamber ULL at a specific transport speed in the direction of the arrow S. Pass the first sputtering chamber SP1 on the transparent substrate 2 In the vicinity of the first sputtering target 13, the first layer of a metal silicide-based single-layer film having a specific film thickness is formed on the main surface of the transparent substrate 2 by reactive sputtering.

Then, when the transparent substrate 2 passes near the third sputtering target 15 of the second sputtering chamber SP2, a metal of a specific thickness is formed on the first layer of metal silicide-based single-layer film by reactive sputtering. Silicide is the second layer of single-layer film.

In the case of forming the phase shift film 3 of the laminated film formed of a three-layer structure, in addition to the sputtering target described above, the second sputtering target 14 of the first sputtering chamber SP1 is also used. The fourth gas introduction port GA22 on the downstream side of the sputtering target 14 supplies a sputtering gas at a specific flow rate, and applies a specific sputtering power to the second sputtering target 14. In this case, the metal silicide-based single-layer film formed when passing near the second sputtering target 14 becomes the second layer of the phase shift film 3 and the metal formed when passing near the third sputtering target 15 The silicide-based single layer film becomes the third layer of the phase shift film 3.

By using the film-forming step of the second film-forming method, a multilayer film composed of two or more layers of a specific film thickness and containing the same metal silicide-based material is formed on the main surface of the transparent substrate 2. Formed phase shift film 3.

In the third film forming method, either of the first film forming method and the second film forming method may be performed first.

For example, first perform a second film formation method, and a plurality of metal silicide-based single-layer films are laminated in a single transfer of the transparent substrate 2. Then, the first film formation method is performed, and then a necessary number of metal silicide-based single layers are laminated. By laminating a film, a phase shift film 3 formed from a laminated film having a predetermined number of laminated layers can be formed.

By using the film forming step of the third film forming method, a multilayer film having three or more layers including the same metal silicide-based material having a specific film thickness is formed on the main surface of the transparent substrate 2. Of phase shift film 3.

After the phase shift film 3 is formed on the main surface of the transparent substrate 2 in this manner, the transparent substrate 2 is taken out to the outside of the sputtering device 11.

The phase shift mask substrate 1 according to the first embodiment is manufactured by such a preparation step and a phase shift film forming step.

According to the phase shift mask base 1 of the first embodiment manufactured in this manner, a phase shift film 3 containing metal, silicon, oxygen, and / or nitrogen is formed on the transparent substrate 2. The phase shift film 3 has a main layer 3a including the same material and a surface oxide layer 3b, which is a surface oxide layer of the main layer 3a. The refractive index at the wavelength of 365 nm of the upper part of the main layer on the outermost surface layer 3b side is smaller than the refractive index of the wavelength of 365 nm at the lower part of the main layer on the transparent substrate 2 side. The phase shift mask substrate 1 having such a structure is capable of patterning its phase shift film 3 into a cross-sectional shape capable of fully exerting a phase shift effect by wet etching. Since the phase shift mask substrate 1 can make the cross-sectional shape of the etched section of the edge portion of the phase shift film pattern 3 'obtained by patterning its phase shift film 3 a cross-sectional shape that can fully exert the effect of phase shift, Therefore, it can be used as an original plate for manufacturing a phase-shifting mask having a phase-shifting film pattern 3 'which improves the resolution and has good CD characteristics.

In addition, the method for manufacturing the phase shift mask substrate 1 according to Embodiment 1 includes a phase shift film forming step, which is performed on the transparent substrate 2 by a sputtering method using a continuous sputtering apparatus. A phase shift film 3 comprising a main layer 3a containing metal, silicon, oxygen, and / or nitrogen and having the same material and a surface oxide layer of the main layer 3a, that is, the outermost layer 3b is formed. This phase shift film formation step uses a first sputtering target 13 containing a metal silicide, and supplies inertia downstream from the first sputtering target 13 in the transport direction of the transparent substrate 2 near the first sputtering target 13. The gas and the active gas for oxidizing and nitriding the phase shift film 3 are performed by reactive sputtering using a mixed gas containing an inert gas and an active gas. According to the phase-shifting film 3 thus formed, a phase-shifting mask base 1 capable of being patterned into a cross-sectional shape capable of sufficiently exerting a phase-shifting effect by wet etching can be manufactured. Since the cross-sectional shape of the etched cross section of the edge portion of the phase shift film pattern 3 'can be a cross-sectional shape that can fully exert the effect of phase shift, a phase shift film that can be patterned to improve resolution and have good CD characteristics can be manufactured. Pattern 3 'phase shift mask substrate 1.

In addition, in Embodiment 1, a gas inlet (for example, when In the case of the sputtering target 13, the second gas introduction port GA12) is described as a phase shift film formation step in which a mixed gas prepared by mixing an inert gas and an active gas in advance is provided, but it is not limited to this, and may not be performed in advance. Mix, and perform phase shift film formation while supplying inert gas and active gas from dedicated gas inlets.

In the first embodiment, the case where the continuous sputtering apparatus 11 having the above-mentioned configuration is used in the film formation step has been described, but a continuous sputtering apparatus having another configuration (for example, without the fourth sputtering target 16) may be used. , Those without a target and a gas inlet, such as the seventh gas introduction port GA41, the eighth gas introduction port GA42, or the like, and those who further add a target and a gas introduction port, etc.).

Furthermore, in the continuous sputtering apparatus shown in FIG. 2, as long as each gas introduction port (a second gas introduction port GA12, a fourth gas introduction port GA22, a sixth gas introduction port GA32, 8 gas introduction port GA42), at least one of the phase shift films 3 of Embodiment 1 can be formed, so it is not necessary to provide each gas introduction port (the first gas introduction port GA11, the third All or part of the gas introduction port GA21, the fifth gas introduction port GA31, and the seventh gas introduction port GA41).

<Embodiment 2>

In the second embodiment, a phase shift mask substrate for manufacturing a display device different from the first embodiment and a method for manufacturing the same are described.

Fig. 3 is a cross-sectional view showing the structure of a phase shift mask base 10 according to a second embodiment of the present invention. It should be noted that the same reference numerals are used for the same components as those in the first embodiment, and the description here is omitted or simplified.

As shown in FIG. 3, the phase shift mask base 10 according to the second embodiment has a structure in which a phase shift film 3 including a metal silicide-based material is laminated on a transparent substrate 2 and an etching mask film 4 including: Including a material having an etching selectivity to a metal silicide-based material such as a chromium-based material.

The manufacturing method of the phase shift mask base 10 of the second embodiment in this configuration includes: preparing Step, which prepares a transparent substrate; a film forming step (hereinafter, referred to as a phase shift film forming step), which forms a phase shift film on the main surface of the transparent substrate by sputtering; and an etching mask film forming step , Which forms an etch mask film on the phase shift film by sputtering.

The substrate preparation step and the film formation step of the phase shift film are the same as those in the first embodiment, so the description here is omitted. Hereinafter, the film formation step of the etching mask film will be described.

Etching mask film forming step

Either the etching mask film 4 may have a light-shielding property or a light-transmitting property. The chromium-based material constituting the etching mask film 4 is not particularly limited as long as it contains chromium (Cr). Examples of the chromium-based material constituting the etching mask film include chromium, oxides of chromium, chromium nitrides, chromium carbides, chromium fluorides, and materials containing at least one of them.

The etching mask film forming step is performed using a sputtering target containing chromium or a chromium compound, for example, in a sputtering gas environment containing a mixed gas, which is a mixed gas of an inert gas and an active gas, and the inert gas contains At least one selected from the group consisting of helium, neon, argon, krypton, and xenon. The active gas includes a group selected from the group consisting of oxygen, nitrogen, carbon dioxide gas, nitrogen oxide gas, hydrocarbon gas, and fluorine gas. At least one of them.

Either the etching mask film 4 may be composed of one layer or the plurality of layers. When the etching mask film 4 is composed of a plurality of layers, for example, there is a case where a laminated structure including a light shielding layer formed on the phase shift film 3 side and an anti-reflection layer formed on the light shielding layer is included, or In the case of a laminated structure of an insulating layer formed by the phase shift film 3 in a contact manner, a light-shielding layer formed on the insulating layer, and an anti-reflection layer formed on the light-shielding layer. Either the light-shielding layer is constituted by one layer or the case is constituted by a plurality of layers. Examples of the light-shielding layer include a chromium nitride film (CrN), a chromium carbide film (CrC), and a chromium carbide film (CrCN). Either the antireflection layer is constituted by one layer or the case is constituted by a plurality of layers. As the anti-reflection layer, for example, A chromium oxynitride film (CrON) is listed. The insulating layer is made of, for example, CrCO or CrCON containing less than 50 atomic% of Cr, and has a thickness of 10 nm to 50 nm. When the etching mask film 4 containing a chromium-based material is wet-etched, metal ions are eluted from the phase shift film 3 containing a metal silicide-based material. At this time, electrons are generated. When an insulating layer is formed in contact with the phase shift film 3, electrons generated when metal ions are eluted from the phase shift film 3 can be prevented from being supplied to the etching mask film 4. Therefore, the in-plane etching rate can be made uniform when the etching mask film 4 is wet-etched.

The etching mask film 4 is formed by the sputtering apparatus 11 (FIG. 2) described in the first embodiment. However, in the second embodiment, the second sputtering target 14, the third sputtering target 15, and the fourth sputtering target 16 are chromium targets or chromium compound targets containing chromium.

When the etching mask film 4 is continuously formed without taking out the transparent substrate 2 to the outside of the sputtering device 11 after forming the phase shift film 3, the transparent substrate 2 mounted on a tray (not shown) is directed toward The direction of the arrow S is reversed, and returns in the order of the carrying-out chamber ULL, the second sputtering chamber SP2, the buffer chamber BU, the first sputtering chamber SP1, and the carrying-in chamber LL. On the other hand, when the transparent substrate 2 is temporarily taken out of the sputtering device 11 after the phase shift film 3 is formed, and the etching mask film 4 is formed, a transparent substrate mounted on a tray (not shown) is formed. 2 After being carried into the carrying chamber LL, as described above, the inside of the sputtering apparatus 11 is set to a specific degree of vacuum.

When an etching mask film 4 including a laminated structure of a light-shielding layer and an anti-reflection layer is formed, the specific gas is introduced from the fourth gas introduction port GA22 under the condition that the inside of the sputtering device 11 has a specific vacuum degree. A flow rate of the sputtering gas, and a specific sputtering power is applied to the second sputtering target 14. A sputtering gas having a specific flow rate is introduced from the sixth gas introduction port GA32, and a specific sputtering power is applied to the third sputtering target 15. A sputtering gas having a specific flow rate is introduced from the eighth gas introduction port GA42, and a specific sputtering power is applied to the fourth sputtering target 16. The application of the sputtering power and the introduction of the sputtering gas are continued until the transparent substrate 2 is transferred to the unloading chamber ULL.

Then, the transparent substrate 2 mounted on a tray (not shown) is carried into the chamber LL, the first sputtering chamber SP1, the buffer chamber BU, and the second sputtering chamber at a specific transfer speed in the direction of the arrow S. SP2, and the order of the ULL out of the chamber. When the transparent substrate 2 passes near the second sputtering target 14 of the first sputtering chamber SP1, a light-shielding layer containing a chromium-based material having a specific film thickness is formed on the phase shift film 3 by reactive sputtering. In addition, when the transparent substrate 2 passes near the third sputtering target 15 and the fourth sputtering target 16 of the second sputtering chamber SP2, a specific film thickness including chromium is formed on the light-shielding layer by reactive sputtering. It is a light-shielding layer or anti-reflection layer of the material.

After the etching mask film 4 including the laminated structure of the light shielding layer and the anti-reflection layer is formed on the phase shift film 3, the transparent substrate 2 is taken out to the outside of the sputtering device 11.

When an etching mask film 4 including a laminated structure including an insulating layer, a light shielding layer, and an anti-reflection layer is formed, after the phase shift film 3 is formed on the transparent substrate 2, the inside of the sputtering device 11 is specified. In a vacuum state, a sputtering gas having a specific flow rate is introduced from the fourth gas introduction port GA22, and a specific sputtering power is applied to the second sputtering target 14.

Then, the transparent substrate 2 mounted on a tray (not shown) is carried into the chamber LL, the first sputtering chamber SP1, the buffer chamber BU, and the second sputtering chamber at a specific transfer speed in the direction of the arrow S. SP2, and the order of the ULL out of the chamber. When the transparent substrate 2 passes near the second sputtering target 14 of the first sputtering chamber SP1, an insulating layer containing a chromium-based material having a specific film thickness is formed on the phase shift film 3 by reactive sputtering.

Then, in order to form a light-shielding layer and an anti-reflection layer, the transparent substrate 2 mounted on a tray (not shown) is moved out of the chamber ULL, the second sputtering chamber SP2, and the buffer in a direction opposite to the arrow S. The chamber BU, the first sputtering chamber SP1, and the carry-in chamber LL are sequentially returned, and as described above, a light-shielding layer and an anti-reflection layer are formed.

After the etching mask film 4 including a laminated structure of an insulating layer, a light shielding layer, and an anti-reflection layer is formed on the phase shift film 3, the transparent substrate 2 is taken out to the outside of the sputtering device 11.

The phase shift mask base 10 for manufacturing the display device according to the second embodiment thus manufactured includes a transparent substrate 2 and a phase shift film 3 formed on the main surface of the transparent substrate 2 and containing gold. It is a silicide-based material; and an etching mask film 4 formed on the phase-shift film 3 and containing a chromium-based material; and is formed as the outermost surface layer 3b of the main layer 3a of the phase-shift film 3 as in the first embodiment. The refractive index at the upper side (hereinafter, referred to as the upper part of the main layer) has a refractive index at a wavelength of 365 nm, which is smaller than the lower part of the transparent substrate 2 side in the main layer 3a (hereinafter, referred to as the lower part of the main layer) at a wavelength of 365 nm The refractive index.

According to the phase shift mask base 10 of the second embodiment manufactured in the same manner as in the first embodiment, the phase shift film can be patterned into a cross-sectional shape that can fully exert the phase shift effect in the wet etching of the phase shift film 3, Thus, an original plate for manufacturing a phase shift mask having a phase shift film pattern with improved resolution and good CD characteristics can be formed. In addition, by including the etching mask film 4 containing a chromium-based material, the adhesion with the resist layer formed thereon can be improved, and the thickness of the resist layer can be reduced.

In the present embodiment, a case where a light-shielding film (etching mask film 4) is laminated on the phase shift film 3 has been described. However, a light-shielding film may be formed between the transparent substrate 2 and the phase shift film 3.

Such a structure can be formed by the following steps: a preparation step that prepares the transparent substrate 2; a film formation step that forms a light-shielding film 4 on the main surface of the transparent substrate 2 by sputtering; a light-shielding film pattern forming step that The light-shielding film 4 is patterned to form a light-shielding film pattern 4 ′; and a phase shift film forming step, which forms a phase-shifting film 3 containing metal, silicon, oxygen, and / or nitrogen on the light-shielding film pattern 4 ′.

As described above, the phase shift mask substrate of the present invention is configured as follows: a phase shift film formed on a transparent substrate and containing metal, silicon, oxygen, and / or nitrogen has a main layer and an outermost surface containing the same material Layer, and the refractive index at the wavelength of 365 nm of the upper part of the main layer on the most surface layer side is smaller than the refractive index of the lower part of the main layer on the transparent substrate side at the wavelength of 365 nm. Therefore, even if any of the phase shift mask substrates of the phase shift mask substrate of the first embodiment and the phase shift mask substrate of the second embodiment is used, the third embodiment and the fourth embodiment described below can be used. In the method for manufacturing a phase shift mask, a cross-sectional shape of an edge portion of a phase shift film pattern formed on a transparent substrate is a cross-sectional shape capable of fully exerting a phase shift effect. Therefore, obtained A phase-shifting mask having a phase-shifting film pattern with improved resolution and good CD characteristics can be obtained.

<Embodiment 3>

In the third embodiment, a method of manufacturing a phase shift mask for manufacturing a display device (a method of manufacturing a phase shift mask based on the phase shift mask base of the first embodiment) will be described.

4 (a) to 4 (e) are cross-sectional views showing the steps of the method for manufacturing a phase shift mask according to Embodiment 3 of the present invention. The same components as those in FIG. 1 are denoted by the same reference numerals, and repeated descriptions are omitted.

The phase shift mask 30 according to the third embodiment has a configuration in which a phase shift film pattern 3 ′ is formed on a transparent substrate 2.

In the manufacturing method of the phase shift mask of the third embodiment thus constructed, first, a resist film pattern is formed on the phase shift film 3 of the phase shift mask substrate 1 (see FIG. 1) described in the first embodiment. 5 'resist film pattern forming step.

In detail, in this resist film pattern forming step, first, as shown in FIG. 4 (a), a phase shift mask base including a phase shift film 3 containing a metal silicide-based material is formed on a transparent substrate 2. 1. Then, as shown in FIG. 4 (b), a resist film 5 is formed on the phase shift film 3. At this time, when the adhesion between the phase shift film 3 and the resist film 5 is insufficient, a surface treatment (for example, six) for improving the adhesion between the phase shift film 3 and the resist film 5 may be performed. Methyldisilazane (HMDS) treatment). Then, as shown in FIG. 4 (c), after a pattern of a specific size is drawn on the resist film 5, the resist film 5 is developed with a specific developing solution to form a resist film pattern 5 ′.

Examples of the pattern drawn on the resist film 5 include a line and gap pattern or a hole pattern.

Next, as shown in FIG. 4 (d), a phase shift film pattern forming step of wet-etching the phase shift film 3 using the resist film pattern 5 ′ as a mask to form the phase shift film pattern 3 ′ is performed.

As the etchant for wet-etching the phase shift film 3, it is not particularly limited as long as it can selectively etch the phase shift film 3 containing a metal silicide-based material. For example, An etching solution including at least one fluorine compound selected from hydrofluoric acid, fluorosilicic acid, and ammonium hydrogen fluoride and at least one oxidant selected from hydrogen peroxide, nitric acid, and sulfuric acid.

After the phase shift film pattern 3 'is formed, as shown in FIG. 4 (e), the resist film pattern 5' is peeled.

The phase shift mask 30 according to the third embodiment is manufactured by such a resist film pattern forming step and a phase shift film pattern forming step.

The phase shift film pattern 3 'has a property of changing the phase of the exposed light. Due to this property, a specific phase difference occurs between the light exposed through the phase shift film pattern 3 ′ and the light exposed through the transparent substrate 2 only. In the case where the exposed light is a composite light including light in a wavelength range of 300 nm to 500 nm, the phase shift film pattern 3 'is formed so as to generate a specific phase difference with respect to light representing a wavelength. For example, when the exposed light is a composite light including i-rays, h-rays, and g-rays, the phase shift film pattern 3 'generates a phase of 180 degrees with respect to any of the i-rays, h-rays, and g-rays. Poor way to form. In order to exert the phase shift effect, for example, the phase difference of the phase shift film pattern 3 'of the i-rays is set to a range of 180 degrees ± 10 degrees, and preferably set to approximately 180 degrees. In addition, for example, the transmittance of the i-ray phase shift film pattern 3 'is preferably set to a range of 1% to 20%, and more preferably set to a range of 3% to 15%.

The composition ratio of the elements of the phase shift film pattern 3 ′ is the surface layer 3 b formed from the most surface of the phase shift film pattern 3 ′ toward the film depth direction, and the interface region between the phase shift film pattern 3 ′ and the transparent substrate 2. The other main layers 3a are substantially uniform. However, the composition is not uniform in the outermost surface layer 3 b formed on the outermost surface of the phase shift film pattern 3 ′ toward the film depth direction and the interface region near the transparent substrate 2.

The cross-sectional shape of the etched cross section of the edge portion of such a phase shift film pattern 3 ′ is difficult to be tapered.

Here, the cross-sectional angle (θ) of the etched section of the edge portion of the phase shift film pattern 3 ′ (refer to FIG. 12 below) is preferably to fully exert the phase shift effect and to be 90 degrees or as close as possible. Near this 90 degree angle.

However, even if the cross-sectional angle (θ) is not 90 degrees or an angle close to the 90 degrees, the phase shift effect can be sufficiently exhibited. For example, even in the etched cross section of the edge portion of the phase shift film pattern 3 ', the etched cross section portion near the edge portion of the transparent substrate 2 in the etched section has a slight skirt portion, as long as the phase shift film pattern is close to the resist film pattern 5'. Most of the etched section of the 3 'edge portion is 90 degrees or an angle close to the 90 degrees, and the phase shift effect can also be fully exerted.

The phase shift mask 30 used for manufacturing the display device manufactured in this way is used for projection exposure with equal exposure to fully exert the phase shift effect. In particular, as the exposure environment, the numerical aperture (NA) is preferably 0.06 to 0.15, more preferably 0.08 to 0.10, and the coherence factor (σ) is preferably 0.5 to 1.0.

According to the method for manufacturing the phase shift mask 30 according to the third embodiment, the phase shift mask 30 is manufactured using the phase shift mask base 1 described in the first embodiment. Therefore, the phase shift mask 30 having the phase shift film pattern 3 'which can fully exert the phase shift effect can be manufactured. Since the phase shift film pattern 3 'can fully exert a phase shift effect, a phase shift mask 30 having a phase shift film pattern 3' having improved resolution and good CD characteristics can be manufactured. The phase shift mask 30 can correspond to the miniaturization of line and gap patterns or contact holes.

In the third embodiment, the manufacturing of the phase shift mask base 1 having a transparent substrate / phase shift film structure 1 as the phase shift mask 30 has been described, but the invention is not limited to this. For example, a phase shift mask base having a configuration of a transparent substrate, a phase shift film, and a resist film (see FIG. 3 (b)) may be used as the original plate for manufacturing the phase shift mask 30.

In Embodiment 3, before the step of forming the resist film pattern, the phase shift film 3 of the phase shift mask substrate 1 may be subjected to film cleaning as needed. The membrane can be cleaned by a known cleaning method. However, it is preferable to use a cleaning method other than a cleaning method using a cleaning liquid (for example, a sulfuric acid hydrogen peroxide mixture) containing a sulfur (S) component. This is because the sulfur (S) component remains on the phase shift film 3 in the film cleaning using the cleaning liquid containing the sulfur (S) component. Therefore, due to the residual sulfur (S) component, when the phase shift film 3 is patterned to obtain the phase shift film pattern 3 ', the cross-sectional shape of the etched cross section of the edge portion is easily tapered. shape.

<Embodiment 4>

In the fourth embodiment, a method for manufacturing a phase shift mask based on the phase shift mask base of the second embodiment will be described.

5 (a) to 5 (h) are cross-sectional views showing steps in a method for manufacturing a phase shift mask according to Embodiment 4 of the present invention. The same components as those in FIG. 3 are denoted by the same reference numerals, and repeated descriptions are omitted.

First, a resist pattern forming step of forming a resist pattern on the etching mask film 4 of the phase shift mask substrate 10 described in the second embodiment is performed.

Specifically, in this resist pattern forming step, first, a resist film 5 is formed on the etching mask film 4 (FIG. 5 (b)). Then, a pattern of a specific size is drawn on the resist film 5. Then, the resist film is developed with a specific developing solution to form a resist pattern 5 '(FIG. 5 (c)).

Examples of the pattern drawn on the resist film 5 include a line and gap pattern or a hole pattern.

Next, an etching mask film pattern forming step of wet etching the etching mask film 4 using the resist pattern 5 'as a mask to form the etching mask film pattern 4' is performed (FIG. 5 (d)).

The etchant for performing wet etching on the etching mask film 4 is not particularly limited as long as it can selectively etch the etching mask film 4. Specifically, an etching solution containing ammonium cerium nitrate and perchloric acid may be mentioned.

Next, a phase shift film pattern forming step of wet-etching the phase shift film 3 using the etching mask film pattern 4 'as a mask to form the phase shift film pattern 3' is performed (FIG. 5 (e)).

The etchant for performing wet etching on the phase shift film 3 is not particularly limited as long as it can selectively etch the phase shift film 3. For example, an etchant containing at least one fluorine compound selected from hydrofluoric acid, fluorosilicic acid, and ammonium hydrogen fluoride and at least one oxidant selected from hydrogen peroxide, nitric acid, and sulfuric acid can be cited. Specifically, an etching solution obtained by diluting a mixed solution of ammonium hydrogen fluoride and hydrogen peroxide with pure water can be mentioned.

In the case of manufacturing a phase shift mask of a type having a light-shielding film pattern on the phase shift film pattern, after the phase shift film pattern 3 ′ is formed, the etching mask film pattern 4 ′ is patterned into a phase shift film pattern 3 'Narrow specific pattern.

Specifically, after the resist film pattern 5 ′ is peeled off, a resist film 55 is formed so as to cover the etching mask film pattern 4 ′, and the resist film 55 is drawn using a laser drawing device and developed. In a rinsing step, a resist film pattern 55 'is formed on the etching mask film pattern 4' (FIG. 5 (f)).

Then, using the resist film pattern 55 'as a mask, the etching mask film 4' is wet-etched with a chromium etchant containing cerium ammonium nitrate and perchloric acid to form a phase shift film pattern 3 '. A narrower etch mask film pattern 4 "(Fig. 5 (g)).

Then, the resist film pattern 55 'is peeled (FIG. 5 (h)).

In this case, the phase shift film pattern 3 ′ has a property of changing the phase of the exposed light, and the etching mask film pattern 4 ″ has a light-shielding property.

Furthermore, when a phase shift mask of a type that does not have a light-shielding film pattern on the phase shift film pattern is manufactured, the etching mask film pattern 4 ′ is peeled after the phase shift film pattern 3 ′ is formed. In this case, the phase shift film pattern 3 'has a property of changing the phase of the exposed light.

Through such a resist pattern forming step, an etching mask film pattern forming step, and a phase shift film pattern forming step, a phase shift mask for manufacturing a display device is manufactured.

The phase shift mask of this embodiment manufactured in this manner includes a transparent substrate and a phase shift film pattern. The phase shift film pattern is formed on the main surface of the transparent substrate and includes a metal silicide-based material. In the case where the phase shift film pattern has a light-shielding film pattern, the etching mask film pattern is further formed, and the etching mask film pattern is formed on the phase shift film pattern and includes a chromium-based material. The portion where the phase shift film pattern is arranged constitutes a phase shift portion, and the exposed portion of the transparent substrate constitutes a light transmitting portion.

Examples of the phase shift film pattern include a line and gap pattern or a hole pattern.

[Example]

Hereinafter, the present invention will be described more specifically based on examples.

(Example 1 and Comparative Example 1)

In Example 1 and Comparative Example 1, a phase shift mask substrate having a phase shift film (material: MoSiN) and an etching mask film on a transparent substrate 2 and a phase shift mask manufactured using the phase shift mask substrate were performed. Instructions.

Furthermore, the phase shift mask substrate 1 of Example 1 introduced a reactive gas (sputtering gas) from a gas introduction port disposed downstream of a sputtering target containing molybdenum silicide (Mo: Si = 1: 4). ), And its phase shift film 3 is formed by reactive sputtering (at this time, the opening degree of the main valve (not shown) of the buffer chamber BU is adjusted, and N ₂ gas is introduced into the second sputtering chamber SP2) For manufacturing, in contrast, the phase shift mask substrate of Comparative Example 1 introduced a reactive gas from a gas introduction port disposed upstream of a sputtering target containing molybdenum silicide (Mo: Si = 1: 4) ( (Sputter gas), and a phase shift film is formed by reactive sputtering (at this time, the opening of the main valve (not shown) of the buffer chamber BU is adjusted, and Ar gas is introduced into the second sputtering chamber SP2), and the two differ from the above.

A. Phase-shifting reticle substrate and manufacturing method thereof

In order to manufacture the phase shift mask substrate 1 of Example 1 and Comparative Example 1 having the above-mentioned configuration, first, a synthetic quartz glass substrate of 8092 size (800 mm × 920 mm) was prepared as the transparent substrate 2.

Then, the transparent substrate 2 is carried into a continuous sputtering apparatus 11 equipped with a sputtering target containing molybdenum silicide (Mo: Si = 1: 4) as shown in FIG. 2, as shown in FIG. 3, on the transparent substrate 2 A phase shift film 3 (film thickness 110 nm) containing molybdenum silicide nitride (MoSiN) is formed on the main surface.

The phase shift film 3 is a second gas introduction port GA12 which is disposed on the downstream side of the first sputtering target 13 containing molybdenum silicide (Mo: Si = 1: 4), and will contain argon (Ar) gas and nitrogen (N ₂ A mixed gas (Ar: 50 sccm, N ₂ : 100 sccm) is introduced into the first sputtering chamber SP1, and the sputtering power is set to 10 kW, and the transfer speed of the transparent substrate 2 is 350 mm / min. It is formed on the transparent substrate 2 by sputtering. The phase shift film 3 (film thickness: 110 nm) was formed by one film formation.

In addition, the film formation of the phase shift film 3 in Example 1 was performed by adjusting the opening degree of the main valve (not shown) of the exhaust device (not shown) connected to the buffer chamber BU from the fifth gas introduction port. GA31 is performed under the condition that nitrogen (N ₂ ) gas is introduced into the second sputtering chamber SP2.

On the other hand, except that the first gas introduction port GA11 disposed on the upstream side of the first sputtering target 13 containing molybdenum silicide (Mo: Si = 1: 4) is set to have the same composition as in Example 1 The mixed gas was introduced at the same flow rate (Ar: 50 sccm, N ₂ : 100 sccm) as in Example 1, and the Ar gas was introduced into the second sputtering chamber SP2 from the fifth gas introduction port GA31. 1 Similarly, a phase shift film (film thickness: 110 nm) formed on the transparent substrate 2 was formed by one film formation, and a phase shift mask base of Comparative Example 1 was obtained.

The phase shift film 3 of the phase shift mask substrate 1 of Example 1 and the phase shift film of the phase shift mask substrate of Comparative Example 1 were analyzed for composition in the depth direction by X-ray photoelectron spectroscopy (XPS).

As a result, in Example 1 and Comparative Example 1, a surface oxide layer (most surface layer 3b) having a film thickness of about 5 nm was formed on the outermost surface layer of the phase shift film and the oxygen content increased toward the film surface side. Outside the vicinity of the interface of the synthetic quartz glass substrate (transparent substrate 2), a main layer 3a having almost no change in the content of each element (Mo, Si, N, O) from a depth of about 5 nm to about 105 nm is formed.

In any of Example 1 and Comparative Example 1, in the main layer 3a, the variation range of the content of each element of molybdenum (Mo), silicon (Si), nitrogen (N), and oxygen (O) was small. And roughly uniform. The content of each element of the main layer 3a of the phase shift film 3 is Mo at 15 atomic%, Si at 38 atomic%, N at 45 atomic%, O at 2 atomic% or less, and the variation of the content of each of them is 5 atomic% or less (The center value (average content) with respect to the content of each element is within ± 2.5 atomic%).

Next, the values of the refractive index (n) and the extinction coefficient (k) of the phase shift films of Example 1 and Comparative Example 1 were measured using a spectroscopic ellipsometer. Spectral scanning is performed at 55 ° and 65 °, and simulation is performed at The mean square error (MSE) is performed under the following conditions: 5.0 or less.

Main layer: Graded layer

Surface layer: Oxide film (Cauchy)

The MSE of Example 1 was 0.880, and the MSE of Comparative Example 1 was 1.034.

FIG. 6 is a graph showing the relationship between the refractive index (n) of the upper part of the main layer and the lower part of the main layer of the phase shift film 3 of the phase shift mask substrate 10 of Example 1 at a wavelength of 190 nm to 1000 nm, and FIG. 7 shows a comparison The relationship between the refractive index (n) of the upper part of the main layer and the lower part of the main layer of the phase shift film of Example 1 at a wavelength of 190 nm to 1000 nm.

As shown in FIG. 6, it can be seen that in this wavelength range, the refractive index (n-Top) of the upper part of the main layer of the phase shift film 3 of the phase-shifting mask substrate 10 of Example 1 is smaller than the refractive index (n-Top) of the lower part of the main layer. Bottom). In particular, the refractive index of the upper part of the main layer is smaller than that of the i-ray (wavelength 365 nm), which is one of the wavelengths of the exposure light source (ultra-high pressure mercury lamp: mixed light of i-rays, h-rays, and g-rays) used in the manufacture of display devices. The refractive index of the lower part of the layer. The refractive index of the upper part of the main layer is 2.60. The refractive index of the lower part of the main layer is 2.74. Refractive index) was -0.14.

On the other hand, as shown in FIG. 7, it can be seen that in this wavelength range, the refractive index (n-Top) of the upper part of the main layer of the phase-shifting film of the phase-shifting mask base of Comparative Example 1 is greater than the refractive index (n- Bottom). In particular, in i-rays (wavelength 365nm), the refractive index of the upper part of the main layer is 2.69, the refractive index of the lower part of the main layer is 2.65, and the difference in refractive index between the lower part of the main layer and the upper part of the main layer (△ n = refraction of the upper part of the main layer) Ratio-refractive index of the lower part of the main layer) is +0.04.

Moreover, in any of Example 1 and Comparative Example 1, the measurement position of the refractive index was set to a depth of about 5 to 7 nm from the outermost surface of the phase shift film on the upper part of the main layer, The measurement position of the refractive index is set to a depth of about 100 to 105 nm from the outermost surface of the phase shift film.

From these results, it is clear that the embodiment 1 in which the phase shift film 3 is formed under the condition that the sputtering gas is supplied from the downstream, and the phase shift film is formed under the condition that the sputtering gas is supplied from the upstream. Compared with Comparative Example 1, the tendency of the refractive index change in the depth direction of the phase shift film is opposite.

In addition, regarding the phase-shifting film of each phase-shifting mask base of Example 1 and Comparative Example 1, the transmittance was measured with a spectrophotometer U-4100 manufactured by Hitachi High-tech Co., and MPM- 100 and the phase difference was measured. It should be noted that the transmittance values in Example 1 and Comparative Example 1 are all Air-based values.

The measurement of the transmittance and phase difference of the phase shift film 3 is based on a substrate (dummy substrate) having a phase shift film. The substrate (dummy substrate) is 6025 size (152 mm ×) provided on the same substrate holder (not shown). A phase shift film 3 (film thickness of 110 nm) is formed on the main surface of the transparent substrate 2 of 152 mm).

As a result, in Example 1 and Comparative Example 1, the transmittance at a wavelength of 365 nm was 5.2%, and the phase difference at a wavelength of 365 nm was 180 degrees.

From this result, it is understood that even if a phase shift film is formed under the condition that a sputtering gas is supplied from downstream, a desired transmittance and phase difference can be obtained.

In addition, regarding the phase shift film 3 of the phase shift mask substrate 10 of Example 1 and Comparative Example 1, the reflectance was measured with a spectrophotometer U-4100 manufactured by Hitachi High-tech Corporation.

As a result, the reflectance spectrum of Example 1 at a wavelength of 200 nm to 800 nm was substantially the same as that of Comparative Example 1. From this result, it is understood that a desired reflectance spectrum can be obtained even if a phase shift film is formed under the condition that a sputtering gas is supplied from the downstream.

Next, a light-shielding layer and an anti-reflection layer serving as an etching masking film 4 are formed on the phase shift film 3. The light-shielding layer and the anti-reflection layer are adjusted relative to the second sputtering target 14 such that the film surface reflectance is 15% or less and the optical density (OD) is 3.0 or more with respect to a specific wavelength (for example, g-ray). Types, flows, and transparent substrates of the fourth gas introduction port GA22, the sixth gas introduction port GA32, and the eighth gas introduction port GA42 near the chromium target of the third sputtering target 15 and the fourth sputtering target 16 The transfer speed and the sputtering power applied to each sputtering target are adjusted appropriately. A mixed gas containing argon (Ar) gas and nitrogen (N ₂ ) gas is introduced from the fourth gas introduction port GA22, and a mixed gas containing argon (Ar) gas and methane (CH ₄ ) gas is introduced from the sixth gas introduction port GA32. A mixed gas containing argon (Ar) gas and nitric oxide (NO) gas is introduced from the eighth gas introduction port GA42. In addition, the application of the sputtering power to each sputtering target and the introduction of the mixed gas from each gas introduction port are continued until the transparent substrate 2 is transferred to the unloading chamber ULL. The transport speed of the transparent substrate 2 was set to 400 mm / minute.

As a result, a light-shielding layer composed of a laminated film of a chromium nitride film (CrN) with a thickness of 25 nm and a chromium carbide film (CrC) with a thickness of 70 nm and a chromium nitride oxide containing 20 nm in thickness were formed on the phase shift film 3 Laminated film of anti-reflection layer of film (CrON).

In this way, an etch mask film 4 having a multilayer structure is formed, and the etch mask film 4 is sequentially formed on the phase shift film 3 with a light-shielding layer composed of a multilayer film of CrN and CrC, and an anti-reflection layer including CrON.

Then, after the second sputtering chamber and the carry-out chamber are completely separated by a partition plate, the carry-out chamber is restored to the atmospheric pressure state, and the transparent substrate on which the phase shift film 3 and the etching mask film 4 are formed is automatically opened. The sputtering device 11 is taken out.

In this way, a phase shift mask substrate 10 having a phase shift film 3 and an etching mask film 4 formed on the transparent substrate 2 is obtained.

B. Phase-shifting photomask and manufacturing method thereof

In order to manufacture the phase shift masks of Example 1 and Comparative Example 1 using the phase shift mask substrates of Example 1 and Comparative Example 1 manufactured as described above, first, the phase shift masks of Example 1 and Comparative Example 1 were used. On the etching mask film 4 of the base, a resist film 5 is applied using a resist coating apparatus.

Then, a resist film 5 having a film thickness of 1000 nm is formed through the heating and cooling steps.

Thereafter, the resist film 5 is drawn using a laser drawing device, and a line and gap pattern having a line pattern width of 2.0 μm and a gap pattern having a width of 2.0 μm is formed on the etching mask film 4 through development and washing steps. Resist film pattern 5 '.

Then, using the resist film pattern 5 'as a mask, the etching mask film 4 is wet-etched with a chromium etchant containing cerium ammonium nitrate and perchloric acid to form an etching mask film pattern 4'.

Next, using the etching mask film pattern 4 'as a mask, the phase shift film 3 is wet-etched by molybdenum silicide etchant obtained by diluting a mixed solution of ammonium hydrogen fluoride and hydrogen peroxide with pure water to form a phase. Transfer film pattern 3 '.

Then, the resist film pattern 5 'is peeled.

Then, using a resist coating apparatus, the resist film 55 is applied so as to cover the etching mask film pattern 4 ′.

Then, a resist film 55 having a thickness of 1000 nm is formed through the heating and cooling steps.

Thereafter, the resist film 55 is drawn using a laser drawing device, and a resist film pattern 55 'having a line pattern width of 1.0 µm is formed on the etching mask film pattern 4' through the development and washing steps.

Then, using the resist film pattern 55 'as a mask, the etching mask film 4' is wet-etched with a chromium etchant containing cerium ammonium nitrate and perchloric acid to form a phase shift film pattern 3 '. Narrow etching mask pattern 4 ".

Then, the resist film pattern 55 'is peeled.

In this way, a phase shift film pattern 3 ′ obtained by patterning the phase shift film 3 on the transparent substrate 2 is obtained, and an etching mask having a narrower width than the phase shift film pattern 3 ′ is formed on the phase shift film pattern 3 ′. The phase shift mask 50 of Example 1 of the mask film pattern 4 "and the phase shift mask of Comparative Example 1.

Before the resist film pattern 5 'was peeled off, the edge portions of each phase shift film pattern 3' of the phase shift mask 50 of Example 1 and the phase shift mask of Comparative Example 1 were observed with a scanning electron microscope. Etching section.

8 is a sectional photograph of an edge portion of the phase shift film pattern 3 'of the phase shift mask of Example 1, and FIG. 9 is a sectional photograph of an edge portion of the phase shift film pattern 3' of the phase shift mask of Comparative Example 1, FIG. 10 is a cross-sectional view for explaining a cross-sectional angle (θ) used as a judgment index of a cross-sectional shape of an edge portion.

In FIG. 10, the cross section of the phase shift film pattern 3 ′ includes upper, lower, and side edges 23 corresponding to the upper surface, the lower surface, and the side surfaces of the phase shift film pattern 3 ′. In FIG. 10, the auxiliary line 21 indicates The position of the upper side corresponding to the upper surface of the phase shift film pattern 3 ', and the auxiliary line 22 indicates the position of the lower side corresponding to the lower surface of the phase shift film pattern 3'. In this case, it is preferable that the angle θ formed by the straight line connecting the upper side and the side contact point 26 and the position 27 of the side where the height of the film is lowered by two thirds of the film thickness from the upper surface to the upper side. It is in the range of 85 degrees to 120 degrees. In FIG. 10, the auxiliary line 24 indicates a position where a height of two thirds of the film thickness is dropped from the upper surface.

As shown in FIG. 8, the cross-section of the phase shift film pattern 3 ′ of Example 1 has a shape such that a portion in contact with the transparent substrate 2 is completely perpendicular, and a portion in contact with the etching mask film pattern 4 ′ is substantially perpendicular. An angle θ formed by a straight line connecting the contact point between the upper side and the side and the position of the side falling from the upper surface by a height of two-thirds of the film thickness is 85 degrees.

Next, CD unevenness of the phase-shifting film pattern of the phase-shifting mask of Example 1 was measured by SIR8000 manufactured by Seiko Instruments Nano Technology. The measurement of the CD unevenness is measured at a 5 × 5 area with an area of 740 mm × 860 mm except for the peripheral area of the substrate. The CD unevenness is an offset width from a target line and a gap pattern (the width of the line pattern: 2.0 μm, the width of the gap pattern: 2.0 μm). In the following examples and comparative examples, the same apparatus was used for the measurement of CD unevenness.

CDs were all 0.090 μm, which was very good.

As shown in FIG. 9, the cross-section of the phase shift film pattern of Comparative Example 1 was a linear tapered shape. The angle θ formed by the straight line connecting the contact point between the upper side and the side and the position of the side where the height of the film is 2/3 of the film thickness from the upper surface is 135 degrees.

Moreover, it turns out that the CD nonuniformity of the phase shift film pattern of the phase shift mask of the comparative example 1 becomes (0.180 micrometer), and is larger than Example 1.

Next, a light intensity distribution curve at a wavelength of 365 nm of Example 1 and Comparative Example 1 will be simulated for an aerial image of light passing through a phase shift mask formed with a phase shift film pattern having a 2.5 μm square contact hole pattern ( Transmittance distribution).

Compared with Comparative Example 1, the light intensity distribution curve of Example 1 has a steep peak intensity at the center of the contact hole, and shows a large change in light intensity at the pattern boundary portion. The peripheral area outside the junction shows little change in light intensity. Therefore, it can be seen that the phase shift mask of Example 1 exhibits a stronger light intensity tilt than that of Comparative Example 1, and has a higher resolution.

(Example 2)

In the second embodiment, a phase shift mask substrate on which the etching mask film 4 is not formed on the phase shift film 3 as in the first embodiment and a phase shift mask manufactured using the phase shift mask substrate will be described.

A. Phase-shifting reticle substrate and manufacturing method thereof

The phase shift film 3 was formed on the transparent substrate 2 to obtain the phase shift mask substrate 1 of the second embodiment in the same manner as in the first embodiment.

B. Phase-shifting photomask and manufacturing method thereof

In order to manufacture the phase shift mask of Example 2 using the phase shift mask substrate 1 of Example 2 described above, first, the surface of the phase shift film 3 of the phase shift mask substrate 1 of Example 2 was subjected to HMDS (hexamethyldi After the silazane) treatment, the resist film 5 is applied using a resist coating apparatus.

Then, a resist film 5 having a film thickness of 1000 nm is formed through the heating and cooling steps.

Thereafter, the resist film 5 is drawn using a laser drawing device, and the resistance of the line and gap pattern with a line pattern width of 2.0 μm and a gap pattern width of 2.0 μm is formed on the phase shift film 3 through development and washing steps. Etch film pattern 5 '.

Next, using the resist film pattern 5 'as a mask, the phase shift film 3 is wet-etched by using a molybdenum silicide etchant obtained by diluting a mixed solution of ammonium hydrogen fluoride and hydrogen peroxide with pure water to form a phase. Transfer film pattern 3 '.

Then, the resist film pattern 5 'is peeled.

In this way, the phase shift mask 30 of Example 2 having the phase shift film pattern 3 ′ patterned on the transparent substrate 2 is obtained.

The etched cross section of the edge portion of the phase shift film pattern 3 'of the phase shift mask 30 of Example 2 was observed with a scanning electron microscope.

As a result, the cross section of the phase shift film pattern 3 'in Example 2 and the phase shift film pattern in Example 1 The 3 'cross section is a slightly linear cone shape, but the line connecting the top and side contact points and the position of the side where the height of 2/3 of the film thickness drops from the top surface is connected to the top side. The formed angle θ is 120 degrees, which is good.

In addition, as in Example 1, the CDs of the phase shift film patterns 3 'of the phase shift mask of Example 2 were all 0.105 μm, which was good.

(Example 3)

The phase shift mask substrate of Example 3 and the phase shift mask manufactured using the phase shift mask substrate are main valves except for an exhaust device (not shown) that is connected to the buffer chamber BU when a phase shift film is formed. (Not shown) is opened, and a mixed gas (Ar: 50 sccm, N ₂ : 100 sccm) containing argon (Ar) gas and nitrogen (N ₂ ) gas is introduced into the second sputtering chamber SP2 from the fifth gas introduction port GA31. Inside and outside, a phase shift mask base and a phase shift mask were produced in the same manner as in Example 1.

As in Example 1, the values of the refractive index (n) and the extinction coefficient (k) of the phase shift film of Example 3 were measured using a spectroscopic ellipsometer. The results (a graph showing the refractive index at the wavelength of 190 nm to 1000 nm of the upper part and the lower part of the main layer of the phase shift film) are shown in FIG. 11.

As shown in FIG. 11, it can be seen that in this wavelength range, the refractive index (n-Top) of the upper part of the main layer of the phase-shifting film 3 of the phase-shifting mask base of Example 3 is smaller than the refractive index (n-Bottom) of the lower part of the main layer. . In particular, for an i-ray (wavelength 365 nm) which is one of the wavelengths of an exposure light source (ultra-high pressure mercury lamp: mixed light of i-rays, h-rays, and g-rays) used in the manufacture of a display device, the refractive index of the upper part of the main layer is less than The refractive index of the lower part of the main layer, the refractive index of the upper part of the main layer is 2.60, the refractive index of the lower part of the main layer is 2.72, and the difference in refractive index between the lower part of the main layer and the upper part of the main layer (△ n = refractive index of the upper part of the main layer-the main layer) The lower refractive index) is -0.12.

In addition, in Example 3, the transmittance at a wavelength of 365 nm was 5.2%, and the phase difference at a wavelength of 365 nm was 180 degrees. The desired transmittance and phase difference were obtained in the same manner as in Example 1. Regarding the phase shift film of the phase shift mask base of Example 3, the reflectance of the phase shift film was measured in the same manner as in Example 1. As a result, the reflectance spectrum of Example 3 at a wavelength of 200 nm to 800 nm was substantially the same as the reflectance spectrum of Example 1.

Next, similar to Example 1, before the resist film pattern 5 'was peeled off, the etched section of the edge portion of the phase shift film pattern 3' of the phase shift mask 30 of Example 3 was observed with a scanning electron microscope. .

FIG. 12 is a cross-sectional photograph of an edge portion of a phase-shifting film pattern 3 'of a phase-shifting mask of Embodiment 3. FIG.

As shown in FIG. 12, the cross-section of the phase-shifting film pattern 3 ′ of Example 3 has the following shape, that is, the skirt of the portion that is in contact with the transparent substrate 2 is very small and approximately vertical, and is in contact with the etching mask film pattern 4 ′. The section is also roughly vertical. The angle θ formed by the straight line connecting the contact point between the upper side and the side and the position of the side where the height of the film drops from the upper surface by two thirds is 97 degrees.

Moreover, the CD of the phase shift film pattern of the phase shift film of Example 3 was all 0.098 μm, which was very good.

(Example 4)

In Example 4, a phase shift mask substrate was fabricated in the same manner as in Example 1 except that the phase shift film 3 of Example 1 was laminated (a four-layer structure), and a phase shift mask was fabricated using the phase shift mask substrate.

A. Phase-shifting reticle substrate and manufacturing method thereof

As the transparent substrate 2, a synthetic quartz glass substrate having the same size as in Example 1 was prepared.

In Example 4, in the phase shift film formation step, the upstream side of the first sputtering target 13 including molybdenum silicide (Mo: Si = 1: 4) disposed in the sputtering device 11 shown in FIG. The first gas introduction port GA11 introduces a mixed gas (Ar: 30 sccm, N ₂ : 30 sccm) containing argon (Ar) gas and nitrogen (N ₂ ) gas, sets the sputtering power to 4 kW, and transports the transparent substrate 2 The speed was set to 400 mm / minute, and a molybdenum silicide nitride film (MoSiN) with a thickness of 27.5 nm was formed on the transparent substrate 2 by reactive sputtering.

Furthermore, when forming a molybdenum silicide nitride film, the opening degree of the main valve (not shown) of the exhaust device (not shown) connected to the buffer chamber BU is reduced to include argon (Ar) gas and nitrogen. (N ₂ ) gas mixed gas (Ar: 30 sccm, N ₂ : 30 sccm) from the fifth gas introduction port GA31 in the second sputtering chamber SP2 will affect the environment of the first sputtering chamber ( The mixed gas introduced into the second sputtering chamber is in a state of being supplied to the downstream side of the first sputtering target 13).

After the first layer of molybdenum silicide nitride film is formed on the transparent substrate 2, the transparent substrate 2 mounted on a tray (not shown) is transported in the direction opposite to the arrow S and returned to the carry-in chamber LL.

Then, the molybdenum silicide nitride film of the second layer, the third layer, and the fourth layer was formed by the same method as that of the molybdenum silicide nitride film of the first layer, and four layers were formed on the transparent substrate 2. A phase shift film with a total thickness of 110nm of a molybdenum silicide nitride film.

The values of the refractive index (n) and the extinction coefficient (k) of the phase shift film of Example 4 were measured using a spectroscopic ellipsometer. The results (a graph showing the refractive index at the wavelength of 190 nm to 1000 nm of the upper part and the lower part of the main layer of the phase shift film) are shown in FIG. 13.

As shown in FIG. 13, it can be seen that in this wavelength range, the refractive index (n-top) of the upper part of the main layer of the phase-shifting film 3 of the phase-shift mask substrate 10 of Example 4 is smaller than the refractive index (n-Bottom) of the lower part of the main layer. ). In particular, for an i-ray (wavelength 365 nm) which is one of the wavelengths of an exposure light source (ultra-high pressure mercury lamp: mixed light of i-rays, h-rays, and g-rays) used in the manufacture of a display device, the refractive index of the upper part of the main layer is less than The refractive index of the lower part of the main layer, the refractive index of the upper part of the main layer is 2.66, the refractive index of the lower part of the main layer is 2.68, and the difference in refractive index between the lower part of the main layer and the upper part of the main layer (△ n = refractive index of the upper part of the main layer-the main layer) The lower refractive index) is -0.02.

In addition, in Example 4, the transmittance at a wavelength of 365 nm was 5.2%, and the phase difference at a wavelength of 365 nm was 180 degrees. The desired transmittance and phase difference were obtained in the same manner as in Example 1. Regarding the phase shift film of the phase shift mask base of Example 4, the reflectance of the phase shift film was measured in the same manner as in Example 1. As a result, the reflectance spectrum of Example 4 at a wavelength of 200 nm to 800 nm was substantially the same as the reflectance spectrum of Example 1.

Next, as in Example 1, before the resist film pattern 5 'was peeled off, the edge portion of the phase shift film pattern 3' of the phase shift mask 50 of Example 4 was observed with a scanning electron microscope. Etched sections.

FIG. 14 is a cross-sectional photograph of an edge portion of a phase-shifting film pattern 3 'of a phase-shifting mask of Embodiment 4. FIG.

As shown in FIG. 14, the cross-section of the phase-shifting film pattern 3 ′ of Example 4 has a shape such that the skirt is placed at a portion that is in contact with the transparent substrate 2, and is substantially perpendicular to the portion that is in contact with the etching mask film pattern. An angle θ formed by a straight line connecting the contact point between the upper side and the side and the position of the side falling from the upper surface by a height of two-thirds of the film thickness is 105 degrees.

Then, an etching mask film 4 is formed on the phase shift film 3 by the same method as in Example 1, and a phase shift mask substrate having the phase shift film 3 and the etching mask film 4 formed on the transparent substrate 2 is obtained. Furthermore, a phase shift mask was produced by the same method as in Example 1.

Moreover, the CD of the phase shift film pattern of the phase shift film of Example 4 was all 0.096 μm, which was good.

In addition, in this Example 4, the phase shift film 3 is a laminated structure, and the film forming conditions of each layer are the same. However, in the film forming conditions of each layer, the more toward the upper layer, the more it becomes "rich in activity." Gas environment (environment that contains more active gas) ".

The examples and comparative examples have been described above.

The difference (△ n) between the refractive index of the lower part of the main layer of the phase shift film 3 of the above Examples 1, 3, 4 and the comparative example at a wavelength of 365 nm relative to the refractive index of the upper part of the main layer at a wavelength of 365 nm (Δn) was formed using the difference The relationship between the cross-sectional angles of the cross-section angles of the phase-shifting film pattern sections of the phase-shifting mask base made of the phase-shifting mask substrate with the phase-shifting film 3 is shown in FIG. 15.

As shown in FIG. 15, when Δn is negative, that is, the refractive index of the phase shift film 3 at the upper part of the main layer at a wavelength of 365 nm is smaller than the refractive index of the lower part of the main layer at a wavelength of 365 nm. (Section angle) is 85 degrees or more and 120 degrees or less. Therefore, the CD unevenness of the phase shift mask is also good. It is more preferable that Δn (n-TOP-n-Bottom) is -0.20 or more and -0.01 or less, and more preferably -0.15 or more and 0.02 or less.

In order to obtain good CD characteristics, the phase shift mask must be tapered with the suppression profile. (Section angle> 90 degrees) Similarly, an inverted cone shape (section angle <90 degrees) is suppressed. If Δn (that is, the difference between the refractive index of the lower part of the main layer and the refractive index of the upper part of the main layer with respect to the wavelength of 365 nm) becomes negative, the cross-sectional shape of the phase shift film pattern becomes an inverted cone shape If it is too much, it tends to fail to obtain good CD characteristics similar to the cross-sectional cone shape. Therefore, in order to suppress the inverted cone shape, Δn (n-TOP-n-Bottom) is preferably -0.20 or more, and more preferably -0.15 or more.

Moreover, in the said embodiment, although the example of the phase shift mask base for manufacture of a display device, and the phase shift mask for manufacture of a display device was demonstrated, it is not limited to this. The phase shift reticle substrate and the phase shift reticle of the present invention can also be applied to semiconductor device manufacturing, MEMS (microelectromechanical system) manufacturing, printed substrate use, and the like.

Moreover, in the said embodiment, although the example in which the size of the transparent substrate was 8092 size (800mm * 920mm) was demonstrated, it is not limited to this, It can also be other sizes. In the case of a phase shift mask substrate used for display device manufacturing, a large transparent substrate is used. The size of the transparent substrate is 10 inches or more on one side. The phase shift mask substrate used for display device manufacturing is transparent. The size of the substrate is, for example, 330 mm × 450 mm or more and 2280 mm × 3130 mm or less.

In the case of a phase shift mask substrate for semiconductor device manufacturing, MEMS manufacturing, and printed circuit boards, a small transparent substrate is used, and the size of the transparent substrate is 9 inches or less on one side. The size of the transparent substrate of the phase shift mask base used in the above-mentioned application is, for example, 63.1 mm × 63.1 mm or more and 228.6 mm × 228.6 mm or less. Generally, 6025 size (152mm × 152mm) or 5009 size (126.6mm × 126.6mm) is used for semiconductor manufacturing and MEMS manufacturing, and 7012 size (177.4mm × 177.4mm) or 9012 size (228.6mm × 228.6nm) is used for printed substrates. ).

In addition, in the above embodiments, the surface layer formed by oxidizing the surface of the phase shift film has been described, but it is not limited to this, and the film density, The outermost layer with different film composition, crystal structure, surface morphology, and surface roughness.

Moreover, in the above embodiment, the example in which the refractive index of the phase shift film is measured using a spectroscopic ellipsometer under simulated conditions of an oxide layer and a gradient layer (Graded Layer) has been described, but it is not limited to this. For example, when an etching mask film of a thin film that can be measured by a spectroscopic ellipsometry is formed on a phase shift film, it can be performed under consideration of simulation conditions of the etching mask film.

Claims (14)

A phase shift mask substrate, characterized in that: a phase shift film containing metal, silicon, and nitrogen is formed on a transparent substrate, and the phase shift film has a main layer having a substantially uniform composition ratio of each element in the film depth direction. And the refractive index at the wavelength of 365 nm of the upper part of the main layer on the uppermost surface layer side measured by a spectroscopic ellipsometer as the outermost layer of the surface oxide layer of the main layer, which is smaller than the main surface of the transparent substrate side The refractive index of the lower part of the layer has a wavelength of 365 nm, and the variation of the content of each element in the depth direction of the film of the main layer is within ± 2.5 atomic% relative to each average content. For example, the phase shift mask substrate of claim 1, wherein the difference (Δn) between the refractive index of the lower part of the main layer at a wavelength of 365 nm and the refractive index of the upper part of the main layer at a wavelength of 365 nm is -0.01 or less. For example, the phase shift mask substrate of claim 1, wherein the difference (Δn) between the refractive index of the lower part of the main layer at a wavelength of 365 nm and the refractive index of the upper part of the main layer at a wavelength of 365 nm is -0.10 or less. The phase shift mask substrate according to any one of claims 1 to 3, wherein the refractive index of the upper part of the main layer at a wavelength of 365 nm is 2.50 or more. The phase shift mask substrate according to any one of claims 1 to 3, wherein an etching mask film is formed on the phase shift film. The phase shift mask substrate according to claim 5, wherein the etching mask film has a light-shielding film, and the light-shielding film has a light-shielding function. The phase shift mask substrate as claimed in claim 5, wherein the etching mask film is a material containing chromium. The phase shift mask substrate according to any one of claims 1 to 3, wherein the phase shift mask substrate is used to make an original version of the phase shift mask by wet etching. A method for manufacturing a phase-shifting photomask substrate, characterized in that the phase-shifting film containing metal, silicon, and nitrogen is formed on a transparent substrate by a sputtering method using a continuous sputtering device. The film has a main layer having a substantially uniform composition ratio of each element in the film depth direction and an outermost surface layer oxidized. The film formation of the above main layer uses a metal silicide sputtering target containing metal and silicon, and uses inertness. In the reactive sputtering of a mixed gas of a gas and a nitrogen-containing active gas, the environment in which the latter half of the main layer has more nitrogen-containing active gas than the first half of the film is formed so that The refractive index at a wavelength of 365 nm of the upper part of the main layer on the most surface layer side measured by a spectroscopic ellipsometer is smaller than the refractive index at a wavelength of 365 nm of the lower part of the main layer on the transparent substrate side. The flow rate of the active gas, and the variation of the content of each element in the depth direction of the film of the main layer is within ± 2.5 atomic% with respect to each average content. For example, the method for manufacturing a phase-shifting mask substrate according to claim 9, wherein the film-forming of the phase-shifting film is formed by supplying the transparent substrate near the sputtering target from a direction in which the transparent substrate is transported on a downstream side with respect to the sputtering target. The nitrogen-containing active gas is carried out in an environment where the latter half of the film formation contains more nitrogen-containing active gas than the first half of the film formation. The method for manufacturing a phase shift mask base according to claim 9 or 10, wherein the refractive index at a wavelength of 365 nm of the lower part of the main layer on the transparent substrate side is set to the wavelength of the upper part of the main layer on the outermost layer side. The difference (Δn) of the refractive index at 365 nm is adjusted so that the flow rate of the active gas containing nitrogen is adjusted to be -0.01 or less. The method for manufacturing a phase shift mask base according to claim 9 or 10, wherein the refractive index at a wavelength of 365 nm of the lower part of the main layer on the transparent substrate side is set to the wavelength of the upper part of the main layer on the outermost layer side. The difference (Δn) in the refractive index at 365 nm is adjusted to -0.10 or less so that the flow rate of the active gas containing nitrogen is adjusted. The method for manufacturing a phase shift mask substrate according to claim 9 or 10, wherein after the film forming step of forming the phase shift film, there is a film forming step of forming an etching mask film on the phase shift film. A method for manufacturing a phase-shifting mask, which uses the phase-shifting mask substrate according to any one of claims 1 to 8, or by using the phase-shifting mask substrate according to any one of claims 9 to 13. A phase-shifting photomask substrate prepared by the method, and patterning the phase-shifting film by wet etching to make a phase-shifting photomask.