KR20200105417A - Photomask blank, method of manufacturing photomask and method of manufacturing display device - Google Patents

Abstract

The present invention relates to a photomask blank which suppresses bleeding at the interface with a transparent substrate onto a transfer pattern formed on a transparent substrate by wet etching a thin film for forming a pattern at an over-etching time. The photomask blank is an original plate for forming a photomask, and the photomask comprises the transfer pattern on the transparent substrate obtained by wet etching the thin film for forming a pattern. The thin film for forming a pattern contains a transition metal, silicon, oxygen, and nitrogen, and the oxygen content obtained by analysis by XPS is 1 atomic% or more and 70 atomic% or less. In addition, when the interface is defined as the position where the content of the transition metal contained in the thin film for forming a pattern obtained by analysis by XPS is 0 atomic%, the ratio of nitrogen to oxygen in a region within 30 nm from the interface toward the surface of the thin film for forming a pattern has a maximum value.

Description

A photomask blank, a method for manufacturing a photomask, and a method for manufacturing a display device TECHNICAL FIELD [PHOTOMASK BLANK, METHOD OF MANUFACTURING PHOTOMASK AND METHOD OF MANUFACTURING DISPLAY DEVICE}

The present invention relates to a photomask blank, a method for manufacturing a photomask, and a method for manufacturing a display device.

In recent years, in a display device such as a flat panel display (FPD), which is a representative of a liquid crystal display (LCD), high definition and high-speed display are rapidly progressing along with a large screen and a wide viewing angle. One of the elements necessary for this high definition and high-speed display is the production of electronic circuit patterns such as elements and wirings with fine and high dimensional accuracy. Photolithography is often used for patterning the electronic circuit for a display device. Accordingly, there is a need for a phase shift mask for manufacturing a display device in which a fine and high-precision pattern is formed.

For example, in Patent Document 1, a thin film containing molybdenum silicide is wetted with an etching solution obtained by diluting phosphoric acid, hydrogen peroxide, and ammonium fluoride in water to minimize damage to a transparent substrate during wet etching of a thin film containing molybdenum silicide. A blank mask for etching a flat panel display and a photo mask using the same are disclosed.

In addition, in Patent Document 2, for the purpose of improving the accuracy of the pattern, the phase shift film 104 includes films of different compositions that can be etched in the same etching solution, and each film of a different composition is stacked one or more times. Disclosed are a phase inversion blank mask and a photo mask formed in the form of at least two or more multilayer films or continuous films.

Patent Document 1: Korean Patent Laid-Open Publication No. 10-2016-0024204 Patent Document 2: Japanese Patent Laid-Open Publication No. 2017-167512

In recent years, as a phase shift mask blank for manufacturing this type of display device, in order to reliably transfer a fine pattern of less than 2.0 μm, the transmittance of the phase shift film to exposure light is 10% or more, and further has optical properties of 20% or more. As the phase shift film, it has been studied to use a phase shift film containing oxygen at a certain ratio (eg, 5 atomic% or more, further 10 atomic% or more).

Further, a phase shift mask blank for manufacturing a display device has a significantly larger size than a phase shift mask blank for a semiconductor device. In the case of forming a phase shift film pattern on a phase shift film of such a large sized phase shift mask blank, even if wet etching is performed in the time from the phase shift film pattern to the exposure of the transparent substrate (just etching time), in-plane distribution It is difficult to avoid the CD deviation of greater than 100 nm. In order to reduce the CD deviation of the phase shift film pattern to less than 100 nm, it is required to perform wet etching for a time longer than the just etching time (over etching time).

When a phase shift film having such an oxygen content of a predetermined or higher, for example, 5 atomic% or higher, and further 10 atomic% or higher, is patterned by wet etching at an over-etching time, a wet etching solution is formed at the interface between the phase shift film and the transparent substrate. It penetrated, and it was found that the etching of the interface portion proceeds rapidly. The cross-sectional shape of the edge portion of the formed phase shift film pattern became a shape in which so-called erosion occurs due to permeation of the wet etching solution.

In the case of a shape in which erosion has occurred in the cross-sectional shape of the edge portion of the phase shift film pattern, the phase shift effect becomes weak. Therefore, the phase shift effect cannot be sufficiently exhibited, and a fine pattern of less than 2.0 μm cannot be stably transferred. When the oxygen content in the phase shift film is set to a predetermined or higher, for example, 5 atomic% or higher, further 10 atomic% or higher, it is difficult to strictly control the cross-sectional shape of the edge portion of the phase shift film pattern, and control the line width (CD). It was very difficult.

In addition, there is a similar problem when forming a light-shielding pattern on a light-shielding film by wet etching in a binary mask blank provided with a light-shielding film containing a transition metal, silicon, oxygen, and nitrogen.

The present invention has been made in order to solve the above conventional problems, and a photomask blank in which permeation at the interface with the transparent substrate is suppressed in a transfer pattern formed on a transparent substrate by wet etching a thin film for pattern formation at an over-etching time. , A photomask manufacturing method and a display device manufacturing method are provided.

In order to solve these problems, the present inventors have carefully examined a means for suppressing penetration at the interface with the transparent substrate in the transfer pattern formed on the transparent substrate by wet etching the pattern forming thin film at an over-etching time. In the thin film for pattern formation containing transition metal, silicon, oxygen, and nitrogen, the inventors initially thought that the absolute amount of oxygen in the thin film for pattern formation is the main cause of permeation at the interface with the transparent substrate. Was doing. However, even if the absolute amount of oxygen in the thin film for pattern formation was about the same, there were some occurrences of permeation at the interface with the transparent substrate and no occurrence. As a result of further investigation, the present inventors have found that the ratio of nitrogen and oxygen in the composition region of the thin film for pattern formation formed on the interface side with the transparent substrate is largely related to the permeation at the interface with the transparent substrate. . In addition, the present inventors further studied, and the content of oxygen obtained by analyzing by XPS (X-ray Photoelectron Spectroscopy: X-ray photoelectron spectroscopy) in the thin film for pattern formation was 1 atomic% or more and 70 atomic% or less (in particular, oxygen The surface of the pattern forming thin film from the interface is defined as the position where the content rate of is 5 atomic% or more and 70 atomic% or less) and the content rate of the transition metal contained in the pattern forming thin film obtained by analyzing by XPS is 0 atomic%. If the ratio of nitrogen to oxygen is configured to have a maximum value in the region within 30 nm toward the direction, even if the transfer pattern is formed by wet etching the pattern forming thin film at the over-etching time, the transfer pattern is at the interface with the transparent substrate. It was found that the permeation of blood was suppressed.

The present inventors speculate as follows for the reason why the permeation at the interface with the transparent substrate is suppressed by the above-described configuration. When the thin film for pattern formation is measured by XPS, as a characteristic of the measurement, a composition gradient region in which the composition of the thin film has a gradient in the region from the interface with the transparent substrate defined by the XPS measurement to 30 nm appears. The transition metal and silicon in the pattern forming thin film are components derived from the target, and the composition ratio thereof becomes almost similar to the composition ratio of the target. On the other hand, both oxygen and nitrogen in the thin film for pattern formation are components originating from gas. Since the amount of gas that can be included in the pattern forming thin film is limited, it is thought that the amount of oxygen decreases when the amount of nitrogen contained increases. Further, while oxygen is an element that accelerates the etching rate of wet etching, nitrogen is an element that slows the etching rate of wet etching. Therefore, the ratio of nitrogen to oxygen (N/O) becomes important in the characteristics of the thin film for pattern formation. In the region within 30 nm from the interface with the transparent substrate specified by XPS measurement, if a thin film for pattern formation having a maximum value of nitrogen to oxygen (N/O), an etching rate appropriately near the interface with the transparent substrate It is speculated that erosion can be suppressed by slowing down and suppressing permeation.

In addition, these speculations are based on knowledge at the present stage and do not limit the scope of the present invention.

The present invention has been made as a result of the close examination as described above, and includes the following configurations.

(Configuration 1)

As a photo mask blank comprising a thin film for pattern formation on a transparent substrate,

The photomask blank is an original plate for forming a photomask, and the photomask is a photomask including a transfer pattern on the transparent substrate obtained by wet etching the thin film for pattern formation,

The pattern forming thin film contains a transition metal, silicon, oxygen, and nitrogen, and the oxygen content obtained by analysis by XPS is 1 atomic% or more and 70 atomic% or less, and the transparent substrate and the pattern When the interface of the forming thin film is defined as a position where the content rate of the transition metal included in the pattern forming thin film obtained by analyzing by the XPS is 0 atomic%, 30 nm from the interface toward the surface of the pattern forming thin film A photo mask blank, characterized in that the ratio of nitrogen to oxygen has a maximum value in the region within.

(Configuration 2)

The photomask blank according to Configuration 1, wherein the transition metal is molybdenum.

(Configuration 3)

The photomask blank according to Configuration 1 or 2, wherein the oxygen content is 5 atomic% or more and 70 atomic% or less.

(Configuration 4)

The photomask blank according to any one of Configurations 1 to 3, wherein the nitrogen content is 35 atomic% or more and 60 atomic% or less.

(Configuration 5)

The photomask blank according to any one of Configurations 1 to 4, wherein the pattern formation thin film includes a columnar structure.

(Configuration 6)

The pattern formation thin film is a phase shift film having optical properties of a transmittance of 1% or more and 80% or less and a phase difference of 160° or more and 200° or less with respect to a representative wavelength of exposure light. Photo mask blank described in one.

(Configuration 7)

The photomask blank according to any one of Configurations 1 to 6, wherein an etching mask film having different etching selectivity with respect to the pattern forming thin film is provided on the pattern forming thin film.

(Configuration 8)

The photo mask blank according to Configuration 7, wherein the etching mask film contains a material containing chromium and substantially not containing silicon.

(Configuration 9)

The step of preparing the photomask blank according to any one of configurations 1 to 6, and

Forming a resist film on the pattern forming thin film, wet etching the pattern forming thin film using the resist film pattern formed with the resist film as a mask, and forming the transfer pattern on the transparent substrate The manufacturing method of the photomask made into.

(Configuration 10)

The step of preparing the photomask blank according to configuration 7 or 8, and

Forming a resist film on the etching mask film, wet etching the etching mask film using the resist film pattern formed from the resist film as a mask, and forming an etching mask film pattern on the pattern forming thin film;

And forming the transfer pattern on the transparent substrate by wet etching the pattern forming thin film using the etching mask film pattern as a mask.

(Composition 11)

A photomask obtained by the method for manufacturing a photomask according to configuration 9 or 10 is mounted on a mask stage of an exposure apparatus, and the transfer pattern formed on the photomask is exposed and transferred to a resist film formed on a display device substrate. A method of manufacturing a display device comprising: a.

According to the photomask blank according to the present invention, even if the pattern forming thin film is wet etched at an over-etching time, it is possible to pattern the pattern forming thin film with a good cross-sectional shape in which permeation at the interface with the transparent substrate is suppressed. can do. Further, by wet etching, a patterning thin film can be formed into a patternable photomask blank in a cross-sectional shape having a small CD variation in in-plane distribution.

Further, according to the method of manufacturing a photo mask according to the present invention, a photo mask is manufactured using the photo mask blank described above. Therefore, it is possible to manufacture a photo mask including a good transfer pattern. In addition, it is possible to manufacture a photomask including a transfer pattern having a small CD variation in in-plane distribution. This photo mask can cope with miniaturization of line and space patterns or contact holes.

Further, according to the method of manufacturing a display device according to the present invention, a display device is manufactured using a photomask manufactured using the photomask blank described above or a photomask obtained by the manufacturing method of the photomask described above. Accordingly, a display device including a fine line and space pattern or a contact hole can be manufactured.

1 is a schematic diagram showing a film configuration of a phase shift mask blank according to a first embodiment.
2 is a schematic diagram showing a film configuration of a phase shift mask blank according to a second embodiment.
3 is a schematic diagram showing a manufacturing process of the phase shift mask according to the third embodiment.
4 is a schematic diagram showing a manufacturing process of the phase shift mask according to the fourth embodiment.
5 is a diagram showing a composition analysis result in the depth direction of the phase shift mask blank of Example 1. FIG.
6 is a cross-sectional photograph of the phase shift mask of Example 1. FIG.
7 is a cross-sectional photograph of the phase shift mask of Example 2. FIG.
8 is a diagram showing a composition analysis result in the depth direction of the phase shift mask blank of Example 3. FIG.
9 is a cross-sectional photograph of the phase shift mask of Example 3. FIG.
10 is a cross-sectional photograph of a phase shift mask of Comparative Example 1. FIG.
11 is a diagram showing a distance from a substrate interface and an N/O ratio by XPS for the phase shift mask blanks of Examples 1 and 2 and Comparative Example 1. FIG.
12 is a diagram showing a distance from a substrate interface and an N/O ratio by XPS for the phase shift mask blank of Example 3. FIG.

Hereinafter, each embodiment of the present invention will be described. In each embodiment, a case where the photo mask blank is a phase shift mask blank and the thin film for pattern formation is a phase shift film is described, but the content of the present invention is not limited thereto.

Embodiment 1. 2.

In Embodiments 1 and 2, a phase shift mask blank is described. In the phase shift mask blank of the first embodiment, a phase shift mask including a phase shift film pattern is formed on a transparent substrate by wet etching the phase shift film using an etching mask film pattern in which a desired pattern is formed on the etching mask film as a mask. It is the original to do. In addition, the phase shift mask blank of Embodiment 2 is for forming a phase shift film including a phase shift film pattern on a transparent substrate by wet etching the phase shift film using a resist film pattern in which a desired pattern is formed on the resist film as a mask. It is the original.

1 is a schematic diagram showing a film configuration of a phase shift mask blank 10 according to a first embodiment.

The phase shift mask blank 10 shown in FIG. 1 includes a transparent substrate 20, a phase shift film 30 formed on the transparent substrate 20, and an etching mask film 40 formed on the phase shift film 30. Equipped.

2 is a schematic diagram showing the film configuration of the phase shift mask blank 10 according to the second embodiment.

The phase shift mask blank 10 shown in FIG. 2 includes a transparent substrate 20 and a phase shift film 30 formed on the transparent substrate 20.

Hereinafter, the transparent substrate 20, the phase shift film 30, and the etching mask film 40 constituting the phase shift mask blank 10 of the first and second embodiments will be described.

The transparent substrate 20 is transparent to exposure light. When there is no surface reflection loss, the transparent substrate 20 has a transmittance of 85% or more with respect to exposure light, preferably 90% or more. The transparent substrate 20 includes a material containing silicon and oxygen, and is made of a glass material such as synthetic quartz glass, quartz glass, aluminosilicate glass, soda lime glass, and low thermal expansion glass (SiO ₂ -TiO ₂ glass, etc.). Configurable. When the transparent substrate 20 is made of low thermal expansion glass, a change in the position of the phase shift film pattern due to thermal deformation of the transparent substrate 20 can be suppressed. In addition, the transparent substrate 20 for phase shift mask blank used for a display device is generally a rectangular substrate, and the length of the short side of the transparent substrate is 300 mm or more. The present invention is a phase shift mask blank capable of providing a phase shift mask capable of stably transferring a fine phase shift film pattern formed on a transparent substrate, for example, less than 2.0 μm, even if the length of the short side of the transparent substrate is larger than 300 mm to be.

The phase shift film 30 is made of a transition metal silicide-based material containing a transition metal, silicon, oxygen, and nitrogen. As the transition metal, molybdenum (Mo), tantalum (Ta), tungsten (W), titanium (Ti), zirconium (Zr), and the like are preferable. When nitrogen is contained, since the refractive index increases, it is preferable in that the film thickness for obtaining a retardation can be made thin. In addition, if the content of nitrogen contained in the phase shift film 30 is increased, the absorption coefficient of the complex refractive index becomes large, and high transmittance cannot be realized. The content rate of nitrogen contained in the phase shift film 30 is preferably 35 atomic% or more and 60 atomic% or less. More preferably, 37 atomic% or more and 55 atomic% or less, and still more preferably 40 atomic% or more and 50 atomic% or less is desired.

Examples of the transition metal silicide-based material include oxynitride of transition metal silicide and oxynitride carbide of transition metal silicide. In addition, if the transition metal silicide-based material is a molybdenum silicide-based material (MoSi-based material), a zirconium silicide-based material (ZrSi-based material), or a molybdenum zirconium silicide-based material (MoZrSi-based material), an excellent pattern cross-sectional shape by wet etching is obtained. It is preferable in that it is easy to obtain.

In addition, the phase shift film 30 may contain other light element components such as carbon and helium for the purpose of reducing film stress and controlling the wet etching rate in addition to oxygen and nitrogen described above.

The phase shift film 30 has a function of adjusting the reflectance of light incident from the transparent substrate 20 side (hereinafter, it may be described as a back surface reflectance), and a function of adjusting the transmittance and phase difference of exposure light. Has.

The phase shift film 30 can be formed by sputtering.

The transmittance of the phase shift film 30 with respect to the exposure light satisfies a value required for the phase shift film 30. The transmittance of the phase shift film 30 is preferably 1% or more and 80% or less, more preferably 5% or more and 70% or less with respect to light of a predetermined wavelength (hereinafter referred to as a representative wavelength) included in the exposure light. If it is 10% or more and 60% or less, it is more preferable. That is, when the exposure light is a composite light including light in a wavelength range of 313 nm or more and 436 nm or less, the phase shift film 30 has the above-described transmittance for light having a representative wavelength included in the wavelength range. For example, when the exposure light is a composite light including i-line, h-line and g-line, the phase shift film 30 has the above-described transmittance for any one of i-line, h-line and g-line.

The transmittance of the phase shift film 30 can be adjusted by the atomic ratio of the transition metal and silicon contained in the phase shift film 30. In order to make the transmittance of the phase shift film 30 the transmittance, the atomic ratio of the transition metal and silicon is configured to be 1:1 or more and 1:15 or less. In order to increase the tolerability (washing resistance) of the phase shift film 30, the atomic ratio of the transition metal and silicon is preferably 1:2 or more and 1:15 or less, more preferably 1:4 or more and 1:10 or less. Do.

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

The phase difference of the phase shift film 30 with respect to the exposure light satisfies a value required for the phase shift film 30. The phase difference of the phase shift film 30 is preferably 160° or more and 200° or less, and more preferably 170° or more and 190° or less with respect to light having a representative wavelength included in the exposure light. With this characteristic, the phase of light having a representative wavelength included in the exposure light can be changed within a range of 160° or more and 200° or less. Accordingly, a phase difference of 160° or more and 200° or less occurs between the light of the representative wavelength transmitted through the phase shift film 30 and the light of the representative wavelength transmitted only the transparent substrate 20. That is, when the exposure light is a composite light including light in a wavelength range of 313 nm or more and 436 nm or less, the phase shift film 30 has the above-described phase difference with respect to light of a representative wavelength included in the wavelength range. For example, when the exposure light is a composite light including i-line, h-line and g-line, the phase shift film 30 has the phase difference described above with respect to any one of i-line, h-line and g-line.

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

The reflectance of the back surface of the phase shift film 30 is 15% or less in the wavelength range of 365 nm to 436 nm, and is preferably 10% or less. Further, the reflectance of the back surface of the phase shift film 30 is preferably 20% or less with respect to the light in the wavelength range of 313 nm to 436 nm, and more preferably 17% or less when the j-line is included in the exposure light. More preferably, it is preferably 15% or less. Further, the reflectance of the back surface of the phase shift film 30 is preferably 0.2% or more in the wavelength range of 365 nm to 436 nm, and preferably 0.2% or more with respect to the light in the wavelength range of 313 nm to 436 nm.

The back surface reflectance can be measured using a spectrophotometer or the like.

The content rate of oxygen contained in the phase shift film 30 is adjusted so that the phase shift film 30 becomes the above-described phase difference and transmittance, and if necessary, the phase shift film 30 becomes the above-described back surface reflectance. Specifically, the phase shift film 30 is configured such that the oxygen content is 1 atomic% or more and 70 atomic% or less. The oxygen content of the phase shift film 30 is preferably 5 atomic% or more and 70 atomic% or less, and further preferably 10 atomic% or more and 60 atomic% or less. This phase shift film 30 may be composed of a plurality of layers or may be composed of a single layer. The phase shift film 30 composed of a single layer is preferable in that an interface is difficult to be formed in the phase shift film 30 and the cross-sectional shape can be easily controlled. On the other hand, the phase shift film 30 composed of a plurality of layers is preferable in terms of easy film formation.

Further, light elements of nitrogen or oxygen contained in the phase shift film 30 may be uniformly included in the film thickness direction of the phase shift film 30, or may increase or decrease stepwise or continuously. In addition, it is preferable that the content of nitrogen and the content of oxygen be set to the above-described predetermined content in a region of 50% or more of the thickness of the phase shift film 30.

In addition, the phase shift film 30 is a position where the content of the transition metal contained in the phase shift film 30 obtained by analyzing the interface between the transparent substrate 20 and the phase shift film 30 is 0 atomic%. When defined as, the ratio of nitrogen to oxygen has a maximum value in a region within 30 nm from this interface toward the surface of the phase shift film 30. In addition, this maximum value is not limited to the maximum value in the mathematical sense, and as shown in FIG. 9, it is believed that the change in N/O seen from the side of the transparent substrate changes from an increase to a decrease in the region within 30 nm of the interface. It shall include possible points.

Further, the phase shift film 30 of the phase shift mask blank 10 is required to have high chemical resistance (washing resistance). It is effective to increase the film density in order to increase the tolerability (washing resistance) of the phase shift film 30. The film density and film stress of the phase shift film 30 are correlated, and in consideration of resistance to weakening (washing resistance), the film stress of the phase shift film 30 is preferably higher. On the other hand, as for the film stress of the phase shift film 30, it is necessary to take into account a positional shift when the phase shift film pattern is formed and the loss of the phase shift film pattern. From the above viewpoint, the film stress of the phase shift film 30 is preferably 0.2 GPa or more and 0.8 GPa or less, and more preferably 0.4 GPa or more and 0.8 GPa or less.

In addition, it is preferable that the phase shift film 30 of the phase shift mask blank 10 includes a columnar structure. The columnar structure can be confirmed by cross-sectional SEM observation of the phase shift film 30. That is, the columnar structure means that the particles of the transition metal silicide compound containing the transition metal constituting the phase shift film 30, silicon, oxygen, and nitrogen are in the thickness direction of the phase shift film 30 (the particles It refers to a state including a columnar particle structure extending toward the deposition direction). By making the phase shift film 30 a columnar structure, side etching at the time of wet etching the phase shift film 30 can be suppressed effectively, and the pattern cross-sectional shape can be made more favorable. Further, as a preferred form of the columnar structure, it is preferable that columnar particles extending in the film thickness direction are irregularly formed in the film thickness direction. More preferably, it is preferable that the columnar particles of the phase shift film 30 have an uneven length in the film thickness direction. In the phase shift film 30, it is preferable that the coarse portions (hereinafter simply referred to as "coarse portions") having a relatively lower density than the columnar particles are continuously formed in the film thickness direction.

The etching mask film 40 is disposed above the phase shift film 30 and includes a material having etching resistance (different etch selectivity) to an etchant for etching the phase shift film 30. Further, the etching mask film 40 may have a function of blocking transmission of exposure light, and the reflectance of the film surface of the phase shift film 30 to the light incident from the phase shift film 30 side is 350 nm to 436 nm. The film may have a function of reducing the reflectance by filming so as to be 15% or less in the reverse direction. It is preferable that the etching mask film 40 is made of a material (chromium-based material) containing chromium and substantially not containing silicon. As the chromium-based material, more specifically, a material containing chromium (Cr) or chromium (Cr) and at least one of oxygen (O), nitrogen (N) and carbon (C) may be mentioned. Alternatively, a material containing chromium (Cr), at least one of oxygen (O), nitrogen (N), and carbon (C), and containing fluorine (F) may be mentioned. For example, examples of the material constituting the etching mask film 40 include Cr, CrO, CrN, CrF, CrCO, CrCN, CrON, CrCON, and CrCONF.

The etching mask film 40 can be formed by sputtering.

When the etching mask film 40 has a function of blocking transmission of exposure light, in the portion where the phase shift film 30 and the etching mask film 40 are laminated, the optical density for exposure light is preferably 3.0 or more. , More preferably 3.5 or more, still more preferably 4.0 or more.

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

The etching mask film 40 may include a single film having a uniform composition depending on the function, may include a plurality of films having different compositions, or may include a single film whose composition continuously changes in the thickness direction. .

In addition, the phase shift mask blank 10 shown in FIG. 1 includes an etching mask film 40 on the phase shift film 30, but includes an etching mask film 40 on the phase shift film 30, and etching The present invention can also be applied to a phase shift mask blank provided with a resist film over the mask film 40.

In addition, in the phase shift mask blank 10, a composition gradient region is formed at the interface between the phase shift film 30 and the etching mask film 40, and in the composition gradient region, the ratio of oxygen is stepwise and It is desirable to configure it to include a continuously increasing area. More specifically, in the depth direction toward the transparent substrate 20 side at least from the interface between the phase shift film 30 and the etching mask film 40 in the composition gradient region, the ratio of oxygen is stepwise and/or continuously It is desirable to have an increasing area.

In addition, the phase shift mask blank 10 is configured such that the content ratio of oxygen to silicon over a region of a depth of 10 nm from the interface between the phase shift film 30 and the etching mask film 40 is 3.0 or less. desirable. In this interface, when the phase shift mask blank 10 was subjected to composition analysis by X-ray photoelectron spectroscopy, the ratio of the transition metal from the phase shift film 30 toward the etching mask film 40 decreased, and for the first time The transition metal content is set to 0 atomic%. In addition, the composition gradient region referred to herein is an interface between the phase shift film 30 and the etching mask film 40 (the ratio of the transition metal decreases from the phase shift film 30 toward the etching mask film 40). The first time the transition metal content is 0 atomic%), and the chromium content decreases from the etching mask film 40 toward the phase shift film 30 to the position where the chromium content becomes 0 atomic% for the first time. Says the realm of.

The content ratio of oxygen to silicon over a region having a depth of 10 nm from the interface between the phase shift film 30 and the etching mask film 40 is preferably 3.0 or less, more preferably 2.8 or less, and furthermore 2.5 or less. It is preferable, and it is more preferable that it is 2.0 or less. Further, from the viewpoint of film quality continuity between the phase shift film 30 and the composition gradient region, the content ratio of oxygen to the silicon is preferably 0.3 or more, more preferably 0.5 or more.

Next, the manufacturing method of the phase shift mask blank 10 of this Embodiment 1 and 2 is demonstrated. The phase shift mask blank 10 shown in FIG. 1 is manufactured by performing the following aging process, a phase shift film formation process, and an etching mask film formation process. The phase shift mask blank 10 shown in FIG. 2 is manufactured by an aging process and a phase shift film formation process.

Hereinafter, each process will be described in detail.

1. Aging process

First, before introducing the transparent substrate 20 into the film forming chamber, particles are blown away from the target by sputtering, and an aging step is performed to bring the surface state of the target closer to the surface state at the time of the thin film formation step. In the aging process in the first and second embodiments, nitrogen gas is introduced into the deposition chamber in addition to noble gas (argon, etc.) with high sputtering efficiency, and plasma of the noble gas and nitrogen gas collide with the surface of the target. The surface of the target is cleaned by bounce off each atom constituting the surface of the target. Then, the noble gas and nitrogen gas are left in the film formation chamber.

2. Phase shift film formation process

Next, a transparent substrate 20 is prepared. If the transparent substrate 20 is transparent to exposure light, it is made of any glass material such as synthetic quartz glass, quartz glass, aluminosilicate glass, soda lime glass, and low thermal expansion glass (SiO ₂ -TiO ₂ glass, etc.). You can do it.

Then, a phase shift film 30 is formed on the transparent substrate 20 by sputtering.

The deposition of the phase shift film 30 is a sputtering target containing a transition metal and silicon which are main components of the material constituting the phase shift film 30, or a sputtering target containing a transition metal and silicon, oxygen and/or nitrogen. And, for example, a sputtering gas atmosphere containing at least one selected from the group consisting of helium gas, neon gas, argon gas, krypton gas and xenon gas, and oxygen gas, nitrogen gas, carbon dioxide It is performed in a sputtering gas atmosphere containing a mixed gas of an active gas containing at least oxygen and nitrogen selected from the group containing gas, nitrogen monoxide gas, and nitrogen dioxide gas.

By the above-described aging process, the phase shift film 30 is formed in a state in which nitrogen remains in the film formation chamber. Therefore, the phase shift film 30 contains nitrogen from the beginning of the film formation. On the other hand, the amount of nitrogen remaining in the film formation chamber is a fixed amount, and a certain amount of time is required for the mixed gas supplied during the phase shift film formation process to move around the sputtering target in the film formation chamber. Therefore, at a relatively early stage from the start of the film formation of the phase shift film 30, most of the nitrogen remaining in the film formation chamber is contained in the phase shift film 30 or exhausted because it is exhausted. The amount of nitrogen is once reduced. On the other hand, as described above, when the amount of nitrogen contained in the phase shift film 30 decreases, the amount of oxygen increases, and it is considered that the ratio of nitrogen to oxygen (N/O) decreases once. After that, the mixed gas supplied into the film forming chamber is spread in the film forming chamber, and the amount of nitrogen in the phase shift film and the ratio of nitrogen to oxygen (N/O) rise again. In this way, the phase shift film 30 has a maximum ratio of nitrogen to oxygen in the vicinity of the transparent substrate 20 side (a region within 30 nm from the interface obtained by analyzing by XPS).

The composition and thickness of the phase shift film 30 are adjusted so that the phase shift film 30 has the above phase difference and transmittance. The composition of the phase shift film 30 can be controlled by the content ratio of the elements constituting the sputtering target (eg, the ratio of the transition metal content and the silicon content), the composition and flow rate of the sputtering gas, and the like. The thickness of the phase shift film 30 can be controlled by sputtering power, sputtering time, or the like. In addition, when the sputtering device is an in-line sputtering device, the thickness of the phase shift film 30 can be controlled also by the transfer speed of the substrate. In this way, control is performed so that the oxygen content of the phase shift film 30 is 1 atomic% or more and 70 atomic% or less.

When the phase shift films 30 each include a single film having a uniform composition, the above-described film forming process is performed only once without changing the composition and flow rate of the sputtering gas. When the phase shift film 30 includes a plurality of films having different compositions, the above-described film formation process is performed a plurality of times by changing the composition and flow rate of the sputtering gas for each film formation process. The phase shift film 30 may be formed using targets having different content ratios of elements constituting the sputtering target. When the phase shift film 30 includes a single film whose composition continuously changes in the thickness direction, the above-described film formation process is performed only once while changing the composition and flow rate of the sputtering gas together with the elapsed time of the film formation process. When performing the film forming process a plurality of times, the sputtering power applied to the sputtering target can be reduced.

3. Surface treatment process

The surface of the phase shift film 30 after forming the phase shift film 30 comprising a transition metal, a transition metal silicide material containing silicon and oxygen is easily oxidized, and oxides of the transition metal are easily generated. In order to suppress permeation by the etching solution due to the presence of the transition metal oxide, a surface treatment step of adjusting the state of surface oxidation of the phase shift film 30 is performed.

As a surface treatment step of adjusting the state of surface oxidation of the phase shift film 30, a method of surface treatment with an acidic aqueous solution, a method of surface treatment with an alkaline aqueous solution, a method of surface treatment by dry treatment such as ashing And the like.

After the etching mask film forming process described later, a composition gradient region is formed at the interface between the phase shift film 30 and the etching mask film 40, and the ratio of oxygen in the composition gradient region is stepwise and/or in the depth direction. Alternatively, if the content ratio of oxygen to silicon is 3.0 or less over a region having a depth of 10 nm from the interface between the phase shift film 30 and the etching mask film 40 and the region that is continuously increasing, You may perform a surface treatment process.

For example, in a method of surface treatment with an acidic aqueous solution or a method of surface treatment with an alkaline aqueous solution, the state of surface oxidation of the phase shift film 30 can be adjusted by appropriately adjusting the concentration, temperature, and time of the acidic or alkaline aqueous solution. have. As a method of surface treatment with an acidic aqueous solution or a method of surface treatment with an alkaline aqueous solution, a substrate with a phase shift film on which a phase shift film 30 is formed on a transparent substrate 20 is immersed in the aqueous solution, or a phase shift film 30 ) And the method of contacting the aqueous solution on top. This surface treatment step is preferably performed from the viewpoint of improving the cross-sectional shape at the interface with the etching mask film 40, but is not an essential step.

In this way, the phase shift mask blank 10 of Embodiment 2 is obtained. In the manufacture of the phase shift mask blank 10 of Embodiment 1, the following etching mask film formation process is further performed.

4. Etch mask film formation process

After performing a surface treatment treatment to adjust the surface oxidation state of the surface of the phase shift film 30, an etching mask film 40 is formed on the phase shift film 30 by sputtering.

In this way, the phase shift mask blank 10 is obtained.

The etching mask film 40 may be formed by using a sputtering target containing chromium or a chromium compound (chromium oxide, chromium nitride, chromium carbide, chromium oxide nitride, chromium oxide nitride carbide, etc.), for example, helium gas, neon gas, argon. A sputtering gas atmosphere containing an inert gas containing at least one selected from the group containing gas, krypton gas, and xenon gas, or selected from the group containing helium gas, neon gas, argon gas, krypton gas and xenon gas Active containing at least one selected from the group consisting of an inert gas containing at least one type of gas and oxygen gas, nitrogen gas, nitrogen monoxide gas, nitrogen dioxide gas, carbon dioxide gas, hydrocarbon-based gas, and fluorine-based gas. It is carried out in a sputtering gas atmosphere containing a gas mixture. Examples of the hydrocarbon-based gas include methane gas, butane gas, propane gas, and styrene gas.

When the etching mask film 40 includes a single film having a uniform composition, the above-described film forming process is performed only once without changing the composition and flow rate of the sputtering gas. When the etching mask film 40 includes a plurality of films having different compositions, the above-described film formation process is performed a plurality of times by changing the composition and flow rate of the sputtering gas for each film formation process. When the etching mask film 40 includes a single film whose composition continuously changes in the thickness direction, the above-described film formation process is performed only once while changing the composition and flow rate of the sputtering gas together with the elapsed time of the film formation process.

In this way, the phase shift mask blank 10 of Embodiment 1 is obtained.

In this way, the phase shift film 30 and the etching mask film 30 are etched by performing a film formation process of the phase shift film 30 and the etching mask film 40, and a surface treatment for adjusting the surface oxidation state of the surface of the phase shift film 30. A composition gradient region is formed at the interface with the mask film 40, and the composition gradient region includes a region in which the ratio of oxygen increases stepwise and/or continuously toward the depth direction, and the phase shift film and the etching The phase shift film 30 and the etching mask film 40 can be formed so that the content ratio of oxygen to silicon over a region of a depth of 10 nm from the interface with the mask film is 3.0 or less.

Further, a surface treatment for adjusting the state of surface oxidation of the surface of the phase shift film 30 has been described, but in the film formation process of the phase shift film 30, the surface of the phase shift film 30 is Including a region in which the ratio of oxygen in the composition gradient region increases stepwise and/or continuously toward the depth direction by changing to a gas type that is difficult to be surface-oxidized or adding the gas type, and phase shifting The content ratio of oxygen to silicon over a region having a depth of 10 nm from the interface between the film and the etching mask film may be 3.0 or less.

In addition, since the phase shift mask blank 10 shown in FIG. 1 includes the etching mask film 40 on the phase shift film 30, when manufacturing the phase shift mask blank 10, the etching mask film is formed. Perform the process. In addition, when manufacturing a phase shift mask blank comprising an etching mask film 40 over the phase shift film 30 and a resist film over the etching mask film 40, the etching mask film 40 is formed after the etching mask film forming step. ) To form a resist film on it. In addition, in the phase shift mask blank 10 shown in FIG. 2, when manufacturing a phase shift mask blank including a resist film on the phase shift film 30, a resist film is formed after the phase shift film forming step.

The phase shift mask blank 10 of the first and second embodiments contains a transition metal, silicon, oxygen, and nitrogen, and the content of oxygen obtained by analysis by XPS is 1 atomic% or more and 70 atomic% or less. (Preferably, the oxygen content is 5 atomic% or more and 70 atomic% or less), and the phase shift film 30 obtained by analyzing the interface between the transparent substrate 20 and the phase shift film 30 by XPS When defined as a position where the content rate of the transition metal contained in is 0 atomic%, the ratio of nitrogen to oxygen in the region within 30 nm from this interface toward the surface of the phase shift film 30 has a maximum value ( 30). Therefore, the phase shift film pattern 30a formed on the transparent substrate 20 by wet etching the phase shift film 30 at an over-etching time is suppressed from seeping at the interface with the transparent substrate 20. In addition, the phase shift mask blank 10 of the first embodiment has a good cross-sectional shape, and a phase shift film pattern 30a having a small CD variation in in-plane distribution and a high transmittance can be formed by wet etching. Accordingly, a phase shift mask blank capable of manufacturing the phase shift mask 100 capable of transferring the highly precise phase shift film pattern 30a with high precision is obtained.

Embodiment 3. 4.

In Embodiments 3 and 4, a method of manufacturing the phase shift mask 100 will be described.

3 is a schematic diagram showing a method of manufacturing a phase shift mask according to the third embodiment. 4 is a schematic diagram showing a method of manufacturing a phase shift mask according to the fourth embodiment.

The manufacturing method of a phase shift mask shown in FIG. 3 is a method of manufacturing a phase shift mask using the phase shift mask blank 10 shown in FIG. 1, and the etching mask film 40 of the following phase shift mask blank 10 ) Forming a resist film on the resist film and drawing and developing a desired pattern on the resist film to form a first resist film pattern 50 (first resist film pattern formation step), and a first resist film pattern ( 50) as a mask and wet etching the etching mask film 40 to form a first etching mask film pattern 40a on the phase shift film 30 (first etching mask film pattern formation step), and 1 Including a step of forming a phase shift film pattern 30a on the transparent substrate 20 by wet etching the phase shift film 30 using the etching mask film pattern 40a as a mask (phase shift film pattern formation step) do. Then, a second resist film pattern forming process and a second etching mask film pattern forming process are further included.

The manufacturing method of the phase shift mask shown in FIG. 4 is a method of manufacturing a phase shift mask using the phase shift mask blank 10 shown in FIG. 2, and a step of forming a resist film on the phase shift mask blank 10 below. And, by drawing and developing a desired pattern on the resist film, the first resist film pattern 50 is formed (the first resist film pattern forming step), and the first resist film pattern 50 is used as a mask. It includes a step of wet etching the shift film 30 to form the phase shift film pattern 30a on the transparent substrate 20 (phase shift film pattern formation step).

Hereinafter, each step of the manufacturing step of the phase shift mask according to the third and fourth embodiments will be described in detail.

Phase shift mask manufacturing process according to Embodiment 3

1. First resist film pattern formation process

In the first resist film pattern forming step, a resist film is first formed on the etching mask film 40 of the phase shift mask blank 10 of the first embodiment. The resist film material to be used is not particularly limited. For example, what is necessary is just to sensitize laser light having any one wavelength selected from the wavelength range of 350 nm to 436 nm, which will be described later. In addition, the resist film may be of a positive type or a negative type.

Thereafter, a desired pattern is drawn on the resist film using laser light having any one wavelength selected from the wavelength range of 350 nm to 436 nm. The pattern to be drawn on the resist film is a pattern to be formed on the phase shift film 30. As a pattern to be drawn on a resist film, a line and space pattern and a contact hole pattern are mentioned.

Thereafter, the resist film is developed with a predetermined developer, and a first resist film pattern 50 is formed on the etching mask film 40 as shown in Fig. 3A.

2. First etching mask film pattern formation process

In the first etching mask film pattern forming step, first, the etching mask film 40 is etched using the first resist film pattern 50 as a mask, thereby forming the first etching mask film pattern 40a. The etching mask film 40 contains chromium (Cr) and is formed of a chromium-based material that does not contain silicon substantially. The etching solution for etching the etching mask film 40 is not particularly limited as long as it can selectively etch the etching mask film 40. Specifically, an etching solution containing cerium ammonium nitrate and perchloric acid can be cited.

After that, the first resist film pattern 50 is peeled off using a resist stripper or by ashing as shown in Fig. 3B. In some cases, the following phase shift film pattern forming step may be performed without peeling the first resist film pattern 50.

3. Phase shift film pattern formation process

In the first phase shift film pattern formation step, the phase shift film 30 is etched using the first etching mask film pattern 40a as a mask, and as shown in Fig. 3(c), the phase shift film pattern 30a To form. As the phase shift film pattern 30a, a line and space pattern and a contact hole pattern are exemplified. The etchant for etching the phase shift film 30 is not particularly limited as long as it is capable of selectively etching the phase shift film 30. For example, an etching solution containing ammonium fluoride, phosphoric acid and hydrogen peroxide, and an etching solution containing ammonium hydrogen fluoride and hydrogen chloride may be mentioned.

In order to improve the cross-sectional shape of the phase shift film pattern 30a, wet etching is longer than the time (just etching time) from the phase shift film pattern 30a to the transparent substrate 20 exposure (over etching time). It is preferable to do it with ). As the over-etching time, in consideration of the influence on the transparent substrate 20 and the like, it is preferable to set it within the time obtained by adding 10% of the just-etching time to the just-etching time.

4. Second resist film pattern formation process

In the second resist film pattern formation process, first, a resist film covering the first etching mask film pattern 40a is formed. The resist film material to be used is not particularly limited. For example, what is necessary is just to sensitize laser light having any one wavelength selected from the wavelength range of 350 nm to 436 nm, which will be described later. In addition, the resist film may be of a positive type or a negative type.

Thereafter, a desired pattern is drawn on the resist film using laser light having any one wavelength selected from the wavelength range of 350 nm to 436 nm. Patterns to be drawn on the resist film are a light shielding band pattern that shields light from an outer circumferential region of a region in which a pattern is formed in the phase shift film 30, and a light shielding band pattern that shields light from the center of the phase shift film pattern. Further, the pattern to be drawn on the resist film may be a pattern without a light-shielding band pattern that blocks light at the center of the phase shift film pattern 30a, depending on the transmittance of the phase shift film 30 to exposure light.

Thereafter, the resist film is developed with a predetermined developer, and a second resist film pattern 60 is formed on the first etching mask film pattern 40a as shown in Fig. 3(d).

5. Second etching mask film pattern formation process

In the second etching mask film pattern formation step, the first etching mask film pattern 40a is etched using the second resist film pattern 60 as a mask, and as shown in Fig. 3(e), the second etching mask film pattern Form (40b). The first etching mask film pattern 40a contains chromium (Cr) and is formed of a chromium-based material that does not contain silicon substantially. The etching solution for etching the first etching mask film pattern 40a is not particularly limited as long as it is capable of selectively etching the first etching mask film pattern 40a. For example, an etching solution containing cerium ammonium nitrate and perchloric acid may be mentioned.

After that, the second resist film pattern 60 is peeled off using a resist stripping solution or by ashing.

In this way, the phase shift mask 100 is obtained.

In addition, in the above description, the case where the etching mask film 40 has a function of blocking transmission of exposure light is described, but only the hard mask function when the etching mask film 40 simply etchs the phase shift film 30. In the case of having, in the above description, the second resist film pattern forming step and the second etching mask film pattern forming step are not performed, and after the phase shift film pattern forming step, the first etching mask film pattern is peeled off and the phase shift mask ( 100).

According to the method for manufacturing a phase shift mask of the second embodiment, since the phase shift mask blank of the first embodiment is used, a phase shift film pattern having a good cross-sectional shape and small CD deviation of the in-plane distribution can be formed. Therefore, it is possible to manufacture a phase shift mask capable of transferring a high-definition phase shift film pattern with high precision. The phase shift mask manufactured as described above can cope with miniaturization of line and space patterns or contact holes.

Phase shift mask manufacturing process according to Embodiment 4

1. Resist film pattern formation process

In the resist film pattern formation process, a resist film is first formed on the phase shift film 30 of the phase shift mask blank 10 of the second embodiment. The resist film material to be used is similar to that described in the third embodiment. Further, if necessary, before forming the resist film, the phase shift film 30 may be subjected to a surface modification treatment in order to improve adhesion to the phase shift film 30. Similar to the above, after the resist film is formed, a desired pattern is drawn on the resist film using laser light having any wavelength selected from a wavelength range of 350 nm to 436 nm. Thereafter, the resist film is developed with a predetermined developer, and a first resist film pattern 50 is formed on the phase shift film 30 as shown in Fig. 4A.

2. Phase shift film pattern formation process

In the phase shift film pattern formation process, the phase shift film 30 is etched using the first resist film pattern 50 as a mask, and a phase shift film pattern 30a is formed as shown in Fig. 4B. The etchant and over-etching time for etching the phase shift film pattern 30a and the phase shift film 30 are similar to those described in the third embodiment.

After that, the first resist film pattern 50 is peeled off using a resist stripping solution or by ashing (Fig. 4(c)).

In this way, the phase shift mask 100 is obtained.

According to the manufacturing method of the phase shift mask of the fourth embodiment, since the phase shift mask blank of the second embodiment is used, there is no decrease in the transmittance of the transparent substrate due to damage to the substrate by wet etching, and the etching time is reduced. It can be shortened and a phase shift film pattern having a good cross-sectional shape can be formed. Therefore, it is possible to manufacture a phase shift mask capable of transferring a high-definition phase shift film pattern with high precision. The phase shift mask manufactured as described above can cope with miniaturization of line and space patterns or contact holes.

Embodiment 5.

In Embodiment 5, a method of manufacturing a display device will be described. The display device uses the phase shift mask 100 manufactured by using the phase shift mask blank 10 described above, or the phase shift mask 100 manufactured by the manufacturing method of the phase shift mask 100 described above. It is manufactured by performing a process used (mask placing process) and a process of exposing and transferring a transfer pattern to a resist film on a display device (pattern transfer process).

Hereinafter, each process will be described in detail.

1. Wit process

In the placing process, the phase shift mask manufactured in Embodiment 3 is placed on the mask stage of the exposure apparatus. Here, the phase shift mask is disposed so as to face the resist film formed on the display device substrate via the projection optical system of the exposure device.

2. Pattern transfer process

In the pattern transfer process, exposure light is irradiated to the phase shift mask 100, and the phase shift film pattern is transferred to a resist film formed on the display device substrate. The exposure light is a composite light including light of a plurality of wavelengths selected from a wavelength range of 365 nm to 436 nm, or monochromatic light selected by cutting a certain wavelength range from a wavelength range of 365 nm to 436 nm with a filter or the like. For example, the exposure light is a composite light including i-line, h-line, and g-line, or monochromatic light of i-line. When composite light is used as the exposure light, since the exposure light intensity can be increased to increase throughput, the manufacturing cost of the display device can be lowered.

According to the display device manufacturing method of the fifth embodiment, CD errors can be suppressed, and a high-resolution, fine line-and-space pattern and a high-definition display device including contact holes can be manufactured.

[Example]

Example 1.

A. Phase shift mask blank and manufacturing method thereof

In order to manufacture the phase shift mask blank of Example 1, molybdenum was first introduced into a chamber of an in-line sputtering apparatus, while introducing a mixed gas of nitrogen (N ₂ ) and argon (Ar) before carrying in the transparent substrate 20. A sputtering power of 6.0 kW was applied to the first sputtering target (molybdenum: silicon = 1:9) containing hypersilicon, and an aging step was performed for 60 minutes.

Then, as the transparent substrate 20, a synthetic quartz glass substrate of 1214 size (1220 mm x 1400 mm) was prepared.

Thereafter, the synthetic quartz glass substrate was mounted on a tray (not shown) with the main surface facing downward, and carried into the chamber of the in-line sputtering apparatus.

In order to form the phase shift film 30 on the main surface of the transparent substrate 20, with the sputtering gas pressure in the first chamber set to 1.7 Pa, argon (Ar) gas, nitrogen (N ₂ ) gas, A mixed gas (Ar: 18 sccm, N ₂ : 15 sccm, He: 50 sccm, NO: 4 sccm) of an inert gas composed of helium (He) gas and nitrogen monoxide gas (NO) as a reactive gas was introduced. Under these film formation conditions, a phase shift film 30 (film thickness: 135 nm) containing an oxynitride of molybdenum silicide was formed on the transparent substrate 20.

Next, the transparent substrate 20 with the phase shift film 30 after the surface treatment is carried into the second chamber, and the inside of the second chamber is set to a predetermined vacuum degree, and argon (Ar) gas and nitrogen (N ₂ ) A gas mixture (Ar: 65 sccm, N ₂ : 15 sccm) was introduced. Then, 1.5 kW of sputtering power was applied to the second sputtering target containing chromium, and chromium nitride (CrN) containing chromium and nitrogen was formed on the phase shift film 30 by reactive sputtering (film thickness 15 nm. ). Next, a mixed gas (30 sccm) of argon (Ar) gas and methane (CH ₄ : 4.9%) gas was introduced in a state in which the inside of the third chamber was set to a predetermined vacuum degree, and the third sputtering target containing chromium was A sputtering power of 8.5 kW was applied, and a chromium carbide (CrC) containing chromium and carbon was formed on CrN by reactive sputtering (film thickness of 60 nm). Finally, in a state in which the inside of the fourth chamber is set to a predetermined degree of vacuum, the mixture of argon (Ar) gas and methane (CH ₄ : 5.5%) gas and nitrogen (N ₂ ) gas and oxygen (O ₂ ) gas A mixed gas (Ar+CH ₄ : 30 sccm, N ₂ : 8 sccm, O ₂ : 3 sccm) was introduced, a sputtering power of 2.0 kW was applied to the fourth sputtering target containing chromium, and chromium and chromium were formed on the CrC by reactive sputtering A chromium carbide oxide nitride (CrCON) containing carbon, oxygen and nitrogen was formed (film thickness 30 nm). As described above, the etching mask film 40 having a stacked structure of a CrN layer, a CrC layer, and a CrCON layer was formed on the phase shift film 30.

In this way, the phase shift mask blank 10 in which the phase shift film 30 and the etching mask film 40 were formed on the transparent substrate 20 was obtained.

For the phase shift film 30 (phase shift film 30 in which the surface of the phase shift film 30 was surface-treated with an alkaline aqueous solution) of the obtained phase shift mask blank 10, MPM-100 manufactured by Lasertech Co., Ltd. The transmittance and the phase difference were measured by. To measure the transmittance and phase difference of the phase shift film 30, a substrate (dummy substrate) with a phase shift film on which a phase shift film 30 was formed on the main surface of a synthetic quartz glass substrate, which was produced by setting in the same tray, was used. I did. The transmittance and phase difference of the phase shift film 30 were measured by taking the substrate with the phase shift film (dummy substrate) out of the chamber before forming the etching mask film 40. As a result, the transmittance was 34% (wavelength: 365 nm), the phase difference was 160 degrees (wavelength: 365 nm), and the back surface reflectance was 11.1% (wavelength: 365 nm).

Further, for the phase shift film 30, the change in flatness was measured using UltraFLAT 200M (manufactured by Corning TROPEL), and the film stress was calculated, and it was 0.24 GPa. This phase shift film 30 had a small amount of change in transmittance and a change amount of phase difference with respect to the chemical liquid (sulfuric acid fruit water, ammonia fruit water, ozone water) used for cleaning the phase shift mask, and had high resistance to chemicals and cleaning resistance.

Moreover, about the obtained phase shift mask blank 10, the film surface reflectance and optical density were measured by the spectrophotometer SolidSpec-3700 manufactured by Shimadzu Corporation. The film surface reflectance of the phase shift mask blank (etching mask film 40) was 8.3% (wavelength: 436 nm) and optical density (OD) was 4.0 (wavelength: 436 nm). It was found that this etching mask film 40 functions as a light-shielding film having a low reflectance on the film surface.

Further, the obtained phase shift mask blank 10 was analyzed for composition in the depth direction by X-ray photoelectron spectroscopy (XPS). 5 shows the results of composition analysis in the depth direction by XPS for the phase shift mask blank of Example 1. FIG. Fig. 5 shows the result of composition analysis of the etching mask film 40 on the phase shift film 30 side and the phase shift film 30 in the phase shift mask blank. The horizontal axis in Fig. 5 represents the depth (nm) of the phase shift mask blank 10 in terms of SiO ₂ based on the outermost surface of the etching mask film 40, and the vertical axis represents the content rate (atomic%). In FIG. 5, each curve represents a change in the content rate of silicon (Si), nitrogen (N), oxygen (O), carbon (C), chromium (Cr), and molybdenum (Mo).

11 is a diagram showing the ratio of the distance from the substrate interface and the N/O by XPS to the phase shift blank masks of Examples 1 and 2 and Comparative Example 1. FIG.

As shown in Fig. 5, in the composition analysis result in the depth direction by XPS for the phase shift mask blank 10, the interface between the phase shift film 30 and the transparent substrate 20 (phase shift film 30) In a region within 30 nm (composition gradient region) from the position where the contained molybdenum content is 0 atomic%) toward the surface of the phase shift film 30, the oxygen content rapidly decreases from the interface with the transparent substrate 20 And then become almost constant. On the other hand, the content of nitrogen rapidly increases from the interface with the transparent substrate 20, and then decreases slightly. That is, as shown in FIG. 11, in Example 1, it was found that the N/O ratio had a maximum value in a distance of 28.4 nm from the interface with the transparent substrate 20, that is, within 30 nm.

B. Phase shift mask and its manufacturing method

In order to manufacture the phase shift mask 100 using the phase shift mask blank 10 manufactured as described above, first, using a resist coating apparatus on the etching mask film 40 of the phase shift mask blank 10 A photoresist film was applied.

Thereafter, a photoresist film having a thickness of 520 nm was formed through a heating/cooling process.

Thereafter, a photoresist film was drawn using a laser writing apparatus, and through a developing and rinsing process, a resist film pattern of a hole pattern having a hole diameter of 1.5 μm was formed on the etching mask film.

Thereafter, using the resist film pattern as a mask, the etching mask film 40 was wet etched with a chromium etching solution containing cerium ammonium nitrate and perchloric acid to form a first etching mask film pattern 40a.

Then, using the first etching mask film pattern 40a as a mask, the phase shift film 30 is wet etched with a molybdenum silicide etchant obtained by diluting a mixed solution of ammonium hydrogen fluoride and hydrogen peroxide with pure water. A pattern 30a was formed. This wet etching was performed with an over-etching time of 110% in order to verticalize the cross-sectional shape and to form a required fine pattern.

After that, the resist film pattern was peeled off.

Thereafter, a photoresist film was applied using a resist coating apparatus to cover the first etching mask film pattern 40a.

Thereafter, through a heating/cooling process, a photoresist film having a thickness of 520 nm was formed.

Thereafter, a photoresist film was drawn using a laser writing apparatus, and through a developing/rinsing process, a second resist film pattern 60 for forming a light shielding band was formed on the first etching mask film pattern 40a.

Thereafter, using the second resist film pattern 60 as a mask, the first etching mask film pattern 40a formed in the transfer pattern formation region was wet etched with a chromium etching solution containing cerium ammonium nitrate and perchloric acid. .

After that, the second resist film pattern 60 was peeled off.

In this way, a light shield including a stacked structure of the phase shift film pattern 30a, the phase shift film pattern 30a, and the second etching mask film pattern 40b is formed in the transfer pattern formation region on the transparent substrate 20. A phase shift mask 100 was obtained.

The cross section of the obtained phase shift mask was observed with a scanning electron microscope. In Examples 1, 2 and Comparative Example 1 below, a scanning electron microscope was used to observe the cross section of the phase shift mask. The cross-sectional photograph of FIG. 6 shows, in the manufacturing process of the phase shift mask of Example 1, wet etching the phase shift film 30 with a molybdenum silicide etching solution using the first etching mask film pattern 40a as a mask. It is a cross-sectional photograph after over-etching) to form the phase shift film pattern 30a, and peeling the resist film pattern.

As shown in FIG. 6, the phase shift film pattern 30a formed on the phase shift mask 100 of Example 1 contained a cross-sectional shape close to the vertical which can fully exhibit a phase shift effect. In addition, in the phase shift film pattern 30a, neither the interface with the etching mask film pattern nor the interface with the substrate was seen. Further, the hem width was small and the in-plane CD deviation was 70 nm, which contained a small phase shift film pattern 30a. Specifically, the cross section of the phase shift film pattern 30a is constituted by an upper surface, a lower surface, and a side surface of the phase shift film pattern 30a. In the cross section of this phase shift film pattern 30a, an angle formed by a portion (upper side) in contact with the upper surface and the side surface and a portion in contact with the side surface and the lower surface (lower side) was 74 degrees. Therefore, in exposure light including light in a wavelength range of 300 nm or more and 500 nm or less, more specifically, in exposure light of complex light including i-line, h-line and g-line, the phase shift mask 100 having an excellent phase shift effect ) Was obtained.

Therefore, it can be said that when the phase shift mask 100 of Example 1 is set on the mask stage of the exposure apparatus and then transferred to the resist film on the display apparatus by exposure, a fine pattern of less than 2.0 μm can be transferred with high precision. have.

Example 2.

A. Phase shift mask blank and manufacturing method thereof

In order to manufacture the phase shift mask blank 10 of Example 2, the aging process was first performed in the same conditions as Example 1 before carrying in the transparent substrate 20 in the chamber of the in-line sputtering apparatus. In addition, in order to form the phase shift film 30 on the main surface of the transparent substrate 20, argon (Ar) gas and nitrogen (N ₂ ) gas in a state in which the sputtering gas pressure in the first chamber is 1.9 Pa. And, an inert gas (Ar: 18 sccm, N ₂ : 13 sccm, He: 50 sccm) composed of helium (He) gas was introduced. Under these film forming conditions, a phase shift film 30 (film thickness: 141 nm) containing an oxynitride of molybdenum silicide was formed on the transparent substrate 20.

Next, after forming the phase shift film 30 on the transparent substrate 20, a CrN layer and a CrC layer on the phase shift film 30 are similar to the first embodiment without surface treatment of the phase shift film 30. An etching mask film 40 having a laminated structure of a layer and a CrCON layer was formed.

In this way, the phase shift mask blank 10 in which the phase shift film 30 and the etching mask film 40 were formed on the transparent substrate 20 was obtained.

For the phase shift film 30 of the obtained phase shift mask blank 10, the transmittance and the phase difference were measured with MPM-100 manufactured by Lasertech. For the measurement of the transmittance and phase difference of the phase shift film, a substrate (dummy substrate) with a phase shift film on which the phase shift film 30 was formed on the main surface of a synthetic quartz glass substrate prepared by setting in the same tray was used. The transmittance and phase difference of the phase shift film 30 were measured by taking the substrate with the phase shift film (dummy substrate) out of the chamber before forming the etching mask film 40. As a result, the transmittance was 33% (wavelength: 365 nm), the phase difference was 171 degrees (wavelength: 365 nm), and the back surface reflectance was 7.8% (wavelength: 365 nm).

Further, for the phase shift film 30, the change in flatness was measured using UltraFLAT 200M (manufactured by Corning TROPEL), and the film stress was calculated, and it was 0.22 GPa. This phase shift film 30 had a small amount of change in transmittance and a change amount of phase difference with respect to the chemical liquid (sulfuric acid fruit water, ammonia fruit water, ozone water) used for cleaning the phase shift mask, and had high chemical resistance and cleanability.

Moreover, about the obtained phase shift mask blank 10, the film surface reflectance and optical density were measured by the spectrophotometer SolidSpec-3700 manufactured by Shimadzu Corporation. The film surface reflectance of the phase shift mask blank 10 (etching mask film 40) was 8.3% (wavelength: 436 nm), and optical density (OD) was 4.0 (wavelength: 436 nm). It was found that this etching mask film 40 functions as a light-shielding film having a low reflectance on the film surface.

Further, the obtained phase shift mask blank 10 was analyzed for composition in the depth direction by X-ray photoelectron spectroscopy (XPS).

As a result, a trend similar to that of Example 1 was exhibited, and in the composition analysis result in the depth direction by XPS for the phase shift mask blank 10, the interface between the phase shift film 30 and the transparent substrate 20 (phase In a region within 30 nm toward the surface of the phase shift film 30 (a composition gradient region) from the position where the content of molybdenum contained in the shift film 30 becomes 0 atomic%), the oxygen content is the transparent substrate 20 Decreases rapidly from the interface with and then becomes almost constant. On the other hand, the content rate of nitrogen rapidly increased from the interface with the transparent substrate 20, and then decreased slightly. That is, as shown in FIG. 11, in Example 2, it was found that the ratio of N/O has a maximum value in a distance of 27.6 nm from the interface with the transparent substrate 20, that is, within 30 nm.

B. Phase shift mask and its manufacturing method

Using the phase shift mask blank 10 manufactured as described above, the phase shift mask 100 was manufactured by the same method as in Example 1. In addition, wet etching was performed with an over-etching time of 110% in order to verticalize the cross-sectional shape and to form a required fine pattern.

The cross section of the obtained phase shift mask 100 was observed with a scanning electron microscope. The cross-sectional photograph of FIG. 7 shows a wet etching (110% over) of the phase shift film 30 with a molybdenum silicide etchant using the first etching mask film pattern 40a as a mask in the manufacturing process of the phase shift mask of Example 2. It is a cross-sectional photograph after performing etching) and forming the phase shift film pattern 30a.

As shown in FIG. 7, the phase shift film pattern 30a formed in the phase shift mask 100 of Example 2 contained a cross-sectional shape close to the vertical which can fully exhibit a phase shift effect. In addition, in the phase shift film pattern 30a, neither the interface with the etching mask film pattern 40b nor the interface with the transparent substrate 20 was seen. Further, a phase shift film pattern 30a having a small hem width and a small in-plane CD deviation of 70 nm was included. Specifically, the cross section of the phase shift film pattern 30a is constituted by an upper surface, a lower surface, and a side surface of the phase shift film pattern 30a. In the cross section of this phase shift film pattern 30a, an angle formed by a portion (upper side) in contact with the upper surface and the side surface and a portion in contact with the side surface and the lower surface (lower side) was 71 degrees. Accordingly, the phase change mask 100 having an excellent phase shift effect in exposure light including light in a wavelength range of 300 nm or more and 500 nm or less, and more specifically, exposure light of complex light including i-line, h-line and g-line Was obtained.

Therefore, when the phase shift mask 100 of the second embodiment is set on the mask stage of the exposure apparatus and the resist film on the display apparatus is subjected to exposure transfer, it can be said that a fine pattern of less than 2.0 μm can be transferred with high precision.

Comparative Example 1.

A. Phase shift mask blank and manufacturing method thereof

In order to manufacture the phase shift mask blank of Comparative Example 1, first, an aging process was performed before carrying in a transparent substrate in a chamber of an in-line sputtering apparatus. However, only argon (Ar) gas was used as the gas introduced in the aging process, and the time was 30 minutes. Other conditions in the aging process were set in the same manner as in Examples 1 and 2. Then, a phase shift film and an etching mask film were formed on the transparent substrate under the same conditions as in Example 1.

In this way, a phase shift mask blank in which a phase shift film and an etching mask film were formed on a transparent substrate was obtained. In addition, the thickness of the phase shift film was 135 nm.

For the phase shift film (phase shift film obtained by purely washing the surface of the phase shift film) of the obtained phase shift mask blank, transmittance and phase difference were measured by MPM-100 manufactured by Lasertech. For the measurement of the transmittance and phase difference of the phase shift film, a substrate with a phase shift film (dummy substrate) having a phase shift film formed on the main surface of a synthetic quartz glass substrate prepared by setting in the same tray was used. The transmittance and phase difference of the phase shift film were measured by taking the substrate with the phase shift film (dummy substrate) out of the chamber before forming the etching mask film. As a result, almost no different from the optical properties of the phase shift film of Example 1, the transmittance was 34% (wavelength: 365 nm), the phase difference was 160 degrees (wavelength: 365 nm), and the back surface reflectance was 11.0% (wavelength: 365 nm).

Further, for the phase shift film, the change in flatness was measured using UltraFLAT 200M (manufactured by Corning TROPEL), and the film stress was calculated, and it was 0.24 GPa. This phase shift film 30 had a small amount of change in transmittance and a change amount of phase difference with respect to the chemical liquid (sulfuric acid fruit water, ammonia fruit water, ozone water) used for cleaning the phase shift mask, and had high chemical resistance and cleanability.

Further, the obtained phase shift mask blank was measured for film surface reflectance and optical density with a spectrophotometer SolidSpec-3700 manufactured by Shimadzu Corporation. The film surface reflectance of the phase shift mask blank (etching mask film) was 8.3% (wavelength: 436 nm) and optical density (OD) was 4.0 (wavelength: 436 nm). It was found that this etching mask film functions as a light-shielding film having a low reflectance on the film surface.

Further, the obtained phase shift mask blank was analyzed for composition in the depth direction by X-ray photoelectron spectroscopy (XPS).

As a result, in the composition analysis result in the depth direction by XPS for the phase shift mask blank, the phase shift from the interface between the phase shift film and the transparent substrate (the position where the content of molybdenum contained in the phase shift film becomes 0 atomic%). In the region within 30 nm toward the surface of the film (composition inclined region), the content of oxygen rapidly decreases from the interface with the transparent substrate and then becomes almost constant. On the other hand, the content of nitrogen rapidly increased from the interface with the transparent substrate, and then gradually increased without changing to a decrease. That is, as shown in FIG. 11, in Comparative Example 1, it was found that the ratio of N/O did not have a maximum value in a region within 30 nm from the interface with the transparent substrate.

B. Phase shift mask and its manufacturing method

Using the phase shift mask blank manufactured as described above, a phase shift mask was manufactured by the same method as in Example 1.

The cross section of the obtained phase shift mask was observed with a scanning electron microscope. The cross-sectional photograph of FIG. 10 shows a phase shift film pattern by wet etching (110% over-etching) the phase shift film with a molybdenum silicide etchant using the first etching mask film pattern as a mask in the manufacturing process of the phase shift mask of Comparative Example 1. Is a cross-sectional photograph after forming and removing the resist film pattern.

As shown in Fig. 10, the phase shift film pattern formed on the phase shift mask of Comparative Example 1 had a shape in which erosion occurred due to permeation in the vicinity of the interface with the transparent substrate. Therefore, in the phase shift mask of Comparative Example 1, it is expected that a fine pattern of less than 2.0 μm cannot be produced with high precision.

Example 3.

A. Phase shift mask blank and manufacturing method thereof

In order to manufacture the phase shift mask blank 10 of Example 3, an aging process was first performed in the same conditions as Example 1 before carrying in the transparent substrate 20 in the chamber of the in-line sputtering apparatus. In Example 3, molybdenum: silicon = 8:92 was used as the first sputtering target containing molybdenum and silicon. And, in order to form the phase shift film 30 on the main surface of the transparent substrate 20, argon (Ar) gas and nitrogen (N ₂ ) gas and the sputtering gas pressure in the first chamber were set to 1.7 Pa. A mixed gas (Ar: 18 sccm, N ₂ : 15 sccm, He: 50 sccm, NO: 4 sccm) of an inert gas composed of helium (He) gas and nitrogen monoxide gas (NO) as a reactive gas was introduced. Under these film formation conditions, a phase shift film 30 (film thickness: 153 nm) containing an oxynitride of molybdenum silicide was formed on the transparent substrate 20.

Next, after forming the phase shift film 30 on the transparent substrate 20, the surface treatment of the phase shift film 30 is not performed, and similarly to the first embodiment, a CrN layer and a CrC layer are formed on the phase shift film 30. An etching mask film 40 having a laminated structure of a layer and a CrCON layer was formed.

In this way, the phase shift mask blank 10 in which the phase shift film 30 and the etching mask film 40 were formed on the transparent substrate 20 was obtained.

For the phase shift film 30 of the obtained phase shift mask blank 10, the transmittance and the phase difference were measured with MPM-100 manufactured by Lasertech. For the measurement of the transmittance and phase difference of the phase shift film, a substrate with a phase shift film (dummy overboard) in which the phase shift film 30 was formed on the main surface of a synthetic quartz glass substrate prepared by setting in the same tray was used. The transmittance and phase difference of the phase shift film 30 were measured by taking the substrate with the phase shift film (dummy substrate) out of the chamber before forming the etching mask film 40. As a result, the transmittance was 37% (wavelength: 365 nm), the phase difference was 187 degrees (wavelength: 365 nm), and the back surface reflectance was 2.5% (wavelength: 365 nm).

In addition, this phase shift film 30 has a small amount of change in transmittance and a change amount of phase difference with respect to the chemical liquid (sulfuric acid fruit water, ammonia fruit water, ozone water) used for cleaning the phase shift mask, and has high chemical resistance and cleanability.

Moreover, about the obtained phase shift mask blank 10, the film surface reflectance and optical density were measured by the spectrophotometer SolidSpec-3700 manufactured by Shimadzu Corporation. The film surface reflectance of the phase shift mask blank 10 (etching mask film 40) was 8.3% (wavelength: 436 nm), and optical density (OD) was 4.0 (wavelength: 436 nm). It was found that this etching mask film 40 functions as a light-shielding film having a low reflectance on the film surface.

Further, the obtained phase shift mask blank 10 was analyzed for composition in the depth direction by X-ray photoelectron spectroscopy (XPS).

As a result, as shown in FIG. 8, a trend similar to that of Example 1 was exhibited, and in the composition analysis result in the depth direction by XPS for the phase shift mask blank 10, the phase shift film 30 and the transparent substrate ( 20) from the interface (position at which the content of molybdenum contained in the phase shift film 30 becomes 0 atomic%) to the surface of the phase shift film 30 within 30 nm (composition gradient region) The content rate rapidly decreases from the interface with the transparent substrate 20 and then becomes almost constant. On the other hand, the content rate of nitrogen rapidly increased from the interface with the transparent substrate 20, and then decreased slightly. That is, as shown in FIG. 12, in Example 3, it was found that the ratio of N/O has a maximum value in a distance of 22.7 nm from the interface with the transparent substrate 20, that is, within 30 nm.

Further, at the center position of the transfer pattern formation region of the obtained phase shift mask blank 10, a cross-sectional SEM (scanning electron microscope) observation was performed at a magnification of 80,000 times, indicating that the phase shift film 30 contained a columnar structure. I could confirm that. That is, it was confirmed that the particles of the molybdenum silicide compound constituting the phase shift film 30 contained a columnar particle structure extending toward the thickness direction of the phase shift film 30. In addition, as for the particle structure of the columnar phase of the phase shift film 30, it was confirmed that the columnar particles in the film thickness direction were irregularly formed, and the length of the columnar particles in the film thickness direction was also uneven. It was also confirmed that the sparse portions of the phase shift film 30 were formed continuously in the film thickness direction.

B. Phase shift mask and its manufacturing method

Using the phase shift mask blank 10 manufactured as described above, the phase shift mask 100 was manufactured by the same method as in Example 1. In addition, wet etching was performed with an over-etching time of 110% in order to verticalize the cross-sectional shape and to form a required fine pattern.

The cross section of the obtained phase shift mask 100 was observed with a scanning electron microscope. The cross-sectional photograph of FIG. 9 shows a wet etching (110% over) of the phase shift film 30 with a molybdenum silicide etchant using the first etching mask film pattern 40a as a mask in the manufacturing process of the phase shift mask of Example 3. It is a cross-sectional photograph after performing etching) and forming the phase shift film pattern 30a.

As shown in FIG. 9, the phase shift film pattern 30a formed in the phase shift mask 100 of Example 3 contained a cross-sectional shape close to perpendicular which can fully exhibit a phase shift effect. In addition, in the phase shift film pattern 30a, neither the interface with the etching mask film pattern 40b nor the interface with the transparent substrate 20 was seen. Further, a phase shift film pattern 30a having a small hem width and a small in-plane CD deviation of 65 nm was included. Specifically, the cross section of the phase shift film pattern 30a is constituted by an upper surface, a lower surface, and a side surface of the phase shift film pattern 30a. In the cross section of this phase shift film pattern 30a, an angle formed by a portion (upper side) in contact with the upper surface and the side surface and a portion in contact with the side surface and the lower surface (lower side) was 81 degrees. Accordingly, the phase change mask 100 having an excellent phase shift effect in exposure light including light in a wavelength range of 300 nm or more and 500 nm or less, and more specifically, exposure light of complex light including i-line, h-line and g-line Was obtained.

Therefore, it can be said that when the phase shift mask 100 of Example 3 is set on the mask stage of the exposure apparatus and transferred to the resist film on the display apparatus by exposure, a fine pattern of less than 2.0 μm can be transferred with high precision. have.

In addition, in the above-described embodiment, the case of using molybdenum as the transition metal has been described, but the same effect as described above is obtained even in the case of other transition metals.

Further, in the above-described embodiments, examples of the phase shift mask blank for manufacturing a display device and a phase shift mask for manufacturing a display device have been described, but the present invention is not limited thereto. The phase shift mask blank or phase shift mask of the present invention can also be applied for semiconductor device manufacturing, MEMS manufacturing, printed circuit boards, and the like.

In addition, in the above-described embodiment, an example in which the size of the transparent substrate is 8092 size (800 mm × 920 mm × 10 mm) has been described, but is not limited thereto. In the case of a phase shift mask blank for manufacturing a display device, a large size transparent substrate is used, and the size of the transparent substrate is 300 mm or more in length on one side. The size of the transparent substrate used for the phase shift mask blank for manufacturing a display device is, for example, 330 mm x 450 mm or more and 2280 mm x 3130 mm or less.

Further, in the case of a phase shift mask blank for semiconductor device manufacturing, MEMS manufacturing, and printed circuit boards, a small sized 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 used for the phase shift mask blank for the above application is, for example, 63.1 mm×63.1 mm or more and 228.6 mm×228.6 mm or less. Typically, for semiconductor manufacturing and MEMS manufacturing, 6025 size (152mm×152mm) or 5009 size (126.6mm×126.6mm) is used, and for printed circuit boards, 7012 size (177.4mm×177.4mm) or 9012 size (228.6mm× 228.6mm) is used.

10...Phase shift mask blank (photo mask blank)
20... transparent substrate
30... phase shift film (thin film for pattern formation)
30a...Phase shift film pattern (transfer pattern)
40... etching mask film
40a... first etching mask film pattern
40b... second etching mask film pattern
50... first resist film pattern
60... second resist film pattern
100...Phase shift mask (photo mask)

Claims (11)

As a photo mask blank comprising a thin film for pattern formation on a transparent substrate,
The photomask blank is an original plate for forming a photomask, and the photomask is a photomask including a transfer pattern on the transparent substrate obtained by wet etching the thin film for pattern formation,
The pattern forming thin film contains a transition metal, silicon, oxygen, and nitrogen, and the oxygen content obtained by analysis by XPS is 1 atomic% or more and 70 atomic% or less, and the transparent substrate and the pattern When the interface of the forming thin film is defined as a position where the content rate of the transition metal included in the pattern forming thin film obtained by analyzing by the XPS is 0 atomic%, 30 nm from the interface toward the surface of the pattern forming thin film A photo mask blank, characterized in that the ratio of nitrogen to oxygen has a maximum value in the region within. The method of claim 1,
The photomask blank, wherein the transition metal is molybdenum. The method of claim 1,
The photomask blank, wherein the oxygen content is 5 atomic% or more and 70 atomic% or less. The method of claim 1,
The photomask blank, wherein the nitrogen content is 35 atomic% or more and 60 atomic% or less. The method of claim 1,
The photo mask blank, characterized in that the thin film for pattern formation comprises a columnar structure. The method of claim 1,
The pattern forming thin film is a phase shift film having optical properties of a transmittance of 1% or more and 80% or less and a phase difference of 160° or more and 200° or less with respect to a representative wavelength of exposure light. The method of claim 1,
A photo mask blank comprising an etching mask film having a different etching selectivity with respect to the pattern forming thin film on the pattern forming thin film. The method of claim 7,
The photo mask blank, wherein the etching mask film contains a material containing chromium and substantially not containing silicon. The step of preparing the photomask blank according to claim 1, and
Forming a resist film on the pattern forming thin film, wet etching the pattern forming thin film using the resist film pattern formed with the resist film as a mask, and forming the transfer pattern on the transparent substrate The manufacturing method of the photomask made into. The step of preparing the photomask blank according to claim 7, and
Forming a resist film on the etching mask film, wet etching the etching mask film using the resist film pattern formed from the resist film as a mask, and forming an etching mask film pattern on the pattern forming thin film;
And forming the transfer pattern on the transparent substrate by wet etching the pattern forming thin film using the etching mask film pattern as a mask. Exposure in which the photomask obtained by the method for manufacturing a photomask according to claim 9 or 10 is placed on a mask stage of an exposure apparatus, and the transfer pattern formed on the photomask is exposed and transferred to a resist film formed on a display device substrate. A method of manufacturing a display device comprising a step.

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