TWI828864B - Photomask blank, method for manufacturing photomask, and method for manufacturing display device - Google Patents

Abstract

Provided is a photomask blank in which, in a transfer pattern formed on a transparent substrate by wet-etching a thin film for pattern formation at an over-etching time, penetration can be prevented at an interface with the transparent substrate.

A photomask blank is an original form for forming a photomask having a transfer pattern on a transparent substrate by wet-etching the thin film for pattern formation. The thin film for pattern formation contains a transition metal, silicon, oxygen, and nitrogen, and contains 1 atomic% or more and 70 atomic% or less oxygen when analyzed by XPS. When an interface of the transparent substrate and the thin film for pattern formation is defined as a position where the content rate of the transition metal contained in the thin film for pattern formation obtained by the XPS is in the position of 0 atomic%, the ratio of nitrogen to oxygen shows the maximum value at a region of 30nm from the interface to the surface of the thin film for pattern formation.

Description

Photomask substrate, photomask manufacturing method, and display device manufacturing method

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

In recent years, display devices such as FPD (Flat Panel Display), represented by LCD (Liquid Crystal Display), have been rapidly developing towards larger screens, wider viewing angles, high definition, and high-speed displays. One of the elements required for this high-definition and high-speed display is the production of electronic circuit patterns such as components and wiring that are fine and have high dimensional accuracy. The patterning of electronic circuits for display devices often uses photolithography. Therefore, there is a need for a phase shift mask for manufacturing display devices in which fine and high-precision patterns are formed.

For example, Patent Document 1 discloses a blank mask for flat panel displays and a photomask using the same. When wet etching a film containing molybdenum silicide, phosphoric acid, hydrogen peroxide, and ammonium fluoride are used in water. The diluted etching solution is used to wet-etch the film containing molybdenum silicide to minimize damage to the transparent substrate. Furthermore, Patent Document 2 discloses a phase inversion blank mask and a photomask. In order to improve the precision of the pattern, the phase inversion film 104 has different compositions that can be etched with the same etching solution. The film is formed in the form of a multilayer film or a continuous film in which at least two layers of films with different compositions are laminated one or more times. [Prior technical literature] [Patent Document]

[Patent Document 1] Korean Patent Application Publication No. 10-2016-0024204 [Patent Document 2] Japanese Patent Application Publication No. 2017-167512

[Problem to be solved by the invention]

In recent years, in order to reliably transfer fine patterns of less than 2.0 μm as a phase shift mask base for manufacturing such display devices, studies have been conducted on using a ratio of a fixed or higher ratio (for example, 5 atomic % or more, and further 10 atomic %). The above) A phase shift film containing oxygen is a phase shift film having optical properties such that the transmittance of the phase shift film for exposure light is 10% or more, and further 20% or more.

In addition, the size of the phase shift mask substrate used for manufacturing display devices is greatly increased compared with the phase shift mask substrate used for manufacturing semiconductor devices. In the case where the phase shift film of a phase shift mask substrate with a larger size forms a phase shift film pattern, even if the wet etching is performed at the right time to expose the transparent substrate to the phase shift film pattern (appropriate etching time), It is unavoidable that the CD (Critical Dimension) deviation of the in-plane distribution is greater than 100 nm. In order to make the CD deviation of the phase shift film pattern less than 100 nm, it is required to perform wet etching with a relatively long etching time (over-etching time).

It is known that when a phase shift film having an oxygen content of more than a specific value, for example, 5 atomic % or more, and further 10 atomic % or more is patterned by wet etching for an excessive etching time, wet etching The liquid will penetrate into the interface between the phase shift film and the transparent substrate, causing the etching of the interface part to proceed in advance. The cross-sectional shape of the edge portion of the formed phase shift film pattern will become a shape that causes so-called erosion due to the penetration of the wet etching liquid.

When the cross-sectional shape of the edge portion of the phase shift film pattern is a shape that causes erosion, the phase shift effect is weakened. Therefore, the phase shift effect cannot be fully exerted, and fine patterns less than 2.0 μm cannot be stably transferred. If the oxygen content in the phase shift film is set to a certain level or more, for example, 5 atomic % or more, or 10 atomic % or more, it will be difficult to strictly control the cross-sectional shape of the edge portion of the phase shift film pattern, making it very difficult to control the line width. (CD). Furthermore, the same problem also exists when a light-shielding pattern is formed on the light-shielding film by wet etching in a binary mask substrate having a light-shielding film containing transition metal, silicon, oxygen, and nitrogen.

The present invention was made in order to solve the above-mentioned previous problems, and an object thereof is to provide a method for suppressing the interface between a transfer pattern formed on a transparent substrate by wet etching a pattern-forming film for an excessive etching time and the interface with the transparent substrate. A photomask substrate where infiltration occurs, a photomask manufacturing method, and a display device manufacturing method. [Technical means to solve problems]

In order to solve these problems, the inventors of the present invention carried out a method of suppressing the occurrence of infiltration at the interface with the transparent substrate in the transfer pattern formed on the transparent substrate by wet etching the pattern forming film for an excessive etching time. Dedicated research. The inventors initially believed that in a pattern-forming film containing a transition metal, silicon, oxygen, and nitrogen, the main factor causing infiltration at the interface with a transparent substrate is the absolute amount of oxygen in the pattern-forming film. However, even if the absolute amount of oxygen in the pattern-forming film is the same, there are cases where penetration occurs at the interface with the transparent substrate and cases where penetration does not occur. The present inventors then conducted further research and found that the ratio of nitrogen to oxygen in the composition region of the pattern forming film formed on the interface side with the transparent substrate has a great influence on the penetration at the interface with the transparent substrate. Then, the present inventors conducted further research and found that if the following structure is adopted, that is, the oxygen content rate in the pattern forming film analyzed by XPS (X-ray Photoelectron Spectroscopy: X-ray photoelectron spectroscopy) It is 1 atomic % or more and 70 atomic % or less (especially, the oxygen content is 5 atomic % or more and 70 atomic % or less), when defined as the content of the transition metal contained in the pattern forming thin film analyzed by XPS When the ratio is 0 atomic %, the ratio of nitrogen to oxygen has a maximum value in the region within 30 nm from the interface to the surface of the pattern forming film. Even if the pattern forming film is wetted for an over-etching time, the ratio of nitrogen to oxygen has a maximum value. The transfer pattern is formed by etching, and the penetration at the interface between the transfer pattern and the transparent substrate is also suppressed. The present inventors speculate that the above-mentioned structure can suppress penetration at the interface with the transparent substrate for the following reasons. When the pattern-forming film is measured by XPS, as a characteristic of the measurement, a composition gradient region in which the composition of the film is gradient appears in a region of 30 nm from the interface with the transparent substrate specified by the XPS measurement. The transition metal and silicon in the pattern forming thin film are components derived from the target, and their composition ratio is approximately the same as that of the target. On the other hand, the oxygen and nitrogen in the pattern forming film are components derived from gases. Since the amount of gas that can be taken into the pattern forming film is limited, it is considered that if the amount of nitrogen taken in increases, the amount of oxygen will decrease. Furthermore, oxygen is an element that accelerates the etching rate of wet etching, whereas nitrogen is an element that slows down the etching rate of wet etching. Therefore, the ratio of nitrogen to oxygen (N/O) becomes important in terms of the characteristics of the pattern forming thin film. It is estimated that if it is a pattern-forming thin film with a maximum value of the ratio of nitrogen to oxygen (N/O) in the region within 30 nm from the interface with the transparent substrate specified by XPS measurement, the etching rate will be between The interface around the transparent substrate moderately slows down, thereby inhibiting penetration and the occurrence of corrosion. Furthermore, these speculations are based on current knowledge and do not limit the scope of the present invention in any way. The present invention is the result of intensive research as described above and has the following constitution.

(composition 1) A photomask substrate, characterized in that it has a pattern forming film on a transparent substrate, The above-mentioned photomask base is used to form the original plate of the photomask, the above-mentioned photomask is obtained by wet etching the above-mentioned pattern forming film, and has a transfer pattern on the above-mentioned transparent substrate, The pattern-forming thin film contains a transition metal, silicon, oxygen, and nitrogen, and the oxygen content obtained by XPS analysis is 1 atomic % or more and 70 atomic % or less, and the transparent substrate and the pattern-forming thin film are combined. The interface is defined as a position within 30 nm from the interface to the surface of the pattern-forming film where the content of the transition metal contained in the pattern-forming film obtained by the XPS analysis is 0 atomic %. In this region, the ratio of nitrogen to oxygen has a maximum value.

(composition 2) The photomask substrate constituting 1 is characterized in that the transition metal is molybdenum.

(composition 3) The photomask base constituting 1 or 2 is characterized in that the oxygen content is 5 atomic % or more and 70 atomic % or less. (Constitution 4) The photomask base constituting any one of 1 to 3 is characterized in that the nitrogen content is 35 atomic % or more and 60 atomic % or less. (Constitution 5) The photomask base constituting any one of items 1 to 4, characterized in that the pattern forming film has a columnar structure.

(composition 6) The photomask base constituting any one of 1 to 5, characterized in that the pattern forming film has a representative wavelength transmittance of 1% or more and 80% or less with respect to exposure light and a phase difference of 160° or more and 200° or less. The optical properties of the phase shift film.

(composition 7) The photomask base according to any one of constitutions 1 to 6, characterized in that the pattern forming film is provided with an etching mask film having different etching selectivities with respect to the pattern forming film.

(composition 8) The photomask base constituting 7 is characterized in that the etching mask film contains a material containing chromium and substantially free of silicon.

(Composition 9) A method for manufacturing a photomask, which is characterized by including the following steps: Preparing a photomask substrate constituting any one of 1 to 6; and A resist film is formed on the pattern-forming film, and the pattern-forming film is wet-etched using the resist film pattern formed from the resist film as a mask to form the transfer pattern on the transparent substrate.

(composition 10) A method for manufacturing a photomask, which is characterized by including the following steps: Prepare the photomask base that constitutes 7 or 8; A resist film is formed on the etching mask film, and the etching mask film is wet-etched using the resist film pattern formed from the resist film as a mask, and the etching mask film is formed on the pattern forming film. pattern; and The pattern forming film is wet-etched using the etching mask film pattern as a mask to form the transfer pattern on the transparent substrate.

(Composition 11) A method of manufacturing a display device, characterized by including an exposure step in which a photomask obtained by the method of manufacturing a photomask of constitution 9 or 10 is placed on a photomask stage of an exposure device, and the photomask formed on the photomask is The above transfer pattern is exposed and transferred to the resist film formed on the display device substrate. [Effects of the invention]

According to the photomask substrate of the present invention, even if the pattern forming film is wet-etched for an excessive etching time, the pattern forming film can be patterned into a cross-sectional shape having a good cross-sectional shape that suppresses infiltration at the interface with the transparent substrate. The photomask base. Furthermore, by wet etching, it is possible to produce a photomask substrate in which the pattern forming film can be patterned into a cross-sectional shape in which the CD deviation of the in-plane distribution is small.

Furthermore, according to the photomask manufacturing method of the present invention, the photomask is manufactured using the above photomask base. Therefore, a photomask with a good transfer pattern can be produced. In addition, it is possible to produce a photomask having a transfer pattern with a smaller CD deviation in the in-plane distribution. This photomask can handle the miniaturization of line and space patterns or contact holes.

Furthermore, according to the manufacturing method of the display device of the present invention, the display device is manufactured using the mask produced using the above-mentioned mask base or the mask obtained by the above-mentioned mask manufacturing method. Therefore, a display device with fine line and gap patterns or contact holes can be manufactured.

Each embodiment of the present invention will be described below. In each embodiment, the case where the mask base is a phase shift mask base and the pattern forming thin film is a phase shift film has been described, but the content of the present invention is not limited to this. Implementation form 1.2. In Embodiments 1 and 2, the phase shift mask base is explained. The phase shift mask substrate of Embodiment 1 is formed on a transparent substrate by wet etching the phase shift film using an etching mask film pattern that forms a desired pattern on the etching mask film as a mask. Master of phase shift mask with phase shift film pattern. In addition, the phase shift mask base of Embodiment 2 is formed on a transparent substrate by wet etching the phase shift film using a resist film pattern formed with a desired pattern on the resist film as a mask. A master plate of a phase shift film with a phase shift film pattern.

FIG. 1 is a schematic diagram showing the film structure of the phase shift mask base 10 according to Embodiment 1. The phase shift mask substrate 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 . FIG. 2 is a schematic diagram showing the film structure of the phase shift mask base 10 according to the second embodiment. The phase shift mask substrate 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 base 10 of Embodiments 1 and 2 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, preferably 90% or more, for exposure light. The transparent substrate 20 includes a material containing silicon and oxygen, and may be composed of glass materials such as synthetic quartz glass, quartz glass, aluminosilicate glass, soda-lime glass, low thermal expansion glass (SiO ₂ -TiO ₂ glass, etc.). When the transparent substrate 20 is made of low thermal expansion glass, positional changes in the phase shift film pattern caused by thermal deformation of the transparent substrate 20 can be suppressed. In addition, the transparent substrate 20 for a phase shift mask base used for a display device generally uses a rectangular substrate and the length of the short side of the transparent substrate is 300 mm or more. The present invention can provide a phase shift mask base for a phase shift mask that can be stably transferred and formed on a transparent substrate even if the length of the short side of the transparent substrate is larger than 300 mm. The above example is a fine phase shift film pattern of less than 2.0 μm.

The phase shift film 30 includes a transition metal silicide-based material containing transition metal, silicon, oxygen, and nitrogen. As the transition metal, molybdenum (Mo), tantalum (Ta), tungsten (W), titanium (Ti), zirconium (Zr), etc. are preferred. If nitrogen is contained, the refractive index can be increased, so it is preferable in terms of a thin film thickness that can be used to obtain a phase difference. Furthermore, if the content rate 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 achieved. The content rate of nitrogen contained in the phase shift film 30 is preferably 35 atomic % or more and 60 atomic % or less. Ideally, the content is more preferably 37 atomic % or more and 55 atomic % or less, and still more preferably 40 atomic % or more and 50 atomic % or less. Examples of transition metal silicide-based materials include transition metal silicide oxynitrides and transition metal silicide carbonitride oxides. 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), it can be easily processed by a wet process It is preferable in terms of obtaining an excellent cross-sectional shape of the pattern during etching. In addition, in addition to the above-mentioned oxygen and nitrogen, the phase shift film 30 may also contain other light element components such as carbon or helium for the purpose of reducing film stress or controlling the wet etching rate. The phase shift film 30 has the function of adjusting the reflectance (hereinafter sometimes referred to as back surface reflectance) for light incident from the transparent substrate 20 side, and the function of adjusting the transmittance and phase difference of the exposed light. The phase shift film 30 can be formed by sputtering.

The transmittance of the phase shift film 30 for exposure light satisfies the value required for the phase shift film 30 . The transmittance of the phase shift film 30 is preferably not less than 1% and not more than 80%, more preferably not less than 5% and not more than 70%, and still more preferably not less than 1% and not more than 80% for the light of a specific wavelength (hereinafter referred to as the representative wavelength) included in the exposure light. More than 10% and less than 60%. That is, when the exposed light is composite light including light in the wavelength range of 313 nm to 436 nm, the phase shift film 30 has the above-mentioned transmittance for the light of the representative wavelength included in the wavelength range. For example, when the exposure light is a composite light including i rays, h rays, and g rays, the phase shift film 30 has the above-mentioned transmittance for any of the i rays, h rays, and g rays. 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 set the transmittance of the phase shift film 30 to the above-mentioned transmittance, the atomic ratio of the transition metal and silicon is 1:1 or more and 1:15 or less. In order to improve the chemical resistance (cleaning 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, and further preferably 1:4 or more and 1:10 or less. . 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 the required value for the phase shift film 30 . The phase difference of the phase shift film 30 is preferably not less than 160° and not more than 200°, more preferably not less than 170° and not more than 190° with respect to the light representative wavelength included in the exposure light. With this property, the phase of the representative wavelength of light contained in the exposed light can be changed within the range of 160° to 200°. Therefore, a phase difference of not less than 160° and not more than 200° is generated between the light of the representative wavelength transmitted through the phase shift film 30 and the light of the representative wavelength transmitted only through the transparent substrate 20 . That is, when the exposed light is composite light including light in the wavelength range of 313 nm to 436 nm, the phase shift film 30 has the above-mentioned phase difference with respect to the light of the representative wavelength included in the wavelength range. For example, when the exposure light is a composite light including i rays, h rays, and g rays, the phase shift film 30 has the above-mentioned phase difference with respect to any one of the i rays, h rays, and g rays. The phase difference can be measured using a phase shift amount measuring device or the like.

The back surface reflectance of the phase shift film 30 is 15% or less in the wavelength range of 365 nm to 436 nm, preferably 10% or less. Furthermore, when the exposure light includes j rays, the backside reflectivity of the phase shift film 30 is preferably 20% or less, more preferably 17% or less, for light in the wavelength range of 313 nm to 436 nm. It is ideal and more preferably 15% or less. In addition, the back surface reflectance of the phase shift film 30 is 0.2% or more in the wavelength range of 365 nm to 436 nm, preferably 0.2% or more for 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 achieves the above-mentioned phase difference and transmittance, and if necessary, so that the phase shift film 30 achieves the above-mentioned back surface reflectivity. Specifically, the phase shift film 30 is configured such that the oxygen content is 1 atomic % or more and 70 atomic % or less. The content rate of oxygen contained in the phase shift film 30 is preferably 5 atomic % or more and 70 atomic % or less, and more preferably 10 atomic % or more and 60 atomic % or less. The phase shift film 30 may include multiple 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 not easily 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 including a plurality of layers is preferable in terms of ease of film formation and the like. In addition, the light element of nitrogen or oxygen contained in the phase shift film 30 may be uniformly contained in the film thickness direction of the phase shift film 30, or may be increased or decreased stepwise or continuously. Furthermore, it is preferable that the nitrogen content and the oxygen content be the above-mentioned specific content in a region of 50% or more of the film thickness of the phase shift film 30 .

Furthermore, when the interface between the transparent substrate 20 and the phase shift film 30 is defined as a position where the content rate of the transition metal contained in the phase shift film 30 obtained by XPS analysis is 0 atomic %, the phase shift film 30 In a region within 30 nm from this interface to the surface of the phase shift film 30, the ratio of nitrogen to oxygen has a maximum value. Furthermore, the maximum value is not limited to the maximum value in the mathematical sense, but also includes the N/O value observed from the transparent substrate side in the region within 30 nm from the above-mentioned interface as shown in Figure 9. The point at which change changes from increase to decrease.

In addition, the phase shift film 30 of the phase shift mask base 10 is required to have high chemical resistance (cleaning resistance). In order to improve the chemical resistance (cleaning resistance) of the phase shift film 30, it is effective to increase the film density. There is a correlation between the film density of the phase shift film 30 and the film stress. Considering chemical resistance (cleaning resistance), the higher the film stress of the phase shift film 30, the better. On the other hand, regarding the film stress of the phase shift film 30, it is necessary to consider the positional shift when forming the phase shift film pattern or the lack of the phase shift film pattern. From the above viewpoint, the film stress of the phase shift film 30 is preferably not less than 0.2 GPa and not more than 0.8 GPa, and further preferably not less than 0.4 GPa and not more than 0.8 GPa. In addition, the phase shift film 30 of the phase shift mask substrate 10 preferably has a columnar structure. The columnar structure can be confirmed by cross-sectional SEM (scanning electron microscope) observation of the phase shift film 30 . That is, the so-called columnar structure means that the particles of the transition metal silicide compound containing transition metal, silicon, oxygen, and nitrogen that constitute the phase shift film 30 extend in the film thickness direction of the phase shift film 30 (the direction in which the above-mentioned particles are deposited). The state of the columnar particle structure. By forming the phase shift film 30 into a columnar structure, side etching during wet etching of the phase shift film 30 can be effectively suppressed, resulting in a better pattern cross-sectional shape. Furthermore, as a preferred form of the columnar structure, columnar particles extending in the film thickness direction are preferably formed irregularly in the film thickness direction. Furthermore, it is preferable that the lengths of the columnar particles of the phase shift film 30 in the film thickness direction are inconsistent. Furthermore, it is preferable that sparse portions (hereinafter, simply referred to as “sparse portions”) having a relatively lower density than columnar particles are formed continuously in the film thickness direction in the phase shift film 30 .

The etching mask film 40 is disposed on the upper side of the phase shift film 30 and includes a material with etching resistance (different etching selectivity) to the etching liquid used to etch the phase shift film 30 . In addition, the etching mask film 40 can have the function of blocking the transmission of exposure light, and further, can also have the function of reducing the film surface reflectivity, so that the phase shift film 30 can reflect the film surface of the light incident from the phase shift film 30 side. The rate becomes less than 15% in the wavelength range of 350 nm to 436 nm. The etching mask film 40 preferably contains a material containing chromium and substantially not containing silicon (chromium-based material). More specifically, the chromium-based material may include chromium (Cr) or a material containing at least one of chromium (Cr) and oxygen (O), nitrogen (N), or carbon (C). Alternatively, a material containing at least one of chromium (Cr) and oxygen (O), nitrogen (N), and carbon (C) and further containing fluorine (F) can be cited. For example, materials 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 the transmission of exposure light, the optical density of the portion where the phase shift film 30 and the etching mask film 40 are laminated relative to the exposure light is preferably 3.0 or more. More preferably, it is 3.5 or more, and still more preferably, it is 4.0 or more. The optical density can be measured using a spectrophotometer or an OD (Optical Density) meter.

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

Furthermore, the phase shift mask substrate 10 shown in FIG. 1 is provided with the etching mask film 40 on the phase shift film 30 , but it may also be provided with the etching mask film 40 on the phase shift film 30 and the etching mask film 40 The present invention is applied to a phase shift mask substrate with a resist film on it.

Furthermore, the phase shift mask substrate 10 is preferably configured such that 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 contained in the composition gradient region gradually and/or gradually increases in the depth direction. A continuously increasing area. More specifically, it is preferable that the ratio of oxygen in the depth direction from the interface between the phase shift film 30 and the etching mask film 40 toward the transparent substrate 20 side is gradually and/or Continuously increasing area. Furthermore, the phase shift mask base 10 is preferably configured to have an oxygen to silicon content ratio of 3.0 or less throughout a region extending to a depth of 10 nm from the interface between the phase shift film 30 and the etching mask film 40 . When the composition of the phase shift mask substrate 10 is analyzed by X-ray photoelectron spectroscopy, the ratio of the transition metal decreases from the phase shift film 30 toward the etching mask film 40, bringing the content of the transition metal to 0 atomic % for the first time. The location is set to this interface. In addition, the composition gradient region mentioned here refers to the 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, and the content of the transition metal becomes The ratio of 0 atomic %) to chromium decreases from the etching mask film 40 toward the phase shift film 30 until the chromium content becomes 0 atomic % for the first time. The content ratio of oxygen to silicon in the region at 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, still more preferably 2.5 or less, and still more preferably Preferably it is 2.0 or less. Furthermore, from the viewpoint of film quality continuity between the phase shift film 30 and the composition gradient region, the content ratio of oxygen to silicon is preferably 0.3 or more, and more preferably 0.5 or more.

Next, the manufacturing method of the phase shift mask base 10 of Embodiment 1 and 2 is demonstrated. The phase shift mask substrate 10 shown in FIG. 1 is manufactured by performing the following aging steps, phase shift film forming steps and etching mask film forming steps. The phase shift mask substrate 10 shown in FIG. 2 is manufactured through an aging step and a phase shift film forming step. Each step is explained in detail below.

1. Aging steps First, an aging step is performed before the transparent substrate 20 is introduced into the film forming chamber. That is, the sputtering method is used to fly particles from the target so that the surface state of the target is close to the surface state during the thin film forming step. In the aging steps of Embodiments 1 and 2, in addition to rare gases (argon gas, etc.) with high sputtering efficiency, nitrogen gas is also introduced into the film-forming chamber, so that the plasma of the rare gas and nitrogen collides with the surface of the target. The atoms constituting the surface of the target are blown away, thereby cleaning the surface of the target. Furthermore, rare gas and nitrogen gas are allowed to remain in the film forming chamber.

2. Phase Shift Film Formation Step Next, the transparent substrate 20 is prepared. The transparent substrate 20 may be made of any glass material such as synthetic quartz glass, quartz glass, aluminosilicate glass, soda-lime glass, low thermal expansion glass (SiO ₂ -TiO ₂ glass, etc.) as long as it is transparent to exposure light. By.

Then, the phase shift film 30 is formed on the transparent substrate 20 by sputtering. The phase shift film 30 is formed using a sputtering target containing a transition metal and silicon as the main components of the material constituting the phase shift film 30, or a sputtering target containing a transition metal, silicon, and oxygen and/or nitrogen. For example, It is carried out in a sputtering gas atmosphere composed of a mixture of a sputtering gas atmosphere and an active gas. The sputtering gas atmosphere consists of at least one inert gas selected from the group consisting of helium, neon, argon, krypton and xenon. Composed of gas, the active gas system is selected from the group consisting of oxygen, nitrogen, carbon dioxide gas, nitric oxide gas, and nitrogen dioxide gas, and contains at least oxygen and nitrogen.

Through the above aging step, the phase shift film 30 is formed with nitrogen remaining in the film forming chamber. Therefore, nitrogen is introduced into the phase shift film 30 from the beginning of film formation. On the other hand, the amount of nitrogen remaining in the film formation chamber is a fixed amount, and it takes a certain amount of time for the mixed gas supplied during the phase shift film formation step 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 taken into the phase shift film 30 or discharged, and therefore is insufficient for the phase shift taken in later. The amount of nitrogen in the membrane is temporarily reduced. On the other hand, it is considered that when the amount of nitrogen introduced into the phase shift film 30 decreases as described above, the amount of oxygen increases, and the ratio of nitrogen to oxygen (N/O) temporarily decreases. Thereafter, the mixed gas supplied to the film forming chamber spreads throughout the film forming chamber, and the amount of nitrogen in the phase shift film and the ratio of nitrogen to oxygen (N/O) increase again. In this manner, the phase shift film 30 has a maximum value in the ratio of nitrogen to oxygen in the vicinity of the transparent substrate 20 side (the region within 30 nm from the interface obtained by XPS analysis). The composition and thickness of the phase shift film 30 are adjusted so that the phase shift film 30 achieves the above-mentioned phase difference and transmittance. The composition of the phase shift film 30 can be controlled by the content ratio of elements constituting the sputtering target (for example, the ratio of the content ratio of transition metal to the content ratio of silicon), 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, etc. In addition, when the sputtering device is a continuous sputtering device, the thickness of the phase shift film 30 can also be controlled by the conveyance speed of the substrate. In this way, the oxygen content of the phase shift film 30 is controlled so that it becomes 1 atomic % or more and 70 atomic % or less.

When the phase shift films 30 are each composed of a single film with a uniform composition, the above-mentioned film forming process is only performed once without changing the composition and flow rate of the sputtering gas. When the phase shift film 30 includes a plurality of films with different compositions, the composition and flow rate of the sputtering gas are changed for each film formation process, and the above film formation process is performed a plurality of times. 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 is composed of a single film whose composition continuously changes in the thickness direction, the composition and flow rate of the sputtering gas are changed with the passage of time in the film formation process and only the above-mentioned film formation process 1 is performed. Second-rate. When performing a plurality of film forming processes, the sputtering power applied to the sputtering target can be reduced.

3. Surface treatment steps After the phase shift film 30 including the transition metal silicide material containing transition metal, silicon and oxygen is formed, the surface of the phase shift film 30 is easily oxidized, and transition metal oxides are easily generated. In order to prevent the etching liquid from penetrating due to the presence of transition metal oxides, a surface treatment step is performed to adjust the surface oxidation state of the phase shift film 30 . Examples of surface treatment steps for adjusting the surface oxidation state of the phase shift film 30 include surface treatment with an acidic aqueous solution, surface treatment with an alkaline aqueous solution, and surface treatment with dry treatment such as ashing. wait. After the etching mask film formation step described below, any surface treatment step can be performed as long as a composition gradient region is formed at the interface between the phase shift film 30 and the etching mask film 40. In the composition gradient region, the ratio of oxygen is In a region that increases stepwise and/or continuously in the depth direction, and further in a region with a depth of 10 nm from the interface between the phase shift film 30 and the etching mask film 40, the oxygen to silicon content ratio becomes 3.0 or less, that is, Can. For example, in the surface treatment method using an acidic aqueous solution or the surface treatment method using an alkaline aqueous solution, the surface of the phase shift film 30 can be adjusted by appropriately adjusting the concentration, temperature, and time of the acidic or alkaline aqueous solution. The state of oxidation. Examples of the surface treatment method using an acidic aqueous solution and the surface treatment method using an alkaline aqueous solution include a method of immersing a substrate with a phase shift film on which the phase shift film 30 is formed on the transparent substrate 20 in the above aqueous solution. Or a method of bringing the above-mentioned aqueous solution into contact with the phase shift film 30, etc. From the viewpoint of improving the cross-sectional shape at the interface with the etching mask film 40, it is preferable to perform this surface treatment step, but it is not a necessary step. In this way, the phase shift mask base 10 of Embodiment 2 can be obtained. The phase shift mask substrate 10 of Embodiment 1 is manufactured by further performing the following steps of forming an etching mask film.

4. Etching mask film formation steps After performing surface 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 a sputtering method. In this way, the phase shift mask substrate 10 is obtained. The etching mask film 40 is formed by using a sputtering target containing chromium or a chromium compound (chromium oxide, chromium nitride, chromium carbide, chromium oxynitride, chromium oxycarbonitride, etc.), for example, in a gas containing helium gas. , a sputtering gas atmosphere composed of at least one inert gas selected from the group consisting of neon, argon, krypton and xenon, or a sputtering gas atmosphere containing a group selected from the group consisting of helium, neon, argon, krypton and xenon A sputter consisting of at least one inert gas and a mixed gas containing at least one active gas selected from the group consisting of oxygen, nitrogen, nitric oxide gas, nitrogen dioxide gas, carbon dioxide gas, hydrocarbon gas, and fluorine gas. Conducted under plating gas atmosphere. Examples of the hydrocarbon-based gas include methane gas, butane gas, propane gas, styrene gas, and the like.

When the etching mask film 40 is composed of a single film with a uniform composition, the above-mentioned film forming process is only performed once without changing the composition and flow rate of the sputtering gas. When the etching mask film 40 includes a plurality of films with different compositions, the composition and flow rate of the sputtering gas are changed for each film-forming process, and the above-mentioned film-forming process is performed a plurality of times. When the etching mask film 40 is composed of a single film whose composition continuously changes in the thickness direction, the composition and flow rate of the sputtering gas are changed with the passage of time in the film formation process, and only the above-mentioned film formation is performed. Process 1 time. In this way, the phase shift mask base 10 of Embodiment 1 can be obtained.

By performing the film formation process of the phase shift film 30 and the etching mask film 40 in this way, and adjusting the surface oxidation state of the surface of the phase shift film 30, the phase shift film 30 and the etching mask film 40 can be formed. In order to form a composition gradient region at the interface between the phase shift film 30 and the etching mask film 40, the composition gradient region includes a region in which the ratio of oxygen increases stepwise and/or continuously in the depth direction, throughout the self-phase shift The content ratio of oxygen to silicon in a region with a depth of 10 nm from the interface between the film and the etching mask film is 3.0 or less.

Furthermore, the surface treatment for adjusting the surface oxidation state of the surface of the phase shift film 30 has been described. However, in the film formation process of the phase shift film 30, the phase shift may be changed in the second half of the film formation process. The surface of the film 30 is not easily oxidized by gas species or by adding the above-mentioned gas species, so that the ratio of oxygen in the composition gradient region including the above-mentioned composition gradient region increases stepwise and/or continuously in the depth direction. The content ratio of oxygen to silicon in a region at a depth of 10 nm from the interface between the phase shift film and the etching mask film is set to 3.0 or less.

Furthermore, the phase shift mask substrate 10 shown in FIG. 1 is provided with an etching mask film 40 on the phase shift film 30. Therefore, when manufacturing the phase shift mask substrate 10, an etching mask film forming step is performed. In addition, when the phase shift mask substrate is manufactured with the etching mask film 40 on the phase shift film 30 and the resist film on the etching mask film 40, after the etching mask film forming step, the etching mask film is A resist film is formed on 40. Furthermore, when a phase shift mask substrate having a resist film on the phase shift film 30 is manufactured in the phase shift mask substrate 10 shown in FIG. 2 , the resist film is formed after the phase shift film forming step.

The phase shift mask base 10 of Embodiments 1 and 2 is configured such that the phase shift film 30 contains a transition metal, silicon, oxygen, and nitrogen, and the oxygen content obtained by XPS analysis is 1 atom. % or more and 70 atomic % or less (preferably, the oxygen content is 5 atomic % or more and 70 atomic % or less), and the interface between the transparent substrate 20 and the phase shift film 30 is defined as the phase shift film analyzed by XPS When the content rate of the transition metal contained in 30 is 0 atomic %, the ratio of nitrogen to oxygen has a maximum value in a region within 30 nm from the interface to the surface of the phase shift film 30 . Thereby, in the phase shift film pattern 30a formed on the transparent substrate 20 by wet-etching the phase shift film 30 with an over-etching time, penetration at the interface with the transparent substrate 20 is suppressed. In addition, the phase shift mask substrate 10 of Embodiment 1 can form a phase shift film pattern 30 a with good cross-sectional shape, small CD deviation in in-plane distribution, and high transmittance by wet etching. Therefore, a phase shift mask substrate capable of manufacturing the phase shift mask 100 capable of transferring the high-definition phase shift film pattern 30a with high accuracy can be obtained.

Implementation form 3.4. In Embodiments 3 and 4, a method of manufacturing the phase shift mask 100 will be described.

FIG. 3 is a schematic diagram showing a manufacturing method of the phase shift mask according to Embodiment 3. FIG. 4 is a schematic diagram showing a manufacturing method of the phase shift mask according to Embodiment 4. The manufacturing method of the phase shift mask shown in Figure 3 is a method of manufacturing the phase shift mask using the phase shift mask substrate 10 shown in Figure 1, including the following on the etching mask film 40 of the phase shift mask substrate 10 The step of forming the resist film is to form a first resist film pattern 50 by drawing a desired pattern on the resist film and developing it (first resist film pattern forming step). The first resist film pattern 50 is The step of wet etching the etching mask film 40 as a mask to form the first etching mask film pattern 40 a on the phase shift film 30 (the first etching mask film pattern forming step), and applying the first etching mask film 40 to the phase shift film 30 . The phase shift film 30 is wet-etched using the film pattern 40a as a mask to form the phase shift film pattern 30a on the transparent substrate 20 (phase shift film pattern forming step). Furthermore, it further includes a second resist film pattern forming step and a second etching mask film pattern forming step.

The manufacturing method of the phase shift mask shown in FIG. 4 is a method of manufacturing the phase shift mask using the phase shift mask substrate 10 shown in FIG. 2, and includes the following steps of forming a resist film on the phase shift mask substrate 10. , forming the first resist film pattern 50 by drawing a desired pattern on the resist film and developing it (first resist film pattern forming step), and using the first resist film pattern 50 as a mask to the opposite surface The transfer film 30 is subjected to wet etching to form a phase shift film pattern 30 a on the transparent substrate 20 (phase shift film pattern forming step). Hereinafter, each step of the manufacturing process of the phase shift mask according to Embodiments 3 and 4 will be described in detail.

Manufacturing steps of phase shift mask according to Embodiment 3 1. First resist film pattern forming step In the first resist film pattern forming step, first, a resist film is formed on the etching mask film 40 of the phase shift mask substrate 10 of the first embodiment. The resist film material used is not particularly limited. For example, it suffices as long as it is sensitive to laser light having any wavelength selected from the following wavelength range of 350 nm to 436 nm. In addition, the resist film may be either a positive type or a negative type. Thereafter, the desired pattern is drawn on the resist film using laser light with any wavelength selected from the wavelength range of 350 nm to 436 nm. The pattern drawn on the resist film is a pattern formed on the phase shift film 30 . Examples of patterns drawn on the resist film include line and space patterns and hole patterns. Thereafter, the resist film is developed using a specific developer, and as shown in FIG. 3(a) , a first resist film pattern 50 is formed on the etching mask film 40 .

2. The first etching mask film pattern formation step 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 to form the first etching mask film pattern 40a. The etching mask film 40 is formed of a chromium-based material containing chromium (Cr) and substantially free of silicon. The etching liquid used to etch the etching mask film 40 is not particularly limited as long as it can selectively etch the etching mask film 40 . Specific examples include an etching solution containing ceric ammonium nitrate and perchloric acid. Thereafter, the first resist film pattern 50 is peeled off using a resist stripping liquid or by ashing as shown in FIG. 3(b) . Depending on the situation, the next step of forming the phase shift film pattern may be performed without peeling off the first resist film pattern 50 .

3. Phase shift film pattern formation steps In the first phase shift film pattern forming step, the phase shift film 30 is etched using the first etching mask film pattern 40a as a mask. As shown in FIG. 3(c), the phase shift film pattern 30a is formed. Examples of the phase shift film pattern 30a include a line and space pattern or a hole pattern. The etching liquid used to etch the phase shift film 30 is not particularly limited as long as it can selectively etch the phase shift film 30 . For example, an etching liquid containing ammonium fluoride, phosphoric acid, and hydrogen peroxide, and an etching liquid containing ammonium bifluoride and hydrogen chloride can be cited. In order to make the cross-sectional shape of the phase shift film pattern 30a good, the wet etching time is preferably longer (an over-etching time) than just enough to expose the transparent substrate 20 to the phase shift film pattern 30a (an appropriate etching time). The over-etching time is preferably a time obtained by adding an appropriate amount of etching time and 10% of the appropriate amount of etching time, taking into consideration the impact on the transparent substrate 20 and the like.

4. Second resist film pattern forming step In the second resist film pattern forming step, first, a resist film covering the first etching mask film pattern 40a is formed. The resist film material used is not particularly limited. For example, it suffices as long as it is sensitive to laser light having any wavelength selected from the following wavelength range of 350 nm to 436 nm. In addition, the resist film may be either a positive type or a negative type. Thereafter, the desired pattern is drawn on the resist film using laser light with any wavelength selected from the wavelength range of 350 nm to 436 nm. The pattern drawn on the resist film is a light-shielding band pattern that blocks light from the outer peripheral area of the area where the pattern is formed in the phase shift film 30, and a light-shielding band pattern that blocks light from the central portion of the phase shift film pattern. Furthermore, depending on the transmittance of the phase shift film 30 to the exposure light, the pattern drawn on the resist film may have a pattern that does not have a light-shielding strip pattern that shields the central portion of the phase shift film pattern 30a from light. Thereafter, the resist film is developed using a specific developer, and as shown in FIG. 3(d) , a second resist film pattern 60 is formed on the first etching mask film pattern 40a.

5. Second etching mask film pattern formation step In the second etching mask film pattern forming step, the first etching mask film pattern 40a is etched using the second resist film pattern 60 as a mask, as shown in FIG. 3(e), to form a second etching mask. Film pattern 40b. The first etching mask film pattern 40a is formed of a chromium-based material containing chromium (Cr) and substantially free of silicon. The etching liquid used to etch the first etching mask film pattern 40a is not particularly limited as long as it can selectively etch the first etching mask film pattern 40a. For example, an etching solution containing ceric ammonium nitrate and perchloric acid can be used. Thereafter, the second resist film pattern 60 is peeled off using a resist stripping liquid or ashing. In this way, the phase shift mask 100 can be obtained. Furthermore, in the above description, the case where the etching mask film 40 has the function of blocking the transmission of exposure light has been described. However, in the case where the etching mask film 40 only has the hardness to etch the phase shift film 30 In the case of the function of the mask, in the above description, the second resist film pattern forming step and the second etching mask film pattern forming step are not performed, but after the phase shift film pattern forming step, the first etching mask is The film pattern is peeled off, and the phase shift mask 100 is produced.

According to the manufacturing method of the phase shift mask of Embodiment 2, the phase shift mask base of Embodiment 1 is used. Therefore, a phase shift film pattern with good cross-sectional shape and small CD deviation in in-plane distribution can be formed. Therefore, a phase shift mask capable of transferring a high-definition phase shift film pattern with high precision can be manufactured. The phase shift mask thus fabricated can cope with the miniaturization of line and space patterns or contact holes.

Manufacturing steps of phase shift mask according to Embodiment 4 1. Resistor film pattern formation step In the resist film pattern forming step, first, a resist film is formed on the phase shift film 30 of the phase shift mask substrate 10 of Embodiment 2. The resist film material used is the same as that described in Embodiment 3. Furthermore, if necessary, the phase shift film 30 may also be surface modified before forming the resist film to ensure good adhesion with the phase shift film 30 . In the same manner as above, after the resist film is formed, a desired pattern is drawn on the resist film using laser light having an arbitrary wavelength selected from the wavelength range of 350 nm to 436 nm. Thereafter, the resist film is developed using a specific developer, and as shown in FIG. 4(a) , a first resist film pattern 50 is formed on the phase shift film 30 . 2. Phase shift film pattern formation steps In the phase shift film pattern forming step, the phase shift film 30 is etched using the first resist film pattern 50 as a mask. As shown in FIG. 4(b) , a phase shift film pattern 30a is formed. The etching liquid or over-etching time for etching the phase shift film pattern 30a or the phase shift film 30 is the same as that described in Embodiment 3. Thereafter, the first resist film pattern 50 is peeled off using a resist stripping liquid or ashing (Fig. 4(c)). In this way, the phase shift mask 100 can be obtained. According to the manufacturing method of the phase shift mask of the fourth embodiment, the phase shift mask substrate of the second embodiment is used. Therefore, the transmittance of the transparent substrate will not be reduced due to the damage caused by the wet etching liquid to the substrate, and the shortening time can be shortened. The etching time can be reduced, and a phase shift film pattern with good cross-sectional shape can be formed. Therefore, a phase shift mask capable of transferring a high-definition phase shift film pattern with high precision can be manufactured. The phase shift mask thus fabricated can cope with the miniaturization of line and space patterns or contact holes.

Implementation form 5. In Embodiment 5, a method of manufacturing a display device will be described. The display device is manufactured by using the phase shift mask 100 manufactured using the above-mentioned phase shift mask substrate 10 or using the above-mentioned manufacturing method of the phase shift mask 100 (mask carrier). (setting step), and a step of exposing and transferring the transfer pattern to the resist film on the display device (pattern transfer step). Each step is explained in detail below.

1. Installation steps In the placement step, the phase shift mask produced in Embodiment 3 is placed on the mask stage of the exposure device. Here, the phase shift mask is arranged in such a manner that the projection optical system of the exposure device is opposed to the resist film formed on the display device substrate.

2. Pattern transfer steps In the pattern transfer step, the phase shift mask 100 is irradiated with exposure light to transfer the phase shift film pattern to the resist film formed on the display device substrate. The exposure light contains composite light of multiple wavelengths selected from the wavelength range of 365 nm to 436 nm or monochromatic light selected by cutting off a certain wavelength range with a filter or the like from the wavelength range of 365 nm to 436 nm. For example, the exposure light includes a composite light of i ray, h ray and g ray or a monochromatic light of i ray. If composite light is used as the exposure light, the exposure light intensity can be increased and the output can be increased. Therefore, the manufacturing cost of the display device can be reduced.

According to the method of manufacturing a display device according to the fifth embodiment, it is possible to manufacture a high-definition display device that can suppress CD errors, has high resolution, and has a fine line and space pattern or contact holes. [Example]

Example 1. A. Phase-shift mask substrate and manufacturing method thereof. In order to manufacture the phase-shift mask substrate of Example 1, first, before loading the transparent substrate 20 into the chamber of the continuous sputtering device, nitrogen gas ( A mixed gas of N ₂ ) and argon (Ar) was introduced, and a sputtering power of 6.0 kW was applied to the first sputtering target containing molybdenum and silicon (molybdenum: silicon = 1:9), and the aging step was performed for 60 minutes.

Next, a 1214-size (1220 mm×1400 mm) synthetic quartz glass substrate is prepared as the transparent substrate 20 . Thereafter, the synthetic quartz glass substrate is placed on a tray (not shown) with the main surface facing downward, and is carried into the chamber of the continuous sputtering apparatus. In order to form the phase shift film 30 on the main surface of the transparent substrate 20, the sputtering gas pressure in the first chamber is 1.7 Pa, including argon (Ar), nitrogen (N ₂ ) and helium ( A mixed gas (Ar: 18 sccm, N ₂ : 15 sccm, He: 50 sccm, NO: 4 sccm) of an inert gas of He and nitrogen oxide gas (NO) which is one of the reactive gases is introduced. Under these film formation conditions, the phase shift film 30 (film thickness: 135 nm) containing molybdenum silicide oxynitride is formed on the transparent substrate 20 .

Then, the surface-treated transparent substrate 20 with the phase shift film 30 is moved into the second chamber, and with the second chamber set to a specific vacuum degree, argon (Ar) and nitrogen (N _{2 )} are added. ) mixed gas (Ar: 65 sccm, N ₂ : 15 sccm) is introduced. Then, a sputtering power of 1.5 kW is applied to the second sputtering target containing chromium, and chromium nitride (CrN) containing chromium and nitrogen is formed on the phase shift film 30 by reactive sputtering (film thickness 15 nm) . Next, with a specific degree of vacuum in the third chamber, a mixed gas (30 sccm) of argon (Ar) and methane (CH ₄ : 4.9%) gas was introduced, and the third chamber containing chromium was introduced. The sputtering target applies a sputtering power of 8.5 kW to form chromium carbide (CrC) containing chromium and carbon (film thickness 60 nm) on CrN through reactive sputtering. Finally, with the fourth chamber set to a specific degree of vacuum, a mixture of argon (Ar) and methane (CH ₄ : 5.5%) and a mixture of nitrogen (N ₂ ) and oxygen (O ₂ ) were added. Mixed gas (Ar+CH ₄ : 30 sccm, N ₂ : 8 sccm, O ₂ : 3 sccm) was introduced, and a sputtering power of 2.0 kW was applied to the fourth sputtering target containing chromium, and reactive sputtering was performed on the Chromium carbonitride oxide (CrCON) containing chromium, carbon, oxygen and nitrogen is formed on CrC (film thickness 30 nm). As above, the etching mask film 40 having a stacked structure of the CrN layer, the CrC layer, and the CrCON layer is formed on the phase shift film 30 . In this way, the phase shift mask substrate 10 with the phase shift film 30 and the etching mask film 40 formed on the transparent substrate 20 is obtained.

The transmittance of the phase shift film 30 of the obtained phase shift mask base 10 (the phase shift film 30 obtained by surface-treating the surface of the phase shift film 30 with an alkali aqueous solution) was measured using MPM-100 manufactured by Lasertec Corporation. and phase difference. The transmittance and phase difference of the phase shift film 30 were measured using a phase shift film-attached substrate (dummy substrate) in which the phase shift film 30 was formed on the main surface of a synthetic quartz glass substrate and was placed on the same tray. The transmittance and phase difference of the phase shift film 30 are measured by taking the substrate (dummy substrate) with the phase shift film 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 reflectance was 11.1% (wavelength: 365 nm). Furthermore, the change in flatness of the phase shift film 30 was measured using UltraFLAT 200M (manufactured by Corning TROPEL Co., Ltd.) and the film stress was calculated. The result was 0.24 GPa. The phase shift film 30 has a small change in transmittance and a change in phase difference with respect to the chemicals (sulfuric acid hydrogen peroxide mixture, ammonia water hydrogen peroxide mixture, ozone water) used in cleaning the phase shift mask, and has a high Antibacterial and cleaning resistance.

Furthermore, the film surface reflectance and optical density of the obtained phase shift mask substrate 10 were measured using a spectrophotometer SolidSpec-3700 manufactured by Shimadzu Corporation. The film surface reflectance of the phase shift mask substrate (etched mask film 40) is 8.3% (wavelength: 436 nm), and the optical density OD is 4.0 (wavelength: 436 nm). It is found that the etching mask film 40 functions as a light-shielding film with a low reflectivity on the film surface.

Furthermore, the composition of the obtained phase shift mask substrate 10 was analyzed in the depth direction by X-ray photoelectron spectroscopy (XPS). FIG. 5 shows the composition analysis results in the depth direction of the phase shift mask substrate of Example 1 by XPS. FIG. 5 shows the composition analysis results of the etching mask film 40 and the phase shift film 30 on the phase shift film 30 side of the phase shift mask substrate. The horizontal axis of FIG. 5 represents the depth (nm) in terms of SiO ₂ of the phase shift mask substrate 10 based on the outermost surface of the etching mask film 40, and the vertical axis represents the content rate (atomic %). In Figure 5, each curve represents the changes in the content rates of silicon (Si), nitrogen (N), oxygen (O), carbon (C), chromium (Cr), and molybdenum (Mo) respectively. 11 is a graph showing the distance from the substrate interface obtained by XPS and the N/O ratio for the phase shift mask substrates of Examples 1 and 2 and Comparative Example 1.

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

B. Phase shift mask and manufacturing method thereof In order to manufacture the phase shift mask 100 using the phase shift mask substrate 10 manufactured in the above manner, first, a photoresist film is coated on the etching mask film 40 of the phase shift mask substrate 10 using a resist coating device. Thereafter, after heating and cooling steps, a photoresist film with a film thickness of 520 nm is formed. Thereafter, a laser drawing device is used to draw the photoresist film, and through development and rinsing steps, a resist film pattern with a hole pattern of 1.5 μm in diameter is formed on the etching mask film.

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

Thereafter, using the first etching mask film pattern 40a as a mask, the phase shift film 30 is wet-etched using a molybdenum silicide etching liquid obtained by diluting a mixed solution of ammonium bifluoride and hydrogen peroxide with pure water to form a phase shift film. Transfer film pattern 30a. In order to verticalize the cross-sectional shape and form the required fine pattern, the wet etching was performed with an over-etching time of 110%. Thereafter, the resist film pattern is peeled off.

Thereafter, a resist coating device is used to apply a photoresist film so as to cover the first etching mask film pattern 40a. Thereafter, after heating and cooling steps, a photoresist film with a film thickness of 520 nm is formed. Thereafter, a laser drawing device is used to draw the photoresist film, and through development and rinsing steps, a second resist film pattern 60 for forming a light shielding strip is 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 area is wet-etched using a chromium etching solution containing cerium ammonium nitrate and perchloric acid. etching. Thereafter, the second resist film pattern 60 is peeled off.

In this way, the phase shift mask 100 is obtained, which has the phase shift film pattern 30a formed in the transfer pattern formation area on the transparent substrate 20, and is composed of a laminated structure of the phase shift film pattern 30a and the second etching mask film pattern 40b. The shading tape.

The cross-section of the obtained phase shift mask was observed with a scanning electron microscope. In the following Example 1, Example 2 and Comparative Example 1, a scanning electron microscope was used to observe the cross section of the phase shift mask. The cross-sectional photograph of FIG. 6 is taken during the manufacturing step of the phase shift mask in Embodiment 1. The first etching mask film pattern 40a is used as a mask, and the phase shift film 30 is wet-etched with molybdenum silicide etching liquid (110 % over-etching) to form a phase shift film pattern 30a, and a cross-sectional photograph after peeling off the resist film pattern.

As shown in FIG. 6 , the phase shift film pattern 30 a formed in the phase shift mask 100 of Embodiment 1 has a nearly vertical cross-sectional shape that can fully exert the phase shift effect. In addition, in the phase shift film pattern 30a, penetration did not occur in any of the interface with the etching mask film pattern and the interface with the substrate. Furthermore, it has a phase shift film pattern 30a with a small bottom width and an in-plane CD deviation as small as 70 nm. Specifically, the cross section of the phase shift film pattern 30a is composed of the upper surface, the lower surface, and the side surfaces of the phase shift film pattern 30a. In the cross-section of the phase shift film pattern 30a, the angle between the portion where the upper surface and the side surface meet (the upper edge) and the portion where the side surface and the lower surface meet (the lower edge) is 74 degrees. Therefore, a phase shift mask 100 can be obtained that exposes light including light in the wavelength range of 300 nm to 500 nm, more specifically, composite light including i rays, h rays, and g rays. It has excellent phase shifting effect under light. Therefore, it is considered that when the phase shift mask 100 of Example 1 is placed on the mask stage of the exposure device and exposed to the resist film transferred to the display device, fine particles less than 2.0 μm can be transferred with high precision. pattern.

Example 2. A. Phase-shift mask substrate and manufacturing method thereof. In order to manufacture the phase-shift mask substrate 10 of Example 2, first, in the chamber of the continuous sputtering device, before loading the transparent substrate 20, and The aging step was performed under the same conditions as Example 1. Then, in order to form the phase shift film 30 on the main surface of the transparent substrate 20, the sputtering gas pressure in the first chamber is set to 1.9 Pa, including argon (Ar), nitrogen (N ₂ ) and Helium (He) inert gas (Ar: 18 sccm, N ₂ : 13 sccm, He: 50 sccm) was introduced. Under these film formation conditions, the phase shift film 30 (film thickness: 141 nm) containing molybdenum silicide oxynitride is formed on the transparent substrate 20 .

Next, after the phase shift film 30 is formed on the transparent substrate 20 , the surface treatment of the phase shift film 30 is not performed. In the same manner as in Example 1, etching is performed to form a stacked structure of the CrN layer, the CrC layer, and the CrCON layer on the phase shift film 30 . Masking film 40. In this way, the phase shift mask substrate 10 with the phase shift film 30 and the etching mask film 40 formed on the transparent substrate 20 is obtained.

The transmittance and phase difference of the phase shift film 30 of the obtained phase shift mask base 10 were measured using MPM-100 manufactured by Lasertec Corporation. The transmittance and phase difference of the phase shift film were measured using a phase shift film-attached substrate (dummy substrate) in which a phase shift film 30 was formed on the main surface of a synthetic quartz glass substrate and was placed on the same tray. The transmittance and phase difference of the phase shift film 30 are measured by taking the substrate (dummy substrate) with the phase shift film 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 reflectance was 7.8% (wavelength: 365 nm). Furthermore, the change in flatness of the phase shift film 30 was measured using UltraFLAT 200M (manufactured by Corning TROPEL Co., Ltd.) and the film stress was calculated. The result was 0.22 GPa. The phase shift film 30 has a relatively small change in transmittance and a change in phase difference with respect to the chemicals used in cleaning the phase shift mask (sulfuric acid hydrogen peroxide mixture, ammonia water hydrogen peroxide mixture, ozone water). High chemical resistance and cleaning resistance.

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

Furthermore, the composition of the obtained phase shift mask substrate 10 in the depth direction was analyzed by X-ray photoelectron spectroscopy (XPS).

As a result, the same tendency as in Example 1 was shown. In the composition analysis results of the phase shift mask substrate 10 in the depth direction by XPS, at the interface between the phase shift film 30 and the transparent substrate 20 (in the phase shift film 30 In the region (composition gradient region) within 30 nm of the surface of the phase shift film 30 (the position where the molybdenum content rate becomes 0 atomic %), the oxygen content rate decreases rapidly from the interface with the transparent substrate 20, and then becomes Roughly fixed. On the other hand, the nitrogen content rapidly increases from the interface with the transparent substrate 20 and then slightly decreases. That is, as shown in FIG. 11 , it is known that in Example 2, the N/O ratio has a maximum value in a region within 27.6 nm from the interface with the transparent substrate 20 , that is, within 30 nm.

B. Phase shift mask and manufacturing method thereof Using the phase shift mask substrate 10 manufactured in the above manner, the phase shift mask 100 is manufactured by the same method as in Embodiment 1. Furthermore, in order to verticalize the cross-sectional shape and form the required fine pattern, wet etching is performed with an over-etching time of 110%. The cross-section of the obtained phase shift mask 100 was observed with a scanning electron microscope. The cross-sectional photograph in FIG. 7 is taken during the manufacturing step of the phase shift mask in Embodiment 2. The first etching mask film pattern 40a is used as a mask, and the phase shift film 30 is wet-etched with molybdenum silicide etching liquid (110 % over-etching), a cross-sectional photo after forming the phase shift film pattern 30a.

As shown in FIG. 7 , the phase shift film pattern 30 a formed in the phase shift mask 100 of Embodiment 2 has a nearly vertical cross-sectional shape that can fully exert the phase shift effect. In addition, penetration did not occur in any of the phase shift film pattern 30a, the interface with the etching mask film pattern 40b, and the interface with the transparent substrate 20. Furthermore, it has a phase shift film pattern 30a with a small bottom width and an in-plane CD deviation as small as 70 nm. Specifically, the cross section of the phase shift film pattern 30a is composed of the upper surface, the lower surface, and the side surfaces of the phase shift film pattern 30a. In the cross-section of the phase shift film pattern 30a, the angle between the part where the upper surface and the side surface are connected (the upper edge) and the part where the side surface and the lower surface are connected (the lower edge) is 71 degrees. Therefore, a phase shift mask 100 is obtained that exposes light including light in the wavelength range of 300 nm to 500 nm, more specifically, exposure light including composite light of i rays, h rays, and g rays. It has excellent phase shifting effect. Therefore, it is considered that when the phase shift mask 100 of Example 2 is placed on the mask stage of the exposure device and exposed to the resist film to be transferred to the display device, it is considered that fine particles less than 2.0 m can be transferred with high precision. pattern.

Comparative example 1. A. Phase shift mask substrate and manufacturing method thereof In order to manufacture the phase shift mask substrate of Comparative Example 1, first, an aging step was performed in the chamber of a continuous sputtering device before the transparent substrate was loaded into the chamber. However, the gas introduced in the aging step was only argon gas (Ar), and the time was set to 30 minutes. Other conditions in the aging step were the same as those in Examples 1 and 2. Furthermore, under the same conditions as in Example 1, a phase shift film and an etching mask film were formed on the transparent substrate. In this way, a phase shift mask substrate with a phase shift film and an etching mask film formed on the transparent substrate is obtained. Furthermore, the film thickness of the phase shift film is 135 nm.

The transmittance and phase difference of the phase shift film of the obtained phase shift mask base (the phase shift film obtained by cleaning the surface of the phase shift film with pure water) were measured using MPM-100 manufactured by Lasertec Corporation. The transmittance and phase difference of the phase shift film were measured using a substrate with a phase shift film (dummy substrate) in which a phase shift film was formed on the main surface of a synthetic quartz glass substrate and placed on the same tray. The transmittance and phase difference of the phase shift film are measured by taking the substrate with the phase shift film (dummy substrate) out of the chamber before forming the etching mask film. The results are basically the same as the optical properties of the phase shift film of Example 1, with a transmittance of 34% (wavelength: 365 nm), a phase difference of 160 degrees (wavelength: 365 nm), and a back reflectance of 11.0% ( Wavelength: 365 nm). Furthermore, the change in flatness of the phase shift film was measured using UltraFLAT 200M (manufactured by Corning TROPEL Co., Ltd.) and the film stress was calculated. The result was 0.24 GPa. The phase shift film 30 has a small change in transmittance and a change in phase difference with respect to the chemical solution (sulfuric acid hydrogen peroxide mixture, ammonia water hydrogen peroxide mixture, ozone water) used in cleaning the phase shift mask, and has High chemical resistance and cleaning resistance.

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

Furthermore, the composition of the obtained phase shift mask substrate in the depth direction was analyzed by X-ray photoelectron spectroscopy (XPS).

As a result, the composition analysis of the phase shift mask substrate in the depth direction by XPS showed that 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 of the surface of the phase shift film (composition gradient region), the oxygen content decreases sharply from the interface with the transparent substrate, and then becomes approximately constant. On the other hand, the nitrogen content rate suddenly increases from the interface with the transparent substrate, and then slowly increases without converting into a decrease. That is, as shown in FIG. 11 , it was found that in Comparative Example 1, the N/O ratio did not have a maximum value in the region within 30 nm from the interface with the transparent substrate.

B. Phase shift mask and manufacturing method thereof Using the phase shift mask substrate manufactured in the above manner, 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 in Figure 10 was taken during the manufacturing step of the phase shift mask of Comparative Example 1. The first etching mask film pattern was used as a mask, and the phase shift film was wet-etched (110%) with molybdenum silicide etching liquid. Over-etching), forming a phase shift film pattern, and a cross-sectional photo after peeling off the resist film pattern.

As shown in FIG. 10 , the phase shift film pattern formed in the phase shift mask of Comparative Example 1 penetrates near the interface with the transparent substrate and has a shape that causes erosion. Therefore, it is predicted that the phase shift mask of Comparative Example 1 cannot produce fine patterns of less than 2.0 μm with high accuracy.

Embodiment 3. A. Phase-shift mask substrate and manufacturing method thereof. In order to manufacture the phase-shift mask substrate 10 of Embodiment 3, first, before moving the transparent substrate 20 into the chamber of the continuous sputtering device, and The aging step was performed under the same conditions as Example 1. In Example 3, molybdenum:silicon=8:92 was used as the first sputtering target containing molybdenum and silicon. Then, in order to form the phase shift film 30 on the main surface of the transparent substrate 20, the sputtering gas pressure in the first chamber is set to 1.7 Pa, including argon (Ar), nitrogen (N ₂ ) and A mixed gas of helium (He) as an inert gas and nitrogen oxide gas (NO) as one of the reactive gases (Ar: 18 sccm, N ₂ : 15 sccm, He: 50 sccm, NO: 4 sccm) is introduced. Under these film formation conditions, the phase shift film 30 (film thickness: 153 nm) containing molybdenum silicide oxynitride is formed on the transparent substrate 20 . Next, after the phase shift film 30 is formed on the transparent substrate 20, the surface treatment of the phase shift film 30 is not performed, and a laminated structure of the CrN layer, the CrC layer, and the CrCON layer is formed on the phase shift film 30 in the same manner as in Example 1. The mask film 40 is etched. In this way, the phase shift mask substrate 10 with the phase shift film 30 and the etching mask film 40 formed on the transparent substrate 20 is obtained.

The transmittance and phase difference of the phase shift film 30 of the obtained phase shift mask base 10 were measured using MPM-100 manufactured by Lasertec Corporation. The transmittance and phase difference of the phase shift film were measured using a phase shift film-attached substrate (dummy substrate) in which a phase shift film 30 was formed on the main surface of a synthetic quartz glass substrate and was placed on the same tray. The transmittance and phase difference of the phase shift film 30 are 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 reflectance was 2.5% (wavelength: 365 nm). In addition, the phase shift film 30 has a small change in transmittance and a change in phase difference with respect to the chemicals (sulfuric acid hydrogen peroxide mixture, ammonia water hydrogen peroxide mixture, ozone water) used in cleaning the phase shift mask. And it has high chemical resistance and cleaning resistance. Furthermore, the film surface reflectance and optical density of the obtained phase shift mask substrate 10 were measured using a spectrophotometer SolidSpec-3700 manufactured by Shimadzu Corporation. The film surface reflectance of the phase shift mask substrate 10 (etching mask film 40) is 8.3% (wavelength: 436 nm), and the optical density OD is 4.0 (wavelength: 436 nm). It is known that the etching mask film 40 functions as a light-shielding film with a low reflectivity on the film surface. Furthermore, the composition of the obtained phase shift mask substrate 10 was analyzed in the depth direction by X-ray photoelectron spectroscopy (XPS). As a result, as shown in FIG. 8 , the same trend as that of Example 1 was reflected. In the composition analysis results of the phase shift mask substrate 10 in the depth direction by XPS, the difference between the self-phase shift film 30 and the transparent substrate 20 was In the interface (the position where the content of molybdenum contained in the phase shift film 30 becomes 0 atomic %) and the region within 30 nm of the surface of the phase shift film 30 (the composition gradient region), the oxygen content is from that of the transparent substrate 20 The interface suddenly decreased, and then became roughly fixed. On the other hand, the nitrogen content rapidly increases from the interface with the transparent substrate 20 and then slightly decreases. That is, as shown in FIG. 12 , it is found that in Example 3, the N/O ratio has a maximum value in a region within 22.7 nm from the interface with the transparent substrate 20 , that is, within 30 nm. Furthermore, a cross-sectional SEM (scanning electron microscope) observation was conducted at a magnification of 80,000 times at the center of the transfer pattern formation area of the obtained phase shift mask substrate 10. As a result, it was confirmed that the phase shift film 30 has a columnar structure. . That is, it was confirmed that the particles of the molybdenum silicide compound constituting the phase shift film 30 have a columnar particle structure extending in the film thickness direction of the phase shift film 30 . Furthermore, it was confirmed that the columnar particle structure of the phase shift film 30 was in such a state that the columnar particles in the film thickness direction were formed irregularly, and the lengths of the columnar particles in the film thickness direction were also inconsistent. In addition, 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 manufacturing method thereof Using the phase shift mask substrate 10 manufactured in the above manner, the phase shift mask 100 is manufactured by the same method as in Embodiment 1. Furthermore, in order to verticalize the cross-sectional shape and form the required fine pattern, wet etching is performed with an over-etching time of 110%. The cross-section of the obtained phase shift mask 100 was observed with a scanning electron microscope. The cross-sectional photograph in Figure 9 is taken during the manufacturing step of the phase shift mask in Embodiment 3. The first etching mask film pattern 40a is used as a mask, and the phase shift film 30 is wet-etched with molybdenum silicide etching liquid (110 % over-etching), a cross-sectional photo after forming the phase shift film pattern 30a. As shown in FIG. 9 , the phase shift film pattern 30 a formed in the phase shift mask 100 of Embodiment 3 has a nearly vertical cross-sectional shape that can fully exert the phase shift effect. In addition, penetration did not occur in any of the phase shift film pattern 30a, the interface with the etching mask film pattern 40b, and the interface with the transparent substrate 20. Furthermore, it has a phase shift film pattern 30a with a small bottom width and an in-plane CD deviation as small as 65 nm. Specifically, the cross section of the phase shift film pattern 30a is composed of the upper surface, the lower surface, and the side surfaces of the phase shift film pattern 30a. In the cross-section of the phase shift film pattern 30a, the angle between the part where the upper surface and the side surface are connected (the upper side) and the part where the side surface and the lower surface are connected (the lower side) is 81 degrees. Therefore, a phase shift mask 100 is obtained that exposes light including light in the wavelength range of 300 nm to 500 nm, more specifically, exposure light including composite light of i rays, h rays, and g rays. It has excellent phase shifting effect. Therefore, when the phase shift mask 100 of Example 3 is placed on the mask stage of the exposure device and exposed to the resist film transferred to the display device, it is considered that fine particles less than 2.0 μm can be transferred with high precision. pattern.

Furthermore, in the above-mentioned embodiments, the case where molybdenum is used as the transition metal has been described, but the same effect as above can be obtained in the case of other transition metals. Furthermore, in the above-mentioned embodiments, examples of the phase shift mask base for display device manufacturing or the phase shift mask for display device manufacturing have been described, but the invention is not limited thereto. The phase shift mask substrate or phase shift mask of the present invention can also be used in semiconductor device manufacturing, MEMS (Micro-Electro-Mechanical System) manufacturing, printed circuit boards, etc. Furthermore, in the above-mentioned embodiment, the example in which the size of the transparent substrate is 8092 size (800 mm×920 mm×10 mm) has been described, but the invention is not limited to this. In the case of a phase shift mask substrate for display device manufacturing, a large size transparent substrate is used, and the size of the transparent substrate is that the length of one side is 300 mm or more. The size of the transparent substrate used in the phase shift mask base for display device manufacturing is, for example, 330 mm × 450 mm or more and 2280 mm × 3130 mm or less. In addition, in the case of phase shift mask substrates for semiconductor device manufacturing, MEMS manufacturing, and printed circuit boards, small size transparent substrates are used, and the size of the transparent substrate is that the length of one side is 9 inches or less. The size of the transparent substrate used for the phase shift mask base for the above-mentioned purposes is, for example, 63.1 mm × 63.1 mm or more and 228.6 mm × 228.6 mm or less. Generally, systems for semiconductor manufacturing and MEMS manufacturing use 6025 size (152 mm × 152 mm) or 5009 size (126.6 mm × 126.6 mm), and systems for printed circuit boards use 7012 size (177.4 mm × 177.4 mm) or 9012 size (228.6 mm×228.6 mm).

10: Phase shift mask base (mask base) 20:Transparent substrate 30: Phase shift film (film for pattern formation) 30a: Phase shift film pattern (transfer pattern) 40: Etching mask film 40a: 1st etching mask film pattern 40b: 2nd etching mask film pattern 50: 1st resist film pattern 60: 2nd resist film pattern 100: Phase shift mask (mask)

FIG. 1 is a schematic diagram showing the film structure of a phase shift mask base according to Embodiment 1. FIG. 2 is a schematic diagram showing the film structure of a phase shift mask base according to Embodiment 2. 3 (a) to (e) are schematic diagrams showing the manufacturing steps of the phase shift mask according to Embodiment 3. 4 (a) to (c) are schematic diagrams showing the manufacturing steps of the phase shift mask according to Embodiment 4. FIG. 5 is a graph showing the results of composition analysis in the depth direction of the phase shift mask substrate of Example 1. Figure 6 is a cross-sectional photograph of the phase shift mask of Example 1. Figure 7 is a cross-sectional photograph of the phase shift mask of Example 2. FIG. 8 is a graph showing the results of composition analysis in the depth direction of the phase shift mask substrate of Example 3. Figure 9 is a cross-sectional photograph of the phase shift mask of Example 3. Figure 10 is a cross-sectional photograph of the phase shift mask of Comparative Example 1. 11 is a graph showing the distance from the substrate interface obtained by XPS and the N/O ratio for the phase shift mask substrates of Examples 1 and 2 and Comparative Example 1. FIG. 12 is a graph showing the distance from the substrate interface obtained by XPS and the ratio of N/O for the phase shift mask substrate of Example 3.

Claims (11)

A photomask substrate, characterized in that it has a pattern forming film on a transparent substrate, The above-mentioned photomask base is used to form the original plate of the photomask, the above-mentioned photomask is obtained by wet etching the above-mentioned pattern forming film, and has a transfer pattern on the above-mentioned transparent substrate, The pattern-forming thin film contains a transition metal, silicon, oxygen, and nitrogen, and the oxygen content obtained by XPS analysis is 1 atomic % or more and 70 atomic % or less, and the transparent substrate and the pattern-forming thin film are combined. The interface is defined as a position within 30 nm from the interface to the surface of the pattern-forming film where the content rate of the transition metal contained in the pattern-forming film obtained by the XPS analysis is 0 atomic %. In this region, the ratio of nitrogen to oxygen has a maximum value. The photomask substrate of claim 1, wherein the transition metal is molybdenum. The photomask substrate according to claim 1 or 2, wherein the oxygen content is 5 atomic % or more and 70 atomic % or less. The photomask substrate according to claim 1 or 2, wherein the nitrogen content is 35 atomic % or more and 60 atomic % or less. The photomask substrate of claim 1 or 2, wherein the pattern forming film has a columnar structure. The photomask substrate according to claim 1 or 2, wherein the pattern forming film has optical characteristics of a transmittance of 1% or more and 80% or less of a representative wavelength of exposure light and a phase difference of 160° or more and 200° or less. Transfer membrane. A photomask substrate according to claim 1 or 2, which is provided with an etching mask film having different etching selectivities for the pattern forming film on the pattern forming film. The photomask substrate of claim 7, wherein the etching mask film includes a material containing chromium and substantially free of silicon. A method for manufacturing a photomask, which is characterized by including the following steps: Prepare a photomask substrate as in any one of claims 1 to 6; and A resist film is formed on the pattern-forming film, and the pattern-forming film is wet-etched using the resist film pattern formed from the resist film as a mask to form the transfer pattern on the transparent substrate. A method for manufacturing a photomask, which is characterized by including the following steps: Preparing the photomask substrate as claimed in claim 7 or 8; A resist film is formed on the etching mask film, and the etching mask film is wet-etched using the resist film pattern formed from the resist film as a mask, and the etching mask film is formed on the pattern forming film. pattern; and The pattern forming film is wet-etched using the etching mask film pattern as a mask to form the transfer pattern on the transparent substrate. A method for manufacturing a display device, characterized in that it includes an exposure step in which a photomask obtained by the photomask manufacturing method according to claim 9 or 10 is placed on a photomask stage of an exposure device, and the photomask formed on the photomask is placed on a photomask stage of an exposure device. The above transfer pattern on the mask is exposed and transferred to the resist film formed on the display device substrate.