TWI758382B - Phase shift mask blanke, method of manufacturing a phase shift mask, and method of manufacturing a display device - Google Patents

Abstract

To provide a phase shift mask blank which is for use in manufacturing a display device and which has a novel phase shift film excellent in wavelength dependency of transmittance.

A phase shift mask blank includes a transparent substrate and a phase shift film formed on the transparent substrate. The phase shift film at least has a phase shift layer having a function of mainly adjusting a transmittance for exposure light and a phase difference, and a metal layer having a function of adjusting a wavelength dependency of transmittance in a wavelength range of not shorter than 365 nm and not longer than 436 nm. The phase shift layer is made of a material containing a metal, silicon, and at least one of nitrogen and oxygen. The metal layer is made of a material composed of a metal and silicon or a material composed of a metal, silicon, and at least one of carbon, fluorine, nitrogen, and oxygen. A content of the metal contained in the metal layer is greater than that of the metal contained in the phase shift layer. Alternatively, a total content of the metal and silicon contained in the metal layer is greater than a total content of the metal and silicon contained in the phase shift layer. In the phase shift film, a wavelength dependency of transmittance is 5.5% or less in a wavelength range of not shorter than 365 nm and not longer than 436 nm.

Description

Phase-shift mask substrate, manufacturing method of phase-shift mask, and manufacturing method of display device

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

When manufacturing a liquid crystal display device or an organic EL (Electroluminescence) display device, semiconductor elements such as transistors are formed by laminating a plurality of conductive films or insulating films subjected to desired patterning. At this time, when patterning each film to be laminated, a photolithography step is often used. For example, in the thin film transistors or LSI (Large-Scale Integration) used in these display devices, there are contact holes formed in the insulating layer by photolithography, and the pattern of the upper layer and the pattern of the lower layer are connected. The constituents of electrical connections. Recently, in such a display device, there has been an increasing demand for displaying a bright and clear image at a sufficiently fast operation speed and reducing power consumption. In order to satisfy such a demand, miniaturization and high integration of the constituent elements of the display device are required. For example, it is desirable to reduce the diameter of the contact hole from 3 μm to 2.5 μm, 2 μm, 1.8 μm, and 1.5 μm. Also, for example, it is preferable to set the gap between the line and the space pattern. The pitch width was refined from 3 μm to 2.5 μm, 2 μm, 1.8 μm, and 1.5 μm.

Against such a background, a photomask for the manufacture of a display device that can cope with the miniaturization of a line and space pattern or a contact hole is expected.

When realizing the miniaturization of line and space patterns or contact holes, the previous photomasks had to produce near-resolution due to the fact that the resolution limit of the exposure machine used in the manufacture of display devices was 3 μm, so there was no sufficient process margin (Process Margin). The product of the minimum line width of the limit. Therefore, there is a problem that the defective rate of the display device increases.

For example, when considering the use of a photomask having a hole pattern for forming contact holes to transfer the hole pattern to a transfer object, if the hole pattern exceeds 3 μm in diameter, the previous photomask can be used. Make a transfer. However, it is very difficult to transfer a hole pattern with a diameter of 3 μm or less, especially a hole pattern with a diameter of 2.5 μm or less. In order to transfer a hole pattern with a diameter of 2.5 μm or less, for example, it is also considered to convert to an exposure machine with a high NA (Numerical Aperture, numerical aperture), but it requires a large investment.

Therefore, in order to improve the resolution and cope with the miniaturization of the line and space pattern or the contact hole, the phase shift photomask is attracting attention as a photomask for the manufacture of display devices.

For example, Patent Document 1 proposes a phase-shift mask base for a display device including a phase-shift film having a structure in which two or more thin films are laminated on a transparent substrate. Although the thin films constituting the phase shift film have different compositions, they all contain substances that can be etched by the same etching solution, and have different etching rates due to different compositions. In Patent Document 1, during patterning of the phase shift film, the etching rate of each thin film constituting the phase shift film is adjusted so that the cross-sectional slope of the edge portion of the phase shift film pattern is formed by a steep angle (steep slope).

The phase-shift film specifically described in Patent Document 1 is a chromium-based phase-shift film having a structure in which three, five, or six layers of chromium carbon oxynitride (CrCON) having different compositions are laminated.

Patent Document 2 discloses that a phase reversal film, a metal film used as an etching mask for the phase reversal film, and a resist film are sequentially laminated on a transparent substrate for FPD (Flat Panel Display). Phase reversal blank reticle. Here, the phase inversion film includes, for example, one of MoSi, MoSiO, MoSiN, MoSiC, MoSiCO, MoSiON, MoSiCN, and MoSiCON, and the metal film (etching mask film) includes a substance having an etching selectivity ratio to the phase inversion film, For example, one of Cr, CrO, CrN, CrC, CrCO, CrON, CrCN, CrCON.

It is described in Patent Document 2 that the phase reversal film preferably has a transmittance of 1% to 40%, preferably a transmittance of 5% to 20%, and has a transmittance of 10% or less for exposure light of composite wavelengths. Transmittance deviation. In addition, Patent Document 2 describes that the phase reversal film preferably has a reflectance of 30% or less, preferably 15% or less, and a reflectance variation of 10% or less with respect to exposure light of composite wavelengths. Here, the deviation refers to the difference between the maximum value and the minimum value among the transmittance and reflectance values of the exposure light of i-ray, h-ray, and g-ray.

However, Patent Document 2 does not describe an example of a specific phase inversion film and a metal film (etched mask film) for satisfying these optical properties.

Such phase-shift masks receive exposure light of various wavelengths output from various exposure machines.

For example, in the case of a phase shift mask used in the manufacture of a display device, as an exposure machine used in the step of transferring the mask pattern, for example, it is known to have output i-ray (wavelength 365nm), h-ray (wavelength 405nm) and G-rays (wavelength 436nm) are light sources (ultra-high pressure UV lamps) of compound light with peak intensity respectively. For example, if the above-mentioned compound light is used as the exposure light in the case where the mask pattern of the phase shift mask is transferred to the main surface of the mother glass substrate whose size has gradually increased with the enlargement of the display device in recent years, The amount of light can be obtained, and the process time can be shortened.

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Korean Registered Patent No. 1282040

[Patent Document 2] Korean Registered Patent No. 1624995

First, in the phase-shift mask and the phase-shift mask substrate for display devices, "the range (variation) of transmittance in the wavelength range of 365 nm or more and 436 nm or less (appropriately referred to as the specific transmittance wavelength dependence) It is basically very difficult to achieve a phase shift film with a small (for example, within 5.5%) of the properties (problem 1). The reason for this is that the composition and film thickness of each layer constituting the phase shift film that must satisfy the required optical properties (retardation, transmittance) are adjusted (these are preferentially adjusted), and the transmittance of the phase shift film is wavelength-dependent. Therefore, only the wavelength dependence of transmittance cannot be independently and freely controlled (adjusted independently to a desired value). Therefore, regarding the specific example of the layer constitution of the phase shift film and the material of each layer being specified, the values obtained by measuring the transmittance and the reflectance are not actually reported.

Therefore, in view of the above-mentioned problem 1, it is desired to provide a novel phase shift film having excellent transmittance wavelength dependence.

In addition, there are phase-shift masks and phase-shift mask substrates for display devices with high transmittance (such as 15% or more, especially 18% or more), the transmittance wavelength dependence is small (such as 5.5 It is extremely difficult to realize a phase shift film within %) (subject 2). The reasons for this include: (1) materials suitable for high transmittance are limited, (2) generally, the wavelength dependence of transmittance tends to increase as the transmittance is made high, and (3) due to this tendency, in order to reduce the To reduce the wavelength dependence of transmittance, it is necessary to greatly reduce the wavelength dependence of transmittance, but it is basically difficult to achieve a large reduction of wavelength dependence of transmittance.

In such a phase shift film having high transmittance, for example, a specific example of transmittance wavelength dependence with a specific transmittance wavelength dependence of less than 5.5% is not reported (problem 3).

Second, the phase-shift film used in the phase-shift mask for a display device previously proposed in Patent Document 1 does not consider the phase-shift film used for patterning the resist film for forming the phase-shift film pattern. It is designed to reflect the effect of laser light on the resist film. Therefore, the front reflectance of the phase shift film for laser drawing light (usually a certain wavelength in the wavelength range of 350 nm to 436 nm) exceeds 20%. As a result, standing waves are generated in the resist film, and the roughness of the edge portion of the resist film pattern is deteriorated. Along with this, there is a problem that the roughness of the edge portion of the phase shift film pattern is deteriorated.

In the above-mentioned Patent Document 2, it is described that the phase reversal film has a reflectance of 30% or less, preferably 15% or less, with respect to exposure light of composite wavelengths, but there is no report on the film structure or film for realizing this. Specific examples related to materials.

Furthermore, the front reflectance at the wavelength of the laser drawing light is preferably 10% or less, and more preferably 5% or less, and it is very difficult to achieve a front reflectance of 10% or less while satisfying various optical properties.

In detail, in the case of a light-shielding film, as long as the light-shielding property (optical density) is satisfied, it is relatively easy to provide an anti-reflection layer and add the characteristics of front reflectance. On the other hand, in the case of a phase shift film, the retardation and transmittance also vary due to the provision of an antireflection layer, so it is not easy to design a film that satisfies the characteristics of the retardation and transmittance while taking into account the characteristics of front reflectance. Therefore, it is more difficult to make the phase shift film satisfy the retardation, transmittance, and transmittance wavelength dependence while taking into account the characteristics of front reflectance (problem 4).

Furthermore, it is expected to exceed the level of reflectance described in Patent Document 2 (for example, "15% or less"). Specifically, for example, the reflectance in the wavelength range of 365 nm or more and 436 nm or less is not reported as 10% or less, or the reflection in the wavelength range of 350 nm or more and 436 nm or less. A specific example with a rate of 15% or less.

Furthermore, the phase shift films used in the phase shift masks for display devices previously proposed in Patent Documents 1 and 2 are not designed in consideration of the back surface reflectance in the wavelength range of 365 nm or more and 436 nm or less.

Therefore, in the case where the back surface reflectance is relatively low, there is a corresponding possibility that the pattern position may be shifted due to thermal expansion caused by thermal absorption of the exposure light of the film.

Therefore, it is not easy for the phase shift film to satisfy the retardation, transmittance, and specific transmittance wavelength dependence, and to take into account the characteristics of the back surface reflectance (problem 5).

The present invention is directed to the above-mentioned problem 1, and the first object of the present invention is to provide a novel phase shift film having excellent transmittance wavelength dependence.

The present invention is directed to the above-mentioned problem 1, and the second object is to provide a novel phase shift film which is excellent in transmittance wavelength dependence and also in other characteristics.

The present invention is directed to the above-mentioned problems 2 and 3, and a third object is to provide a novel phase shift film having excellent transmittance wavelength dependence even with high transmittance.

The present invention is directed to the above-mentioned problems 1, 2, and 3, and a fourth object is to provide a novel phase-shift film having excellent transmittance wavelength dependence.

The present invention has been made in view of the above-mentioned problem 4, and a fifth object is to provide a novel phase shift film having excellent transmittance wavelength dependence and also excellent front reflectance characteristics.

The present invention is directed to the above-mentioned problem 5, and a sixth object is to provide a novel phase shift film which is excellent in the wavelength dependence of transmittance and which is also excellent in back reflectance characteristics.

An object of the present invention is to provide a phase-shift mask substrate for manufacturing a display device including the phase-shift film of the present invention, a method for manufacturing a phase-shift mask using the phase-shift mask substrate, and a phase-shift mask using the phase-shift mask The manufacturing method of the display device.

The inventors of the present invention have made efforts in research and development in order to provide a novel phase shift film having excellent transmittance wavelength dependence.

First, the present inventors found that a ZrSi-based material containing Zr and Si is suitable as a material having a transmittance of 15% or more in the wavelength region of exposure light (including multiple waves of i-ray, h-ray, and g-ray). The material used in the phase shift film for high transmittance.

In addition, it is considered that the higher the transmittance of the phase shift film, the more difficult it is to reduce the wavelength dependence of the transmittance. Specifically, even if various adjustments are made, it is considered that, for example, within a wavelength range of 365 nm or more and 436 nm or less (appropriately referred to as a "specific wavelength range"), generally if the transmittance is about 20%, the specific wavelength range The wavelength dependence of transmittance (the variation of transmittance) can only be reduced to about 10%.

Furthermore, in the phase shift film, it is considered that the "wavelength dependence of transmittance in the range of wavelength 365 nm or more and 436 nm or less" (appropriately referred to as "specific transmittance wavelength dependence") is different from ZrSi-based materials (such as ZrSiON, Compared with ZrSiN and ZrSiO), MoSi-based materials (eg, MoSiN, MoSiON, MoSiOCN) have better transmittance wavelength dependence.

Furthermore, the inventors of the present invention learned during the research process that ZrSi-based materials (such as ZrSiON, ZrSiN, ZrSiO) have high transmittance (for example, at a wavelength of 365 nm) with the adjustment of the composition (such as high oxidation). 16%, 20%, 30%, 40% transmittance), the specific transmittance wavelength dependence gradually increases (for example, the specific transmittance wavelength dependence becomes 11%, 18%, 21%, 25%) . It was found that because of this tendency, it is very difficult to reduce the wavelength dependence of specific transmittance.

Furthermore, the present inventors have found out that ZrSi-based monolayer films (especially ZrSiON, ZrSiO, etc. containing oxygen (O)) have a problem that it is very difficult to control the in-plane distribution of transmittance. think The reason for this is that the ZrSi-based monolayer film containing oxygen (O) has the characteristic that the transmittance changes rapidly (the angle of the transmittance-wavelength curve becomes steep) at a wavelength of 300 nm to around 400 nm. At this time, when the film thickness of the ZrSi-based monolayer film containing oxygen (O) varies, the transmittance-wavelength curve also shifts to the short wavelength side or the long wavelength side, and the transmittance varies. Therefore, it becomes difficult to control the in-plane distribution of transmittance due to the in-plane difference in the film thickness of the ZrSi-based monolayer film containing oxygen (O).

In the above situation, the inventors of the present invention determined a phase shift layer (such as ZrSiON, whose composition is adjusted to a high transmittance) and a metal layer (such as ZrSi, the content of Zr, or the sum of Zr and Si). The content ratio is higher than the content ratio of Zr contained in the above-mentioned phase-shift layer or ZrSi) of the total content ratio of Zr and Si contained in the above-mentioned phase-shift layer. It was unexpectedly found as follows: Contrary to the above general understanding, even if In the case of high transmittance (for example, 15% or more, 16% or more, and further 18% or more) in a specific wavelength range (function 5), the wavelength dependence of the specific transmittance can also be compared with the general knowledge above. Relatively extreme reduction (for example, within 5.5%) (function 1) can satisfy both the requirements of function 5 and function 1. At this time, it is known that the metal layer (such as ZrSi, the content of Zr or the total content of Zr and Si is higher than the content of Zr contained in the above-mentioned phase shift layer or the sum of Zr and Si contained in the phase shift layer. The content of ZrSi) has the function/function of adjusting the wavelength dependence of the specific transmittance of the phase shift layer (eg ZrSiON) as a single layer. Specifically, it is found that the metal layer (eg ZrSi) has the effect of reducing the wavelength dependence of the phase shift layer (eg ZrSiON) by a specific value (specific amplitude) (for example, 10%) or more with the specific transmittance wavelength dependence of a single layer/ function (transmittance wavelength dependence reduction function).

When the transmittance is high (eg, 15% or more, 16% or more, and further 18% or more) and the wavelength dependence of the specific transmittance is so low (eg, within 5.5%), the resolution is very good. The reason for this is that the amount of light of wavelengths other than 365 nm (405 nm, 436 nm) interferes with the light of 365 nm less. Since the resolution is very good, it is possible to manufacture a fine pattern (for example, 1.8 μm or less) display device.

Furthermore, in the present invention, the wavelength dependence can be reduced (the slope of the transmittance-wavelength curve becomes flat (the slope becomes smaller) compared to the case where both the transmittance and the reflectance are a single layer in a specific wavelength range). ), so even if the film thickness is slightly different in the plane (for example, between the central part and the outer peripheral part) during the film formation, the in-plane distribution of transmittance and reflectance becomes very good. Therefore, a display device with small in-plane variation in CD (Critical Dimension) precision of the fine pattern can be manufactured.

Furthermore, the inventors of the present invention have found out that a phase shift layer (for example, ZrSiON) that mainly adjusts the transmittance and retardation of the exposure light and a metal layer ( The combination of metal layers (eg, ZrSi) having the function of reducing the wavelength dependence of transmittance to exposure light can realize a phase shift film with a specific transmittance wavelength dependence of less than 4.0% and an extremely excellent transmittance wavelength dependence (Subject 3).

In addition, the inventors of the present invention have found that the above-mentioned situation is achieved in the same manner even when the metal layer is replaced with a metal silicide-based material such as MoSi and TiSi, although there is a difference in degree.

The inventors of the present invention learned that, in the above case, even if the phase shift layer (MoSiON) (including the normal transmittance with transmittance of about 1% to 12% at the exposure wavelength is used to the transmittance with the exposure wavelength of 15% or more) In the case of combining the metal layer (MoSi) with the metal layer (MoSi), or the phase shift layer (TiSiON) (including the normal transmittance to high transmittance) and the metal layer (TiSi), there is a degree of difference, but also achieve the same.

The inventors of the present invention further conducted research and found that, in a phase shift film including two or more layered films, by combining a specific phase shift layer (eg, ZrSiON, MoSiON, TiSiON, etc.) with a specific metal layer (such as ZrSi, MoSi, TiSi, etc.) can be combined (in different order), which can greatly reduce the wavelength dependence of specific transmittance (for example, can be set within 5.5%) (function 1), and can control the back surface reflectivity (feature 4).

In addition, the inventors of the present invention learned that, in a phase shift film including a three-layer laminate film, a specific phase shift layer (such as ZrSiON, MoSiON, TiSiON, etc.), a specific metal layer (such as ZrSi, etc.) are sequentially formed from the substrate side. , MoSi, TiSi, etc.) and specific reflectance reduction layers (such as ZrSiON, MoSiON, TiSiON, CrO, CrOCN, CrON, etc.) are combined to have all the following functions: It can reduce the wavelength dependence of specific transmittance (function 1) (for example, it can be reduced to within 5.5%), the front reflectance can be reduced (function 2), and the front reflectance can be reduced (for example, below 10%) (function 3), and the back reflectance can be controlled (function 4) .

Furthermore, in the phase shift film comprising two or more or three-layer laminate films, the phase shift film using a Cr-based material as the uppermost layer has good adhesion to the resist film formed thereon.

The present invention has the following constitution.

(Constitution 1)

A phase-shift mask substrate, which is a phase-shift mask substrate for display device manufacturing, is characterized by comprising: a transparent substrate; and a phase-shift film formed on the transparent substrate; the phase-shift film comprises two or more layers of Laminated film, the phase shift film at least has: a phase shift layer, which has the function of mainly adjusting the transmittance and retardation of exposure light; and a metal layer, which has the function of adjusting the transmittance in the wavelength range of 365 nm or more and 436 nm or less The function of wavelength dependence; with regard to the above-mentioned phase-shift film, the transmittance and retardation of the above-mentioned phase-shift film to exposure light have specific optical properties, and the above-mentioned phase-shift layer contains at least one of metal, silicon, nitrogen and oxygen. The above-mentioned metal layer includes a material composed of metal and silicon or a material composed of metal, silicon and carbon, fluorine, A material composed of at least one of nitrogen and oxygen, the content of the metal contained in the above-mentioned metal layer is greater than the content of the metal contained in the above-mentioned phase-shift layer, or the sum of the metal and silicon contained in the above-mentioned metal layer The content ratio is greater than the total content ratio of the metal and silicon contained in the phase shift layer, and the wavelength dependence of the transmittance of the phase shift film in the wavelength range of 365 nm or more and 436 nm or less is within 5.5%.

(Constitution 2)

A phase-shift mask substrate, which is a phase-shift mask substrate for display device manufacturing, is characterized by comprising: a transparent substrate; and a phase-shift film formed on the transparent substrate; the phase-shift film has: a phase-shift layer , which has the function of mainly adjusting the transmittance and retardation of the exposure light; the reflectance reduction layer, which is arranged on the upper side of the phase shift layer, and has the function of reflecting the light incident from the front side of the phase shift film a function of reducing the rate; and a metal layer disposed between the above-mentioned phase shift layer and the above-mentioned reflectivity reducing layer, and having the function of adjusting the wavelength dependence of transmittance in the range of wavelength 365 nm or more and 436 nm or less; The laminated structure of the shift layer, the metal layer and the reflectance reduction layer has specific optical properties for the transmittance and retardation of the phase shift film to the exposure light, and the phase shift layer includes metal, silicon, nitrogen and oxygen. At least one of the materials, the above-mentioned metal layer contains a material composed of metal and silicon, or a material composed of at least one of metal, silicon and carbon, fluorine, nitrogen, and oxygen, and the metal contained in the above-mentioned metal layer contains is more than the metal content contained in the above-mentioned phase-shift layer, or the total content of metal and silicon contained in the above-mentioned metal layer is more than the total content of metal and silicon contained in the above-mentioned phase-shift layer, The wavelength dependence of transmittance of the said phase shift film in the wavelength range of 365 nm or more and 436 nm or less is within 5.5%.

(Composition 3)

According to the phase-shift mask substrate of 1 or 2, the transmittance of the phase-shift film at a wavelength of 365 nm is in the range of 1% or more and 50% or less.

(Composition 4)

According to the phase-shift mask substrate of 1 or 2, it is characterized in that the transmittance of the phase-shift film at a wavelength of 365 nm is in the range of 15% or more and 50% or less.

(Constitution 5)

The phase-shift mask substrate constituting any one of 2 to 4 is characterized in that: with respect to the phase-shift film, the front-side reflectance of the phase-shift film with respect to light incident from the front-side of the phase-shift film is 365 nm~ 10% or less in the wavelength region of 436nm.

(Constitution 6)

The phase-shift mask substrate constituting any one of 2 to 5 is characterized in that: with respect to the phase-shift film, the front reflectance of the phase-shift film with respect to light incident from the side of the phase-shift film is between 350 nm and 436 nm. 15% or less in the wavelength region.

(Constitution 7)

The phase-shift mask substrate constituting any one of 1 to 6 is characterized in that the back surface reflectance of the phase-shift film for light incident from the back side of the transparent substrate is 20 in the wavelength region of 365 nm to 436 nm. %above.

(Composition 8)

The phase-shift mask substrate according to any one of 2 to 7 is formed, wherein the reflectance reduction layer comprises a material including metal, silicon and at least one of nitrogen, oxygen and carbon or includes a metal and a material of at least one of nitrogen, oxygen and carbon.

(Constitution 9)

According to the phase-shift mask substrate constituting any one of 2, 5, 6, and 8, the metal constituting the phase-shift layer is any one of Zr, Mo, Ti, Ta, and W, which constitutes the above-mentioned phase shift layer. The metal of the metal layer is any one of Zr, Mo, Ti, Ta, and W, and the metal constituting the above-mentioned reflectance reduction layer is any one of Zr, Mo, Cr, Ti, Ta, and W.

(composition 10)

The phase-shift mask substrate constituting any one of 2, 5, 6, 8, and 9 is characterized in that: the metal constituting each of the phase-shift layer and the metal layer, or the phase-shift layer, the metal layer, and the The metal of each layer of the above-mentioned reflectance reduction layer is the same metal.

(Composition 11)

The phase-shift mask substrate according to any one of the constitutions 1 to 10 is characterized by having a light-shielding film formed on the above-mentioned phase-shift film.

(composition 12)

The phase-shift mask substrate of the configuration 11 is characterized in that: with respect to the light-shielding film, the film surface reflectance of the light-shielding film for light incident from the front side of the light-shielding film is 15% in a wavelength region of 350 nm to 436 nm. the following.

(composition 13)

A method for manufacturing a phase-shift mask, which is a method for manufacturing a phase-shift mask for display device manufacturing, characterized by comprising the following steps: phase-shift a phase-shift mask substrate as constituted in any one of 1 to 10 A resist film is formed on the film, and by using laser light having any wavelength selected from the wavelength region of 350 nm to 436 nm The drawing process and the developing process form a resist film pattern; and the phase shift film pattern is formed by etching the phase shift film using the resist film pattern as a mask.

(composition 14)

A method for manufacturing a phase-shift mask, which is a method for manufacturing a phase-shift mask for display device manufacturing, characterized by comprising the following steps: forming a resist on a light-shielding film such as a phase-shift mask substrate constituting 11 or 12 A resist film is formed, and a resist film pattern is formed by a drawing process and a development process using a laser light having any wavelength selected from a wavelength range of 350 nm to 436 nm; the above resist film pattern is used as a mask. The light-shielding film is etched to form a light-shielding film pattern; and the phase-shift film is etched using the light-shielding film pattern as a mask to form a phase-shift film pattern.

(composition 15)

A method of manufacturing a display device, characterized by comprising: a step of disposing a phase-shift mask, wherein a resist film-attached substrate with a resist film formed on the substrate is subjected to the phase-shifting process such as the configuration 13 or 14. A phase-shift mask obtained by a method of manufacturing a mask is disposed opposite to the resist film; and a pattern transfer step of irradiating the phase-shift mask with compound exposure including i-rays, h-rays and g-rays The above-mentioned phase shift film pattern is transferred by light.

ADVANTAGE OF THE INVENTION According to this invention, the novel phase shift film which is excellent in the wavelength dependence of transmittance can be provided.

ADVANTAGE OF THE INVENTION According to this invention, the novel phase shift film excellent in the wavelength dependence of transmittance and other characteristics can be provided.

According to the present invention, it is possible to provide a novel phase shift film having excellent transmittance wavelength dependence even with high transmittance.

ADVANTAGE OF THE INVENTION According to this invention, the novel phase shift film which is excellent in the wavelength dependence of transmittance can be provided.

According to the present invention, it is possible to provide a novel phase shift film having excellent transmittance wavelength dependence and also excellent front reflectance characteristics.

ADVANTAGE OF THE INVENTION According to this invention, the novel phase shift film which is excellent in the wavelength dependence of transmittance and the back surface reflectance characteristic can be provided.

According to the present invention, there can be provided a phase-shift mask substrate for manufacturing a display device including the phase-shift film of the present invention, a method for manufacturing a phase-shift mask using the phase-shift mask substrate, and a phase-shift mask using the phase-shift mask The manufacturing method of the display device.

10: Phase shift mask substrate

20: Transparent substrate

30: Phase shift film

31: Phase Shift Layer

32: Reflectivity reducing layer

33: Metal layer

40: Light-shielding film pattern

45: shading film

46: shading layer

47: Front reflectance reduction layer

FIG. 1 is a schematic view showing the film structure of the phase-shift mask base of the present invention.

FIG. 2 is a schematic view showing another film structure of the phase-shift mask substrate of the present invention.

FIG. 3 is a schematic view showing another film structure of the phase-shift mask substrate of the present invention.

FIG. 4 is a graph showing the transmittance spectrum of the phase shift film of the phase shift mask substrate of Example 1 of the present invention.

5 is a graph showing the front reflectance spectrum of the phase-shift film of the phase-shift mask substrate of Example 1 of the present invention.

FIG. 6 is a graph showing the backside reflectance spectrum of the phase-shift film of the phase-shift mask substrate of Example 1 of the present invention.

7 is a graph showing the transmittance spectrum of the phase-shift film of the phase-shift mask substrate of Example 2 of the present invention.

8 is a graph showing the front reflectance spectrum of the phase-shift film of the phase-shift mask substrate of Example 2 of the present invention.

FIG. 9 is a graph showing the backside reflectance spectrum of the phase-shift film of the phase-shift mask substrate of Example 2 of the present invention.

FIG. 10 is a graph showing the transmittance spectrum of the phase shift film of the phase shift mask substrate of Comparative Example 1. FIG.

11 is a graph showing the front reflectance spectrum of the phase-shift film of the phase-shift mask substrate of Comparative Example 1. FIG.

FIG. 12 is a graph showing the back surface reflectance spectrum of the phase shift film of the phase shift mask substrate of Comparative Example 1. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the following embodiment is an aspect when the present invention is embodied, and the present invention is not limited to this scope. In the drawings, there are cases where the same or equivalent parts are given the same symbols and their descriptions are simplified or omitted.

(Embodiment 1)

In Embodiment 1, the phase shift mask base will be described.

FIG. 1 is a schematic view showing the film structure of the phase shift mask substrate 10 .

The phase-shift mask base 10 includes: a transparent substrate 20 which is transparent (has translucency) with respect to exposure light; and a phase-shift film 30 which is disposed on the transparent substrate 20 . In FIG. 1 , the phase shift film 30 has a laminated structure of a phase shift layer 31 , a metal layer 33 and a reflectance reduction layer 32 sequentially arranged from the transparent substrate 20 side, but the phase shift film 30 may also have a self-transparent substrate. The layered structure of the phase shift layer 31 and the metal layer 33 arranged in sequence on the 20 side.

The phase shift layer 31 is disposed on the main surface of the transparent substrate 20 . The phase shift layer 31 has an adjusted pair of exposure The function of light transmittance and phase difference.

The phase shift layer 31 is formed of a material including metal (M), silicon (Si), and at least one of nitrogen (N) and oxygen (O). In addition, the phase shift layer 31 may also be made of a material including at least one of metal (M), silicon (Si), nitrogen (N) and oxygen (O), and further including at least one of carbon (C) and fluorine (F). form. For example, as a material for forming the phase shift layer 31, metal silicide oxynitride (MSiON), metal silicide nitride (MSiN), metal silicide oxide (MSiO), metal silicide oxycarbide nitride ( MSiOCN), metal silicide nitride carbide (MSiCN), metal silicide oxycarbide (MSiOC), metal silicide oxynitride fluoride (MSiONF), metal silicide oxynitride fluoride (MSiNF), metal silicide oxynitride Fluoride (MSiOF), metal silicide oxycarbonitride fluoride (MSiOCNF), metal silicide carbonitride fluoride (MSiCNF), metal silicide oxycarbide fluoride (MSiOCF), etc.

The metal (M) constituting the phase shift layer 31 is typically zirconium (Zr) and then molybdenum (Mo). As another metal (M) which comprises the phase shift layer 31, transition metals, such as titanium (Ti), tantalum (Ta), and tungsten (W), are mentioned.

For example, as the material constituting the phase shift layer 31, ZrSiON, ZrSiN, ZrSiO, ZrSiOCN, ZrSiCN, ZrSiCO, ZrSiONF, ZrSiNF, ZrSiOF, ZrSiOCNF, ZrSiCNF, and ZrSiOCF can be mentioned.

For example, as a material constituting the phase shift layer 31, MoSiON, MoSiN, MoSiO, MoSiOCN, MoSiCN, MoSiCO, MoSiONF, MoSiNF, MoSiOF, MoSiOCNF, MoSiCNF, and MoSiOCF can be mentioned.

For example, as a material constituting the phase shift layer 31, TiSiON, TiSiN, TiSiO, TiSiOCN, TiSiCN, TiSiCO, TiSiONF, TiSiNF, TiSiOF, TiSiOCNF, TiSiCNF, and TiSiOCF are mentioned.

The phase shift layer 31 may contain elements other than those listed above within a range not departing from the effects of the present invention. Furthermore, in order to obtain the optical properties of the phase shift film 30 of the present invention, the ratio (atomic ratio) of metal (M) to silicon (Si) in the metal silicide (MSi) of the phase shift layer 31 (atomic ratio) is preferably M:Si=1 : 1 or more and 1:9 or less. In the case of patterning the phase shift film 30 by wet etching, the ratio (atomic ratio) of metal (M) to silicon (Si) in the phase shift layer 31 is desirable from the viewpoint of making the pattern cross section good. ) is M:Si=1:1 or more and 1:8 or less, more preferably M:Si=1:1 or more and 1:4 or less.

Moreover, the metal (M) which comprises the phase shift layer 31 may be an alloy containing one or more kinds of the metals listed above.

The phase shift layer 31 can be formed by sputtering.

The reflectance reduction layer 32 is arranged on the upper side of the phase shift layer 31 . The reflectance reduction layer 32 has a function of reducing the reflectance of light incident from the front side of the phase shift film 30 (ie, the side opposite to the transparent substrate 20 side with respect to the reflectance reduction layer 32 ).

The reflectance reduction layer 32 may be formed of a material including metal (M), silicon (Si), and at least one of nitrogen (N) and oxygen (O). In addition, the reflectance reduction layer 32 may also be composed of a metal (M), silicon (Si), at least one of nitrogen (N) and oxygen (O), and at least one of carbon (C) and fluorine (F). material formation. For example, as the material for forming the reflectance reduction layer 32, the same material as the material for forming the phase shift layer 31 described above can be used.

In addition, the reflectance reduction layer 32 may be made of a material including metal (M) and at least one of nitrogen (N), oxygen (O), carbon (C), and fluorine (F), or a material including metal (M), silicon (Si) ) and at least one of nitrogen (N), oxygen (O), carbon (C) and fluorine (F). For example, as a material for forming the reflectance reduction layer 32, metal oxide (MO), metal oxynitride (MON), metal oxycarbonitride (MOCN), metal oxycarbide (MOC), and metal oxyfluoride can be mentioned. compound (MOF), Metal Oxidation Carbonitride Fluoride (MONF), Metal Oxidation Carbonitride Fluoride (MOCNF), Metal Oxidation Carbide Fluoride (MOCF), Metal Nitride (MN), Metal Carbonitride (MCN), Metal Fluoride (MF), Metal Nitride Fluoride (MNF), Metal Carbide Nitride Fluoride (MCNF), Metal Carbide Fluoride (MCF), etc.

The metal (M) constituting the reflectance reduction layer 32 is typically zirconium (Zr), molybdenum (Mo), and chromium (Cr). Transition metals such as titanium (Ti), tantalum (Ta), and tungsten (W) can be mentioned as other metals (M) constituting the reflectance reduction layer 32 .

For example, as a material for forming the reflectance reduction layer 32, ZrSiON, ZrSiN, ZrSiO, ZrSiOCN, ZrSiCN, ZrSiCO, ZrSiONF, ZrSiNF, ZrSiOF, ZrSiOCNF, ZrSiCNF, and ZrSiOCF can be mentioned.

For example, as a material for forming the reflectance reduction layer 32, MoSiON, MoSiN, MoSiO, MoSiOCN, MoSiCN, MoSiCO, MoSiONF, MoSiNF, MoSiOF, MoSiOCNF, MoSiCNF, and MoSiOCF can be mentioned.

For example, as a material for forming the reflectance reduction layer 32, TiSiON, TiSiN, TiSiO, TiSiOCN, TiSiCN, TiSiCO, TiSiONF, TiSiNF, TiSiOF, TiSiOCNF, TiSiCNF, and TiSiOCF are mentioned.

For example, the reflectance reducing layer 32 may be composed of chromium oxide (CrO), chromium oxynitride (CrON), chromium oxycarbide nitride (CrOCN), chromium oxycarbide (CrCO), chromium oxyfluoride (CrOF), chromium oxide Chromium oxycarbide nitride fluoride (CrONF), Chromium oxycarbide nitride fluoride (CrOCNF), Chromium oxycarbide fluoride (CrOCF), Chromium nitride (CrN), Chromium carbide nitride (CrCN), Chromium fluoride (CrF), Chromium-based materials such as chromium nitride fluoride (CrNF), chromium carbonitride fluoride (CrCNF), and chromium carbide fluoride (CrCF) are formed.

The reflectance reduction layer 32 may also include the above-mentioned ones within the scope not departing from the effects of the present invention. Elements other than those listed.

In addition, when the material of the reflectance reduction layer 32 is a metal silicide (MSi)-based material, in order to obtain the optical properties of the phase shift film 30 of the present invention, the ratio of metal (M) to silicon (Si) (atomic ratio ) is preferably M:Si=1:1 or more and 1:9 or less. In the case where the phase shift film 30 is patterned by wet etching, the ratio (atoms) of metal (M) to silicon (Si) in the reflectance reduction layer 32 is desirable from the viewpoint of making the pattern profile good. ratio) is M:Si=1:2 or more and 1:8 or less, more preferably M:Si=1:2 or more and 1:4 or less.

Moreover, the metal (M) which comprises the phase shift layer 31 may be an alloy containing one or more kinds of the metals listed above.

The reflectance reduction layer 32 can be formed by sputtering.

The metal layer 33 is arranged between the phase shift layer 31 and the reflectance reduction layer 32 . The metal layer 33 mainly has a role/function of adjusting the wavelength dependence of the transmittance of the phase shift layer 31 as a single layer. Specifically, the metal layer 33 has a role/function of reducing the wavelength dependence of the transmittance of the phase shift layer 31 by a specific value (specific width) or more mainly in a single layer. The metal layer 33 has an action/function to control the wavelength dependence of the transmittance of the phase shift film 30 in the entire laminate to be equal to or less than a specific value. In addition to these functions/functions, the metal layer 33 also has the function of adjusting the transmittance of the light to be exposed, and in combination with the reflectance reduction layer 32, the metal layer 33 has the function of adjusting the transmittance of the self-phase shift film 30 on the front side (and the transparent substrate 20 side) It is the function of reducing the reflectance of incident light on the opposite side. The metal layer 33 has a function of improving the back surface reflectance of the light incident from the back surface side of the transparent substrate 20 by the phase shift film 30 in combination with the phase shift layer 31 . The back surface of the transparent substrate 20 means the main surface on the opposite side to the phase shift film 30 among the two main surfaces of the transparent substrate 20 .

The metal layer 33 is made of a material composed of metal (M) and silicon (Si), or a metal (M), silicon (Si) and carbon (C), fluorine (F), nitrogen (N), oxygen (O) at least one of the constituents. In addition, the metal layer 33 includes The content rate of the contained metal is higher than that of the metal contained in the phase shift layer 31 or the total content rate of the metal and silicon contained in the metal layer 33 is greater than the sum of the metal and silicon contained in the phase shift layer 31 material content.

For example, as a material for forming the metal layer 33, metal silicide (MSi), metal silicide carbide (MSiC), and metal silicide carbide fluoride (MSiCF) can be mentioned.

The metal (M) constituting the metal layer 33 is typically zirconium (Zr). Transition metals such as molybdenum (Mo), titanium (Ti), tantalum (Ta), and tungsten (W) can be mentioned as other metals (M) constituting the metal layer 33 .

For example, as a material for forming the metal layer 33, ZrSi, ZrSiC, ZrSiCF, ZrSiN, ZrSiCN, etc. are mentioned.

For example, as a material for forming the metal layer 33, MoSi, MoSiC, MoSiCF, MoSiN, MoSiCN, etc. are mentioned.

For example, as a material for forming the metal layer 33, TiSi, TiSiC, TiSiCF, TiSiN, TiSiCN, etc. are mentioned.

When the metal layer 33 is a metal silicide (MSi), in order to obtain the optical properties of the phase shift film 30 of the present invention, the ratio (atomic ratio) of metal (M) to silicon (Si) in the metal layer 33 is preferably M:Si=1:1 or more and 1:9 or less. In the case of patterning the phase shift film 30 by wet etching, it is desirable that the ratio of metal (M) to silicon (Si) in the metal layer 33 is M:Si from the viewpoint of making the pattern profile good =1:2 or more and 1:8 or less, more preferably M:Si=1:2 or more and 1:4 or less.

Moreover, the metal (M) which comprises the metal layer 33 may be an alloy containing 1 or more types of the metal mentioned above.

In addition, by providing the metal layer 33, the sheet resistance of the phase shift film is reduced, so that the charging of the phase shift mask base and the phase shift mask can be prevented. When the metal layer 33 is not provided, it is easy to be damaged due to charging. Causes foreign matter to adhere or electrostatic breakdown.

The metal layer 33 may contain elements other than those listed above within a range not departing from the effects of the present invention.

The metal layer 33 can be formed by sputtering.

The metal layer 33 has a metal element (M) content (at %) higher than the metal element (M) content (at %) of the reflectance reduction layer 32, or the metal layer 33 is composed of the metal element (M) and silicon ( The total content ratio (atomic %) of Si) is higher than the total content ratio (atomic %) of the metal element (M) and silicon (Si) in the reflectance reduction layer 32 .

The difference between the metal element (M) content of the metal layer 33 and the metal element (M) content of the reflectance reduction layer 32 , or the total content and reflectance of the metal element (M) and silicon (Si) of the metal layer 33 The difference in the total content of the metal element (M) and the silicon (Si) in the reduction layer 32 is preferably 30 to 90 atomic %, more preferably 50 to 80 atomic %. Furthermore, if the difference between the content of the metal element (M) or the total content of the metal element (M) and silicon (Si) is 60 to 80 atomic %, the relationship between the metal layer 33 and the reflectance reduction layer 32 can be increased. The reflectance of the interface in the above-mentioned wavelength region (wavelength of 365 nm, or wavelength region of 365 nm to 436 nm) is preferable in order to further exert the effect of reducing reflectance.

Furthermore, the etching rate of the metal layer 33 can be improved by making the metal silicide-based material of metal (M) and silicon (Si) contain carbon (C), fluorine (F), nitrogen (N), and oxygen (O). Adjustment. For example, by including carbon (C), fluorine (F), or nitrogen (N) in the metal silicide-based material of metal (M) and silicon (Si), the wet etching rate can be slowed down. In addition, the etching rate of the reflectance reduction layer 32 and the phase shift layer 31 formed above and below the metal layer 33 can be controlled by making the metal (M) and silicon (Si) metal silicide materials contain carbon (C) or Fluorine (F) or nitrogen (N) slows down the wet etching rate, and can increase the wet etching rate by including oxygen (O) in the metal silicide-based material of metal (M) and silicon (Si). By these operations, it is possible to form a phase shift The etching rate of each layer of the film 30 is controlled so that the cross-sectional shape of the phase shift film 30 after etching is good.

Furthermore, the metal layer 33 has a metal element (M) content higher than the metal element (M) content of the phase shift layer 31 .

The difference between the metal element (M) content of the metal layer 33 and the metal element (M) content of the phase shift layer 31 is preferably 30 to 90 atomic %, more preferably 50 to 80 atomic %. If the difference in the content of the metal element (M) between the metal layer 33 and the phase shift layer 31 is 60 to 80 atomic %, the interface between the metal layer 33 and the phase shift layer 31 can be increased in the above-mentioned wavelength region (wavelength of 365 nm, or 365 nm). ~436nm wavelength region) the back reflectivity, so that the back reflectivity can be further improved, so it is better.

The metal element (M) content rate can be measured using an X-ray photoelectron spectroscopy apparatus (XPS: X-ray Photoelectron Spectroscopy (X-ray Photoelectron Spectroscopy) or ESCA: Electron Spectroscopy for Chemical Analysis (Electron Spectroscopy).

The thickness of the phase shift layer 31 in the phase shift film 30 is preferably in the range of, for example, 50 nm or more and 140 nm or less, and furthermore, 60 nm or more and 120 nm or less, but not limited thereto. From the viewpoint of improving the back surface reflectance, the thickness of the phase shift layer 31 is preferably 70 nm or more and 95 nm or less, and more preferably 70 nm or more and 85 nm or less.

The thickness of the metal layer 33 in the phase shift film 30 is preferably thinner than that of the phase shift layer 31 . The thickness of the metal layer 33 in the phase shift film 30 is preferably thinner than the thickness of the reflectance reduction layer 32 . The thickness of the metal layer 33 in the phase shift film 30 varies depending on the type of metal (M). For example, it is preferably within a range of 2.5 nm or more and 50 nm or less, and furthermore, 2.5 nm or more and 40 nm or less, but not limited to this. . It is substantially difficult to form the metal layer 33 uniformly over the substrate surface with a thickness of less than 2.5 nm. In addition, if the metal layer 33 is formed with a thickness exceeding 50 nm, the transmittance will decrease, for example, the transmittance of the phase shift film 30 at a wavelength of 365 nm may be lower than 1%. From the viewpoint of improving the frontal reflectance, The thickness of the metal layer 33 is preferably thicker. From the viewpoint of improving the reflectance of the back surface, the thickness of the metal layer 33 is 25 nm or more. From the above viewpoint, the film thickness of the metal layer 33 is preferably 25 nm or more and 50 nm or less, and more preferably 25 nm or more and 40 nm or less.

The thickness of the reflectance reduction layer 32 in the phase shift film 30 is preferably in the range of, for example, 15 nm or more and 40 nm or less, and more preferably 20 nm or more and 35 nm or less, but is not limited thereto.

Each of the phase shift layer 31 , the metal layer 33 and the reflectance reduction layer 32 preferably has a refractive index of 2.0 or more in the wavelength region of 365 nm to 436 nm. If it has a refractive index of 2.0 or more, the film thickness of the phase shift film 30 required for obtaining desired optical properties (transmittance and retardation) can be reduced. Therefore, the phase-shift mask produced using the phase-shift mask substrate 10 provided with the phase-shift film 30 can have a phase-shift film pattern having excellent pattern cross-sectional shape and excellent CD uniformity.

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

The transmittance and retardation of the phase-shift film 30 of the exposure light are specified by the laminated structure of the phase-shift layer 31 and the metal layer 33, or the laminated structure of the phase-shift layer 31, the metal layer 33 and the reflectance reduction layer 32. The optical characteristics of the transmittance, and the wavelength dependence of transmittance (the variation of transmittance) has a specific value.

The transmittance of the phase shift film 30 to the exposure light satisfies a value required as the phase shift film 30 . The transmittance of the phase shift film 30 is preferably 1% or more and 50% or less with respect to light of a specific wavelength (hereinafter, referred to as a representative wavelength) included in the exposure light. In the case of the high transmittance type, the transmittance of the phase shift film 30 is 15% or more and 50% or less. That is, when the exposure light is compound light including j-rays (wavelength: 313 nm), i-rays (wavelength: 365 nm), h-rays (wavelength: 405 nm), and g-rays (wavelength: 436 nm), the phase shift film 30 will The light of the representative wavelength contained in this wavelength range has the above-mentioned transmittance. Further, for example, when the exposure light is composite light including i-rays, h-rays, and g-rays, the phase shift film 30 has the above-mentioned transmission for any of i-rays, h-rays, and g-rays Rate.

The phase difference of the phase shift film 30 with respect to the exposure light satisfies a value required as the phase shift film 30 . For the light of the representative wavelength included in the exposure light, the phase difference of the phase shift film 30 is preferably 160° to 200°, more preferably 170° to 190°. Thereby, the phase of the light of the representative wavelength included in the exposure light can be changed to 160°~200°. Therefore, a phase difference of 160 to 200° is generated between the light of the representative wavelength passing through the phase shift film 30 and the light of the representative wavelength only passing through the transparent substrate 20 . That is, when the exposure light is composite light including light in the wavelength range of 313 nm or more and 436 nm or less, the phase shift film 30 has the above-mentioned retardation of the light of the representative wavelength included in the wavelength range. For example, when the exposure light is composite light including i-rays, h-rays, and g-rays, the phase shift film 30 has the above-described phase difference with respect to any of i-rays, h-rays, and g-rays.

The wavelength dependence of the transmittance of the phase shift film 30 in a wavelength range of 365 nm or more and 436 nm or less is within 5.5%.

The transmittance, transmittance wavelength dependence and retardation of the phase shift film 30 can be determined by adjusting the phase shift layer 31 and the metal layer 33 constituting the phase shift film 30 , or the phase shift layer 31 , the metal layer 33 and the reflectance reduction layer 32 . The material, composition and thickness of each layer are adjusted and controlled. Therefore, in Embodiment 1, the phase shift layer 31 and the metal layer 33, or the phase shift layer 31, the metal layer 33, or the phase shift layer 31, the metal layer 33, are adjusted so that the transmittance, the transmittance wavelength dependence, and the retardation of the phase shift film 30 have the above-mentioned specific optical characteristics. The material, composition and thickness of each layer of the layer 33 and the reflectance reduction layer 32 . Furthermore, the transmittance and transmittance wavelength dependence of the phase shift film 30 mainly affect the material, composition and thickness of the phase shift layer 31 and the metal layer 33 . The refractive index and retardation (phase shift amount) of the phase shift film 30 mainly affect the material, composition and thickness of the phase shift layer 31 .

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

The front reflectance of the phase shift film 30 for light incident from the front side of the phase shift film 30 is 10% or less in the wavelength region of 365 nm to 436 nm, and/or for light incident from the front side of the phase shift film 30 The front reflectance of the light phase shift film 30 is 15% or less in the wavelength region of 350 nm to 436 nm. If the front reflectivity of the phase shift film 30 is 10% or less in the wavelength region of 365 nm to 436 nm and/or the front reflectivity of the phase shift film 30 is 15% or less in the wavelength region of 350 nm to 436 nm, the phase shift When a resist film is formed on the film 30 and pattern drawing is performed by a laser drawing machine or the like, it is less affected by a standing wave generated by the overlap of the light used for drawing and its reflected light. Therefore, at the time of pattern drawing, the roughness of the edge portion of the pattern cross section of the resist film on the phase shift film 30 can be suppressed, so that the pattern precision can be improved. Therefore, a phase shift mask with excellent pattern accuracy can be formed. In addition, the frontal reflectivity to exposure light decreases, so that when a phase shift mask is used for pattern transfer to manufacture a display device, blurring of the transferred pattern due to reflected light from the display device substrate can be prevented ( spot) or CD error.

The variation range of the front reflectivity of the phase shift film 30 is preferably 10% or less in the wavelength region of 365 nm to 436 nm, more preferably 8% or less, more preferably 5% or less, and more preferably 3% or less . In addition, the fluctuation range of the front reflectance of the phase shift film 30 is preferably 12% or less in the wavelength region of 350 nm to 436 nm, more preferably 10% or less, more preferably 8% or less, and more preferably 5% %the following.

The back surface reflectance of the phase shift film 30 to light incident from the back surface side of the transparent substrate 20 is one of i-rays (365 nm), h-rays (405 nm), and g-rays (436 nm), preferably two or more. At the wavelength, more preferably 15% or more, more preferably 18% or more, more preferably 20% or more, and still more preferably 30% or more in the wavelength region of 365 nm to 436 nm. Thereby, the pattern position shift caused by thermal absorption and thermal expansion of the exposure light by the phase shift film 30 can be reduced. In addition, the variation range of the back reflectivity of the phase shift film 30 is preferably set to 20% or less in the wavelength region of 365 nm to 436 nm, more preferably 15% or less, more preferably 10% or less, and more preferably 5% or less.

The front reflectivity of the phase shift film 30 and its variation range can be controlled by adjusting the refractive index, extinction coefficient and thickness of each layer of the phase shift layer 31 , the metal layer 33 and the reflectance reduction layer 32 constituting the phase shift film 30 . Since the extinction coefficient and the refractive index can be controlled by adjusting the composition, in the first embodiment, the phase shift layer 31 and the metal layer are adjusted so that the front reflectance of the phase shift film 30 and its variation range have the above-mentioned specific physical properties 33 and the material, composition and thickness of each layer of the reflectance reduction layer 32 . The reflectivity of the back surface of the phase shift film 30 is also the same. Furthermore, the front reflectivity of the phase shift film 30 and its variation range mainly affect the material, composition and thickness of each layer of the metal layer 33 and the reflectivity reduction layer 32 . In addition, the back reflectivity of the phase shift film 30 and its variation range mainly affect the material, composition and thickness of the metal layer 33 and the phase shift layer 31 .

The front reflectance and the back reflectance can be measured using a spectrophotometer or the like. The fluctuation range of the front reflectance is obtained from the difference between the maximum reflectance and the minimum reflectance in the wavelength range of 350nm to 436nm, or the wavelength range of 365nm to 436nm. In addition, the fluctuation range of the back surface reflectance was calculated|required from the difference of the maximum reflectance and the minimum reflectance in the wavelength region of 365nm - 436nm.

The phase shift layer 31 may include a single film with uniform composition, may include a plurality of films with different compositions, may include a single film whose composition continuously changes in the thickness direction, or may include different compositions. A plurality of films and the plurality of films respectively include a case where the composition of the film continuously changes in the thickness direction. The same applies to the metal layer 33 and the reflectance reduction layer 32 .

FIG. 2 is a schematic view showing another film configuration of the phase-shift mask substrate 10 . As shown in FIG. 2 , the phase-shift mask base 10 may also include a light-shielding film pattern 40 between the transparent substrate 20 and the phase-shift film 30 .

When the phase-shift mask base 10 is provided with the light-shielding film pattern 40 , the light-shielding film pattern 40 is disposed on the main surface of the transparent substrate 20 . The light-shielding film pattern 40 has the function of blocking the transmission of exposure light.

The material for forming the light-shielding film pattern 40 is not particularly limited as long as it has a function of blocking the transmission of exposure light. For example, a chromium-based material, a material containing the above-mentioned metal (M) (M: any one of Zr, Mo, Ti, Ta, and W), and a material containing the above-mentioned metal (M) and silicon (Si) can be mentioned. Wait. Examples of the chromium-based material include chromium (Cr), or a chromium compound containing at least one of chromium (Cr), carbon (C), and nitrogen (N). In addition, a chromium compound containing at least one of chromium (Cr), oxygen (O), and fluorine (F), or a chromium compound containing at least one of chromium (Cr), carbon (C), and nitrogen (N), and further A chromium compound of at least one of oxygen (O) and fluorine (F). For example, Cr, CrC, CrN, CrO, CrCN, CrON, CrCO, and CrCON are mentioned as a material for forming the light-shielding film pattern 40 .

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

In the portion where the phase shift film 30 and the light-shielding film pattern 40 are laminated, the optical density to the exposure light is preferably 3 or more, more preferably 4 or more, and still more preferably 5 or more.

The optical density can be measured using a spectrophotometer, an OD (Optical Density) meter, or the like.

The light-shielding film pattern 40 may include a single film with a uniform composition, may include a plurality of films with different compositions, or may include a single film with a continuously changing composition in the thickness direction. In addition, the light-shielding film pattern 40 may include a plurality of films having different compositions, and each of the plurality of films includes a film whose composition continuously changes in the thickness direction.

Furthermore, in FIGS. 1 and 2 , the phase shift mask substrate 10 may also include a resist film on the phase shift film 30 .

FIG. 3 is a schematic view showing another film configuration of the phase-shift mask substrate 10 .

The phase shift mask base 10 may also include a transparent substrate 20 and be formed on the transparent substrate 20 The phase shift film 30 is further formed with a light shielding film 45 on the phase shift film 30 . In addition, a resist film (illustration omitted) may be formed on the light shielding film 45 .

In this case, as the light-shielding film 45, the same content as that described in the light-shielding film pattern 40 can be applied. For example, as the material of the light-shielding film 45, the same material as the material for forming the light-shielding film pattern 40 can be used. The light-shielding film 45 with anti-reflection function can also be formed with a front reflectance reduction layer 47 for reducing the surface reflectance of the light-shielding film 45 for reducing the light incident from the front side of the light-shielding film 45 as required. In this case, the light-shielding film 45 has a structure including a light-shielding layer 46 having a function of blocking the transmission of exposure light from the phase shift film 30 side, and a front reflectance reduction layer 47 . Furthermore, when the light-shielding film 45 is provided with the front surface reflectance reduction layer 47, it is preferable that the surface reflectance of the film with the front surface reflection reduction layer 47 is 10% or less in the wavelength region of 365 nm to 436 nm, and/or the front surface. The reflectance of the film surface of the reflectance reduction layer 47 has a characteristic of being 15% or less in the wavelength region of 350 nm to 436 nm. Furthermore, other functional films may also be formed between the phase shift film 30 shown in FIG. 2 and the light-shielding film pattern 40 , between the phase shift film 30 and the light-shielding film 45 shown in FIG. As said other functional film, an etching stopper film, an etching mask film, etc. are mentioned.

Next, the manufacturing method of the phase shift mask base 10 of Embodiment 1 is demonstrated.

The phase shift mask substrate 10 is manufactured by performing the following preparation steps and phase shift film forming steps.

Hereinafter, each step will be described in detail.

(preparatory steps)

In the preparation step, the transparent substrate 20 is first prepared. The material of the transparent substrate 20 is not particularly limited as long as it has translucency to the light used for exposure. For example, the material of the transparent substrate 20 includes synthetic quartz glass, soda lime glass, and alkali-free glass. The transparent substrate 20 is, for example, When it is assumed that there is no surface reflection loss, it has a transmittance of 85% or more, preferably 90% or more, to the exposure light.

In the case of manufacturing the phase-shift mask base 10 having the light-shielding film pattern 40 ( FIG. 2 ), a light-shielding film containing, for example, a chromium-based material is formed on the transparent substrate 20 by sputtering. Then, a resist film pattern is formed on the light-shielding film, and the light-shielding film pattern 40 is formed by etching the light-shielding film using the resist film pattern as a mask. After that, the resist film pattern is peeled off. These steps are omitted when manufacturing the phase-shift mask substrate 10 having the light-shielding film pattern 40 .

(Phase Shift Film Formation Step)

In the phase shift film forming step, the phase shift film 30 is formed on the transparent substrate 20 by sputtering. Here, when the light-shielding film pattern 40 ( FIG. 2 ) is formed on the transparent substrate 20 , the phase shift film 30 is formed so as to cover the light-shielding film pattern 40 .

The phase shift film 30 is formed by forming a phase shift layer 31 on the main surface of the transparent substrate 20 and forming a metal layer 33 on the phase shift layer 31 . Alternatively, the phase shift film 30 is formed by forming the phase shift layer 31 on the main surface of the transparent substrate 20 , forming the metal layer 33 on the phase shift layer 31 , and forming the reflectance reducing layer 32 on the metal layer 33 . .

The phase shift layer 31 and the reflectance reduction layer 32 are formed by sputtering one or more of metal (M), metal (M) compound, metal silicide (MSi) or metal silicide (MSi) compound. Coating targets, for example, in an inert gas containing at least one selected from the group consisting of helium, neon, argon, krypton and xenon and containing a gas selected from oxygen, nitrogen, nitric oxide, nitrogen dioxide , in a sputtering gas environment consisting of a mixture of at least one active gas from the group consisting of carbon dioxide gas, hydrocarbon-based gas, and fluorine-based gas. As a hydrocarbon type gas, a methane gas, a butane gas, a propane gas, a styrene gas etc. are mentioned, for example.

The metal layer 33 is formed by using a metal (M), a metal (M) compound, and a metal silicide. (MSi) or one or more sputtering targets of metal silicide (MSi) compounds, for example, in a sputtering target containing at least one selected from the group consisting of helium, neon, argon, krypton, and xenon carried out in an inert gas environment. When the metal layer 33 contains carbon, the film formation of the metal layer 33 is performed in a sputtering gas environment composed of a mixed gas of the above-mentioned inert gas and the above-mentioned hydrocarbon-based gas. When the metal layer 33 contains nitrogen, oxygen, and fluorine, the film formation of the metal layer 33 is performed in the same manner as the film formation of the phase shift layer 31 and the reflectance reduction layer 32 described above.

When the phase shift layer 31 and the metal layer 33 are formed, or when the phase shift layer 31, the metal layer 33 and the reflectance reduction layer 32 are formed, the materials of each of the phase shift layer 31, the metal layer 33 and the reflectance reduction layer 32, The composition and thickness are such that the transmittance and retardation of the phase-shift film 30 have the above-mentioned specific optical characteristics, and the transmittance wavelength dependence (the range of change of transmittance) of the phase-shift film 30 has the above-mentioned specific characteristics, and the phase-shift film 30 has the above-mentioned specific characteristics. The front reflectivity and its variation range, and the back reflectivity and its variation range have the above-mentioned specific characteristics to be adjusted. The composition of each layer of the phase shift layer 31 , the metal layer 33 and the reflectance reduction layer 32 can be controlled by the composition and flow rate of the sputtering gas. The thickness of each layer of the phase shift layer 31 , the metal layer 33 and the reflectance reduction layer 32 can be controlled by sputtering power, sputtering time and the like. In addition, when the sputtering apparatus is an in-line sputtering apparatus, the thickness of each layer of the phase shift layer 31 , the metal layer 33 and the reflectance reduction layer 32 can also be controlled by the conveyance speed of the substrate.

In the case where the phase shift layer 31 includes a single film with a uniform composition, the above-described film forming process is performed only once without changing the composition and flow rate of the sputtering gas. When the phase shift layer 31 includes a plurality of films with different compositions, the composition and flow rate of the sputtering gas are changed every time the film formation treatment is performed, and the above film formation treatment is performed a plurality of times. When the phase shift layer 31 includes a single film whose composition is continuously changed in the thickness direction, the above-described film-forming treatment is performed only once while changing the composition and flow rate of the sputtering gas. In the case where the phase shift layer 31 includes a plurality of films with different compositions and the plurality of films respectively include films whose compositions are continuously changed in the thickness direction, the composition and flow rate of the sputtering gas are changed simultaneously. The above-mentioned film-forming treatment is carried out a plurality of times on one side.

The film formation of the metal layer 33 and the film formation of the reflectance reduction layer 32 are also the same. In the case where the film formation process is performed a plurality of times, the sputtering power applied to the sputtering target can be reduced.

The phase shift layer 31 , the metal layer 33 and the reflectance reduction layer 32 are preferably formed by sputtering equipment, and the transparent substrate 20 is not taken out of the equipment (ie, not exposed to the atmosphere) and continuously formed. By forming a film continuously without taking the transparent substrate 20 out of the device, accidental surface oxidation or surface carbonization of each layer can be prevented. Unexpected surface oxidation or surface carbonization of each layer allows laser light used for drawing the resist film formed on the phase shift film 30 or the phase shift film pattern to be transferred to the resist formed on the display device substrate. The reflectance of the exposure light used for etching the film may change, and the etching rate of the oxidized portion or the carbonized portion may be changed.

The phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 can be continuously formed into a film using an in-line sputtering apparatus or a cluster sputtering apparatus without exposing the substrate to the atmosphere.

Furthermore, as shown in FIG. 3 , in the case of manufacturing the phase-shift mask base 10 having the phase-shift film 30 and the light-shielding film 45 on the transparent substrate 20 , the phase-shift film 30 is formed by the above-mentioned phase-shift film forming step. After that, a light shielding film 45 is formed on the phase shift film 30 .

(Light-shielding film forming step)

In the light-shielding film forming step, a light-shielding film 45 is formed on the phase shift film 30 by sputtering.

The light-shielding film 45 is formed by forming a light-shielding layer 46 on the phase shift film 30, and forming a front reflectance reduction layer 47 on the light-shielding layer 46 as necessary. The light shielding layer 46 and the front reflectance reduction layer 47 are formed by sputtering one or more of metal (M), metal (M) compound, metal silicide (MSi) or metal silicide (MSi) compound. Coating targets, for example, in an inert gas comprising at least one selected from the group consisting of helium, neon, argon, krypton and xenon and a gas comprising oxygen, nitrogen, nitric oxide, nitrogen dioxide , carbon dioxide gas, hydrocarbon gas, The sputtering gas environment is performed in a sputtering gas environment composed of a mixed gas of at least one active gas among the group consisting of fluorine-based gases, or a sputtering gas environment containing at least one of the above-mentioned inert gases. As a hydrocarbon type gas, a methane gas, a butane gas, a propane gas, a styrene gas etc. are mentioned, for example.

When forming the light shielding layer 46 and the front reflectance reduction layer 47, the material, composition and thickness of each layer of the light shielding layer 46 and the front reflectance reduction layer 47 are based on the part where the phase shift film 30 and the light shielding film 45 are laminated, and are exposed to light. The optical density of the light or the reflectance of the film surface is adjusted in such a way that the above-mentioned specific optical characteristics are obtained. The composition of each layer of the light shielding layer 46 and the front reflectance reduction layer 47 can be controlled by the composition and flow rate of the sputtering gas. The thickness of each layer of the light shielding layer 46 and the front reflectance reduction layer 47 can be controlled by sputtering power, sputtering time, and the like. Moreover, when the sputtering apparatus is an in-line sputtering apparatus, the thickness of each layer of the light shielding layer 46 and the front reflectance reduction layer 47 can also be controlled by the conveyance speed of the substrate.

When each layer of the light-shielding layer 46 and the front reflectance reduction layer 47 includes a single film with a uniform composition, the above-described film forming process is performed only once without changing the composition and flow rate of the sputtering gas. When each layer of the light shielding layer 46 and the front reflectance reduction layer 47 includes a plurality of films with different compositions, each time a film formation process is performed, the composition and flow rate of the sputtering gas are changed, and the above film formation process is performed a plurality of times. When each layer of the light shielding layer 46 and the front reflectance reduction layer 47 includes a single film whose composition continuously changes in the thickness direction, the above-described film forming process is performed only once while changing the composition and flow rate of the sputtering gas. When each layer of the light shielding layer 46 and the front reflectance reduction layer 47 includes a plurality of films with different compositions, and the plurality of films respectively include films with a continuously changing composition in the thickness direction, the composition and flow rate of the sputtering gas are changed while changing , while performing the above-mentioned film forming treatment several times.

The light shielding layer 46 and the front reflectance reduction layer 47 can be continuously formed into a film using an in-line sputtering apparatus or a cluster sputtering apparatus without exposing the substrate to the atmosphere.

Furthermore, in the case of manufacturing the phase shift mask substrate 10 provided with the resist film, the resist film is then formed on the light shielding film.

The phase-shift mask substrate 10 of the first embodiment has the phase-shift layer 31 and the metal layer 33 as the phase-shift film 30, so the retardation and transmittance satisfy specific optical characteristics, and the light transmittance is transmitted in the wavelength range of 365 nm or more and 436 nm or less. Excellent rate wavelength dependence (within 5.5%). Further, the phase shift mask substrate 10 having the phase shift film 30 including the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 has a phase difference and transmittance that satisfy specific optical characteristics, and are within 365 nm or more and 436 nm or less. In the wavelength range, the transmittance wavelength dependence is excellent (within 5.5%), the front reflectance characteristics are also excellent (10% or less), and the back reflectance characteristics are also excellent.

(Embodiment 2)

In Embodiment 2, the manufacturing method of the phase shift mask using the phase shift mask base 10 of Embodiment 1 is demonstrated. Embodiment 2 includes Embodiment 2-1 and Embodiment 2-2. Embodiment 2-1 is a method of manufacturing a phase shift mask using the phase shift mask base 10 having the phase shift film 30 and the resist film formed on the transparent substrate 20 . Embodiment 2-2 is a method of manufacturing a phase shift mask using the phase shift mask base 10 in which the phase shift film 30 , the light shielding film 45 , and the resist film are formed on the transparent substrate 20 . In the manufacturing method of the phase shift mask of Embodiment 2-1, a phase shift mask is manufactured by performing the following resist film pattern formation process and phase shift film pattern formation process. Moreover, the manufacturing method of the phase shift mask of Embodiment 2-2 manufactures a phase shift mask by carrying out the following resist film pattern formation process, light-shielding film pattern formation process, and phase shift film pattern formation process.

Hereinafter, each step will be described in detail.

(resist film pattern forming 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 the first embodiment described in FIG. 1 or FIG. 2 . The resist film used The material is not particularly limited. The resist film material is, for example, one that is sensitive to laser light having any wavelength selected from the following wavelength region of 350 nm to 436 nm, or is used for laser light with any wavelength selected from the wavelength region of 365 nm to 436 nm. Sensitive. In addition, the resist film may be either positive type or negative type.

After that, use laser light with any wavelength selected from the wavelength range of 350 nm to 436 nm, or laser light with any wavelength selected from the wavelength range of 365 nm to 436 nm to draw a specific pattern on the resist film . As the pattern drawn on the resist film, a line-and-space pattern or a hole pattern is exemplified.

After that, the resist film is developed with a specific developing solution to form a resist film pattern on the phase shift film 30 .

Furthermore, in the case where the phase shift mask substrate 10 already has a resist film on the phase shift film 30, the above-mentioned step of forming the resist film on the phase shift film 30 is omitted.

(Light-shielding film pattern forming step)

In the light-shielding film pattern forming step in the manufacturing method of the phase shift mask of Embodiment 2-2, the light-shielding film 45 ( FIG. 3 ) is etched using the resist film pattern as a mask to form a light-shielding film pattern.

The etching medium (etching solution, etching gas) for etching the light-shielding film 45 is not particularly limited as long as it can selectively etch each of the light-shielding layer 46 and the front reflectance reduction layer 47 constituting the light-shielding film 45 .

Specifically, for example, as an etching solution for wet-etching a metal silicide-based material, one containing at least one fluorine compound selected from the group consisting of hydrofluoric acid, hydrofluorosilicic acid, and ammonium hydrogen fluoride and hydrogen peroxide can be mentioned. , nitric acid, and an etching solution of at least one oxidant in sulfuric acid, or an etching solution containing hydrogen peroxide, ammonium fluoride, and at least one oxidant selected from phosphoric acid, sulfuric acid, and nitric acid. As an etching gas for dry-etching the metal silicide-based material layer, a fluorine-based gas and a chlorine-based gas can be mentioned. Examples of the fluorine-based gas include carbon tetrafluoride gas (CF ₄ ), trifluoromethane gas (CHF ₃ ), sulfur hexafluoride gas (SF ₆ ), or oxygen gas (O ₂ ) mixed with these gases. By.

Moreover, as an etching liquid which wet-etches a chromium type material, the etching solution containing ceric ammonium nitrate and perchloric acid, or the etching gas containing the mixed gas of chlorine gas and oxygen gas is mentioned, for example.

(Phase Shift Film Pattern Forming Step)

In the phase shift film pattern forming step, in the manufacturing method of the phase shift mask of Embodiment 2-1, first, the phase shift film 30 is etched using the resist film pattern as a mask to form a phase shift film pattern. On the other hand, in the manufacturing method of the phase shift mask of Embodiment 2-2, the light-shielding film 45 is etched using the resist film pattern as a mask to form a light-shielding film pattern, and then the light-shielding film pattern is used as a mask pair The phase shift film 30 is etched to form a phase shift film pattern.

The etching medium (etching solution, etching gas) for etching the phase-shift film 30 only needs to be able to selectively etch each of the phase-shift layer 31 , the metal layer 33 , and the reflectance reduction layer 32 constituting the phase-shift film 30 , there is no special restriction.

Specifically, for example, as an etching solution for wet-etching a metal silicide-based material, one containing at least one fluorine compound selected from the group consisting of hydrofluoric acid, hydrofluorosilicic acid, and ammonium hydrogen fluoride, and a peroxide selected from the group consisting of An etching solution containing at least one oxidant among hydrogen, nitric acid, and sulfuric acid, or an etching solution containing hydrogen peroxide, ammonium fluoride, and at least one oxidant selected from phosphoric acid, sulfuric acid, and nitric acid. As an etching gas for dry-etching the metal silicide-based material layer, a fluorine-based gas and a chlorine-based gas can be mentioned. Examples of the fluorine-based gas include carbon tetrafluoride gas (CF ₄ ), trifluoromethane gas (CHF ₃ ), sulfur hexafluoride gas (SF ₆ ), or oxygen gas (O ₂ ) mixed with these gases. By.

Moreover, for example, as an etchant for wet-etching a chromium-based material, there may be mentioned: An etching solution of ceric ammonium nitrate and perchloric acid or an etching gas containing a mixed gas of chlorine and oxygen.

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

In the manufacturing method of the phase-shift mask of the embodiment 2-2, the light-shielding film pattern can also be removed by an etching medium for etching the light-shielding film 45, or the phase-shifting film pattern with the phase-shifting film is formed on the phase-shifting film pattern. In the case of light-shielding film patterns with different pattern sizes, after forming a resist film pattern on the light-shielding film pattern again, the light-shielding film pattern forming step is performed using the resist film pattern as a mask.

The phase-shift mask of the second embodiment has the phase-shift layer 31 and the metal layer 33 as the phase-shift film 30. Therefore, on the basis of satisfying the specific optical characteristics of retardation and transmittance, in the wavelength range of 365 nm or more and 436 nm or less , excellent transmittance wavelength dependence (within 5.5%). Furthermore, the phase-shift mask substrate 10 having the phase-shift film 30 including the phase-shift layer 31, the metal layer 33, and the reflectance-reducing layer 32 can satisfy the specific optical characteristics of the retardation and transmittance, and the thickness is 365 nm or more and In the wavelength range of 436 nm or less, the wavelength dependence of transmittance is excellent (within 5.5%), and the front reflectance characteristics are also excellent (10% or less), and the back reflectance characteristics are also excellent. Moreover, corresponding to the excellent characteristics of the phase shift mask, it has the characteristic of improving the resolution of the transfer pattern transferred to the display device substrate.

(Embodiment 3)

In Embodiment 3, the manufacturing method of a display device is demonstrated. The display device is manufactured by carrying out the following mask placement step and pattern transfer step.

Hereinafter, each step will be described in detail.

(Mounting step)

In the placing step (arranging step), the phase shift mask manufactured in Embodiment 2 is placed (arranged) on the mask placing table of the exposure apparatus. Here, the phase-shift mask is patterned to form surface-side spacers The projection optical system of the exposure apparatus is arranged so as to face the resist film formed on the display apparatus substrate.

(Pattern transfer step)

In the pattern transfer step, the phase shift mask 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 includes composite light of light with a plurality of wavelengths selected from the wavelength region of 365 nm to 436 nm, composite light of light of a plurality of wavelengths selected from the wavelength region of 313 nm to 436 nm, or the use of filters, etc. The wavelength range of 313nm~436nm cuts off the selected monochromatic light in a certain wavelength range. For example, the exposure light is compound light including i-rays, h-rays and g-rays, or mixed light including j-rays, i-rays, h-rays and g-rays, or monochromatic light of i-rays. If the compound light is used as the light for exposure, the intensity of the light for exposure can be increased and the throughput can be increased, so the manufacturing cost of the display device can be reduced.

According to the manufacturing method of the display device of Embodiment 3, a high-resolution, high-definition display device can be manufactured. For example, fine patterns (eg, 1.8 μm contact holes) can be formed.

(Embodiment 4)

In Embodiment 4, a specific example of the phase shift mask base will be described.

As described above, the present inventors have found that, in a phase shift film including a three-layer laminate film, a specific phase shift layer (for example, ZrSiON, MoSiON, TiSiON, etc.), a specific metal Layers (intermediate layers) (such as ZrSi, MoSi, TiSi, etc.), and specific reflectivity reducing layers (such as ZrSiON, MoSiON, TiSiON, CrO, CrOCN, CrON, etc.) are combined to have all of the following functions: reduce Specific wavelength dependence of transmittance (function 1) (for example, it can be reduced to within 5.5%), frontal reflectance can be reduced (function 2), and frontal reflectance can be reduced (for example, 10% or less) (function 3), Backside reflectivity can be controlled (function 4). In addition, it was found that the characteristic of high transmittance can be combined (function 5).

As a representative example of the above, a phase shift film composed of three layers of a phase shift layer including ZrSiON, a metal layer including ZrSi, and a reflectance reduction layer including ZrSiON in this order from the transparent substrate side can be mentioned.

Moreover, the phase shift film which consists of three layers of the phase shift layer containing MoSiON, the metal layer containing MoSi, and the reflectance reduction layer containing MoSiON in this order from the transparent substrate side can be mentioned.

Taking these as a basis, and substituting the materials of each layer with the materials listed above as the materials that can be selected in each layer are included in the present invention.

Furthermore, the present inventors have found that in a phase shift film composed of three layers of a phase shift layer including ZrSiON, a metal layer including ZrSi, and a reflectance reduction layer including ZrSiON in this order from the transparent substrate side, if the When the film thickness of the metal layer including ZrSi becomes thinner (eg, 2.5 nm or more and less than 20 nm, eg, 10 nm), the transmittance increases, but the reflectance also increases. And it is known that if the allowable range of reflectance is increased (for example, the upper limit is increased to "20% or less"), the transmittance can be about 45%.

The inventors of the present invention know that the high transmittance can be up to about 30% when the low reflectance range (eg, 10% or less) is maintained. When maintaining a low reflectance range (eg, 10% or less), the thickness of the metal layer including ZrSi is preferably 20 nm or more and 35 nm or less, for example.

In addition, the inventors of the present invention have found that, for example, in the phase shift film composed of the three layers of the ZrSi system, if the film thickness of the metal layer containing ZrSi is increased (for example, 40 to 60 nm), the normal transmittance ( 3% or more and less than 15%, especially 3% or more and 12% or less) or low transmittance (1% or more and less than 3%).

Furthermore, for example, in a phase shift film composed of three layers including a phase shift layer including ZrSiON, a metal layer including ZrSi, and a reflectance reduction layer including ZrSiON in this order from the transparent substrate side, the phase shift layer including ZrSiON increases. When the degree of oxidation of the transferred layer becomes high, the transmittance becomes high (the transmittance increases high).

Also, for example, in the above, when the transmittance of the phase shift layer containing ZrSiON is increased (adjusted to a high transmittance), the portion becomes a high transmittance. In addition, in this case, the film thickness of the metal layer containing ZrSi can be increased by the amount by which the transmittance increases.

Furthermore, the present inventors have found that, for example, in a phase shift film composed of three layers of a phase shift layer including ZrSiON, a metal layer including ZrSi, and a reflectance reduction layer including ZrSiON in this order from the transparent substrate side, if the If the reflectance reducing layer is replaced from ZrSiON to CrOCN or MoSiON, the transmittance can be controlled to a normal transmittance (for example, about 6%).

As described above, the inventors of the present invention have found that, by combining the phase shift layer containing ZrSiON, the reflectance reducing layer containing ZrSiON, and the metal layer containing ZrSi, a transmittance of 15% or more can be obtained and a high transmittance can be obtained, In addition, the specific transmittance wavelength dependence is less than 4.0%, and the transmittance wavelength dependence is extremely excellent in the phase shift film.

In the present invention, the layer containing the above-mentioned ZrSi-containing material (appropriately referred to as a ZrSi-based layer) is two-layered, the ZrSi-based layer is three-layered, and the ZrSi-based layer is a multi-layered phase-shift film. The same applies to other metal silicide-based material layers. When the ZrSi-based layer is a phase-shift film with a multi-layered structure, the ZrSi-based material has the advantages of chemical resistance, high wet etching speed, and good pattern cross-section shape.

Furthermore, the transmittance in the wavelength range of 365 nm or more and 436 nm or less is required to be 2% or less, and the transmittance is required to be a phase shift layer with a low transmittance of less than 2% and 1% or more.

For example, even if the transmittance of the phase-shift layer is about 6%, the resist will be exposed to light due to the exposure light passing through the phase-shift part in the phase-shift mask, so that the resist will be reduced accordingly. On the other hand, by fulfilling the above-mentioned requirements, it is possible to further reduce the influence of film reduction on the resist film of the transfer target body due to the exposure light transmitted through the phase shift portion in the phase shift mask.

In the present invention, it is known that in the above-mentioned two or more phase-shift layers, or the above-mentioned three-layer phase-shift layer, for example, by controlling the thickness of the metal layer, or changing the phase-shift layer or the reflectance-reducing layer to transmittance Lower materials can meet the above requirements.

In the present invention, from the transparent substrate side, the phase shift layer including ZrSiON and the two-layer phase shift layer including ZrSi metal layer are sequentially set, or the phase shift layer including ZrSiON is sequentially set from the transparent substrate side. In the three-layer phase shift layer consisting of / metal layer containing ZrSi / reflectivity reducing layer containing ZrSiON (there are cases abbreviated as two layers of ZiSi type and three layers of ZiSi type respectively in the specification), the metal layer is separated from ZrSi When replacing with the case of TiSi, the same situation as above can be achieved. In the case of replacing the material of the metal layer from ZrSi with MoSi, the same situation as above can also be achieved.

In the present invention, when the metal layer is replaced from ZrSi to MoSi in the above-mentioned ZiSi-based 2-layer or ZiSi-based 3-layer, the same situation as the above can be realized. However, the etching rate of the metal layer varies.

In the present invention, when the reflectance reducing layer is replaced from ZrSiON to MoSiON in the above-mentioned ZiSi-based 2-layer or ZiSi-based 3-layer, although high transmittance cannot be maintained, normal transmittance can be obtained. Other aspects may be the same as above.

[Example]

Hereinafter, based on an Example and a comparative example, this invention is demonstrated more concretely. In addition, the following Example 1, 2 is an example of this invention, and does not limit this invention.

Example 1 includes Examples 1-1 to 1-3.

(Example 1-1)

(Phase Shift Mask Base)

In Example 1-1, the phase of the composition of QZ (transparent substrate)/ZrSiON/ZrSi/ZrSiON Move the reticle base for illustration.

The phase-shift film in the phase-shift mask base of Example 1-1 consists of a phase-shift layer (ZrSiON, film thickness of 73 nm), a metal layer (ZrSi, film thickness of 30 nm) and a reflectance reduction that are sequentially arranged from the transparent substrate side layer (ZrSiON, film thickness 30 nm).

As the transparent substrate, a synthetic quartz glass substrate (QZ) having a size of 800 mm×920 mm and a thickness of 10 mm was used. The two main surfaces of the transparent substrate are mirror-polished. The two main surfaces of the transparent substrates used in the following Examples and Comparative Examples were mirror-polished in the same manner.

The phase-shift film with the phase-shift layer, the metal layer, and the reflectance-reducing layer laminated on the transparent substrate has a refractive index of 2.55 at a wavelength of 365 nm, and an extinction coefficient of 0.127 at a wavelength of 365 nm.

In addition, the refractive index and extinction coefficient of the phase shift film were measured using n & k Analyzer 1280 (trade name) manufactured by n & k Technology.

The content ratio of each element in the phase shift layer (ZrSiON) was 22 atomic % for Zr, 22 atomic % for Si, 14 atomic % for O, and 42 atomic % for N.

The content ratio of each element in the metal layer (ZrSi) was 50 atomic % for Zr and 50 atomic % for Si.

The content ratio of each element in the reflectance reduction layer (ZrSiON) was 17 atomic % for Zr, 17 atomic % for Si, 20 atomic % for O, and 46 atomic % for N.

In addition, the content rate of each said element was measured by X-ray photoelectron spectroscopy (XPS). In the following Examples and Comparative Examples, the same apparatuses were used for the measurement of the element content.

With the above three-layer structure, the phase shift film has a transmittance of 19.2% at a wavelength of 365 nm, 21.7% at a wavelength of 405 nm, and 23.1% at a wavelength of 436 nm. In addition, the variation width (transmittance wavelength dependence) of the transmittance of the phase shift film was 3.9% in the wavelength region of 365 nm to 436 nm.

The phase difference of the phase shift film was 199.7° at a wavelength of 365 nm, 174.2° at a wavelength of 405 nm, and 160.3° at a wavelength of 436 nm due to the above-mentioned three-layer structure. In addition, the variation width of the retardation of the phase shift film was 39.4° in the wavelength region of 365 nm to 436 nm.

FIG. 4 shows the transmittance spectrum of the phase shift film of the phase shift mask substrate of Example 1-1.

In addition, the transmittance and retardation were measured using MPM-100 (trade name) manufactured by Lasertec. In the following Examples and Comparative Examples, the same apparatuses were used for the measurement of transmittance and phase difference, respectively. In addition, the value of the transmittance in an Example and a comparative example is the value of Air reference|standard.

The front reflectance of the phase shift film is 10.5% at 350nm, 7.9% at 365nm, 6.3% at 405nm, 6.2% at 413nm, and 5.7 at 436nm %. In addition, the fluctuation range of the front reflectance of the phase shift film was 2.2% in the wavelength region of 365 nm to 436 nm. In addition, the fluctuation range of the front reflectance of the phase shift film was 4.8% in the wavelength region of 350 nm to 436 nm.

FIG. 5 shows the front reflectance spectrum of the phase shift film of the phase shift mask substrate of Example 1-1.

In addition, the front reflectance was measured using SolidSpec-3700 (trade name) by Shimadzu Corporation. In the following Examples and Comparative Examples, the same apparatuses were used for the measurement of the front reflectance, respectively.

The back reflectivity of the phase shift film was 24.5% at a wavelength of 365 nm, 40.2% at a wavelength of 405 nm, and 44.4% at a wavelength of 436 nm. Moreover, the fluctuation range of the back surface reflectance of this phase shift film was 20.0% in the wavelength region of 365nm - 436nm.

FIG. 6 shows the backside reflectance spectrum of the phase-shift film of the phase-shift mask substrate of Example 1-1.

In addition, the back surface reflectance was measured using the SolidSpec-3700 (trade name) by Shimadzu Corporation. In the following Examples and Comparative Examples, the same apparatuses were used for the measurement of the back reflectance, respectively.

(Fabrication of Phase Shift Mask Base)

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

First, a synthetic quartz glass substrate as a transparent substrate is prepared.

Then, the transparent substrate was carried into the sputtering chamber of the sputtering apparatus.

After that, a sputtering power of 5.0 kW was applied to a ZrSi target (Zr:Si=1:2) (atomic (%) ratio) arranged in the sputtering chamber, while argon (Ar) and oxygen (O ₂ ) A mixed gas of nitrogen and nitrogen (N ₂ ) was introduced into the sputtering chamber, and a phase shift layer with a film thickness of 73 nm containing ZrSiON was formed on the main surface of the transparent substrate on one side. Here, the mixed gas system was introduced into the sputtering chamber at a flow rate of 50 sccm for Ar, 5 sccm for O ₂ , and 50 sccm for N ₂ .

Thereafter, a sputtering power of 2.0 kW was applied to a ZrSi target (Zr:Si=1:2) (atomic (%) ratio), and argon gas (Ar) was introduced into the sputtering chamber to form the phase shift layer. The film includes a metal layer of ZrSi with a film thickness of 30 nm. Here, argon gas (Ar) was introduced into the sputtering chamber at a flow rate of 100 sccm.

After that, while applying a sputtering power of 5.0 kW to a ZrSi target (Zr:Si=1:2) (atomic (%) ratio), a mixture of argon (Ar), oxygen (O ₂ ), and nitrogen (N ₂ ) was mixed. The mixed gas was introduced into the sputtering chamber, and a reflectance reduction layer with a thickness of 30 nm containing ZrSiON was formed on one side of the metal layer. Here, the mixed gas system was introduced into the sputtering chamber at a flow rate of 50 sccm for Ar, 10 sccm for O ₂ , and 50 sccm for N ₂ .

Thereafter, the transparent substrate on which the phase shift film composed of the phase shift layer (ZrSiON, film thickness 73 nm), metal layer (ZrSi, film thickness 30 nm), and reflectance reduction layer (ZrSiON, film thickness 30 nm) was formed was self-sputtering Remove from device and wash.

(Manufacture of Phase Shift Mask)

Using the above-described phase-shift mask substrate, a phase-shift mask was fabricated by the following method.

First, a resist film containing a novolak-based positive photoresist is formed on the phase-shift film of the above-mentioned phase-shift mask base. At this time, after HMDS (hexamethyldisilazane, hexamethyldisilazane) processing is performed on the phase shift film, a resist film is formed.

Thereafter, a specific pattern (line and space pattern of 1.8 μm) was drawn on the resist film by a laser drawing machine using laser light with a wavelength of 413 nm.

Then, the resist film is developed with a specific developing solution to form a resist film pattern on the phase shift film. At this time, the deterioration of the roughness of the edge part of the resist film pattern cross section, which is considered to be caused by the influence of the standing wave, was not confirmed.

Then, the phase shift film is etched using the resist film pattern as a mask to form a phase shift film pattern. Each of the phase shift layer, the metal layer, and the reflectance reduction layer constituting the phase shift film is formed of a zirconium silicide-based material including zirconium (Zr) and silicon (Si). Therefore, the phase shift layer, the metal layer and the reflectance reduction layer can be etched by the same etching solution. Here, as the etching solution for etching the phase shift film, a zirconium silicide etching solution obtained by diluting a mixed solution of hydrogen peroxide, ammonium fluoride and phosphoric acid with pure water was used.

Then, the resist film pattern is peeled off using a resist stripping liquid.

The phase shift film pattern cross section of the phase shift photomask manufactured using the above phase shift photomask substrate is to such an extent that it does not affect the characteristics of the photomask.

In addition, the phase shift film pattern cross section of the phase shift mask was observed using an electron microscope (JSM7401F (trade name) by JEOL Ltd.). In the following Examples and Comparative Examples, the same apparatuses were used for observation of the cross section of the phase shift film pattern, respectively.

The CD difference of the phase-shift film pattern of the phase-shift mask manufactured using the above-mentioned phase-shift mask base was good at 55 nm. The CD difference distance was set as the offset width of the target line and space pattern (width of line pattern=1.8 μm, width of space pattern: 1.8 μm).

In addition, the CD difference of the phase shift film pattern of the phase shift mask was measured using the SIR8000 manufactured by Seiko Instruments Nano Technology. In the following Examples and Comparative Examples, the same apparatuses were used for the measurement of the CD difference of the phase-shift film patterns, respectively.

The above-mentioned phase-shift mask substrate and phase-shift mask satisfy the specific optical characteristics of retardation and transmittance and set high transmittance (19.2%) at the wavelength of 365nm, the wavelength above 365nm and below 436nm Within the range, the transmittance wavelength dependence is also excellent (4.0%), the front reflectance characteristics are also excellent (7.9% or less), and the back reflectance characteristics are also excellent (24.5% or more), which have both characteristics. In addition, it was confirmed that, corresponding to the excellent characteristics of the phase-shift mask, the positional shift during pattern transfer was suppressed, and the resolution of the transfer pattern transferred to the display device substrate was improved, and the pattern line width was 1.8 μm. The line and space patterns are transferred without CD errors. Furthermore, the pattern transfer step using the phase-shift mask in the manufacturing steps of the display device is set to the projection exposure of equal-magnification exposure with an aperture number (NA) of 0.1, and the exposure light is set to include i-ray, h-ray and Compound light of g-rays. Hereinafter, the manufacturing steps of the display devices in Examples 1-2, 1-3, Example 2, and Comparative Example 1 were performed under the exposure conditions.

(Example 1-2)

(Phase Shift Mask Base)

In Example 1-2, the phase-shift mask substrate composed of QZ/ZrSiON/MoSi/ZrSiON will be described.

In Example 1-2, only the metal layer is different from the phase-shift mask substrate of Example 1-1.

The phase-shift film in the phase-shift mask base of Example 1-2 consists of a phase-shift layer (ZrSiON, film thickness of 73 nm), a metal layer (MoSi, film thickness of 10 nm) and a reflectance reduction that are sequentially arranged from the transparent substrate side layer (ZrSiON, film thickness 30 nm).

The value of the content ratio of each element in the phase shift layer (ZrSiON) and the reflectance reduction layer (ZrSiON) and the Example 1-1 is the same.

The content of each element in the metal layer (MoSi) was 33 atomic % for Mo and 67 atomic % for Si.

With the above three-layer structure, the transmittance of the phase-shift film is lower than that of Example 1-1, and within the range of the usual transmittance of 3% to 10%, the transmittance of the phase-shift film varies (transmittance wavelength Dependence) within 5.5% in the wavelength range of 365nm to 436nm.

With the above-mentioned three-layer structure, the phase shift film has a phase difference in the range of 160° to 200° at a wavelength of 365 nm.

In addition, the front reflectance of the phase shift film is 10% or less in the wavelength region of 365 nm to 436 nm. Furthermore, the front reflectance of the phase shift film is 15% or less in the wavelength region of 350 nm to 436 nm.

In addition, the back surface reflectance of the phase shift film is also 20% or more in the wavelength region of 365 nm to 436 nm.

(Fabrication of Phase Shift Mask Base and Phase Shift Mask)

In Example 1-2, during the film formation of the metal layer, a sputtering power of 1.5 kW was applied to the MoSi target (Mo:Si=1:2) (atomic (%) ratio), while argon (Ar) It was introduced into a sputtering chamber, and a metal layer with a thickness of 10 nm including MoSi was formed on the phase shift layer on one side. Here, argon gas (Ar) was introduced into the sputtering chamber at a flow rate of 120 sccm.

The phase-shift mask substrate and the phase-shift mask of Example 1-2 can be manufactured by the same method as Example 1-1 in other aspects.

The CD difference of the phase-shift film pattern of the phase-shift mask manufactured using the above-mentioned phase-shift mask base was good at 62 nm. The phase-shift mask base and the phase-shift mask satisfy specific optical properties of retardation and transmittance, and have excellent wavelength dependence of transmittance, and are also excellent in front reflectivity and back reflectivity, and have both properties. In addition, it was confirmed that, corresponding to the excellent characteristics of the phase shift mask, The positional deviation during pattern transfer is also suppressed, and the resolution of the transfer pattern transferred to the display device substrate is improved, and the line and space pattern with a pattern line width of 1.8 μm is transferred without CD errors. print.

(Example 1-3)

In Example 1-3, the phase-shift mask base comprising the light-shielding film of the QZ/ZrSiON/ZrSi/Cr-based material will be described.

The phase-shift mask substrate of Example 1-3 differs from the phase-shift mask substrate of Example 1-1 in that a phase-shift film without a reflectance reduction layer is formed, and a phase-shift film having The anti-reflection function includes a light-shielding film of Cr-based materials.

That is, the phase shift film in the phase shift mask base of Examples 1-3 is composed of a phase shift layer (ZrSiON, film thickness 130 nm) and a metal layer (MoSi, film thickness 10 nm) sequentially arranged from the transparent substrate side. In addition, the light-shielding film formed on the phase shift film containing a Cr-based material was a light-shielding film with an antireflection function containing CrN (film thickness 25 nm)/CrCN (film thickness 70 nm)/CrON (film thickness 25 nm). The light-shielding film has a laminated structure of CrN/CrCN/CrON, and the film surface reflectance of the light-shielding film is less than 10% at the wavelength of 413 nm of laser drawing light.

With the above-mentioned two-layer structure, the transmittance of the phase-shift film is about 12% at a wavelength of 365 nm, and the variation range of the transmittance of the phase-shift film (the wavelength dependence of transmittance) is within 5.5% in the wavelength region of 365 nm to 436 nm.

With the above-mentioned two-layer structure, the phase shift film has a retardation in the range of 160° to 200° at a wavelength of 365 nm.

In addition, in the phase-shift mask substrates of Examples 1-3, the front reflectivity of the phase-shift film is less than 10% at the wavelength of 413 nm of the laser drawing light, and the back-side reflectivity of the phase-shift film is at the wavelength of 365 nm to 436 nm. In the region, it is more than 18%.

(Manufacture of Phase Shift Mask)

Using the above-described phase-shift mask substrate, a phase-shift mask was fabricated by the following method.

First, a resist film including a novolak-based positive photoresist is formed on the light-shielding film of the above-mentioned phase-shift mask base. Thereafter, a specific pattern (line and space pattern of 1.8 μm) was drawn on the resist film by a laser drawing machine using laser light with a wavelength of 413 nm.

Then, the resist film is developed with a specific developing solution to form a resist film pattern on the light-shielding film. At this time, the deterioration of the roughness of the edge part of the resist film pattern cross section, which is considered to be caused by the influence of the standing wave, was not confirmed.

Then, using the resist film pattern as a mask and using a chromium etching solution containing ceric ammonium nitrate and perchloric acid to etch the light-shielding film to form a light-shielding film pattern, then use the light-shielding film pattern as a mask and use The zirconium silicide etching solution of Example 1-1 was etched to form a phase shift film pattern.

Then, the resist film pattern was peeled off using a resist stripping solution, and further, the light-shielding film pattern was peeled off using a chromium etching solution.

The CD difference of the phase shift film pattern of the phase shift mask manufactured using the above-mentioned phase shift mask base was good at 56 nm.

The phase-shift mask base and the phase-shift mask described above satisfy specific optical properties of retardation and transmittance, are excellent in wavelength dependence of transmittance, and are also excellent in backside reflectance properties and have both properties. In addition, it was confirmed that, corresponding to the excellent characteristics of the phase-shift mask, the positional shift during pattern transfer was suppressed, and the resolution of the transfer pattern transferred to the display device substrate was improved, and the pattern line width was 1.8 μm. The line and space patterns are transferred without CD errors.

(Example 2)

In Example 2, the phase-shift mask base for the composition of QZ/MoSiON/MoSi/MoSiON explained at the bottom.

The phase-shift film in the phase-shift mask base of Example 2 consists of a phase-shift layer (MoSiON, with a thickness of 100 nm), a metal layer (MoSi, with a thickness of 10 nm) and a reflectance reduction layer ( MoSiON, film thickness of 50 nm).

The phase shift film which is laminated with the phase shift layer, the metal layer and the reflectance reduction layer on the transparent substrate has a refractive index of 2.06 at a wavelength of 365 nm, and an extinction coefficient of 0.354 at a wavelength of 365 nm.

The content ratio of each element in the phase shift layer (MoSiON) is 30 atomic % of Mo, 20 atomic % of Si, 20 atomic % of O, and 30 atomic % of N.

The content of each element in the metal layer (MoSi) was 33 atomic % for Mo and 67 atomic % for Si.

The content rate of each element in the reflectance reduction layer (MoSiON) was 30 atomic % for Mo, 20 atomic % for Si, 30 atomic % for O, and 20 atomic % for N.

With the above three-layer structure, the transmittance of the phase shift film is 4.7% at a wavelength of 365 nm, 7.0% at a wavelength of 405 nm, and 8.8% at a wavelength of 436 nm. In addition, the variation width (transmittance wavelength dependence) of the transmittance of the phase shift film was 4.1% in the wavelength region of 365 nm to 436 nm.

FIG. 7 shows the transmittance spectrum of the phase-shift film of the phase-shift mask substrate of Example 2. FIG.

With the above three-layer structure, the phase shift film has a phase difference of 177.1° at a wavelength of 365 nm, 159.0° at a wavelength of 405 nm, and 147.3° at a wavelength of 436 nm. In addition, the fluctuation range of the retardation of the phase shift film was 29.8° in the wavelength region of 365 nm to 436 nm.

The front reflectance of the phase shift film is 4.1% at 350nm, 3.0% at 365nm, 2.4% at 405nm, 2.6% at 413nm, and 3.5 at 436nm %. In addition, the fluctuation range of the front reflectance of the phase shift film was 1.1% in the wavelength region of 365 nm to 436 nm. In addition, the fluctuation range of the front reflectivity of the phase shift film is 1.7% in the wavelength region of 350nm~436nm.

FIG. 8 shows the front reflectance spectrum of the phase-shift film of the phase-shift mask substrate of Example 2. FIG.

FIG. 9 shows the backside reflectance spectrum of the phase-shift film of the phase-shift mask substrate of Example 2. FIG.

The backside reflectance of the phase shift film was 19.6% at a wavelength of 365 nm, 23.0% at a wavelength of 405 nm, and 23.6% at a wavelength of 436 nm. Moreover, the fluctuation range of the back surface reflectance of this phase shift film was 3.9% in the wavelength region of 365nm - 436nm.

The phase shift mask substrate of Example 2 was manufactured by the following method.

First, a synthetic quartz glass substrate as a transparent substrate is prepared. The two main surfaces of the transparent substrate are mirror-polished.

Then, the transparent substrate was carried into the sputtering chamber of the sputtering apparatus.

Thereafter, a sputtering power of 5.0 kW was applied to a MoSi target (Mo:Si=1:4) (atomic (%) ratio) arranged in the sputtering chamber, while argon (Ar) and oxygen (O ₂ ) A mixed gas of nitrogen and nitrogen (N ₂ ) was introduced into the sputtering chamber, and a phase shift layer with a thickness of 100 nm containing MoSiON was formed on the main surface of the transparent substrate on one side. Here, the mixed gas system was introduced into the sputtering chamber at a flow rate of 60 sccm for Ar, 40 sccm for O ₂ , and 50 sccm for N ₂ .

Thereafter, a sputtering power of 6.0 kW was applied to a MoSi target (Mo:Si=1:2) (atomic (%) ratio), and argon gas (Ar) was introduced into the sputtering chamber to form the phase shift layer. The film includes a metal layer of MoSi with a thickness of 10 nm. Here, argon gas (Ar) was introduced into the sputtering chamber at a flow rate of 100 sccm.

Thereafter, a sputtering power of 5.0 kW was applied to a MoSi target (Mo:Si=1:4) (atomic (%) ratio), while argon (Ar), oxygen (O ₂ ) and nitrogen (N ₂ ) were mixed together. The mixed gas was introduced into the sputtering chamber, and a reflectance reduction layer with a thickness of 50 nm containing MoSiON was formed on one side of the metal layer. Here, the mixed gas system was introduced into the sputtering chamber at a flow rate of 50 sccm for Ar, 50 sccm for O ₂ , and 60 sccm for N ₂ .

After that, the transparent substrate on which the phase shift film composed of the phase shift layer (MoSiON, the film thickness of 100 nm), the metal layer (MoSi, the film thickness of 10 nm), and the reflectance reduction layer (MoSiON, the film thickness of 50 nm) was formed was self-sputtered. Remove from device and wash.

Using the above-described phase-shift mask substrate, a phase-shift mask was fabricated by the following method.

First, a resist film containing a novolak-based positive photoresist is formed on the phase-shift film of the above-mentioned phase-shift mask base. At this time, a resist film is formed after subjecting the phase shift film to HMDS treatment.

Thereafter, a specific pattern (line and space pattern of 1.8 μm) was drawn on the resist film by a laser drawing machine using laser light with a wavelength of 413 nm.

Then, the resist film is developed with a specific developing solution to form a resist film pattern on the phase shift film. At this time, the deterioration of the roughness of the edge part of the resist film pattern cross section, which is considered to be caused by the influence of the standing wave, was not confirmed.

Then, the phase shift film is etched using the resist film pattern as a mask to form a phase shift film pattern. Each of the phase shift layer, the metal layer, and the reflectance reduction layer constituting the phase shift film is formed of a molybdenum silicide-based material including molybdenum (Mo) and silicon (Si). Therefore, the phase shift layer, the metal layer and the reflectance reduction layer can be etched by the same etching solution. Here, as the etching solution for etching the phase shift film, a molybdenum silicide etching solution obtained by diluting a mixed solution of ammonium hydrogen fluoride and hydrogen peroxide with pure water was used.

Then, the resist film pattern is peeled off using a resist stripping liquid.

The phase-shift film pattern profile of the phase-shift mask manufactured using the above-mentioned phase-shift mask substrate is to the extent that the characteristics of the mask are not affected.

The CD difference of the phase-shift film pattern of the phase-shift mask manufactured using the above-mentioned phase-shift mask base was good at 63 nm. The CD difference distance is set as the target line and space pattern (width of line pattern: 1.8 The width of the μm gap pattern: the offset amplitude of 1.8 μm).

The above-mentioned phase-shift mask substrate and phase-shift mask satisfy specific optical properties of retardation and transmittance, and in the wavelength range of 365 nm or more and 436 nm or less, the transmittance wavelength dependence is excellent (4.1%), and the front reflectance The characteristics are also excellent (3.5% or less), and the back surface reflectance characteristics are also excellent (19.64% or more), and have both characteristics. In addition, it was confirmed that, corresponding to the excellent characteristics of the phase-shift mask, the positional shift during pattern transfer was suppressed, and the resolution of the transfer pattern transferred to the display device substrate was improved, and the pattern line width was 1.8 μm. The line and space patterns are transferred without CD errors.

(Comparative Example 1)

The phase-shift film in the phase-shift mask substrate of Comparative Example 1 was composed of only the phase-shift layer (CrOCN, film thickness 122 nm). The phase-shift mask substrate of Comparative Example 1 differs from the phase-shift mask substrate of the above-mentioned embodiment in that the phase-shift film does not have a metal layer and a reflectance reduction layer.

The phase-shift film in the phase-shift mask base of Comparative Example 1 was formed under the following film-forming conditions.

The content of each element in the phase shift film (CrOCN) was 44 atomic % for Cr, 8 atomic % for C, 30 atomic % for O, and 18 atomic % for N.

The transmittance of the phase shift film was 4.6% at a wavelength of 365 nm, 8.0% at a wavelength of 405 nm, and 11.0% at a wavelength of 436 nm. In addition, the variation width (transmittance wavelength dependence) of the transmittance of the phase shift film was 6.4% in the wavelength region of 365 nm to 436 nm.

With the above-mentioned one-layer structure, the phase shift film has a retardation of 179.6° at a wavelength of 365 nm, 164.7° at a wavelength of 405 nm, 161.7° at a wavelength of 413 nm, and 153.1° at a wavelength of 436 nm. In addition, the fluctuation range of the retardation of the phase shift film was 26.5° in the wavelength region of 365 nm to 436 nm.

FIG. 10 shows the transmittance spectrum of the phase-shift film of the phase-shift mask substrate of Comparative Example 1. FIG.

In addition, the front reflectance of the phase shift film was 24.0% at a wavelength of 365 nm, 25.1% at a wavelength of 405 nm, 25.3% at a wavelength of 413 nm, and 26.0% at a wavelength of 436 nm. In addition, the fluctuation range of the front reflectance of the phase shift film was 2.0% in the wavelength region of 365 nm to 436 nm.

FIG. 11 shows the front reflectance spectrum of the phase shift film in the phase shift mask substrate of Comparative Example 1. FIG.

In addition, the back surface reflectance of the phase shift film was 17.9% at a wavelength of 365 nm, 19.9% at a wavelength of 405 nm, and 20.3% at a wavelength of 436 nm. In addition, the fluctuation range of the back surface reflectance of the phase shift film was 2.4% in the wavelength region of 365 nm to 436 nm.

FIG. 12 shows the backside reflectance spectrum of the phase shift film in the phase shift mask substrate of Comparative Example 1. FIG.

(Fabrication of Phase Shift Mask Base)

The phase shift mask base of the comparative example 1 was manufactured by the following method.

First, a synthetic quartz glass substrate as a transparent substrate is prepared.

Then, the transparent substrate was carried into the sputtering chamber of the sputtering apparatus.

After that, a sputtering power of 3.5 kW was applied to the chromium target disposed in the sputtering chamber, and a mixed gas of argon (Ar), nitrogen (N ₂ ) and carbon dioxide gas (CO ₂ ) was introduced into the sputtering chamber to produce A phase shift film with a film thickness of 122 nm including CrOCN was formed. Here, the mixed gas system was introduced into the sputtering chamber at a flow rate of 46 sccm for Ar, 32 sccm for N ₂ and 18.5 sccm for CO ₂ .

Then, the transparent substrate on which the phase shift film was formed was taken out from the sputtering apparatus and washed.

(Manufacture of Phase Shift Mask)

Using the above-described phase-shift mask substrate, a phase-shift mask was fabricated by the following method.

First, a resist film comprising a novolak-based positive photoresist is formed on the phase-shift film of the above-mentioned phase-shift mask base. After that, the laser beam with wavelength 413nm was used in the laser tracing machine. The resist film traces a specific pattern (1.8 μm line and space pattern). Then, the resist film is developed with a specific developing solution to form a resist film pattern on the phase shift film.

Thereafter, the phase shift film is etched with a chromium etching solution containing ceric ammonium nitrate and perchloric acid using the resist film pattern as a mask to form a phase shift film pattern. The etchant film pattern is peeled off.

The CD difference of the phase-shifting film pattern of the phase-shifting mask manufactured using the above-mentioned phase-shifting mask substrate was 90 nm, which did not reach the level required for the phase-shifting mask used in the manufacture of high-resolution, high-definition display devices.

The CD of the phase-shift mask of the above-mentioned comparative example 1 has a large difference, and the film surface reflectance of the phase-shift film pattern to the exposure light is relatively high, so the above-mentioned phase-shift mask cannot be used to produce high-resolution, high-definition displays. device.

As described above, the present invention has been described in detail based on a plurality of embodiments and examples, but the present invention is not limited to these embodiments and examples. As long as one has ordinary knowledge in the corresponding field, it is obvious that changes or improvements can be made within the technical idea of the present invention.

10: Phase shift mask substrate

20: Transparent substrate

30: Phase shift film

31: Phase Shift Layer

32: Reflectivity reducing layer

33: Metal layer

Claims (15)

A phase-shift mask substrate, which is a phase-shift mask substrate for display device manufacturing, is characterized in that: it includes a transparent substrate and a phase-shift film formed on the transparent substrate, wherein the phase-shift film includes two or more lamination layers The above-mentioned phase-shift film at least has a phase-shift layer and a metal layer, the phase-shift layer has the function of mainly adjusting the transmittance and retardation of the exposed light, and the metal layer has the function of adjusting the wavelength above 365 nm and below 436 nm The function of wavelength dependence of transmittance in the above-mentioned phase-shift film, the transmittance and retardation of the above-mentioned phase-shift film for exposure light have specific optical characteristics, and the above-mentioned phase-shift layer includes metal, silicon, and nitrogen and A material of at least one of oxygen, the metal layer includes a material composed of metal and silicon, or a material composed of metal, silicon, and at least one of carbon, fluorine, nitrogen, and oxygen, The metal included in the metal layer The content rate is higher than the content rate of the metal contained in the above-mentioned phase-shift layer, or the total content rate of the metal and silicon contained in the above-mentioned metal layer is greater than the total content rate of the metal and silicon contained in the above-mentioned phase-shift layer. , the wavelength dependence of the transmittance of the above-mentioned phase shift film in the wavelength range of 365 nm or more and 436 nm or less is within 5.5%. A phase-shift mask substrate, which is a phase-shift mask substrate for display device manufacturing, is characterized in that: a transparent substrate and a phase-shift film formed on the transparent substrate, wherein the phase-shift film has a phase-shift layer, a reflection A rate reduction layer and a metal layer, the phase shift layer has the function of mainly adjusting the transmittance and retardation of the exposed light, the reflectivity reduction layer is arranged on the upper side of the phase shift layer, and has the function of making the phase shift film The function of reducing the reflectance of light incident on the front side, the metal layer is disposed between the above-mentioned phase shift layer and the above-mentioned reflectance reducing layer, and has the ability to adjust the wavelength dependence of the transmittance in the range from 365 nm to 436 nm. The function of properties is that by the laminated structure of the phase shift layer, the metal layer and the reflectance reduction layer, the transmittance and retardation of the phase shift film of the exposure light have specific optical properties, and the phase shift layer includes A material comprising metal, silicon, and at least one of nitrogen and oxygen, the above-mentioned metal layer comprising a material consisting of metal and silicon, or a material consisting of metal, silicon, and at least one of carbon, fluorine, nitrogen and oxygen, The content rate of the metal contained in the above-mentioned metal layer is more than the content rate of the metal contained in the above-mentioned phase-shift layer, or the total content rate of the metal and silicon contained in the above-mentioned metal layer is more than that contained in the above-mentioned phase-shift layer. The total content ratio of metal and silicon, the wavelength dependence of transmittance of the phase shift film in the range of wavelength 365 nm or more and 436 nm or less is within 5.5%. The phase-shift mask substrate according to claim 1 or 2, wherein the transmittance of the phase-shift film at a wavelength of 365 nm is in the range of 1% or more and 50% or less. The phase-shift mask substrate of claim 1 or 2, wherein the transmittance of the phase-shift film at a wavelength of 365 nm is in the range of 15% or more and 50% or less. The phase-shift mask substrate of claim 2, wherein, with respect to the phase-shift film, the front-side reflectance of the phase-shift film to light incident from the front-side side of the phase-shift film in the wavelength region of 365 nm to 436 nm is: 10% or less. The phase-shift mask substrate of claim 2, wherein, with respect to the phase-shift film, the front-side reflectance of the phase-shift film to light incident from the front-side side of the phase-shift film in the wavelength region of 350 nm to 436 nm is 15% or less. The phase shift mask substrate of claim 1 or 2, wherein the back surface reflectance of the phase shift film for light incident from the back side of the transparent substrate is 20% or more in the wavelength region of 365 nm to 436 nm. The phase shift photomask substrate of claim 2, wherein the reflectance reduction layer comprises a material including metal, silicon, and at least one of nitrogen, oxygen, and carbon, or a metal and at least one of nitrogen, oxygen, and carbon material. The phase-shift mask substrate of claim 2, wherein the metal constituting the phase-shift layer is any one of Zr, Mo, Ti, Ta, and W, and the metal constituting the metal layer is Zr, Mo, Ti, Ta , and any one of W, the metal constituting the above-mentioned reflectance reduction layer is any one of Zr, Mo, Cr, Ti, Ta, and W. The phase-shift mask substrate of claim 2, wherein the metal constituting each of the phase-shift layer and the metal layer, or the metal constituting each of the phase-shift layer, the metal layer, and the reflectance reduction layer is the same metal. The phase-shift mask substrate according to claim 1 or 2, comprising a light-shielding film formed on the above-mentioned phase-shift film. The phase-shift mask substrate according to claim 11, wherein, with respect to the light-shielding film, the film surface reflectance of the light-shielding film for light incident from the front side of the light-shielding film is 15% in a wavelength region of 350 nm to 436 nm the following. A method for manufacturing a phase-shift mask, which is a method for manufacturing a phase-shift mask for display device manufacturing, characterized in that it has the following steps: A resist film is formed on the transfer film, and a resist film pattern is formed by a drawing process using a laser light having any wavelength selected from a wavelength region of 350 nm to 436 nm, and a development process; and The etchant film pattern is used as a mask to etch the phase shift film to form a phase shift film pattern. A method for manufacturing a phase-shift mask, which is a method for manufacturing a phase-shift mask for display device manufacturing, characterized in that it has the following steps: A resist film is formed, and a resist film pattern is formed by a drawing process and a development process using laser light having any wavelength selected from a wavelength range of 350 nm to 436 nm; the above resist film pattern is used as a mask The mask etches the light-shielding film to form a light-shielding film pattern; and the phase-shift film is etched using the light-shielding film pattern as a mask to form a phase-shift film pattern. A method of manufacturing a display device, characterized by comprising: a step of disposing a phase-shift mask, in which a resist film-attached substrate with a resist film is formed on the substrate, using the phase as claimed in claim 13 or 14 A phase-shift mask obtained by a manufacturing method of a mask is disposed opposite to the above-mentioned resist film; and a pattern transfer step of irradiating the above-mentioned phase-shift mask with compound exposure including i-ray, h-ray and g-ray The above-mentioned phase shift film pattern is transferred by the light.

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