TW201608329A - Phase shift mask substrate and manufacturing method thereof and method for manufacturing phase shift mask - Google Patents

Abstract

An object of the present invention is to provide a phase shift mask substrate that allows a phase shift film to be patterned, through wet etching, into a cross-sectional profile that fully exhibits a phase shift effect and a manufacturing method thereof, and a method for manufacturing a phase shift mask comprising a phase shift film pattern that fully exhibits a phase shift effect. A phase shift mask substrate 1 comprises a structure having a phase shift film 3 containing chromium, oxygen, and nitrogen formed on a transparent substrate 2. The phase shift film 3 comprises a main layer 3a and a topmost layer 3b made of the same material. A top portion of the main layer on the side of the topmost layer 3 has refractive index for wavelengths less than 365nm that is less than a refractive index of a bottom portion of the main layer on the side of the transparent substrate 2 for wavelengths less than 365nm.

Description

Phase shift mask substrate, method of manufacturing the same, and method of manufacturing phase shift mask

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

At present, as a method employed in a liquid crystal display device, there is a VA (Vertical Alignment) method or an IPS (In Plane Switching) method. By such means, realization of a liquid crystal display device with high definition, high-speed display performance, and wide viewing angle is sought. In a liquid crystal display device to which such a method is applied, a pixel electrode is formed from a line and a space pattern of a transparent conductive film, whereby a response speed and a viewing angle can be improved. Recently, from the viewpoint of further improvement in response speed and viewing angle, or improvement in light use efficiency of a liquid crystal display device, that is, reduction in power consumption or contrast of a liquid crystal display device, it is required to miniaturize the width between lines and gap patterns. . For example, it is desirable to narrow the width between the line and the gap pattern (the total of the line width L and the gap width S) from 6 μm to 5 μm, and further narrow from 5 μm to 4 μm. In this case, at least one of the line width L and the gap width S is less than 3 μm. For example, there are many cases where L < 3 μm, or L ≦ 2 μm, or S < 3 μm, or S ≦ 2 μm.

Further, when manufacturing a liquid crystal display device or an organic EL (Electroluminescence) display device, an element such as a transistor is formed by laminating a plurality of conductive films or insulating films which have been subjected to patterning as needed. At this time, the photolithography step is often used in the patterning of the respective films of the laminate. For example, thin film transistors used in such display devices (Thin Film) In the case of a plurality of patterns constituting the TFT, the contact hole formed in the passivation film (insulating layer) penetrates the insulating layer and is electrically connected to the connection portion located on the lower layer side. At this time, if the pattern on the upper layer side and the lower layer side is not accurately positioned, and the shape of the contact hole is not formed, the accurate operation of the display device cannot be ensured. Further, here, it is also necessary to improve the display performance, and to realize a high integration of the element patterns, and to seek to refine the pattern. That is, it is necessary that the diameter of the hole pattern is also less than 3 μm. For example, a hole pattern having a diameter of 2.5 μm or less and further a diameter of 2.0 μm or less is required, and it is considered that in a near future, it is also desired to form a pattern having a diameter of 1.5 μm or less lower than the diameter of 2.0 μm.

In view of such a background, it is desirable to cope with, for example, a mask for manufacturing a display device which can cope with the minimization of line and gap patterns or contact holes.

In the case of realizing the miniaturization of the line and gap pattern or the contact hole, in the conventional mask, since the resolution limit of the exposure apparatus for manufacturing the display device is 3 μm, in the case of a sufficient process Margin, it is not allowed. Products that produce a minimum line width close to the resolution limit are not produced. Therefore, there is a problem that the defective rate of the display device becomes high.

For example, when a reticle having a hole pattern for forming a contact hole is used and transferred to a transfer target, if it is a hole pattern having a diameter of more than 3 μm, the transfer can be performed using the previous reticle. . However, it is very difficult to transfer a hole pattern having a diameter of 3 μm or less, particularly a hole pattern having a diameter of 2.5 μm or less. In order to transfer a hole pattern having a diameter of 2.5 μm or less, for example, it is also considered to convert to an exposure machine having a high NA (numerical aperture), but a large investment is required.

Therefore, in order to improve the resolution, the line and gap patterns or the contact holes are made fine. For example, as a mask for manufacturing a display device, a phase shift mask is attracting attention.

Recently, for example, a ray mask for manufacturing a semiconductor device such as an LSI (Large Scale Integration) or a super LSI that can be used when manufacturing a display device has been developed, and a phase shift mask having a chrome-based phase shift film has been developed. .

As a prior chrome-based phase shift mask, it is known that it is formed on a transparent substrate. A phase shift mask base of a chromium-based phase shift film formed by laminating a plurality of single-layer film layers having different compositions is used as a manufacturing original (Patent Documents 1 and 2).

Patent Document 1 discloses a phase shift mask having a transparent substrate and having a transparent region on a transparent substrate and a multilayer film containing a chromium compound formed by a physical vapor deposition method such as sputtering. The area of the translucent layer (refer to claim 1). Further, in the phase shift mask, the resist pattern formed on the translucent layer is used as an etching mask, and wet etching is performed by using a Cr etching solution (see page 5 (constitution 1). )) or by dry etching using chlorine gas + oxygen (see page 5 (Structure 1), page 7 (Structure 9)), thereby obtaining a vertical processing profile and obtaining physical cleaning such as brush cleaning. A phase shift mask with good washability (refer to page 8, line 1 to page 8, line 12).

Further, it is described that the translucent layer including the multilayer film can control the etching characteristics according to the structure of each layer, and a vertical etching defect can be obtained as compared with the single layer under the same continuous etching condition (refer to page 5). Line 23). The translucent layer is composed of, for example, a first semi-shield film 2 (having a film thickness of 65 nm) containing CrON and a second semi-shield film 3 (having a film thickness of 65 nm) containing CrOCN (see page 6 (Configuration 6), FIG. 1). ). The refractive index n at a wavelength of 356 nm of the first semi-shielding film 2 (CrON) and the second semi-shielding film 3 (CrOCN) is 2.3 and 2.4, respectively (see page 6 (constitution 4) and page 6 (composition 6)) .

Patent Document 2 describes a phase shift mask having a transparent substrate and having a translucent region and a transparent region on a transparent substrate, the translucent region being a semitransparent film comprising a multilayer film of a chromium or chromium compound. Composition. Further, in the phase shift mask, a resist pattern formed on a semitransparent film is used as an etching mask, and wet etching is performed by using a Cr etching solution (refer to page 7, line 17). Go to page 7 and line 26), dry etching using chlorine + oxygen (see page 7 on line 17 to page 7 and line 26) or CH ₂ Cl ₂ (dichloromethane) + oxygen (see page 10) Line 14 to page 10, line 18, page 13, line 19 to page 14, line 6) are patterned to obtain a good halftone phase shift mask (refer to page 10, line 19 to Page 10, line 23, page 13, line 19 to page 14, line 6).

The translucent film of the phase shift mask is formed by laminating a plurality of single-layer films of different kinds of materials (refer to page 5, line 6 to page 5, line 17, Figure 1 to Figure 3). When the translucent film has a two-layer structure, for example, a layer film 3 containing a layer of CrNCN (film thickness: 125 nm) formed on the side of the transparent substrate 1 and a film formed on the film 3 is formed. (Film thickness: 9 nm) (refer to page 5, line 6 to page 5, line 17, Fig. 1). The refractive index n of the i-ray (wavelength 365 nm) of one film 3 and one film 4 is 2.4 and 1.9, respectively (refer to page 10, line 6 to page 10, line 11). Further, when the semitransparent film has a three-layer structure, for example, a layer film 8 containing CrN formed on the film 7 on the side of the transparent substrate 1 and containing a film 7 of a CrOCN (film thickness: 70 nm) formed on the film 7 is formed. (film thickness: 5 nm) and a film of a CrOCN layer 9 (thickness: 54.9 nm) formed on the film 8 (see page 5, line 6 to page 5, line 17, Fig. 3). The refractive index n of the i-ray (wavelength 365 nm) of a film 7, a film 8, and a film 9 is 2.46, 1.94, and 2.46, respectively (refer to page 25, line 25 to page 12, line 5).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 3312702

[Patent Document 2] Japanese Patent No. 3262302

The inventors of the present invention have conducted an effort to study a phase shift mask having a chromium-based phase shift film. As a result, when the resist pattern is used as a mask and the chromium-based phase shift film is patterned by wet etching, the wet etching solution penetrates into the interface between the resist film and the chromium-based phase shift film. The etching of the interface portion is performed faster. Therefore, the cross-sectional shape of the edge portion of the formed chromium-based phase shift film pattern is a tapered shape which is inclined over the entire edge portion and is trailing toward the transparent substrate.

When the cross-sectional shape of the edge portion of the chrome-based phase shift film pattern is a tapered shape, the phase shift effect is reduced as the film thickness of the edge portion of the chrome-based phase shift film pattern is reduced. If it is weakened. Therefore, the chrome-based phase shift film pattern cannot sufficiently exhibit the phase shift effect. Further, the penetration of the wet etching liquid into the interface between the resist film and the chromium-based phase shift film is caused by poor adhesion between the chromium-based phase shift film and the resist film. Therefore, it is difficult to strictly control the cross-sectional shape of the edge portion of the chromium-based phase shift film pattern, and the resolution cannot be sufficiently obtained, and the control of the line width (CD) is extremely difficult.

Further, in order to solve such problems, the inventors of the present invention have made an effort to study a method of perpendicularizing the cross-sectional shape of the edge portion of the chromium-based phase shift film pattern. Heretofore, for example, a method has been developed in which the film composition of the chromium-based phase shift film has a gradient by adjusting the content of nitrogen which makes the etching rate faster or the content of carbon which slows the etching rate. The etching rate in the film thickness direction is changed (for example, refer to Patent Documents 1 and 2). All of the methods are as follows: in order to vertically profile the edge portion of the phase shift film pattern, different materials having different etching characteristics are selected, and a plurality of single-layer film layers including the different materials are laminated. It is a phase shifting film. However, in these methods, as the size of the transparent substrate becomes larger, it is difficult to ensure film thickness distribution, composition control, and particularly uniformity of cross-sectional shape in the large plate surface. In the case of a phase shift film in which the transmittance, the phase difference, and the in-plane uniformity of the cross-sectional shape cannot be ensured, the desired phase shift effect cannot be stably obtained, and it is very difficult to obtain a phase shift mask having a good in-plane CD range. .

Accordingly, the present invention has been made in view of the above problems, and an object thereof is to provide a phase shift mask substrate capable of patterning a phase shift film into a cross-sectional shape capable of exhibiting a phase shift effect by wet etching and A method of manufacturing the same, and a method of manufacturing a phase shift mask having a phase shift film pattern capable of exhibiting a phase shift effect.

In order to solve the above problems, the present invention has the following configuration.

(Configuration 1) A phase shift mask substrate characterized in that a phase shift film containing chromium, oxygen, and nitrogen is formed on a transparent substrate, and the phase shift film has a main layer containing the same material. And the most surface layer, the most The refractive index at a wavelength of 365 nm in the upper portion of the main layer on the surface layer side is smaller than the refractive index at a wavelength of 365 nm in the lower portion of the main layer on the side of the transparent substrate.

(Configuration 2) The phase shift mask substrate according to the first aspect, wherein a refractive index at a wavelength of 365 nm in the lower portion of the main layer is 2.50 or more, and a refractive index at a wavelength of 365 nm in the upper portion of the main layer is 2.45 or less.

(Configuration 3) The phase shift mask substrate of the first or second aspect, wherein a difference between a refractive index at a wavelength of 365 nm in the upper portion of the main layer and a refractive index at a wavelength of 365 nm in a lower portion of the main layer is 0.05 or more 0.25 or less.

(Aspect 4) The phase shift mask substrate according to any one of 1 to 3, wherein the outermost layer has a film density of 2.0 g/cm ³ or more.

(Aspect 5) The phase shift mask substrate according to any one of 1 to 4, wherein the phase shift film further contains carbon.

(Configuration 6) A method of manufacturing a phase shift mask substrate, characterized in that a phase shift containing chromium, oxygen and nitrogen is formed on a transparent substrate by sputtering using an inline sputtering apparatus. Film shifter, and The method for manufacturing a phase shift mask substrate has a film forming step of forming a phase shift film having a main layer and a top surface layer of the same material on the transparent substrate, wherein the film forming step uses a splash containing chromium And plating an inert gas and an active gas for oxidizing and nitriding the phase shifting film with respect to a downstream side of the sputtering target in a conveying direction of the transparent substrate in the vicinity of the sputtering target, and Film formation is carried out by reactive sputtering including a mixed gas of the above inert gas and the above reactive gas.

Further, by the manufacturing method of the configuration 6, the phase shift mask substrate of the configuration 1 can be manufactured.

(Configuration 7) The method for producing a phase shift mask substrate according to the sixth aspect, wherein a refractive index at a wavelength of 365 nm in the upper portion of the main layer on the outermost layer side is smaller than a lower portion of the main layer on the transparent substrate side The refractive index at a wavelength of 365 nm.

(Configuration 8) The method for producing a phase shift mask substrate according to Structure 6 or 7, characterized in that after the film forming step, vacuum ultraviolet irradiation is performed on the outermost surface of the phase shift film by vacuum ultraviolet irradiation treatment. step.

(Configuration 9) The method of manufacturing a phase shift mask base according to the eighth aspect, wherein in the vacuum ultraviolet irradiation processing step, the film density of the outermost surface of the phase shift film is changed to 2.0 g/cm ³ the above.

(Aspect 10) The method for producing a phase shift mask substrate according to any one of the items 6 to 9, characterized in that the mixed gas further includes an active gas which carbonizes the phase shift film.

(Structure 11) A method of manufacturing a phase shift mask, characterized in that the phase shift mask substrate according to any one of the configurations 1 to 5, or by any one of the configurations 6 to 10 Forming a resist pattern on the phase shift film of the phase shift mask substrate produced by the method for manufacturing a phase shift mask substrate, and using the resist pattern as a mask for the phase shift film Wet etching is performed to form a phase shift film pattern on the transparent substrate.

As described above, according to the phase shift mask substrate of the present invention, a phase shift film containing chromium, oxygen and nitrogen is formed on the transparent substrate. The phase shifting film has a main layer and a topmost layer including the same material, and a refractive index at a wavelength of 365 nm in an upper portion of the main layer on the outermost layer side is smaller than a refractive index at a wavelength of 365 nm in a lower portion of the main layer on the transparent substrate side. rate. The phase shift film of the phase shift mask substrate having such a configuration can be patterned by wet etching into a cross-sectional shape that can sufficiently exhibit a phase shift effect. Since the phase shift mask base can have a cross-sectional shape of the edge portion of the phase shift film pattern obtained by patterning the phase shift film into a cross-sectional shape capable of sufficiently exhibiting a phase shift effect, it can be formed A master for manufacturing a phase shift mask having improved resolution and a phase shift film pattern having good CD characteristics.

Moreover, according to the method for fabricating a phase shift mask substrate of the present invention, there is a film forming step of forming a film containing chromium, oxygen, and the like on a transparent substrate by a sputtering method using a continuous sputtering apparatus. Nitrogen and has a phase shifting film comprising a main layer and a topmost layer of the same material. In the film forming step, a sputtering target containing chromium is used, and an inert gas is supplied to the downstream side of the sputtering target in the conveying direction of the transparent substrate in the vicinity of the sputtering target, and the phase shifting film is caused. The active gas oxidized and nitrided is formed by reactive sputtering using a mixed gas containing the inert gas and the reactive gas. According to such a manufacturing method, it is possible to manufacture a phase shift mask substrate which can pattern (etch) the phase shift film into a cross-sectional shape in which the phase shift effect can be sufficiently exhibited. Since the cross-sectional shape of the edge portion of the phase shift film pattern can be made into a cross-sectional shape in which the phase shift effect can be sufficiently exhibited, it is possible to manufacture a phase which is improved in resolution and can be patterned into a phase shift film pattern having a good CD characteristic. Offset the reticle base.

Further, according to the method of manufacturing a phase shift mask of the present invention, the phase shift mask is manufactured using the phase shift mask substrate. Therefore, it is possible to manufacture a phase shift mask having a phase shift film pattern that can sufficiently exhibit a phase shift effect. Since the phase shift film pattern can sufficiently exhibit the phase shift effect, it is possible to manufacture a phase shift mask having a phase shift film pattern having improved CD characteristics and having improved resolution. The phase shift mask can cope with the miniaturization of the line and gap patterns or contact holes.

1, 10‧‧‧ phase shift mask base

2‧‧‧Transparent substrate

3‧‧‧ phase offset film

3a‧‧‧main floor

3b‧‧‧ the most surface layer

3'‧‧‧ phase offset film pattern

4‧‧‧Shade film

4'‧‧‧Shade film pattern

5‧‧‧Resist film

5'‧‧‧resist pattern

11‧‧‧ Sputtering device

13‧‧‧1st sputtering target

14‧‧‧2nd Sputtering Target

15‧‧‧3rd Sputtering Target

30, 31‧‧‧ phase offset mask

BU‧‧‧ buffer chamber

C1, C2‧‧‧ intersection

F‧‧‧etched profile

GA11‧‧‧1st gas inlet

GA12‧‧‧2nd gas inlet

GA21‧‧‧3rd gas inlet

GA22‧‧‧4th gas inlet

GA31‧‧‧5th gas inlet

GA32‧‧‧6th gas inlet

LL‧‧‧ moving into the chamber

S‧‧‧ arrow

SP1‧‧‧1st sputtering chamber

SP2‧‧‧2nd sputtering chamber

T‧‧‧ film thickness

ULL‧‧‧ moving out of the chamber

Θ‧‧‧section angle

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

Figure 2 is a schematic view showing a continuous sputtering apparatus which can be used for film formation of a phase shift mask substrate.

3 (a) to (e) are cross-sectional views showing respective steps of a method of manufacturing a phase shift mask according to a third embodiment of the present invention.

Figure 4 is a cross-sectional view showing the configuration of a phase shift mask base according to a fourth embodiment of the present invention. view.

5(a) to 5(f) are cross-sectional views showing respective steps of a method of manufacturing the phase shift mask substrate shown in Fig. 4.

6(a) to 6(e) are cross-sectional views showing respective steps of a method of manufacturing a phase shift mask according to a fifth embodiment of the present invention using the phase shift mask substrate shown in Figs. 4 and 5(f). .

Fig. 7 is a view showing the refractive index at a wavelength of 190 nm to 1000 nm in the upper portion of the main layer and the lower portion of the main layer of the phase shift film of the phase shift mask substrate of Example 1.

Fig. 8 is a view showing the refractive index at a wavelength of 190 nm to 1000 nm in the upper portion of the main layer and the lower portion of the main layer of the phase shift film of the phase shift mask substrate of Comparative Example 1.

Fig. 9 is a graph showing the refractive index at a wavelength of 365 nm from the outermost layer of the phase shift film of the phase shift mask substrate of the first embodiment and the comparative example 1 to the lower portion of the main layer.

Fig. 10 is a cross-sectional view showing a cross-sectional shape of an edge portion of the phase shift film pattern of the first embodiment.

Fig. 11 is a cross-sectional photograph showing a cross-sectional shape of an edge portion of the phase shift film pattern of Comparative Example 1.

Figure 12 is a cross-sectional view for explaining a cross-sectional angle in a cross section of an edge portion of a phase shift film pattern of a phase shift mask.

Fig. 13 is a view showing the refractive index at a wavelength of 190 nm to 1000 nm in the upper portion of the main layer and the lower portion of the main layer of the phase shift film of the phase shift mask substrate of Example 2.

Fig. 14 is a view showing the refractive index at a wavelength of 190 nm to 1000 nm in the upper portion of the main layer and the lower portion of the main layer of the phase shift film of the phase shift mask substrate of Comparative Example 2.

Fig. 15 is a view showing the refractive index at a wavelength of 365 nm from the outermost layer of the phase shift film of the phase shift mask substrate of Example 2 and Comparative Example 2 to the lower portion of the main layer.

Fig. 16 is a cross-sectional view showing a cross-sectional shape of an edge portion of the phase shift film pattern of the second embodiment.

Figure 17 is a cross-sectional view showing the edge portion of the phase shift film pattern of Comparative Example 2. Profile photo.

Hereinafter, a phase shift mask base according to an embodiment of the present invention, a method of manufacturing the same, and a method of manufacturing a phase shift mask using the phase shift mask base will be described in detail.

Embodiment 1.

In the first embodiment, a phase shift mask base (transparent substrate/phase shift film) for manufacturing a display device and a method of manufacturing the same will be described.

1 is a cross-sectional view showing a configuration of a phase shift mask base according to Embodiment 1 of the present invention, and FIG. 2 is a schematic view showing a continuous sputtering apparatus which can be used for film formation of a phase shift mask base.

As shown in FIG. 1, the phase shift mask substrate 1 of the first embodiment has a configuration in which a phase shift film 3 containing chromium, oxygen, and nitrogen is formed on a transparent substrate 2.

The method for manufacturing the phase shift mask substrate 1 of the first embodiment configured in this manner includes a preparation step of preparing a transparent substrate 2, and a film formation step (hereinafter, sometimes referred to as a phase shift film formation step). This is formed by filming a phase shift film 3 containing chromium, oxygen, and nitrogen on the main surface of the transparent substrate 2 by sputtering.

Hereinafter, each step will be described in detail.

1. Preparation steps

First, the transparent substrate 2 is prepared.

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

2. Phase shift film formation step

Next, as shown in FIG. 1, a phase shift film 3 containing chromium, oxygen, and nitrogen is formed on the main surface of the transparent substrate 2 by a sputtering method using a continuous sputtering apparatus.

In detail, in the phase shift film forming step, a film forming step of applying a sputtering power using a sputtering target containing chromium and opposing the sputtering direction of the transparent substrate 2 in the vicinity of the sputtering target is performed. An inert gas and an active gas for oxidizing and nitriding the phase shifting film are supplied to the downstream side of the sputtering target, and chromium, oxygen, and the like are formed by reactive sputtering using a mixed gas containing an inert gas and an active gas. The phase of the nitrogen shifts the film 3.

Here, the inert gas and the active gas supplied from the downstream side with respect to the sputtering target may be mixed before or after the supply. For example, the inert gas may be mixed with the active gas in advance at a specific flow rate, and then the mixed gas may be supplied from a gas inlet port, or the inert gas and the reactive gas may be supplied to a specific flow rate from a dedicated gas inlet.

The phase shift film 3 has a property of changing the phase of the exposed light (phase shift effect). According to this property, a specific phase difference is generated between the light that has passed through the phase shift film 3 and the light that has passed through only the transparent substrate 2. When the light to be exposed is a composite light including light in a wavelength range of 300 nm or more and 500 nm or less, the phase shift film 3 is formed to generate a specific phase difference with respect to light of a representative wavelength. For example, when the exposed light is a composite light including i-rays, h-rays, and g-rays, the phase shift film 3 generates a phase difference of 180 degrees for any of the i-ray, the h-ray, and the g-ray. The way is formed. Further, in order to exhibit the phase shift effect, for example, the phase difference of the phase shift film 3 under the i-ray is set to a range of 180 degrees ± 10 degrees, preferably set to approximately 180 degrees. Further, for example, the transmittance of the phase shift film 3 under the i-ray is preferably set to a range of 1% or more and 20% or less. In particular, the vacuum ultraviolet ray (hereinafter sometimes referred to as VUV) irradiation treatment described in the second embodiment below affects the film quality of the outermost surface of the phase shift film 3, and as a result, the phase shift by wet etching is utilized. In the aspect of pattern formation of the film to sufficiently exhibit the cross-sectional shape of the phase effect, it is preferable to use a film composition in which the transmittance of the phase shift film 3 under the i-ray is set to a range of 3% or more and 15% or less.

The phase shift film 3 is made of a chromium-based material containing at least chromium (Cr), oxygen (O), and nitrogen (N). In addition to the above three elements, the chromium-based material may further contain carbon (C) as needed. to When a chromium-based material containing carbon is used, the chemical resistance and the washing resistance of the phase shift film 3 can be improved.

Specifically, examples of the chromium-based material constituting the phase shift film 3 include chromium oxynitride (CrON) and chromium carbon oxynitride (CrOCN). Further, these chromium-based materials may contain hydrogen (H) or fluorine (F) within a range not deviating from the effects of the present invention.

The phase shift film 3 can be formed, for example, by a sputtering target or a sputtering gas atmosphere as described below.

As the sputtering target used for the film formation phase shift film 3, those containing chromium (Cr) are selected. Specific examples include chromium (Cr), chromium nitride, chromium oxide, chromium carbide, chromium nitrogen oxide, chromium carbonitride, chromium carbon oxide, and chromium carbon nitrogen. Oxide.

The sputtering gas atmosphere when the phase shifting film 3 is formed includes an inert gas and an active gas which oxidizes and nitrides the phase shift film. Examples of the inert gas include helium (He), helium (Ne), argon (Ar), and helium (Kr) which are gases which do not contain the film constituent components of the phase shift film 3 which is formed. Helium (Xe), which selects at least one of the gases. Examples of the active gas include oxygen (O ₂ ), nitrogen (N ₂ ), nitrogen monoxide (NO) gas, and nitrogen dioxide (NO) as a gas containing a film constituent component of the phase shift film 3 which is formed into a film. ₂ ) Gas, and nitrous oxide (N ₂ O) gas, at least one of which is selected. Further, the sputtering gas may include an active gas that carbonizes the phase shift film. Examples of the active gas that carbonizes include carbon monoxide (CO) gas, carbon dioxide (CO ₂ ) gas, and hydrocarbon-based gas, and at least one of these gases is selected. Examples of the hydrocarbon-based gas include methane gas, butane gas, propane gas, and styrene gas. Further, the sputtering gas may contain a fluorine-based gas as an active gas in a supply amount within a range that does not deviate from the effects of the present invention. Examples of the fluorine-based gas include CF ₄ gas, CHF ₃ gas, SF ₆ gas, or oxygen gas mixed with the gas.

The combination of the material of the sputtering target and the gas species of the sputtering gas atmosphere, or the ratio of the reactive gas to the inert gas in the sputtering gas atmosphere is based on the phase shift The type or composition of the material of the film 3 is appropriately determined.

The film thickness of the phase shift film 3 is appropriately adjusted in a range of 80 nm or more and 180 nm or less in order to obtain a desired optical characteristic (phase difference).

As shown in FIG. 1, the phase shift film 3 has a main layer 3a containing the same material, and an outermost layer 3b formed in the depth direction from the outermost surface of the main layer 3a by oxidation of the surface after film formation. The main layer 3a is a main body region of the phase shift film 3, and exhibits a characteristic that the composition ratio of each element in the film depth direction is substantially uniform (at least substantially uniform in the analysis result by X-ray photoelectron spectroscopy). Phase shifting effect of phase shifting film 3.

The phase shift film 3 may be a single layer film and a laminated film. In the case where the phase shift film 3 is formed of a laminated film, it is preferable to make the composition and the composition ratio uniform between the interfaces of the respective layers, and thereafter, for example, the etching rate during wet etching is fixed, thereby preventing the etching in the cross section. The so-called corrosion phenomenon. Further, in the case of a laminated film, it is preferred to carry out the film forming step of the phase shift film 3 in plural times under the same film forming conditions. The plurality of film forming steps are preferably carried out continuously in the same continuous sputtering apparatus. In the case where a plurality of film forming steps are continuously performed, for example, a continuous sputtering apparatus as described below is used. Further, in the case where a plurality of film forming steps are performed, the sputtering power applied to the sputtering target when the film phase shifting film 3 is formed can be reduced.

Further, the film thickness of the outermost layer 3b is preferably, for example, 0.1 nm or more and 10 nm or less, but is not limited to this range.

By the phase shift film forming step, the upper portion of the outermost layer 3b side of the main layer 3a of the phase shift film 3 (hereinafter, sometimes referred to as the upper portion of the main layer) can have a refractive index smaller than that at the wavelength of 365 nm. The refractive index at a wavelength of 365 nm in the lower portion of the layer 3a on the side of the transparent substrate 2 (hereinafter, sometimes referred to as the lower portion of the main layer). The phase shift film 3 having such a configuration can be formed into a cross-sectional shape in which the phase effect can be sufficiently exhibited by patterning by wet etching.

Further, it is preferable that the refractive index at a wavelength of 365 nm in the lower portion of the main layer is 2.50 or more, and the refractive index at a wavelength of 365 nm in the upper portion of the main layer is 2.45 or less. Further, it is preferable that the refractive index at a wavelength of 365 nm in the upper portion of the main layer and the refractive index at a wavelength of 365 nm in the lower portion of the main layer are preferable. The difference is 0.05 or more and 0.25 or less. When the difference in refractive index at a wavelength of 365 nm is less than 0.05 or exceeds 0.25, it may be difficult to form a cross-sectional shape which is capable of exerting a phase effect by patterning of the phase shift film 3 by wet etching.

Furthermore, the phase shift film forming step is not limited to the wavelength 365 nm, and is, for example, in the range of wavelength 190 nm to wavelength 1000 nm, so that the refractive index of the upper portion of the main layer at the measurement wavelength is also smaller than the refractive index of the lower portion of the main layer ( Refer to Figure 7 and Figure 13 below.

The content of each element constituting the phase shift film 3 is appropriately adjusted so as to achieve desired optical characteristics (transparency with respect to light of exposure, phase difference).

Further, when the material constituting the phase shift film 3 is CrON, the content of each element of the main layer 3a is determined by X-ray photoelectron spectroscopy (hereinafter, sometimes referred to as XPS). As a result of the analysis, the chromium is adjusted to a range of 35 atom% or more and 65 atom% or less, oxygen of 16 atom% or more and 50 atom% or less, and nitrogen of 6 atom% or more and 30 atom% or less. Preferably, the chromium is 41 atom% or more and 58 atom% or less, the oxygen is 21 atom% or more and 43 atom% or less, and the nitrogen is 11 atom% or more and 24 atom% or less.

In the case where the material constituting the phase shift film 3 is CrCOCN, the content of each element of the main layer 3a is represented by the result of analysis by XPS, and the chromium is 35 atom% or more and 60 atom% or less, oxygen. The ratio is adjusted to be 15 atom% or more and 45 atom% or less, nitrogen to 5 atom% or more and 25 atom% or less, and carbon of 2 atom% or more and 15 atom% or less. Preferably, the chromium is 40 atom% or more and 55 atom% or less, the oxygen is 20 atom% or more and 40 atom% or less, the nitrogen is 10 atom% or more and 20 atom% or less, and the carbon is 3 atom% or more and 10 atom%. the following.

Further, as described above, in the main layer 3a of the phase shift film 3, the composition ratio of each element in the film depth direction is substantially uniform. Here, the composition ratio of each element in the film depth direction is substantially uniform, and the center value of the content of each element in the film depth direction of the phase shift film 3 obtained by the film forming conditions in the film forming step is used as a reference. The content of each element of the main layer 3a falls Within the range of the specific range of variation of the center content. For example, when the material constituting the phase shift film 3 is CrON, the fluctuation range of chromium is ±5.0 atom% with respect to the center content of chromium, and the fluctuation range of oxygen is ±6.5 atom% with respect to the center content of oxygen, nitrogen The variation range is ±4.5 atom% with respect to the center content of nitrogen. Preferably, the fluctuation range of chromium is ±3.5 atom%, the fluctuation range of oxygen is ±5.5 atom%, and the fluctuation range of nitrogen is ±3.5 atom%. Further, in the case where the material constituting the phase shift film 3 is CrCOCN, the fluctuation range of chromium is ±5.0 atom% with respect to the center content of chromium, and the fluctuation range of oxygen is ±6.5 atom% with respect to the center content of oxygen, nitrogen The variation range is ±4.5 atom% with respect to the center content of nitrogen, and the fluctuation range of carbon is ±4.0 atom% with respect to the center content of carbon. Preferably, the fluctuation range of chromium is ±3.5 atom%, the fluctuation range of oxygen is ±5.5 atom%, the fluctuation range of nitrogen is ±3.5 atom%, and the fluctuation range of carbon is ±3.0 atom%.

Further, the composition ratio of each element in the film depth direction in the main layer 3a of the phase shift film 3 is substantially uniform in order to impart a compositional change in the stepwise or continuous direction of the film thickness direction, which is formed by film formation. In the step, the film phase shift film 3 is formed without performing an operation of changing the supply method or the supply amount of the sputtering material or the sputtering gas.

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

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

The transparent substrate 2 mounted on a tray (not shown) can be carried into the chamber LL, the first sputtering chamber SP1, the buffer chamber BU, the second sputtering chamber SP2, and the specific conveying speed in the direction of the arrow S. The order of moving out of the chamber ULL is carried. Further, the transparent substrate 2 mounted on a tray (not shown) can carry out the chamber ULL, the second sputtering chamber SP2, the buffer chamber BU, the first sputtering chamber SP1, and the direction opposite to the arrow S. The order of loading into the chamber LL is returned.

Carrying into the chamber LL and the first sputtering chamber SP1, and the second sputtering chamber SP2 and the carrying chamber The chambers ULL are separated by partition plates. Further, the carry-in chamber LL and the carry-out chamber ULL can be partially separated from the outside of the sputtering apparatus 11 by the partition plate.

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

In the first sputtering chamber SP1, a first sputtering target 13 containing chromium to form the phase shift film 3 is disposed on the loading chamber LL side, and an arrow is formed on the transparent substrate 2 in the vicinity of the first sputtering target 13. S indicates that the first gas introduction port GA11 is disposed at a position upstream of the first sputtering target 13 in the transport direction, and a second gas introduction port is disposed at a position downstream of the first sputtering target 13 GA12. Further, in the first sputtering chamber SP1, a second sputtering target 14 containing chromium to form the phase shift film 3 is disposed on the buffer chamber BU side, and the transparent substrate 2 in the vicinity of the second sputtering target 14 is disposed. The third gas introduction port GA21 is disposed at a position upstream of the second sputtering target 14 in the transport direction indicated by an arrow S, and the fourth gas is disposed at a position downstream of the second sputtering target 14 The inlet GA22.

Here, the interval between the first sputtering target 13 and the downstream second gas introduction port GA12 is set to be wider than the interval between the first sputtering target 13 and the upstream first gas introduction port GA11. The reason for this is that the sputtering gas atmosphere is changed by providing a distance between the sputtering target and the downstream side gas introduction port. Similarly to this, the distance between the second sputtering target 14 and the fourth gas inlet port GA22 on the downstream side is also set to be wider than the interval between the second sputtering target 14 and the third gas inlet port GA21 on the upstream side.

In the first sputtering chamber SP1, it is preferable to set the distance between the sputtering target and the gas inlet port on the downstream side to, for example, 15 cm or more and 50 cm or less, and to place the sputtering target and the gas inlet port on the upstream side. The interval is set to, for example, 1 cm or more and 5 cm or less.

In the second sputtering chamber SP2, a third sputtering target 15 containing chromium for forming the phase shift film 3 is disposed on the buffer chamber BU side, and an arrow is formed on the transparent substrate 2 in the vicinity of the third sputtering target 15. The fifth gas introduction port GA31 is disposed at a position on the upstream side of the third sputtering target 15 in the transport direction, and the sixth gas is disposed on the downstream side of the third sputtering target 15 in the transport direction. Guide GA32.

Here, similarly to the first sputtering chamber SP1, the interval between the third sputtering target 15 and the downstream sixth gas introduction port GA32 is set to be smaller than that of the third sputtering target 15 and the upstream fifth gas introduction. The gap between the ports GA31 is wide.

In the second sputtering chamber SP2, the interval between the sputtering target and the gas inlet port on the downstream side is preferably set to, for example, 15 cm or more and 50 cm or less, similarly to the first sputtering chamber SP1. The distance between the sputtering target and the gas introduction port on the upstream side is set to, for example, 1 cm or more and 5 cm or less.

In FIG. 2, the first sputtering target 13, the second sputtering target 14, and the third sputtering target 15 are indicated by hatching.

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

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

Next, after the inside of the sputtering apparatus 11 is made to have a specific degree of vacuum, for example, the second gas introduction port GA12 on the downstream side of the first sputtering target 13 is a mixture of a specific flow rate of a sputtering gas containing an inert gas and an active gas. The form of the gas is introduced into the first sputtering chamber SP1, and a specific sputtering power is applied to the first sputtering target 13. The application of the sputtering power and the introduction of the sputtering gas continue until the transparent substrate 2 is transferred to the carry-out chamber ULL.

It is considered that the supply of the sputtering gas from the downstream side increases the existence rate of the inert gas having a relatively long flying distance on the upstream side of the chamber (the portion away from the second gas introduction port GA12). The content of the inert gas is more than a specific content of an inert gas-containing sputtering gas atmosphere. In addition, it is considered that the sputtering gas atmosphere having a tendency to gradually decrease the content of the inert gas to a specific content (the influence of the difference in the flying distance gradually disappears) in the period from the upstream side to the downstream side is close to the second gas inlet port. The position of GA12 becomes a sputtering gas atmosphere containing a specific content of inert gas and active gas.

Thereafter, the transparent substrate 2 mounted on a tray (not shown) is loaded into the chamber LL, the first sputtering chamber SP1, the buffer chamber BU, and the second sputtering in a direction of the arrow S at a specific conveyance speed. The chamber SP2 and the carry-out chamber ULL are transported in the order. When the transparent substrate 2 passes through the vicinity of the first sputtering target 13 of the first sputtering chamber SP1, it is formed of the same chromium-based material by a specific thickness on the main surface of the transparent substrate 2 by reactive sputtering. The phase shift film 3 comprising a single layer film. The film formation of the phase shift film 3 is performed in the above-described sputtering gas atmosphere. Therefore, the film formation in the lower portion of the main layer of the phase shift film 3 is performed on the upstream side of the chamber, mainly in the atmosphere of a sputtering gas rich in inert gas, and the film formation on the upper portion of the main layer is on the downstream side, mainly including The inert gas of a specific content and the reactive gas are sprayed in an atmosphere of a sputtering gas. It is considered that the film formation of the main layer 3a of the phase shift film 3 is promoted by the reactive sputtering of the sputtering gas atmosphere, with the transparent substrate 2 passing through the lower half of the film formation on the downstream side. Therefore, it is considered that the refractive index at a wavelength of 365 nm is lowered from the lower portion of the autonomous layer to the upper portion of the main layer, and the refractive index at a wavelength of 365 nm in the upper portion of the main layer can be made smaller than the refractive index at a wavelength of 365 nm in the lower portion of the main layer. According to the phase shift film 3 formed in this manner, the cross-sectional shape of the edge portion of the phase shift film pattern 3' obtained by patterning by wet etching can be sufficiently shifted. The vertical cross-sectional shape of the effect or near the vertical cross-sectional shape.

Here, the factor of the verticalization of the cross-sectional shape of the etched cross section of the edge portion of the phase shift film pattern 3' will be described. The main factor of the verticalization of the cross-sectional shape is the difference between the phase-shift film pattern 3' and the resist film (the degree of penetration of the etching solution), the isotropic/anisotropic etching, and the etching speed in the depth direction of the film. Wait.

In the case where the film is formed by the downstream supply condition of the sputtering gas in the present embodiment, the refractive index at a wavelength of 365 nm in the depth direction is smaller at the upper portion of the main layer and larger at the lower portion of the main layer. Therefore, in the etched cross section of the edge portion of the phase shift film pattern 3', the etching speed of the upper portion of the main layer becomes slow, and the etching speed of the lower portion of the main layer becomes faster. It is considered that the isotropic etching can be prevented from advancing excessively toward the upper portion of the main layer during the period before the isotropic etching reaches the lower portion of the main layer, thereby making the cross-sectional shape of the etched cross section perpendicular.

On the other hand, when the first gas introduction port 11 disposed on the upstream side of the first sputtering target 13 is supplied with a sputtering gas to form a phase-shift film, the specific phase is included from the upstream side to the downstream side. The content of the inert gas and the sputtering gas atmosphere of the active gas is considered to be the main layer of the phase shifting film from the film forming front half before the transparent substrate 2 passes over the first sputtering target 13 to the film forming half after passing. Film formation advances. When the film is formed by the upstream supply condition of the sputtering gas, the refractive index at a wavelength of 365 nm rises from the lower portion of the autonomous layer to the upper portion of the main layer, so that the refractive index at the wavelength of 365 nm at the upper portion of the main layer becomes lower than the wavelength of the lower portion of the main layer. The refractive index at 365 nm is large. The cross-sectional shape of the etched cross section of the edge portion of the phase shift film pattern obtained by patterning the phase shift film formed in this manner by wet etching is tapered.

Here, the reason why the cross-sectional shape of the etched cross section of the edge portion of the phase shift film pattern is tapered is that the refractive index at a wavelength of 365 nm is larger at the upper portion of the main layer and smaller at the lower portion of the main layer, so the phase shift film In the etched cross section of the edge portion of the pattern, the etching speed of the upper portion of the main layer is increased, and the etching speed at the lower portion of the main layer is slow. It is considered that the isotropic etching progresses toward the upper portion of the main layer before the isotropic etching reaches the lower portion of the main layer, so that the cross-sectional shape of the etched cross section is tapered.

Further, during the film formation of the phase shift film 3, the main valve (not shown) of the exhaust device (not shown) connected to the buffer chamber BU may be closed to stop the exhaust. Further, the transparent substrate 2 can be transported without flowing the sputtering gas in the second sputtering chamber SP2 while the main valve (not shown) is closed.

Further, the second sputtering target 14 may be used instead of the first sputtering target 13 to form a film of the phase shift film 3 including the single layer film. In this case, the fourth gas introduction port GA22 on the downstream side of the second sputtering target 14 introduces a sputtering gas having a specific flow rate into the first sputtering chamber SP1, and applies a specific coating to the second sputtering target 14. Sputter power. Further, the third sputtering target 15 of the second sputtering chamber SP2 may be used instead of the first sputtering target 13 or the second sputtering target 14 of the first sputtering chamber SP1 to perform phase shift including a single layer film. Film formation of film 3 is removed. In this case, from the third sputtering target 15 The sixth gas introduction port GA32 on the downstream side introduces a sputtering gas having a specific flow rate into the second sputtering chamber SP2, and applies a specific sputtering power to the third sputtering target 15.

The case where the phase shift film 3 including the laminated film is formed (multiple film formation) will be described.

In this case, there is a film forming method in which the first film forming method is repeated to carry out the conveyance in the direction of the arrow S of the transparent substrate 2 and the conveyance in the direction opposite to the arrow S, and the direction of the arrow S in each direction In the transfer, the chromium-based single layer film constituting one of the phase shift films 3 is sequentially laminated to form the phase shift film 3, and the second film forming method is applied to the direction of the arrow S of the transparent substrate 2. In the first transfer, at least two of the first sputtering target 13, the second sputtering target 14, and the third sputtering target 15 are used to sequentially form a chromium single layer constituting a part of the phase shift film 3. The film formation phase shift film 3; and the third film formation method, which combines the first film formation method and the second film formation method. These film formation methods are appropriately selected depending on the number of layers of the phase shift film 3.

In the film forming method, similarly to the film formation of the phase shift film 3 including the single layer film, when the transparent substrate 2 is transported in the direction of the arrow S, the sputtering target used for film formation is used. The downstream side is supplied with a sputtering gas of a specific flow rate to form a film of the phase shift film 3.

The first film formation method is carried out, for example, in the following order.

The single layer film formed in the above manner is used as the first layer of the chromium-based single layer film constituting one part of the phase shift film 3, and thereafter, the transparent substrate 2 is sequentially moved out of the cavity in the direction opposite to the arrow S. The chamber ULL is returned to the loading chamber LL, and the second layer of the chromium-based single layer film constituting one of the phase shifting films 3 is formed again in the same manner as the film formation of the chromium-based single layer film of the first layer.

The same applies to the case where the film formation of the third layer of the chromium-based single layer film constituting one of the phase shifting films 3 is performed.

By the film formation step using the first film formation method, a phase shift film 3 having a specific film thickness is formed on the main surface of the transparent substrate 2, and the phase shift film 3 is made of the same chromium-based material. Further, it includes a laminated film of a laminated structure of two or more layers.

The second film formation method is carried out, for example, in the following order.

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

Then, after the inside of the sputtering apparatus 11 has a specific degree of vacuum, the second gas introduction port GA12 on the downstream side of the first sputtering target 13 introduces a sputtering gas having a specific flow rate into the first sputtering chamber SP1. The sixth gas introduction port GA32 on the downstream side of the third sputtering target 15 introduces a sputtering gas having the same composition as the sputtering gas introduced into the first sputtering chamber SP1 to the second sputtering chamber at a specific flow rate. In SP2, specific sputtering power is applied to each of the first sputtering target 13 and the third sputtering target 15. The application of the sputtering power and the introduction of the sputtering gas continue until the transparent substrate 2 is transferred to the carry-out chamber ULL.

Thereafter, the transparent substrate 2 is sequentially carried into the chamber LL in the direction of the arrow S at a specific conveyance speed, and is transported to the carry-out chamber ULL. When the transparent substrate 2 passes through the vicinity of the first sputtering target 13 of the first sputtering chamber SP1, a chromium-based single-layer film having a specific film thickness is formed on the main surface of the transparent substrate 2 by reactive sputtering. 1 story.

Thereafter, when the transparent substrate 2 passes through the vicinity of the third sputtering target 15 of the second sputtering chamber SP2, a chromium film having a specific film thickness is formed on the first chromium-based single layer film by reactive sputtering. The second layer of the single layer film.

In the case of performing film formation of the phase shift film 3 including the laminated film having a three-layer structure, in addition to the sputtering target, the second sputtering target 14 of the first sputtering chamber SP1 is used, from the second The fourth gas introduction port GA22 on the downstream side of the sputtering target 14 supplies a sputtering gas at a specific flow rate, and applies a specific sputtering power to the second sputtering target 14. In this case, the chromium-based single-layer film formed by the vicinity of the second sputtering target 14 serves as the second layer of the phase shift film 3, and the chromium-based single film formed when passing through the vicinity of the third sputtering target 15 The layer film becomes the third layer of the phase shift film 3.

By the film formation step using the second film formation method, a phase shift film 3 having a specific film thickness is formed on the main surface of the transparent substrate 2, and the phase shift film 3 is made of the same chromium-based material. Further, it includes a laminated film of a laminated structure of two or more layers.

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

For example, the second film forming method may be used to laminate a plurality of chromium-based single-layer films in the primary transfer of the transparent substrate 2, and then the first film forming method may be performed to further laminate the desired number of layers of the chromium-based single layer. The film is thereby formed into a film of the phase shift film 3 including a laminated film having a predetermined number of layers.

By the film forming step using the third film forming method, a phase shift film 3 having a specific film thickness is formed on the main surface of the transparent substrate 2, and the phase shift film 3 is made of the same chrome-based material. Further, it includes a laminate film having a plurality of layers of three or more layers.

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

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

According to the phase shift mask substrate 1 of the first embodiment manufactured in this manner, the phase shift film 3 containing chromium, oxygen, and nitrogen is formed on the transparent substrate 2. The phase shift film 3 has a main layer 3a containing the same material, and an outermost layer 3b as a surface oxide layer of the main layer 3a. The refractive index at a wavelength of 365 nm in the upper portion of the main layer on the outermost layer 3b side is smaller than the refractive index at a wavelength of 365 nm in the lower portion of the main layer on the side of the transparent substrate 2. The phase shift film 3 having the phase shift mask base 1 having such a configuration can be patterned by wet etching into a cross-sectional shape in which the phase shift effect can be sufficiently exhibited. Since the phase shift mask base 1 can make the cross-sectional shape of the etched section of the edge portion of the phase shift film pattern 3' obtained by patterning the phase shift film 3 thereof, the phase shift effect can be sufficiently exerted. Since the cross-sectional shape is formed, it is possible to form a precursor for manufacturing a phase shift mask having a phase shift film pattern 3' having improved CD characteristics and having excellent CD characteristics.

Further, according to the method of manufacturing the phase shift mask substrate 1 of the first embodiment, the phase shift film formation of the phase shift film 3 formed on the transparent substrate 2 by the sputtering method using the continuous sputtering apparatus is included. Step, the phase shift film 3 contains chromium, oxygen and nitrogen, and has the same The main layer 3a of the material and the outermost layer 3b which is the surface oxide layer of the main layer 3a. In the phase shift film forming step, the first sputtering target 13 containing chromium is used, and the downstream side of the first sputtering target 13 is transferred from the transparent substrate 2 in the vicinity of the first sputtering target 13 An inert gas and an active gas for oxidizing and nitriding the phase shift film 3 are supplied by reactive sputtering using a mixed gas containing an inert gas and an active gas. It is possible to manufacture the phase shift mask substrate 1 in which the phase shift film 3 formed in this manner can be patterned by wet etching into a cross-sectional shape in which the phase shift effect can be sufficiently exhibited. Since the cross-sectional shape of the etched cross section of the edge portion of the phase shift film pattern 3' can be made into a cross-sectional shape in which the phase shift effect can be sufficiently exhibited, it is possible to manufacture a phase which is improved in resolution and can be patterned into a good CD characteristic. The phase of the offset film pattern 3' is shifted by the mask substrate 1.

In the first embodiment, a mixture of an inert gas and an active gas is supplied in advance from a gas introduction port (for example, a second gas introduction port GA12 when the first sputtering target 13 is used). Although the phase shift film forming step of the gas has been described, the present invention is not limited thereto, and the phase shift film forming step may be performed while supplying the inert gas and the active gas from the dedicated gas introduction port without mixing in advance. .

Further, in the first embodiment, the case where the continuous sputtering apparatus 11 having the above configuration is used in the film formation step has been described, but a continuous sputtering apparatus having another configuration may be used. For example, in the second sputtering chamber SP2, the fourth sputtering target including the chromium for forming the phase shift film 3 is disposed in the second sputtering chamber SP2 (not shown). In the transparent substrate 2 in the vicinity of the fourth sputtering target, a seventh gas introduction port (not shown) is disposed at a position upstream of the fourth sputtering target in the transport direction indicated by an arrow S, An eighth gas introduction port (not shown) is disposed at a position on the downstream side of the fourth sputtering target. As described above, when the fourth sputtering target (not shown) is disposed, the fourth sputtering is preferably performed in the same manner as the arrangement relationship between the other sputtering target and the gas introduction ports disposed on both sides in the conveying direction. The distance between the plating target (not shown) and the eighth gas inlet port (not shown) on the downstream side is set to be smaller than the fourth sputtering target (not shown) and the seventh gas inlet port (not shown) on the upstream side. The interval is wide.

Further, in the continuous sputtering apparatus shown in FIG. 2, the second gas introduction port GA12 disposed on the downstream side of the first sputtering target 13 and the downstream side of the second sputtering target 14 are disposed. At least one of the gas introduction port GA22 and the sixth gas introduction port GA32 disposed on the downstream side of the third sputtering target 15 can form the phase shift film 3 in the first embodiment, and therefore The first gas introduction port GA11 disposed on the upstream side of the first sputtering target 13 , the third gas introduction port GA21 disposed on the upstream side of the second sputtering target 14 , and the upstream of the third sputtering target 15 are disposed. All or part of the fifth gas introduction port GA31 on the side.

Embodiment 2.

In the second embodiment, a method of manufacturing a phase shift mask base (transparent substrate/phase shift film) for manufacturing a display device different from the first embodiment will be described.

The phase shift mask base 1 of the second embodiment has a configuration in which a phase shift film 3 containing chromium, oxygen, and nitrogen and having been irradiated with VUV is formed on the transparent substrate 2. Further, the phase shift mask substrate 1 of the second embodiment has the same film configuration as that of the phase shift mask substrate 1 of the first embodiment shown in Fig. 1 in terms of appearance.

The method for manufacturing the phase shift mask substrate 1 of the second embodiment configured in this manner includes a VUV irradiation step for the phase shift mask substrate 1 described in the first embodiment or by the embodiment. The phase shift film 3 of the phase shift mask substrate 1 obtained by the method of manufacturing the phase shift mask substrate described in FIG. 1 is performed.

Hereinafter, the VUV irradiation step will be described in detail.

In the VUV irradiation step, the VUV irradiation treatment is performed on the outermost surface of the phase shift film 3.

Here, the VUV irradiation treatment refers to a modification process in which a VUV irradiation device is disposed at a predetermined interval along the surface direction of the phase shift film 3 as an object to be irradiated. The irradiation unit (not shown) (not shown) scans the outermost surface of the VUV from the irradiation unit (not shown).

The VUV used in the VUV irradiation treatment refers to a shorter wavelength in ultraviolet rays. VUV is known to be primarily attenuated by absorption in the atmosphere, but prevents attenuation in a vacuum. Yu Ben In the invention, VUV means ultraviolet light having a wavelength of 10 nm to 200 nm, and preferably used at a wavelength of 100 nm to 200 nm. Specifically, as VUV, for example, excimer light having a wavelength of 126 nm (argon), a wavelength of 146 nm (氪), and a wavelength of 172 nm (氙) can be used. In the present invention, it is preferable to use xenon excimer light having a wavelength of 172 nm. Further, the heat treatment may be performed in conjunction with the VUV irradiation or the heat treatment may be performed after the VUV irradiation. However, the reforming effect can be obtained even if heating at a high temperature (for example, 200 ° C or higher) is not particularly performed.

The VUV irradiation conditions in the VUV irradiation treatment are preferably as follows.

The irradiation atmosphere is not particularly limited, and may be an inert gas such as nitrogen or a vacuum, but a modification effect can be obtained even in the atmosphere. However, in the case of performing VUV irradiation treatment in the atmosphere, it is preferable to reduce the distance between the irradiation portion (not shown) of the VUV irradiation device and the outermost surface of the phase shift film 3 in consideration of the attenuation rate of VUV.

As the VUV irradiation energy, the key is to set the energy sufficient to reform the phase shift film 3. For example, it is 20 J/cm ² or more, preferably 30 J/cm ² or more, and more preferably 40 J/cm ² or more with respect to the outermost surface of the phase shift film 3. Further, from the viewpoint of irradiation efficiency, it is preferably 60 J/cm ² or less.

For the VUV irradiation, for example, an irradiation unit (not shown) having a light source (not shown) having an illuminance of 30 W/cm ² to 50 W/cm ² may be used, and the outermost surface of the phase shift film 3 may be irradiated for 20 minutes or longer. When the scanning is performed on the same portion of the outermost surface in a plurality of times, the irradiation is performed for the total time). Specifically, when the light source (not shown) has an illuminance of 40 W/cm ² , the length of the irradiation region is 200 mm, the scanning speed is 10 mm/sec, and the attenuation rate is 70%. The irradiation energy of 45 J/cm ² was applied to the outermost surface by VUV irradiation for about 20 minutes. Here, the attenuation rate refers to a ratio of the amount of residual after attenuation to the amount of irradiation from an irradiation unit (not shown).

Further, from the viewpoint of the attenuation rate or the irradiation efficiency of the transparent substrate 2, the VUV irradiation is preferably performed not from the side of the transparent substrate 2 but from the outermost surface side of the phase shift film 3.

The phase shift film 3 of the phase shift mask substrate 1 of the second embodiment manufactured in this manner was modified by a VUV irradiation step, and the film density of the outermost surface of the phase shift film 3 was 2.0 g/cm ³ the above. From the viewpoint of improving chemical resistance and washing resistance, the film density at the outermost surface is preferably 2.0 g/cm ³ or more, and more preferably 2.2 g/cm ³ or more.

The phase shift film 3 has the following characteristics due to the VUV irradiation step.

(1) The maximum value of the refractive index at the wavelength of 365 nm of the outermost layer 3b of the phase shift film 3 is made smaller in the VUV irradiation step than in the case where the VUV irradiation step is not performed, so that the depth direction of the refractive index is made The tendency to decrease is small, and the tendency of the refractive index in the depth direction of the main layer 3a at a wavelength of 365 nm is reduced, whereby the refractive index difference in the depth direction of the phase shift film 3 can be reduced (for example, Refer to Example 1 (Fig. 9) and Example 2 (Fig. 15) below. Here, the reason why the refractive index of the outermost layer 3b is lowered is considered to be that the apparent refractive index is lowered due to an increase in surface roughness due to the VUV irradiation step. By such a modification process, the phase shift film 3 having a lower refractive index in the upper portion of the main layer of the phase shift film 3 and a higher refractive index in the lower portion of the main layer can be obtained, and thus the phase shift film 3 is patterned. In the etched cross section of the edge portion of the obtained phase shift film pattern 3', the etching speed of the upper portion of the main layer becomes slow, and the etching speed of the lower portion of the main layer becomes faster, so that the taper of the cross-sectional shape of the etched cross section is suppressed. It is a cross-sectional shape that can fully exert the phase shift effect. Further, by the VUV irradiation step, the maximum value and the decreasing tendency of the refractive index of the outermost layer 3b are reduced, and the tendency of the refractive index of the main layer 3a to rise is small, which is considered to be the case in the phase shifting film 3. Since the change in the refractive index is small, the isotropic etching in the above-described patterning is easily promoted, and as a result, it is possible to suppress the taper of the cross-sectional shape of the etched cross section.

On the other hand, when a sputtering target containing chromium is used, an inert gas is supplied to the upstream side of the sputtering target in the transfer direction from the transparent substrate in the vicinity of the sputtering target, and the phase shift film is formed. The previous phase shifting of the mask substrate of the phase shifting film formed by the oxidation and nitriding active gas is compared with the case where the VUV irradiation step is not performed, and the VUV irradiation step causes the phase shifting film to be the outermost layer of the film. For example, the maximum value of the refractive index at a wavelength of 365 nm is small, and the tendency to increase the depth direction of the refractive index is increased, so that the main layer is an example. When the decrease in the depth direction of the refractive index at a wavelength of 365 nm is small or substantially flat, the refractive index difference in the depth direction of the phase shift film 3 is increased (for example, refer to the following Comparative Example 1). Fig. 9), Comparative Example 2 (Fig. 15)).

(2) The VUV treatment step has an effect of improving the wettability of the outermost surface, so that the adhesion between the phase shift film 3 and the resist film can be improved. Therefore, the penetration of the etching liquid into the interface between the resist film and the phase shift film 3 is slowed by the VUV treatment, thereby suppressing the taper.

(3) Modification in which the film density at the outermost surface becomes higher can be performed in the VUV irradiation step. The reason why the film density of the outermost surface of the phase shift film 3 rises is considered to be because, by the VUV irradiation treatment, the vacancies around the chromium atoms existing on the outermost surface are supplied with other atoms to fill the vacancies. As another atom, an oxygen atom is mentioned, for example. In this case, it is considered that the density of the "CrO" at the outermost surface is increased due to the filling of the vacancies by the oxygen atoms, and as a result, the film density at the outermost surface is increased.

Specifically, the film density on the outermost surface can be made 2.0 g/cm ³ or more by the VUV irradiation step. In addition, it is considered that the increase in the film density on the outermost surface may be one of the reasons for improving the adhesion to the resist film 5 used for patterning the phase shift film 3.

Further, it is considered that if the increase in the film density at the outermost surface is caused by the increase in the density of "CrO" as described above, the assumption is made by the profile of the etched section of the edge portion of the phase shift film pattern 3'. The shape was confirmed by the effect that the cross-sectional shape of the phase shift effect was sufficiently exhibited. In other words, it is considered that when oxygen (O) is supplied to the outermost surface, the content of nitrogen (N) which increases the etching rate is relatively reduced, so that isotropy when patterning the phase shift film 3 is performed. In the etching (wet etching), in the etched cross section of the edge portion, the etching speed of the portion to be etched (near the outermost surface) in the vicinity of the resist film 5 becomes slow. Therefore, in the portion to be etched in the vicinity of the resist film 5, after the main surface of the transparent substrate 2 is exposed by etching, it can be maintained until the lower portion of the edge portion is affected, in the portion of the etched portion near the resist film 5. The occurrence of so-called corrosion phenomena caused by the etching liquid is reduced.

Furthermore, the film density at the outermost surface can be performed, for example, by X-ray reflectance analysis (XRR). Determination. The values of the film density at the outermost surface in the examples and the comparative examples were obtained by the following simulation conditions, that is, when the simulation was performed by dividing the film thickness direction of the phase shift film 3 into a plurality of portions, The numerical index Fit R indicating the appropriateness of the fitting is 0.025 or less.

(4) The composition ratio of each element in the film depth direction of the main layer 3a is not changed in the VUV irradiation step. Therefore, the composition ratio of each element in the film depth direction of the main layer 3a is substantially uniform as in the case where the VUV irradiation step is not performed. In other words, even if the VUV irradiation step is performed, the composition ratio of each element in the film depth direction of the main layer 3a of the phase shift film 3 before the VUV irradiation step is not largely changed, so that the phase shift film 3 can be maintained. Required optical characteristics (transmittance, phase difference).

(5) As described above, in the VUV irradiation step, the transmittance of the phase shift film 3 at the time of film formation is hardly changed, and the phase shift film 3 can be patterned completely differently from the case where the VUV irradiation step is not performed. The cross-sectional shape of the etched cross section of the edge portion of the obtained phase shift film pattern 3' is a cross-sectional shape that can sufficiently exhibit the phase shift effect. Further, the reflectance of the phase shift film 3 at the time of film formation is hardly changed in the VUV irradiation step. This case shows that it is possible to control the CD unevenness of the phase shift film pattern 3' to a very narrow range, and it is considered that the VUV irradiation step is also effective in this respect.

The phase shift mask substrate 1 of the second embodiment is manufactured by a preparation step, a phase shift film forming step, and a VUV irradiation step.

According to the phase shift mask substrate 1 of the second embodiment manufactured in this manner, the phase shift film 3 containing chromium, oxygen, and nitrogen and subjected to VUV irradiation treatment is formed on the transparent substrate 2. Similarly to the first embodiment, the phase shift film 3 has a main layer 3a containing the same material and an outermost layer 3b as a surface oxide layer of the main layer 3a. The refractive index at a wavelength of 365 nm at the upper portion of the main layer on the outermost layer 3b side is smaller than the refractive index at a wavelength of 365 nm at the lower portion of the main layer on the side of the transparent substrate 2, and the film density at the outermost surface is 2.0 g/cm ³ or more. Therefore, the phase shift film 3 of the phase shift mask base 1 can be patterned by wet etching to have a cross-sectional shape in which the phase shift effect can be sufficiently exerted. Since the phase shift mask substrate 1 can make the cross-sectional shape of the etched cross section of the edge portion of the phase shift film pattern obtained by patterning the phase shift film 3 into a cross section which can sufficiently exhibit the phase shift effect Since the shape is formed, it is possible to form a precursor for manufacturing a phase shift mask having improved phase resolution and a phase shift film pattern having excellent CD characteristics.

Further, the method of manufacturing the phase shift mask substrate 1 according to the second embodiment includes a phase shift film forming step of forming a film phase on the transparent substrate 2 by a sputtering method using a continuous sputtering apparatus. An offset film 3 comprising chromium, oxygen and nitrogen, and having a main layer 3a comprising the same material, and a surface layer 3b as a surface oxide layer of the main layer 3a; and a VUV irradiation step The VUV irradiation treatment is performed on the outermost surface of the film-formed phase shift film 3. In the phase shift film forming step, the first sputtering target 13 is used in the same manner as in the first embodiment, and the inert gas and the active gas are supplied from the downstream side to the first sputtering target 13 and the inert gas is contained. The film is formed by reactive sputtering of a mixed gas of a gas and an active gas. Thereby, the refractive index at a wavelength of 365 nm in the upper portion of the main layer on the outermost layer 3b side of the phase shifting film 3 of the film formation film can be made smaller than the refractive index at a wavelength of 365 nm in the lower portion of the main layer on the side of the transparent substrate 2. Further, the VUV irradiation step reduces the maximum value of the refractive index of the outermost layer 3b of the phase shift film 3, for example, at a wavelength of 365 nm, and tends to reduce the refractive index, so that the main layer 3a has a wavelength of, for example, 365 nm. The tendency of the increase in the refractive index is small, and the film density on the outermost surface is made 2.0 g/cm ³ or more. Therefore, it is possible to manufacture the phase shift mask substrate 1 in which the phase shift film 3 can be patterned by wet etching into a cross-sectional shape in which the phase shift effect can be sufficiently exerted. Since the cross-sectional shape of the etched cross section of the edge portion of the phase shift film pattern can be made into a cross-sectional shape that can sufficiently exhibit the phase shift effect, it is possible to manufacture a phase shift which is improved in resolution and can be patterned into a good CD characteristic. The phase of the film pattern is shifted by the mask substrate 1.

Further, the phase shift film 3 of the transparent substrate 2 formed by the phase shift film forming step in the second embodiment may be subjected to a VUV irradiation step as a subsequent step immediately after film formation, or may be performed. After being stored in a specific box at a specific time after film formation, A VUV irradiation step is performed. The storage may be, for example, about one month, but is not limited thereto. If the VUV treatment step is carried out before storage, even if it is stored for about 1 month, whether it is washed or not (excluding sulfuric acid washing), the resist pattern is used as a mask and the phase shift formed by wet etching is used. The cross-sectional shape of the transfer film pattern was better than that of the cross-sectional shape without VUV treatment. When the VUV irradiation step is performed after storage, it is not necessary to perform specific film cleaning. During storage, the exposed portion of the outermost surface of the phase shifting film 3 may be slightly contaminated, but even if it is assumed to be contaminated, it does not affect the modification effect of the VUV irradiation step. Preferably, it is preferred to carry out the VUV irradiation step immediately before the formation of the resist film. Further, in the manufacturing process of the photomask substrate, if the surface of the phase shift film 3 is subjected to sulfuric acid washing, and then a resist pattern is formed on the phase shift film 3, the cross-sectional shape of the phase shift film pattern becomes a cone. Although the shape is changed, after the sulfuric acid is washed in the phase shift film 3 and the VUV is irradiated before the resist film is formed, the cross-sectional shape of the phase shift film pattern is less likely to be tapered, and there is a possibility that it can be made vertical. That is, when the surface of the phase shift film 3 is subjected to sulfuric acid washing, the adhesion between the resist film and the film surface of the phase shift film 3 is remarkably lowered, so that the resist pattern is used as a mask after the wet etching process. Since the cross-sectional shape is a very large tapered shape, the resolution of the phase shift film cannot be effectively utilized. By performing the VUV irradiation step after the sulfuric acid of the phase shift film 3 is washed, the cross-sectional shape of the phase shift film pattern can be greatly improved. Further, the VUV irradiation step is performed by reducing the sulfur component by rinsing after the sulfuric acid washing of the phase shift film 3 is strengthened, and the cross-sectional shape of the phase shift film pattern may be made vertical.

The phase shift mask substrate 1 of the second embodiment which has been subjected to the VUV irradiation step can also be used as a manufacturing original plate in the manufacturing method of the phase shift mask immediately after the VUV irradiation step. Moreover, even if the phase shift mask base 1 is stored in a specific case at a specific time, the effect of improving the phase shift film 3 by the VUV irradiation process can be maintained. Therefore, it can be used as a manufacturing original plate in the manufacturing method of the phase shift mask after storage. Thus, since the phase shift mask substrate 1 can be stored, a certain amount of phase shift mask base can be stored. 1. It can be used to improve the operability when it is shipped or when a phase shift mask is manufactured. Further, the storage may be, for example, about 2 weeks, but is not limited thereto.

Embodiment 3.

In the third embodiment, a method of manufacturing a phase shift mask (transparent substrate/phase shift film pattern) for manufacturing a display device will be described.

3(a) to 3(e) are cross-sectional views showing respective steps of a method of manufacturing a phase shift mask according to a third embodiment of the present invention, and the same components as those in Figs. 1 and 2 are denoted by the same reference numerals and are omitted. Repeat the instructions.

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

In the method of manufacturing a phase shift mask according to the third embodiment configured as described above, first, a resist pattern forming step is performed on the phase shift mask substrate 1 described in the first or second embodiment (see The resist pattern 5' is formed on the phase shift film 3 of the phase shift mask substrate 1 obtained by the method for fabricating the phase shift mask substrate described in the first or second embodiment.

Specifically, in the resist pattern forming step, first, as shown in FIG. 3(a), a phase shift mask substrate on which the phase shift film 3 containing a chromium-based material is formed on the transparent substrate 2 is prepared. 1. Thereafter, as shown in FIG. 3(b), a resist film 5 is formed on the phase shift film 3. Thereafter, as shown in FIG. 3(c), after the resist film 5 is drawn with a pattern of a specific size, the resist film 5 is developed with a specific developer to form a resist pattern 5'.

As the pattern drawn on the resist film 5, a line and gap pattern or a hole pattern can be cited.

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

The etching liquid for wet etching the phase shift film 3 is not particularly limited as long as it can selectively etch the phase shift film 3 containing a chromium-based material. Specifically In other words, an etching solution containing cerium ammonium nitrate and perchloric acid can be mentioned.

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

The phase shift mask 30 of the third embodiment is manufactured by the resist pattern forming step and the phase shift film pattern forming step.

The phase shift film pattern 3' has the property of changing the phase of the exposed light, similarly to the phase shift film 3 of the phase shift mask substrate 1. By this property, a specific phase difference is generated between the light that is transmitted through the phase shift film pattern 3' and the light that is transmitted only through the transparent substrate 2. In the case where the light to be exposed is a composite light including light in a wavelength range of 300 nm or more and 500 nm or less, the phase shift film pattern 3' is formed to generate a specific phase difference with respect to light of a representative wavelength. For example, when the exposed light is a composite light including i-rays, h-rays, and g-rays, the phase-shifted film pattern 3' produces a phase of 180 degrees with respect to any of i-rays, h-rays, and g-rays. The poor way is formed. Moreover, in order to exhibit the phase shift effect, for example, the phase difference of the phase shift film pattern 3' of the i-ray is set to a range of 180 degrees ± 10 degrees, preferably set to approximately 180 degrees. Further, for example, the transmittance of the phase shift film pattern 3' of the i-ray is preferably set to be 1% or more and 20% or less, and particularly preferably in the range of 3% or more and 15% or less.

The composition of each element of the phase shift film pattern 3' is larger than the outermost surface layer 3b formed by the phase shift film pattern 3' from the outermost surface toward the film depth direction, and the phase shift film pattern 3' and the transparent substrate 2 The main layer 3a outside the interface area is substantially uniform. However, the composition of the phase shift film pattern 3' from the outermost surface toward the film depth direction and the interface region close to the transparent substrate 2 are not uniform.

With respect to the cross-sectional shape of the etched cross section of the edge portion of the phase shift film pattern 3', since the outermost surface of the phase shift film 3 is subjected to the above-described VUV irradiation treatment, it is not easy to have a tapered shape.

Here, as for the cross-sectional angle (θ) of the etched cross section of the edge portion of the phase shift film pattern 3 ′ (see FIG. 12 below), it is preferable to sufficiently exhibit the phase shift effect. It is 90 degrees or close to the angle of 90 degrees.

However, even if the section angle (θ) is not 90 degrees or close to the angle of 90 degrees, the phase shift effect can be sufficiently exerted. For example, even in the etched section of the edge portion of the phase shift film pattern 3', a portion of the etched portion near the edge portion of the transparent substrate 2 has a slight hem portion as long as the phase shift film pattern is close to the resist film pattern 5'. When most of the etched section of the edge portion of 3' is 90 degrees or close to the angle of 90 degrees, the phase shift effect can be sufficiently exerted.

The phase shift mask 30 for manufacturing a display device manufactured in this manner is used for projection exposure of a double exposure and sufficiently exhibits a phase shift effect. In particular, as the exposure environment, the numerical aperture (NA) is preferably from 0.06 to 0.15, more preferably from 0.08 to 0.10, and the homology factor (σ) is preferably from 0.5 to 1.0.

According to the method of manufacturing the phase shift mask 30 of the third embodiment, the phase shift mask substrate 1 described in the first embodiment or the second embodiment or the phase shift mask substrate described in the first or second embodiment is used. The phase shift mask substrate 1 obtained by the manufacturing method is used to manufacture the phase shift mask 30. Therefore, it is possible to manufacture the phase shift mask 30 having the phase shift film pattern 3' which can sufficiently exhibit the phase shift effect. Since the phase shift film pattern 3' can sufficiently exhibit the phase shift effect, the phase shift mask 30 having the phase shift film pattern 3' having excellent CD characteristics can be manufactured with improved resolution. The phase shift mask 30 can cope with the miniaturization of the line and gap patterns or contact holes.

In the third embodiment, the original substrate for manufacturing the phase shift mask 30 is described using a phase shift mask substrate 1 having a transparent substrate/phase shift film. However, the present invention is not limited thereto. For example, a phase shift mask base having a configuration of a transparent substrate/phase shift film/resist film (see FIG. 3(b)) may be used as a master for manufacturing the phase shift mask 30.

Further, in the third embodiment, the phase shift film 3 of the phase shift mask base 1 may be subjected to film cleaning as needed before the resist pattern forming step. A well-known washing method can be used for film washing. However, it is preferred to use a cleaning liquid (for example, sulfur) other than using a component containing sulfur (S). A washing method other than the washing method of the acid hydrogen peroxide mixture). This is because the sulfur (S) component remains on the phase shift film 3 during the film cleaning using the cleaning liquid containing the sulfur (S) component. Therefore, when the phase shift film 3 is patterned by the residual sulfur (S) component to obtain the phase shift film pattern 3', the cross-sectional shape of the edge portion to be etched is easily tapered.

Embodiment 4.

In the fourth embodiment, a phase shift mask base (transparent substrate/light shielding film pattern/phase shift film) for manufacturing a display device and a method for manufacturing the same will be described.

4 is a cross-sectional view showing a configuration of a phase shift mask base according to a fourth embodiment of the present invention, and FIGS. 5(a) to 5(f) are views showing a method of manufacturing the phase shift mask base shown in FIG. 4. The same components as those in FIGS. 1 to 3 are denoted by the same reference numerals, and the description thereof will not be repeated.

The phase shift mask substrate 10 of the fourth embodiment includes: a transparent substrate 2; a light shielding film pattern 4' formed on a main surface of the transparent substrate 2; and a phase shift film 3 formed on the light shielding film pattern 4. 'and on the main surface of the transparent substrate 2.

The method for manufacturing the phase shift mask substrate 10 according to the fourth embodiment configured as described above includes a preparation step of preparing a transparent substrate 2, and a film formation step (hereinafter sometimes referred to as a light shielding film forming step), which is attached to a light shielding film 4 is formed on the main surface of the transparent substrate 2 by sputtering; a light shielding film pattern forming step of patterning the light shielding film 4 to form a light shielding film pattern 4'; and a phase shift film forming step. A phase shift film 3 containing chromium, oxygen, and nitrogen is formed on the light-shielding film pattern 4'.

Hereinafter, each step will be described in detail.

1. Preparation steps

First, the transparent substrate 2 is prepared.

This preparation step is carried out in the same manner as the preparation step in the first embodiment.

2. Light shielding film forming step

Next, as shown in FIG. 5(a), the light shielding film 4 is formed on the main surface of the transparent substrate 2 by sputtering.

Specifically, in the light shielding film forming step, a sputtering process is performed in which a sputtering power is applied in a sputtering gas atmosphere to form a film forming step of the light shielding film 4 containing a specific material.

The light-shielding film 4 is adjusted so that the optical density of the light-shielding film 4 is adjusted so that the optical density of the light to be exposed is 2.8 or more, preferably 3.0 or more, in total with the phase shift film 3.

The material constituting the light shielding film 4 is not particularly limited, and is preferably a material used for the mask substrate. Examples of the material used for the base of the photomask include a material containing chromium, a material containing niobium, and a material containing metal and niobium (Si) (metal chelate material). The material containing chromium is not particularly limited as long as it contains chromium (Cr), and examples thereof include chromium (Cr), chromium oxide, chromium nitride, chromium carbide, and chromium fluoride. The material containing ruthenium is not particularly limited as long as it contains ruthenium (Ta), and examples thereof include ruthenium (Ta), an oxide of ruthenium, and a nitride of ruthenium. Examples of the metal telluride material include a nitride of a metal telluride, an oxide of a metal telluride, a nitrogen oxide of a metal telluride, a carbonitride of a metal telluride, a carbon oxide of a metal telluride, and a metal. Carbonitrides of tellurides. Examples of the metal include transition metals such as molybdenum (Mo), tantalum (Ta), tungsten (W), and titanium (Ti). The composition of the metal and tantalum can be adjusted from the viewpoint of the optical characteristics of the light shielding film 4. The ratio of the metal to the ruthenium is appropriately selected depending on the kind of the metal or the optical characteristics required for the light-shielding film, and is preferably metal: 矽 = 1:1 or more and 1:9 or less.

Further, the material constituting the light shielding film 4 may optionally contain other elements such as oxygen (O), nitrogen (N), and carbon (C).

The light-shielding film 4 may be in the case of one layer and the case of a plurality of layers. The case where the light-shielding film 4 is composed of a plurality of layers, for example, a laminated structure composed of a light-shielding layer formed on the phase shift film 3 side and an anti-reflection layer formed on the light-shielding layer. The light shielding layer may be any of a case composed of one layer and a case of a plurality of layers. Make Examples of the light shielding layer include a chromium nitride film (CrN), a chromium carbonization film (CrC), and a chromium carbon nitride film (CrCN). The antireflection layer is provided on the surface of the light shielding film in order to reduce the reflectance of the exposed light, and the antireflection layer may be formed of one layer or a plurality of layers. As the antireflection layer, for example, a chromium oxynitride film (CrON) can be cited.

The film formation of the light shielding film 4 is a sputtering apparatus such as a cluster type sputtering apparatus or a continuous sputtering apparatus.

The light shielding film 4 can be formed, for example, by a sputtering target or a sputtering gas atmosphere as described below.

As a sputtering target used for forming the light-shielding film 4 made of a material containing chromium, a chromium (Cr) or chromium compound is selected. Specific examples include chromium (Cr), chromium nitride, chromium oxide, chromium carbide, chromium nitrogen oxide, chromium carbonitride, chromium carbon oxide, and chromium carbon nitrogen. Oxide.

The sputtering gas atmosphere when forming the light shielding film 4 composed of a material containing chromium is composed of a mixed gas of an active gas and an inert gas, and the active gas contains a gas selected from nitrogen (N ₂ ) and nitrogen monoxide (NO). a group consisting of nitrogen dioxide (NO ₂ ) gas, nitrous oxide (N ₂ O) gas, carbon monoxide (CO) gas, carbon dioxide (CO ₂ ) gas, oxygen (O ₂ ), hydrocarbon gas, and fluorine gas In at least one of the inert gas, the inert gas comprises at least one selected from the group consisting of helium (He), helium (Ne), argon (Ar), helium (Kr), and xenon (Xe). Examples of the hydrocarbon-based gas include methane gas, butane gas, propane gas, and styrene gas.

The combination of the material of the sputtering target and the gas type of the sputtering gas atmosphere, or the mixing ratio of the active gas and the inert gas in the sputtering gas atmosphere is appropriately determined depending on the type or composition of the chromium-based material constituting the light shielding film 4. .

As a sputtering target used for forming a light-shielding film 4 made of a material containing ruthenium, a ruthenium (Ta) or ruthenium compound is selected. Specifically, tantalum (Ta), an oxide of cerium, and a nitride of cerium are exemplified.

The sputtering gas atmosphere when the light shielding film 4 composed of the material containing germanium is formed is composed of a mixed gas of an active gas and an inert gas, and the active gas contains a gas selected from nitrogen (N ₂ ) and nitrogen monoxide (NO). At least one of a group consisting of nitrogen dioxide (NO ₂ ) gas, nitrous oxide (N ₂ O) gas, carbon monoxide (CO) gas, carbon dioxide (CO ₂ ) gas, and oxygen (O ₂ ), the inert gas It comprises at least one selected from the group consisting of helium (He), helium (Ne), argon (Ar), helium (Kr), and xenon (Xe).

The combination of the material of the sputtering target and the gas type of the sputtering gas atmosphere, or the mixing ratio of the active gas and the inert gas in the sputtering gas atmosphere is appropriately selected depending on the kind or composition of the material constituting the light shielding film 4 Decide.

The sputtering target used for forming the light-shielding film 4 containing a metal halide material is selected from the group consisting of a metal and bismuth (Si). Specific examples thereof include a metal telluride, a nitride of a metal telluride, an oxide of a metal telluride, a carbide of a metal telluride, a nitrogen oxide of a metal telluride, a carbonitride of a metal telluride, and a metal telluride. Carbon oxides of matter, and carbon oxynitrides of metal halides.

The sputtering gas atmosphere when the light shielding film 4 containing the metal halide material is formed is composed of a mixed gas of an active gas and an inert gas, and the active gas contains a gas selected from the group consisting of nitrogen (N ₂ ) and nitrogen monoxide (NO). At least one of a group consisting of nitrogen dioxide (NO ₂ ) gas, nitrous oxide (N ₂ O) gas, carbon monoxide (CO) gas, carbon dioxide (CO ₂ ) gas, and oxygen (O ₂ ), the inert gas containing At least one selected from the group consisting of helium (He), helium (Ne), argon (Ar), helium (Kr), and xenon (Xe) is selected.

The combination of the material of the sputtering target and the gas species of the sputtering gas atmosphere, or the mixing ratio of the active gas and the inert gas in the sputtering gas atmosphere is appropriately selected depending on the kind or composition of the metal halide material constituting the light shielding film 4. Decide.

The light shielding film forming step can be performed, for example, using the sputtering apparatus 11 shown in FIG. 2.

Here, a case where the light shielding film 4 made of a material containing chromium is formed will be described as an example.

First, for example, forming a cover structure composed of a light shielding layer and an antireflection layer In the case of the photo film 4, the first sputtering target 13 containing chromium which is a light shielding layer for forming the light shielding film 4 is disposed in the first sputtering chamber SP1, and is disposed in the second sputtering chamber SP2 to form a light shielding layer. The third sputtering target 15 containing chromium in the antireflection layer of the film 4.

Thereafter, in order to form the light shielding film 4, the transparent substrate 2 mounted on a tray (not shown) is carried into the carrying chamber LL.

Then, in a state where the inside of the sputtering apparatus 11 is a specific degree of vacuum, a sputtering gas having a specific flow rate is introduced from the second gas introduction port GA12, and a specific sputtering power is applied to the first sputtering target 13. Further, a sputtering gas having a specific flow rate is introduced from the sixth gas introduction port GA32, and a specific sputtering power is applied to the third sputtering target 15. The application of the sputtering power and the introduction of the sputtering gas continue until the transparent substrate 2 is transferred to the carry-out chamber ULL.

Thereafter, the transparent substrate 2 mounted on a tray (not shown) is loaded into the chamber LL, the first sputtering chamber SP1, the buffer chamber BU, and the second sputtering in a direction of the arrow S at a specific conveyance speed. The chamber SP2 and the carry-out chamber ULL are transported in the order. When the transparent substrate 2 passes through the vicinity of the first sputtering target 13 of the first sputtering chamber SP1, a light-shielding layer containing a chromium-based material having a specific film thickness is formed by reactive sputtering on the main surface of the transparent substrate 2. Further, when the transparent substrate 2 passes through the vicinity of the third sputtering target 15 of the second sputtering chamber SP2, an antireflection layer containing a chromium-based material having a specific film thickness is formed by reactive sputtering on the light shielding layer.

After the light shielding film 4 having a laminated structure composed of a light shielding layer and an antireflection layer is formed on the main surface of the transparent substrate 2, the transparent substrate 2 is taken out to the outside of the sputtering apparatus 11.

3. Light-shielding film pattern forming step

Next, a light shielding film pattern forming step of forming the light shielding film pattern 4' on the main surface of the transparent substrate 2 is performed.

Specifically, in the light shielding film pattern forming step, first, as shown in FIG. 5(b), a resist film 5 is formed on the light shielding film 4. Thereafter, as shown in FIG. 5(c), after the resist film 5 is drawn with a pattern of a specific size, the resist film 5 is developed with a specific developer to form a resist pattern 5'.

As the pattern drawn on the resist film 5, a line and gap pattern or a hole pattern can be cited.

Next, as shown in FIG. 5(d), a light-shielding film pattern forming step is performed in which the light-shielding film 4 is wet-etched using the resist pattern 5' as a mask to form a light-shielding film pattern 4'.

When the light-shielding film 4 contains a chromium-based material, the etching liquid for wet etching the light-shielding film 4 is not particularly limited as long as it can selectively etch the light-shielding film 4. Specifically, an etching solution containing cerium ammonium nitrate and perchloric acid is mentioned.

When the light shielding film 4 contains a metal halide material, the etching liquid for wet etching the light shielding film 4 is not particularly limited as long as it can selectively etch the light shielding film 4. For example, an etching solution containing at least one fluorine compound selected from the group consisting of hydrofluoric acid, hydroquinone fluoric acid, and ammonium hydrogen fluoride, and at least one oxidizing agent selected from the group consisting of hydrogen peroxide, nitric acid, and sulfuric acid may be mentioned. Specifically, an etching solution obtained by diluting a mixed solution of ammonium hydrogen fluoride and hydrogen peroxide with pure water is used.

When the light shielding film 4 contains a lanthanoid material, the etching liquid which wet-etches the light shielding film 4 is not particularly limited as long as it can selectively etch the light shielding film 4. Specifically, an etching solution containing sodium hydroxide and hydrogen peroxide can be mentioned.

After the light shielding film pattern 4' is formed, as shown in FIG. 5(e), the resist pattern 5' is peeled off.

4. Phase shift film formation step

Next, as shown in FIG. 5(f), a phase shift film forming step of forming the phase shift film 3 on the light-shielding film pattern 4' on the transparent substrate 2 is performed.

This phase shift film forming step is performed in the same manner as the phase shift film forming step in the first embodiment.

The phase shift mask substrate 10 of the fourth embodiment is manufactured by such a preparation step, a light shielding film forming step, a light shielding film pattern forming step, and a phase shift film forming step.

According to the phase shift mask substrate 10 of the fourth embodiment manufactured in this manner, the phase shift film 3 containing chromium, oxygen, and nitrogen is formed by interposing the light shielding film pattern 4' on the main surface of the transparent substrate 2, and The phase shift film 3 is directly formed on the main surface of the transparent substrate 2. The phase The offset film 3 has a main layer 3a containing the same material, and an outermost layer 3b as a surface oxide layer of the main layer 3a. The refractive index at a wavelength of 365 nm in the upper portion of the main layer on the outermost layer 3b side is smaller than the refractive index at a wavelength of 365 nm in the lower portion of the main layer on the side of the transparent substrate 2. The phase shift film 3 having the phase shift mask substrate 10 having such a configuration can be patterned by wet etching into a cross-sectional shape in which the phase shift effect can be sufficiently exhibited. The phase shift mask base 10 can make the cross-sectional shape of the etched section of the edge portion of the phase shift film pattern 3' obtained by patterning the phase shift film 3 into a phase shift effect. Since the cross-sectional shape is good, it is possible to form a manufacturing original plate of a phase shift mask having improved resolution and a phase shift film pattern having excellent CD characteristics.

Further, the method of manufacturing the phase shift mask substrate 10 according to the fourth embodiment includes a film forming step of interposing a light shielding film pattern on the main surface of the transparent substrate 2 by sputtering using a continuous sputtering apparatus. Forming the phase shift film 3 and forming a phase shift film 3 directly on the main surface of the transparent substrate 2, the phase shift film 3 containing chromium, oxygen and nitrogen, and having a main layer 3a containing the same material, And the outermost layer 3b which is the surface oxide layer of the main layer 3a. In the phase shift film forming step, the first sputtering target 13 containing chromium is used, and is downstream from the first sputtering target 13 in the transport direction of the transparent substrate 2 in the vicinity of the first sputtering target 13 . The inert gas and the active gas for oxidizing and nitriding the phase shift film 3 are supplied to the side, and the film is formed by reactive sputtering using a mixed gas containing an inert gas and an active gas. It is possible to manufacture the phase shift mask substrate 10 in which the phase shift film 3 formed in this manner can be patterned by wet etching into a cross-sectional shape in which the phase shift effect can be sufficiently exerted. Since the cross-sectional shape of the etched cross section of the edge portion of the phase shift film pattern can be made into a cross-sectional shape that can sufficiently exhibit the phase shift effect, it is possible to manufacture a phase shift which is improved in resolution and can be patterned into a good CD characteristic. The phase of the film pattern is offset from the reticle substrate 10.

Further, in the fourth embodiment, similarly to the second embodiment, after the phase shift film forming step, the VUV irradiation step may be performed on the outermost surface of the phase shift film 3.

Embodiment 5.

In the fifth embodiment, a method of manufacturing a phase shift mask (transparent substrate/light shielding film pattern/phase shift film pattern) for manufacturing a display device will be described.

6(a) to 6(e) are cross-sectional views showing respective steps of a method of manufacturing a phase shift mask according to a fifth embodiment of the present invention using the phase shift mask substrate shown in Fig. 4, and The same components as those in FIG. 5 are denoted by the same reference numerals and the description thereof will not be repeated.

The phase shift mask 31 manufactured by the method for manufacturing a phase shift mask base according to the fifth embodiment has a configuration in which a light-shielding film pattern 4' is interposed on the main surface of the transparent substrate 2 to form chromium. The phases of the oxygen and nitrogen are shifted from the film pattern 3', and the phase shift film pattern 3' is directly formed on the main surface of the transparent substrate 2.

In the method of manufacturing a phase shift mask according to the fifth embodiment of the present invention, first, a resist pattern forming step is performed on the phase shift mask substrate 10 described in the fourth embodiment (see FIG. 4). Or a resist pattern formed on the phase shift film 3 of the phase shift mask substrate 10 (see FIG. 5(f)) obtained by the method for manufacturing a phase shift mask substrate described in the fourth embodiment 5'.

In detail, in the resist pattern forming step, first, as shown in FIG. 6(a), a phase shift mask substrate 10 is prepared, which is shielded from the light shielding film pattern 4' on the main surface of the transparent substrate 2. On the other hand, a phase shift film 3 containing chromium, oxygen, and nitrogen is formed, and the phase shift film 3 is directly formed on the main surface of the transparent substrate 2. Thereafter, as shown in FIG. 6(b), a resist film 5 is formed on the phase shift film 3. Thereafter, as shown in FIG. 6(c), after the resist film 5 is drawn with a pattern of a specific size, the resist film 5 is developed with a specific developer to form a resist pattern 5'.

As the pattern drawn on the resist film 5, a line and gap pattern or a hole pattern can be cited.

Next, as shown in FIG. 6(d), a phase shift film pattern forming step of wet etching the phase shift film 3 using the resist pattern 5' as a mask to form a phase shift film is performed. Pattern 3'.

The etching liquid for wet etching the phase shift film 3 is not particularly limited as long as it can selectively etch the phase shift film 3 containing a chromium-based material. Specifically, An etching solution containing cerium ammonium nitrate and perchloric acid is listed.

The obtained phase shift film pattern 3' has the property of changing the phase of the exposed light, similarly to the phase shift film pattern 3' in the second embodiment, and the cross-sectional shape of the etched cross section of the edge portion is formed by the present Since the phase shift film of the invention and the outermost surface of the phase shift film 3 are subjected to the above-described VUV irradiation treatment, they are not easily tapered.

After the phase shift film pattern 3' is formed, as shown in FIG. 6(e), the resist pattern 5' is peeled off.

The phase shift mask 31 of the fifth embodiment is manufactured by the resist pattern forming step and the phase shift film pattern forming step.

The phase shift mask 31 for manufacturing a display device manufactured in this manner is used for projection exposure of a double exposure and sufficiently exerts a phase shift effect. In particular, as the exposure environment, the numerical aperture (NA) is preferably from 0.06 to 0.15, more preferably from 0.08 to 0.10, and the homology factor (σ) is preferably from 0.5 to 1.0.

According to the method of manufacturing the phase shift mask 31 of the fifth embodiment, the phase shift mask substrate 10 described in the fourth embodiment or the phase shift mask substrate manufacturing method described in the fourth embodiment is used. The phase shift mask substrate 10 is phase-shifted to produce a phase shift mask 31. Therefore, it is possible to manufacture the phase shift mask 31 having the phase shift film pattern 3' which can sufficiently exhibit the phase shift effect. Since the phase shift film pattern 3' can sufficiently exhibit the phase shift effect, the phase shift mask 31 having the phase shift film pattern 3' having excellent CD characteristics can be manufactured with improved resolution. The phase shift mask 31 can cope with the miniaturization of the line and gap patterns or contact holes.

Further, in the fifth embodiment, a phase shift mask having a configuration of a transparent substrate/light shielding film pattern/phase shift film (see FIG. 6(a)) is used as the original plate for manufacturing the phase shift mask 31. The substrate 10 has been described, but is not limited thereto. For example, a phase shift mask base having a configuration of a transparent substrate/light shielding film pattern/phase shift film/resist film (see FIG. 6(b)) may be used as a manufacturing original plate of the phase shift mask 31.

Further, in the fifth embodiment, in the same manner as in the third embodiment, the resist pattern may be used. Before the step of forming the film, the phase shift film 3 of the phase shift mask substrate 10 is subjected to film cleaning as needed. A well-known washing method can be used for film washing. However, it is preferable to use a washing method other than the washing method of the washing liquid containing the sulfur (S) component (for example, a sulfuric acid hydrogen peroxide mixture).

[Examples]

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

Example 1 and Comparative Example 1.

In the first embodiment and the comparative example 1, a phase shift mask substrate having a phase shift film (material: CrOCN) and a phase shift mask manufactured using the phase shift mask substrate will be described.

Further, the phase shift mask substrate 1 of the first embodiment introduces a reactive gas (sputtering gas) from a gas introduction port disposed on the downstream side of the sputtering target containing chromium, and is formed by reactive sputtering. The film is phase-shifted by the film 3 (in this case, the main valve (not shown) of the buffer chamber BU is closed, and no gas flows in the second sputtering chamber SP2), whereas the comparative example 1 is used. The phase shift mask base is formed by introducing a reactive gas (sputtering gas) from a gas introduction port disposed on the upstream side of the sputtering target containing chromium and forming a phase shift film by reactive sputtering. The main valve (not shown) of the buffer chamber BU is opened, and the same gas is supplied to the second sputtering chamber SP2 to be manufactured, which is different in this respect.

A. Phase shift mask substrate and method of manufacturing the same

In order to manufacture the phase shift mask base 1 of the first embodiment and the first comparative example described above, first, a synthetic quartz glass substrate of 8092 size (800 mm × 920 mm) was prepared as the transparent substrate 2.

Thereafter, the transparent substrate 2 is carried into the continuous sputtering apparatus 11 having the sputtering target containing chromium as shown in FIG. 2, and as shown in FIG. 1, the film is formed on the main surface of the transparent substrate 2 to contain carbon and nitrogen. Chromium oxide (CrOCN) phase shift film 3 (film thickness 125 nm).

In the first sputtering chamber SP1, the phase shift film 3 is introduced with argon (Ar) and carbon dioxide (CO) from the second gas introduction port GA12 disposed on the downstream side of the first sputtering target 13 containing chromium. ₂ ) a mixed gas of gas and nitrogen (N ₂ ) (Ar: 46 sccm, N ₂ : 46 sccm, CO ₂ : 45 sccm), the sputtering power was set to 3.5 kw, and the transport speed of the transparent substrate 2 was set to 200 mm/min. And forming a film on the transparent substrate 2 by reactive sputtering. The phase shift film 3 (film thickness: 125 nm) was formed by one film formation.

Further, the film formation of the phase shift film 3 of the first embodiment is such that the main valve (not shown) of the exhaust unit (not shown) connected to the buffer chamber BU is closed to stop the exhaust, and the second step is not performed. It is carried out under the condition that a sputtering gas is introduced into the sputtering chamber SP2. In the case where the phase shift film 3 is formed under this condition, since the possibility of tapering the cross-sectional shape of the edge portion of the phase shift film pattern is expected, the phase shift is avoided in order to avoid the taper. The film formation conditions were adjusted so that the transmittance of the film 3 was less than 5%.

On the other hand, the first gas introduction port GA11 disposed on the upstream side of the first sputtering target 13 containing chromium has a flow rate different from that of the first embodiment (Ar: 46 sccm, N ₂ : 46 sccm, CO ₂ : 35 sccm) A phase shift film formed on the transparent substrate 2 was formed by one film formation in the same manner as in Example 1 except that the mixed gas of the same components as in Example 1 was used, and the sputtering power was changed to 3.40 kW. (Film thickness: 125 nm), the phase shift mask substrate of Comparative Example 1 was obtained.

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

As a result, in the first and comparative examples 1, the surface oxide layer having a film thickness of about 8 nm which is increased toward the film surface side and having a larger oxygen content is formed on the outermost layer of the phase shift film, and the synthetic quartz is removed. In addition to the vicinity of the interface of the glass substrate (transparent substrate 2), a main layer in which the content of each element (Cr, C, O, N) hardly changes is formed at a depth of about 8 nm to about 115 nm.

In any of the first embodiment and the comparative example 1, the content of each element of chromium (Cr), oxygen (O), nitrogen (N), and carbon (C) in the main layer is small, and It is roughly uniform. The content of each element in the main layer of the phase shift film is 50±3 atom%, O is 29±5 atom%, and N is 15±3. Atomic %, C is 6 ± 3 atom%.

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

Main layer: laminated film (step layer)

The outermost layer: oxide film (Kexi layer)

The MSE of Example 1 was 4.852, and the MSE of Comparative Example 1 was 4.867.

Fig. 7 is a view showing the relationship between the refractive index (n) at a wavelength of 190 nm to 1000 nm in the upper portion of the main layer and the lower portion of the main layer of the phase shift film 3 of the phase shift mask substrate 1 of the first embodiment. 8 shows the relationship between the refractive index (n) at a wavelength of 190 nm to 1000 nm in the upper portion of the main layer and the lower portion of the main layer of the phase shift film of the phase shift mask substrate of Comparative Example 1, and FIG. 9 shows A graph of the refractive index at a wavelength of 365 nm from the outermost layer of the phase shifting film of the phase shift mask substrate of the first embodiment and the comparative example 1 to the lower portion of the main layer.

As shown in FIG. 7, it is understood that the refractive index of the upper portion of the main layer of the phase shift film 3 in the phase shift mask substrate 1 of the first embodiment is smaller than the refractive index of the lower portion of the main layer in the wavelength range. In particular, in the i-ray (wavelength 365 nm) which is one of the wavelengths of the light source for exposure (the ultrahigh pressure mercury lamp: mixed light of i-ray, h-ray, and g-ray) used for manufacturing the display device, the refractive index of the upper portion of the main layer It is smaller than the refractive index of the lower portion of the main layer, the refractive index of the upper portion of the main layer is 2.41, and the refractive index of the lower portion of the main layer is 2.60.

On the other hand, as shown in FIG. 8, it is understood that in the wavelength range, the refractive index of the upper portion of the main layer of the phase shift film in the phase shift mask substrate of Comparative Example 1 is larger than the refractive index of the lower portion of the main layer. Especially at the i-ray (wavelength 365 nm), the refractive index of the upper portion of the main layer is 2.60, and the refractive index of the lower portion of the main layer is 2.53.

Further, in either of the first embodiment and the comparative example 1, the measurement position of the refractive index is set at a depth of about 10 nm from the uppermost surface of the phase shifting film in the upper portion of the main layer, in the lower portion of the main layer. It is set to be about 100 nm from the depth of the outermost surface of the phase shift film.

Further, as shown in Fig. 9, in the first embodiment, the tendency is shown in the outermost layer 3b of the phase shift film 3, the refractive index at a wavelength of 365 nm is decreased, and the refractive index at a wavelength of 365 nm in the main layer 3a. On the other hand, in Comparative Example 1, the refractive index at a wavelength of 365 nm was increased in the outermost layer of the phase shift film, and the refractive index at a wavelength of 365 nm was decreased in the main layer. As disclosed in the results, it is understood that the first embodiment in which the film phase shift film 3 is formed by the downstream supply condition of the sputtering gas and the film phase shift film formed by the upstream supply condition of the sputtering gas are compared with the first example. The change in the refractive index in the depth direction of the phase shift film tends to be completely opposite.

With respect to the phase shift film of the phase shift mask substrate of Example 1 and Comparative Example 1, the film density at the outermost surface was measured by X-ray reflectance analysis (XRR).

Further, the film density at the outermost surface was measured for the film density of the phase shift film 3 at a depth of 2.2 nm from the surface layer in the depth direction. As a result, the film density on the outermost surface of the phase shift film 3 of Example 1 was 2.36 g/cm ³ , and the film density on the outermost surface of the phase shift film of Comparative Example 1 was 2.28 g/cm ³ . Further, the numerical index Fit R indicating the appropriateness of the fitting when calculating the film density was 0.012 in Example 1, and 0.013 in Comparative Example 1.

Further, with respect to the phase shift film of each of the phase shift mask substrates of Example 1 and Comparative Example 1, the transmittance was measured by a spectrophotometer U-4100 manufactured by Hitachi High-Technologies Co., Ltd., and the MPM manufactured by Lasertec Co., Ltd. was used. -100 measures the phase difference. Further, the values of the transmittances in Example 1 and Comparative Example 1 were all values based on the air.

In the measurement of the transmittance and the phase difference of the phase shift film 3, a phase shift is formed on the main surface of the transparent substrate 2 of 6025 size (152 mm × 152 mm) provided on the same substrate holder (not shown). A substrate (virtual substrate) with a phase shifting film of film 3 (film thickness: 125 nm).

As a result, the transmittance at a wavelength of 365 nm of Example 1 was 3.0%, and the transmittance at a wavelength of 365 nm of Comparative Example 1 was 5.3%.

Further, the phase difference at a wavelength of 365 nm of Example 1 was 185 degrees, and the phase difference at a wavelength of 365 nm of Comparative Example 1 was 181.8 degrees. From this result, it was found that the desired phase difference was obtained even if the phase shift film was formed by the downstream supply conditions of the sputtering gas.

Further, with respect to the phase shift film of the phase shift mask base of Example 1 and Comparative Example 1, the reflectance was measured by a spectrophotometer U-4100 manufactured by Hitachi High-Technologies Co., Ltd.

As a result, the reflectance spectrum of Example 1 at a wavelength of 200 nm to 800 nm was substantially the same as the reflectance spectrum of Comparative Example 1. From this result, it was found that the desired reflectance spectrum was obtained even if the phase shift film was formed by the downstream supply conditions of the sputtering gas.

B. Phase shift mask and manufacturing method thereof

In order to manufacture the phase shift masks of Example 1 and Comparative Example 1 using the phase shift mask substrates of Example 1 and Comparative Example 1 manufactured in the above manner, first, the phase shifts of Example 1 and Comparative Example 1 were made. On the phase shift film 3 of the shift cover substrate, the resist film 5 is applied using a resist coating device.

Thereafter, a resist film 5 having a film thickness of 1000 nm is formed through a heating and cooling step.

Thereafter, the resist film 5 is drawn using a laser drawing device, and a line and gap pattern having a line pattern width of 2.0 μm and a gap pattern width of 2.0 μm is formed on the phase shift film 3 via development and rinsing steps. Resist film pattern 5'.

Thereafter, the phase shift film 3 is wet-etched by a chromium etching solution containing cerium ammonium nitrate and perchloric acid using the resist pattern 5' as a mask to form a phase shift film pattern 3'.

Thereafter, the resist pattern 5' is peeled off.

In this manner, the phase shift mask 30 of the first embodiment in which the phase shift film pattern 3' formed by patterning the phase shift film 3 not subjected to the VUV irradiation treatment is formed on the transparent substrate 2 (transparent substrate/phase) The offset film pattern) and the phase shift mask (transparent substrate/phase shift film pattern) of Comparative Example 1.

The phase of the embodiment 1 was examined by a scanning electron microscope before the resist pattern 5' was peeled off. The etched cross section of the edge portion of each of the phase shift film patterns 3' of the offset mask 30 and the phase shift mask of Comparative Example 1 was observed.

Figure 10 is a cross-sectional photograph showing the edge portion of the phase shift film pattern 3' of the phase shift mask of the first embodiment, and Figure 11 is a cross section of the edge portion of the phase shift film pattern of the phase shift mask of Comparative Example 1. FIG. 12 is a cross-sectional view for explaining a cross-sectional angle (θ) which is a judgment index of a cross-sectional shape of an edge portion.

In FIG. 12, the film thickness of the phase shift film 3 is set to T, and the auxiliary line drawn from the depth of the outermost surface T/10 of the phase shift film 3 is set to L1, which will be the main point of the transparent substrate 2. The auxiliary line drawn on the height of the front side T/10 is set to L2, the intersection of the etched section F of the phase shift film 3 and the auxiliary line L1 is C1, and the intersection of the etched section F and the auxiliary line L2 is set to C2. . Here, the cross-sectional angle (θ) is an angle formed by the connection line connecting the intersection point C1 and the intersection point C2 with the main surface of the transparent substrate 2.

Further, the resist interface angle is an angle formed by the etched section F in the vicinity of the resist and the outermost surface, and the transparent substrate interface angle is an angle formed by the etched section F in the vicinity of the transparent substrate and the main surface of the transparent substrate.

Further, the tapered lower surface length is obtained by directly projecting one of the intersections of the etched section F and the outermost surface in the vicinity of the resist in a vertical direction onto the main surface of the transparent substrate and the etched profile F near the transparent substrate. The length of one of the points at the front end of the pendulum portion.

The resist interface of the edge portion of Example 1 shown in Fig. 10 has a resist interface angle of 100 degrees, a transparent substrate interface angle of 50 degrees, a tapered lower surface length of 50 nm, and a section angle (θ) of 80 degrees.

On the other hand, the resist interface of the edge portion of Comparative Example 1 shown in FIG. 11 has a resist interface angle of 155 degrees, a transparent substrate interface angle of 25 degrees, a tapered lower surface length of 200 nm, and a section angle (θ). It is 25 degrees. Further, the cross-section to be etched of Comparative Example 1 was a tapered shape which was dragged lower than the length of the etched section of Example 1.

As revealed by the results, it can be seen that the etched profile in Example 1 has a comparative ratio. The section angle (θ) which is much larger than the etched section in Example 1 is closer to the vertical section shape. That is, by forming a phase shift film under the supply condition of the sputtering gas downstream, the cross-sectional angle (θ) of the edge portion to be etched is increased.

Next, CD unevenness of the phase shift film pattern of the phase shift mask of Example 1 was measured by SIR8000 manufactured by Seiko Instruments Nanotechnology Co., Ltd. The measurement of CD unevenness was performed at a position of 5 × 5 on a region other than the peripheral region of the substrate other than the peripheral region. The CD unevenness is a deviation width from the target line and gap pattern (width of the line pattern: 2.0 μm, width of the gap pattern: 2.0 μm). In the following examples and comparative examples, the same apparatus was used for the measurement of CD unevenness.

If the CD is not 0.087 μm, it is very good.

It can be seen that the CD of the phase shift film pattern of the phase shift mask of Comparative Example 1 is not 0.205 μm, which is larger than that of the first embodiment.

Next, the light in the space of 365 nm of Example 1 and Comparative Example 1 obtained by simulating a spatial image of light through a phase shifting mask having a phase shift film pattern having a contact hole pattern of 2.5 μm square was simulated. The intensity distribution curves (transmittance distributions) were compared.

The light intensity distribution curve of Example 1 was compared with Comparative Example 1, and showed a sharp peak intensity at the center of the contact hole, and a large change in light intensity at the boundary portion of the pattern, and a peripheral region outside the boundary portion of the pattern. The light intensity changes little. Therefore, it is understood that the phase shift mask of the first embodiment exhibits a stronger light intensity gradient than that of Comparative Example 1, and the resolution is high.

Example 2 and Comparative Example 2.

In the second embodiment and the comparative example 2, the phase shift film (material: CrOCN) having the VUV irradiation treatment after the film formation of the phase shift film 3 is different from the first embodiment and the comparative example 1. The offset mask substrate and the phase shift mask manufactured using the phase shift mask substrate will be described.

Further, in the phase shift mask substrate 1 of the second embodiment, in the same manner as in the first embodiment, a splash is used. The phase shift film 3 was formed by the downstream supply conditions of the plating gas, and then the VUV irradiation treatment was performed to manufacture the film. In contrast, the phase shift mask base of Comparative Example 2 was splashed in the same manner as in Comparative Example 1. The phase shift film is formed by the upstream supply conditions of the plating gas, and then the VUV irradiation treatment is performed to manufacture the film gas, which is different in this respect.

A. Phase shift mask substrate and method of manufacturing the same

A synthetic quartz glass substrate having the same dimensions as in Example 1 was prepared as the transparent substrate 2.

In the second embodiment, in the phase shift film forming step, the sputtering device 11 shown in FIG. 2 is disposed on the second gas introduction port GA12 on the downstream side of the first sputtering target 13 including chromium, and compared with In the same flow rate as in Example 1 (Ar: 46 sccm, N ₂ : 46 sccm, CO ₂ : 35 sccm), a mixed gas of the same components as in Example 1 was introduced, and the sputtering power was set to 3.55 kW. The film formation conditions other than the above were the same as in the first embodiment, and the phase shift film 3 (film thickness: 125 nm) was formed by one film formation.

On the other hand, in Comparative Example 2, the phase shift film forming step was carried out under the same film forming conditions as in Comparative Example 1, and a phase shift film (film thickness: 125 nm) was formed by one film formation.

Thereafter, the outermost surfaces of the phase shift films of Example 2 and Comparative Example 2 were subjected to VUV irradiation treatment.

In the VUV irradiation treatment, an irradiation device (not shown) that irradiates VUV (氙 分子 excimer light, wavelength 172 nm) with an energy of 40 mW/cm ² is used, and the surface of the phase shift film 3 is equivalent to an irradiation energy of 45 J/cm ^{2 .} Irradiation.

Thus, the phase shift mask substrate 1 of Example 2 in which the phase shift film 3 subjected to the VUV irradiation treatment was formed and the phase shift light of Comparative Example 2 in which the phase shift film subjected to the VUV irradiation treatment was formed were obtained. Cover base.

In the phase shift film of the phase shift mask substrate of Example 2 and Comparative Example 2, the composition in the depth direction was analyzed by X-ray photoelectron spectroscopy (XPS), and the depth directions of Example 2 and Comparative Example 2 were observed. The content of each element (Cr, C, O, N) showed the same tendency to change as in Example 1.

Next, in the same manner as in Example 1, the values of the refractive index (n) and the extinction coefficient (k) of the phase shift film of Example 2 were measured by a spectroscopic ellipsometer. Further, the MSE of Example 2 was 4.498, and the MSE of Comparative Example 2 was 4.505.

Fig. 13 is a view showing the relationship between the refractive index (n) at a wavelength of 190 nm to 1000 nm in the upper portion of the main layer and the lower portion of the main layer of the phase shift film 3 of Example 2, and Fig. 14 shows the relationship with respect to Comparative Example 2 The relationship between the upper portion of the main layer of the phase shift film and the refractive index (n) at a wavelength of 190 nm to 1000 nm in the lower portion of the main layer, and Fig. 15 shows the phase shift mask with respect to Example 2 and Comparative Example 2. A plot of the refractive index at a wavelength of 365 nm from the outermost layer of the substrate to the lower portion of the main layer.

As shown in FIG. 13, it is understood that the refractive index of the upper portion of the main layer of the phase shift film 3 in the phase shift mask substrate 1 of the second embodiment is smaller than the refractive index of the lower portion of the main layer in the wavelength range. In particular, in the i-ray (wavelength 365 nm) which is one of the wavelengths of the light source for exposure (the ultrahigh pressure mercury lamp: mixed light of i-ray, h-ray, and g-ray) used for manufacturing the display device, the refractive index of the upper portion of the main layer For 2.43, the refractive index of the lower portion of the main layer is 2.57.

On the other hand, as shown in FIG. 14, it is understood that the refractive index of the upper portion of the main layer of the phase shift film in the phase shift mask substrate of Comparative Example 2 is substantially the same as the refractive index of the lower portion of the main layer in the wavelength range. Especially at the i-ray (wavelength 365 nm), the refractive index of the upper portion of the main layer was 2.59, and the refractive index of the lower portion of the main layer was 2.57.

Further, as shown in Fig. 15, in the second embodiment, as in the first embodiment, the tendency is shown in the outermost layer 3b of the phase shift film 3 to decrease the refractive index at a wavelength of 365 nm in the main layer 3a. In contrast, in Comparative Example 2, in the same manner as in Comparative Example 1, the following tendency was observed: in the outermost layer of the phase shift film, the refractive index at a wavelength of 365 nm increased. In the layer, the refractive index at a wavelength of 365 nm is reduced. As revealed from the results, it is understood that Example 2 in which the phase shift film 3 is formed by the downstream supply condition of the sputtering gas is compared with Comparative Example 2 in which the phase shift film is formed by the upstream supply condition of the sputtering gas. Even in the case of the VUV irradiation treatment, similarly to the relationship between the first embodiment and the comparative example 1, The tendency of the refractive index in the depth direction of the phase shift film to change becomes completely opposite.

Further, it is understood that in the second embodiment shown in Fig. 15, the refractive index at the wavelength of 365 nm of the outermost layer 3b of the phase shifting film 3 is made larger than that of the first embodiment of Fig. 9 in which the VUV irradiation step is not performed. The value is reduced from about 2.77 to about 2.70, so that the decrease in the refractive index tends to be small, and the tendency of the refractive index at the wavelength of 365 nm of the main layer 3a tends to be small.

On the other hand, in Comparative Example 2 shown in Fig. 15, it was found that the refractive index of the outermost layer of the phase shifting film, for example, at a wavelength of 365 nm, was compared with that of Comparative Example 1 of Fig. 9 in which the VUV irradiation step was not performed. The maximum value is reduced from about 2.5 to about 2.38, so that the tendency of the refractive index to rise is increased, and the decrease in the refractive index of the main layer, for example, at a wavelength of 365 nm, tends to be small or substantially flat.

With respect to the phase shift film of the phase shift mask base of Example 2 and Comparative Example 2, the film density of the outermost surface was measured by X-ray reflectance analysis (XRR) in the same manner as in Example 1. The film density on the outermost surface of Example 2 was 2.33 g/cm ³ , and the film density on the outermost surface of Comparative Example 2 was 2.29 g/cm ³ . Further, the numerical index Fit R indicating the appropriateness of the fitting when calculating the film density was 0.013 in Example 2 and 0.012 in Comparative Example 2.

Next, in the same manner as in Example 1, the phase shift film of the phase shift mask base of Example 2 and Comparative Example 2 was measured for transmittance, reflectance, and phase difference.

As a result, the transmittance at a wavelength of 365 nm of Example 2 was 5.1%, and the phase difference at a wavelength of 365 nm of Example 2 was 182.0 degrees. The reflectance spectrum of Example 2 was substantially the same as that of Example 1.

On the other hand, the transmittance at a wavelength of 365 nm of Comparative Example 2 was 5.4%, and the phase difference at a wavelength of 365 nm of Comparative Example 2 was 181.5 degrees. The reflectance spectrum of Comparative Example 2 was substantially the same as that of Example 1.

B. Phase shift mask and manufacturing method thereof

The phase shift masks of Example 2 and Comparative Example 2 were produced in the same manner as in Example 1 using the phase shift mask substrates of Example 2 and Comparative Example 2 produced as described above.

In this way, the phase substrate obtained by the VUV irradiation treatment is formed on the transparent substrate 2 The phase shift mask 30 (transparent substrate/phase shift film pattern) of the second embodiment of the phase shift film pattern 3' patterned by the transfer film 3 is formed.

On the other hand, in the same manner as in the second embodiment, the phase shift light of Comparative Example 2 in which the phase shift film pattern obtained by patterning the phase shift film subjected to the VUV irradiation treatment was formed on the transparent substrate 2 was obtained. Cover (transparent substrate / phase shift film pattern).

The etched cross section of the edge portion of the phase shift film pattern of the phase shift masks of Example 2 and Comparative Example 2 was observed by a scanning electron microscope before the resist pattern was peeled off.

The etched section of the edge portion of Example 2 shown in Fig. 16 has a resist interface angle of 90 degrees, a transparent substrate interface angle of 90 degrees, a tapered lower surface length of 0 nm, and a section angle (θ) of 90 degrees.

As revealed from the results, it is understood that the etched section in the embodiment 2 has a larger cross-sectional angle (θ) than the etched section in the first embodiment, and is closer to the vertical cross-sectional shape. That is, by the VUV irradiation treatment, the cross-sectional angle (θ) of the etched section of the edge portion becomes large.

The resist interface of the edge portion of Comparative Example 2 shown in Fig. 17 has an resist interface angle of 130 degrees, a transparent substrate interface angle of 50 degrees, a tapered lower surface length of 80 nm, and a section angle (θ) of 50 degrees.

As revealed from the results, it is understood that the etched cross section in Comparative Example 2 has a cross-sectional angle (θ) larger than that of the etched cross section in Comparative Example 1, and the tapered lower surface length is shortened to be slightly closer to the vertical cross-sectional shape. That is, by the VUV irradiation treatment, the cross-sectional angle (θ) of the etched section of the edge portion becomes large.

Next, CD unevenness of the phase shift film pattern of the phase shift masks of Example 2 and Comparative Example 2 was measured in the same manner as in Example 1.

The CD unevenness of Example 2 was relatively good and was 0.059 μm. As revealed from the results, it was found that the CD unevenness of Example 2 was smaller than that of Example 1 in which the VUV irradiation step was not accepted.

On the other hand, the CD unevenness of Comparative Example 2 was 0.156 μm. As revealed from the results, it is understood that the CD unevenness of Comparative Example 2 is smaller than the CD unevenness of Comparative Example 1 which does not receive the VUV irradiation step, but the CD unevenness of Examples 1 and 2 of the downstream supply conditions of the sputtering gas is not uniform. More than big.

Next, the light intensity distribution curve (transmittance distribution) at a wavelength of 365 nm was examined in the same manner as in Example 1.

The light intensity distribution curve of Example 2 showed a case where it had a sharp peak intensity at the center of the contact hole and a large change in light intensity at the boundary portion of the pattern, and the peripheral region on the outer side of the boundary portion of the pattern, compared with Comparative Example 2. The light intensity changes little. Therefore, it is understood that the phase shift mask of the second embodiment exhibits a stronger light intensity gradient than that of Comparative Example 2, and the resolution is high.

Example 3 and Comparative Example 3.

In the third embodiment and the third comparative example, a phase shift mask substrate having a phase shift film 3 (material: CrON) and a phase shift mask manufactured using the phase shift mask substrate will be described.

Further, in the phase shift mask substrate 1 of the third embodiment, the phase shift film 3 was formed by the downstream supply conditions of the sputtering gas in the same manner as in the first embodiment, and the phase of the comparative example 3 was produced. In the same manner as in Comparative Example 1, the offset mask base was produced by film-forming a phase shift film under the upstream supply conditions of the sputtering gas, and the two were different in this respect.

A. Phase shift mask substrate and method of manufacturing the same

A synthetic quartz glass substrate having the same dimensions as in Example 1 was prepared as the transparent substrate 2.

Thereafter, the transparent substrate 2 is introduced into the continuous sputtering apparatus 11 shown in FIG. 2, and a phase shift film 3 containing chromium oxynitride (CrON) is formed on the main surface of the transparent substrate 2 by one film formation. (film thickness 157 nm), thereby obtaining a phase shift mask substrate 1.

The phase shift film 3 introduces a mixed gas containing argon (Ar) and nitrogen monoxide (NO) gas from the second gas introduction port GA12 on the downstream side of the first sputtering target 13 containing chromium (Ar: 46). Sccm, NO: 50 sccm), the sputtering power was set to 3.5 kw, and the transport speed of the transparent substrate 2 was set to 400 mm/min, and film formation was performed on the transparent substrate 2 by reactive sputtering.

On the other hand, in the comparative example 3, in the phase shift film forming step, the first gas introduction port GA11 disposed on the upstream side of the first sputtering target 13 including chromium from the sputtering apparatus 11 shown in FIG. A mixed gas of the same composition as in Example 3 was introduced, and the sputtering power was set to 7.85 kW. The film formation conditions other than this were such that the phase shift film 3 (film thickness: 157 nm) was formed by one film formation in the same manner as in Example 3, and the phase shift mask substrate of Comparative Example 3 was obtained.

In the phase shift film of the phase shift mask substrate of Example 3 and Comparative Example 3, the composition analysis in the depth direction by XPS revealed that both of Example 3 and Comparative Example 3 were in the depth direction. The content of each element (Cr, O, N) is substantially constant in the main layer, and changes in the same tendency as in the first embodiment in the outermost layer and the interface region close to the transparent substrate 2.

Next, the refractive index (n) and the extinction coefficient (k) of the phase shift film 3 of Example 3 and Comparative Example 3 were measured by a spectroscopic ellipsometer in the same manner as in Example 1. Further, the MSE of Example 3 was 4.458, and the MSE of Comparative Example 3 was 4.500.

Next, in the same manner as in Example 1, the refractive index, the transmittance, the reflectance, and the phase difference of the phase shift film of the phase shift mask base of Example 3 and Comparative Example 3 were measured.

As a result, the refractive index of the upper portion of the main layer at i-ray (wavelength 365 nm) of Example 3 was 2.42, and the refractive index of the lower portion of the main layer was 2.56. The transmittance at a wavelength of 365 nm of Example 3 was 5.6%, and the phase difference at a wavelength of 365 nm of Example 3 was 179 degrees. The reflectance spectrum of Example 3 was substantially the same as that of Example 1.

On the other hand, in the i-ray (wavelength 365 nm) of Comparative Example 3, the refractive index of the upper portion of the main layer was 2.61, and the refractive index of the lower portion of the main layer was 2.49. The transmittance at a wavelength of 365 nm of Comparative Example 3 was 6.0%, and the phase difference at a wavelength of 365 nm of Comparative Example 3 was 178 degrees. The reflectance spectrum of Comparative Example 3 was substantially the same as that of Example 3.

With respect to the outermost surfaces of the phase shifting films of the phase shift mask substrates of Example 3 and Comparative Example 3, the film density was measured by X-ray reflectance analysis (XRR) in the same manner as in Example 1, and as a result, Example 3 was obtained. The film density at the outermost surface was 1.84 g/cm ³ , and the film density at the outermost surface of Comparative Example 3 was 1.82 g/cm ³ . Further, the numerical index Fit R indicating the appropriateness of the fitting when calculating the film density was 0.011 in Example 3 and 0.013 in Comparative Example 3.

B. Phase shift mask and manufacturing method thereof

The phase shift masks of Example 3 and Comparative Example 3 were produced in the same manner as in Example 1 using the phase shift mask substrates of Example 3 and Comparative Example 3 produced as described above.

Thus, the phase shift mask 30 (transparent substrate/phase shift film pattern) of the third embodiment in which the phase shift film pattern 3' is formed on the transparent substrate 2 is obtained, and the phase shift film pattern 3' is made The phase shift film 3 which is formed by filming downstream of the sputtering gas and which has not been subjected to the VUV irradiation step is patterned.

On the other hand, a phase shift mask (transparent substrate/phase shift film pattern) of Comparative Example 3 in which a phase shift film pattern is formed on the transparent substrate 2 is obtained, which is a sputtering gas pattern The phase shift film obtained by the upstream supply condition film formation and not subjected to the VUV irradiation step is patterned.

The etched cross section of the edge portion of the phase shift film pattern of the phase shift masks of Example 3 and Comparative Example 3 was observed by a scanning electron microscope before the resist pattern was peeled off.

The resist interface of the edge portion of Example 3 had a resist interface angle of 105 degrees, a transparent substrate interface angle of 45 degrees, a tapered lower surface length of 65 nm, and a section angle (θ) of 75 degrees.

On the other hand, in the edge portion of Comparative Example 3, the resist interface angle of the etched section was 140 degrees, the transparent substrate interface angle was 40 degrees, the tapered lower surface length was 150 nm, and the sectional angle (θ) was 40 degrees.

As revealed from the results, it is understood that the etched section in Example 3 has a section angle (θ) which is particularly large as compared with the etched section in Comparative Example 3, and the section shape of Comparative Example 3 It becomes a tapered shape that is dragged under the length of the third embodiment.

Next, in the same manner as in Example 1, the CD unevenness of the phase shift film pattern of the phase shift masks of Example 3 and Comparative Example 3 was measured.

The CD unevenness of Example 3 was relatively good, and was 0.106 μm. On the other hand, the CD of Comparative Example 3 was not 0.175 μm.

Next, the light intensity distribution curve (transmittance distribution) at a wavelength of 365 nm was examined in the same manner as in Example 1.

The light intensity distribution curve of Example 3 showed a case where it had a sharp peak intensity at the center of the contact hole and a large change in light intensity at the boundary portion of the pattern, and the peripheral region on the outer side of the boundary portion of the pattern, compared with Comparative Example 3. The light intensity changes little. Therefore, it is understood that the phase shift mask of the third embodiment exhibits a stronger light intensity gradient than that of Comparative Example 3, and exhibits a high resolution.

Example 4.

In the fourth embodiment, the phase shift mask substrate having the phase shift film 3 subjected to the VUV irradiation treatment in the same manner as in the second embodiment, using CrON as a constituent material in the same manner as in the third embodiment, and the phase shift mask are used. The phase shift mask manufactured by the substrate will be described.

A. Phase shift mask substrate and method of manufacturing the same

A synthetic quartz glass substrate having the same dimensions as in Example 1 was prepared as the transparent substrate 2.

Thereafter, the transparent substrate 2 is introduced into the continuous sputtering apparatus 11 shown in FIG. 2, and a phase shift film containing chromium oxynitride (CrON) is formed on the main surface of the transparent substrate 2 by one film formation. 3 (film thickness 157 nm), thereby obtaining a phase shift mask substrate 1.

The phase shift film 3 is introduced from a second gas introduction port GA12 on the downstream side of the first sputtering target 13 containing chromium, and a mixed gas containing Ar gas (Ar) and nitrogen monoxide (NO) gas is introduced (Ar: 46 sccm, NO: 70 sccm), the sputtering power was set to 8.0 kW, the transport speed of the transparent substrate 2 was set to 400 mm/min, and film formation was performed on the transparent substrate 2 by reactive sputtering.

Thereafter, the outermost surface of the phase shift film 3 was subjected to the same irradiation conditions as in the second embodiment. VUV irradiation treatment.

In this manner, the phase shift mask substrate 1 on which the phase shift film 3 subjected to the VUV irradiation treatment is formed on the transparent substrate 2 is obtained.

When the phase shift film 3 of the phase shift mask substrate 1 of the fourth embodiment was subjected to composition analysis in the depth direction by XPS, it was found that the content of each element (Cr, O, N) in the depth direction was the same as that of the third embodiment. The tendency to change.

Next, in the same manner as in the first embodiment, the values of the refractive index (n) and the extinction coefficient (k) of the phase shift film 3 of the third embodiment were measured by a spectroscopic ellipsometer. Further, the MSE of Example 4 was 4.489.

Next, in the same manner as in the first embodiment, the refractive index, the transmittance, the reflectance, and the phase difference of the phase shift film 3 of the phase shift mask base 1 of Example 4 were measured.

As a result, the refractive index of the upper portion of the main layer at i-ray (wavelength 365 nm) of Example 4 was 2.45, and the refractive index of the lower portion of the main layer was 2.53. The transmittance at a wavelength of 365 nm of Example 4 was 5.7%, and the phase difference at a wavelength of 365 nm of Example 4 was 179 degrees. The reflectance spectrum of Example 4 was substantially the same as that of Example 3.

With respect to the outermost surface of the phase shift film 3 of the phase shift mask substrate 1 of Example 4, the film density was measured by X-ray reflectance analysis (XRR) in the same manner as in Example 1, and as a result, the film density at the outermost surface was measured. It is 2.19 g/cm ³ . Further, the numerical value Fit R which indicates the appropriateness of the fitting when calculating the film density was 0.013 in Example 4.

B. Phase shift mask and manufacturing method thereof

In the same manner as in the first embodiment, the phase shift mask 30 in which the phase shift film pattern 3' obtained by patterning the phase shift film 3 subjected to the VUV irradiation treatment is formed on the transparent substrate 2 is obtained.

The etched cross section of the edge portion of the phase shift film pattern 3' of the phase shift mask 30 of Example 4 was observed by a scanning electron microscope before the resist pattern 5' was peeled off.

As a result, the resist interface angle of the etched section of the edge portion of Example 4 was At 90 degrees, the interface angle of the transparent substrate is 90 degrees, the length of the lower surface of the cone is 0 nm, and the angle of the section (θ) is 90 degrees. That is, the etched profile of the phase shift film pattern 3' of Example 4 which is subjected to VUV irradiation treatment using CrON as a constituent material and the phase shift film of Example 3 which is a constituent material of CrON and which is not subjected to the VUV irradiation step The etched section of the pattern 3' is likewise completely devoid of hem and completely has a vertical cross-sectional shape.

Next, in the same manner as in the first embodiment, the CD unevenness of the phase shift film pattern of the phase shift mask 30 of the fourth embodiment was measured.

The CD unevenness was good and was 0.062 μm.

Next, the light intensity distribution curve (transmittance distribution) at a wavelength of 365 nm was examined in the same manner as in Example 1.

The light intensity distribution curve of Example 4 showed a light intensity gradient similar to that of the phase shift mask of Example 2, and it was found that the resolution was high.

In the above embodiment, the phase shift film 3 formed on the transparent substrate 2 is exemplified as a phase shift mask substrate 1 of a single layer film, but the invention is not limited thereto. Even if it is a laminated film of a two-layer structure, a three-layer structure, or a four-layer structure in which the phase shift film 3 is made of the same material, the same effects as those of the above-described embodiment are exhibited.

Further, in the above embodiment, the phase shift mask substrate 1 in which only the phase shift film 3 is formed on the transparent substrate 2, and the phase shift light in which only the phase shift film pattern 3' is formed on the transparent substrate 2 The cover 30 has been described as an example, but is not limited thereto. When the phase of the light-shielding film pattern 4 ′ and the phase shift film 3 is shifted on the transparent substrate 2 (see FIG. 4 ), the phase shift film 3 and the resist film 5 are provided on the transparent substrate 2 . When the phase is shifted by the mask substrate (see FIG. 5(b)), the phase shift mask 31 having the light shielding film pattern 4' and the phase shift film pattern 3' on the transparent substrate 2 (refer to FIG. 6 In the case of e)), the same effects as those of the above embodiment can be exerted.

Further, the phase shift mask substrate (not shown) having the phase shift film 3 and the light shielding film 4 on the transparent substrate 2 may be provided with the light shielding film 4 formed on the phase shift film 3 as a light blocking film. A layered structure of a layer, a light shielding layer, and an antireflection layer.

Further, in the above-described embodiment, the phase shift mask substrate for display device manufacturing or the phase shift mask for display device manufacturing has been described, but the invention is not limited thereto. The phase shift mask base or phase shift mask of the present invention can also be applied to semiconductor device manufacturing, MEMS (Micro Electro Mechanical Systems) manufacturing, printed circuit boards, and the like.

Further, in the above embodiment, the example in which the size of the transparent substrate is 8092 (800 mm × 920 mm) has been described. However, the present invention is not limited thereto, and may be other sizes. In the case of a phase shift mask substrate for display device manufacturing, a large transparent substrate having a length of one side of 10 inches or more and a transparent substrate used for a phase shift mask substrate for display device manufacturing is used. The size is, for example, 330 mm × 450 mm or more and 2280 mm × 3130 mm or less.

Further, in the case of a semiconductor device manufacturing, a MEMS manufacturing, or a phase shifting mask substrate for a printed circuit board, a small transparent substrate having a length of one side of 9 inches or less is used. The size of the transparent substrate used for the phase shift mask substrate for the above use is, for example, 63.1 mm × 63.1 mm or more and 228.6 mm × 228.6 mm or less. Generally, for semiconductor manufacturing and MEMS manufacturing, 6025 size (152 mm × 152 mm) or 5009 size (126.6 mm × 126.6 mm) is used, and for printed circuit boards, 7012 size (177.4 mm × 177.4 mm) or 9012 size (228.6 mm) is used. ×228.6mm).

1‧‧‧ phase shift mask base

2‧‧‧Transparent substrate

3‧‧‧ phase offset film

3a‧‧‧main floor

3b‧‧‧ the most surface layer

Claims (11)

A phase shift mask substrate characterized in that a phase shift film containing chromium, oxygen and nitrogen is formed on a transparent substrate, and the phase shift film has a main layer containing the same material and an outermost surface The layer has a refractive index at a wavelength of 365 nm at the upper portion of the main layer on the outermost layer side and a refractive index at a wavelength of 365 nm at a lower portion of the main layer on the transparent substrate side. The phase shift mask substrate according to claim 1, wherein a refractive index at a wavelength of 365 nm in the lower portion of the main layer is 2.50 or more, and a refractive index at a wavelength of 365 nm in the upper portion of the main layer is 2.45 or less. The phase shift mask substrate according to claim 1 or 2, wherein a difference between a refractive index at a wavelength of 365 nm in the upper portion of the main layer and a refractive index at a wavelength of 365 nm in a lower portion of the main layer is 0.05 or more and 0.25 or less. The phase shift mask substrate of claim 1 or 2, wherein the film density of the outermost layer is 2.0 g/cm ³ or more. The phase shift mask substrate of claim 1 or 2 wherein the phase shifting film further contains carbon. A method for manufacturing a phase shift mask substrate, characterized in that the phase shift film containing chromium, oxygen and nitrogen is formed on a transparent substrate by a sputtering method using a continuous sputtering device, and the phase The method for manufacturing an offset mask substrate has a film forming step of forming a phase shift film having a main layer and a topmost layer of the same material on the transparent substrate, wherein the film forming step uses a sputtering target containing chromium And supplying an inert gas and an active gas for oxidizing and nitriding the phase shifting film to the downstream side of the sputtering target in a transport direction of the transparent substrate in the vicinity of the sputtering target, and using the active gas by using Reactive splash of a mixture of the above inert gas and the above reactive gas Plating is carried out to form a film. The method of manufacturing a phase shift mask substrate according to claim 6, wherein a refractive index at a wavelength of 365 nm of the upper portion of the main layer on the outermost layer side is smaller than a refractive index at a wavelength of 365 nm at a lower portion of the main layer on the transparent substrate side. . A method of producing a phase shift mask substrate according to claim 6 or 7, wherein after the film forming step, a vacuum ultraviolet ray irradiation step of subjecting the outermost surface of the phase shift film to vacuum ultraviolet ray irradiation is performed. A method of producing a phase shift mask substrate according to claim 8, wherein in the vacuum ultraviolet irradiation step, a film density of the outermost surface of the phase shift film is changed to 2.0 g/cm ³ or more. A method of manufacturing a phase shift mask substrate according to claim 6 or 7, wherein said mixed gas further comprises an active gas which carbonizes said phase shift film. A method of manufacturing a phase shift mask, characterized by the phase shift mask substrate according to any one of claims 1 to 5, or by phase shifting according to any one of claims 6 to 10. Forming a resist pattern on the phase shift film of the phase shift mask substrate produced by the method of manufacturing the mask base, and performing wet etching on the phase shift film using the resist pattern as a mask A phase shift film pattern is formed on the transparent substrate.