CN117518704A - Phase shift mask blank, method for manufacturing phase shift mask using the same, and method for manufacturing display device - Google Patents

Phase shift mask blank, method for manufacturing phase shift mask using the same, and method for manufacturing display device Download PDF

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Publication number
CN117518704A
CN117518704A CN202311459935.1A CN202311459935A CN117518704A CN 117518704 A CN117518704 A CN 117518704A CN 202311459935 A CN202311459935 A CN 202311459935A CN 117518704 A CN117518704 A CN 117518704A
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phase shift
film
layer
metal
pattern
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坪井诚治
安森顺一
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Hoya Corp
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Hoya Corp
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Priority claimed from CN201810034453.4A external-priority patent/CN108319103B/en
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    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03FPHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F1/00Originals for photomechanical production of textured or patterned surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles therefor; Containers specially adapted therefor; Preparation thereof
    • G03F1/26Phase shift masks [PSM]; PSM blanks; Preparation thereof
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03FPHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F1/00Originals for photomechanical production of textured or patterned surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles therefor; Containers specially adapted therefor; Preparation thereof
    • G03F1/66Containers specially adapted for masks, mask blanks or pellicles; Preparation thereof
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03FPHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F1/00Originals for photomechanical production of textured or patterned surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles therefor; Containers specially adapted therefor; Preparation thereof
    • G03F1/68Preparation processes not covered by groups G03F1/20 - G03F1/50
    • G03F1/80Etching
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03FPHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/004Photosensitive materials
    • G03F7/09Photosensitive materials characterised by structural details, e.g. supports, auxiliary layers
    • G03F7/091Photosensitive materials characterised by structural details, e.g. supports, auxiliary layers characterised by antireflection means or light filtering or absorbing means, e.g. anti-halation, contrast enhancement
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03FPHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70Microphotolithographic exposure; Apparatus therefor
    • G03F7/708Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
    • G03F7/7095Materials, e.g. materials for housing, stage or other support having particular properties, e.g. weight, strength, conductivity, thermal expansion coefficient
    • G03F7/70958Optical materials or coatings, e.g. with particular transmittance, reflectance or anti-reflection properties

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  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Epidemiology (AREA)
  • Public Health (AREA)
  • Architecture (AREA)
  • Structural Engineering (AREA)
  • Preparing Plates And Mask In Photomechanical Process (AREA)
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Abstract

The present invention provides a phase shift mask blank for forming a phase shift mask for a display device, which has excellent pattern cross-sectional shape and excellent CD uniformity, and forms a fine pattern to make transfer accuracy good. The phase shift mask blank includes a phase shift film formed of a metal material or a metal silicide material on a transparent substrate, the phase shift film including a phase shift layer, an antireflection layer disposed on an upper side of the phase shift layer, and an intermediate layer disposed between the phase shift layer and the antireflection layer, the intermediate layer being a metal material having a higher metal content than that of the antireflection layer or a metal silicide material having a higher total content than that of the metal and silicon of the antireflection layer, the film surface reflectance of the phase shift film being 15% or less in a wavelength range of 350nm to 436nm, and the back surface reflectance of the phase shift film being 20% or less in a wavelength range of 365nm to 436nm with respect to light incident from the transparent substrate side.

Description

Phase shift mask blank, method for manufacturing phase shift mask using the same, and method for manufacturing display device
The present application is a divisional application of application having a date of application of 2018, 1-15, application No. 201810034453.4, and entitled "method of manufacturing a phase shift mask blank and a phase shift mask using the same, and method of manufacturing a display device".
Technical Field
The present invention relates to a phase shift mask blank, a method for manufacturing a phase shift mask using the same, and a method for manufacturing a display device.
Background
In recent years, with high resolution and high definition of display devices such as FPDs (flat panel displays and Flat Panel Display), a phase shift mask for display devices having an excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern formed thereon has been demanded.
In addition, due to the low price of a display device such as an FPD, it is necessary to reduce the manufacturing cost of a phase shift mask. In the case of a conventional phase shift mask blank in which a light shielding film is formed on a phase shift film, a resist film pattern is used as a mask to etch the light shielding film to form a light shielding film pattern, then the light shielding film pattern is used as a mask to etch the phase shift film to form a phase shift film pattern, and then the resist film pattern is peeled off to peel off the light shielding film pattern, thereby manufacturing a phase shift mask having the phase shift film pattern. On the other hand, in the case of a phase shift mask blank in which the light shielding film is not formed on the phase shift film, the formation step and the peeling step of the light shielding film pattern on the phase shift film are not required, and the manufacturing cost can be reduced.
In response to such recent circumstances, there is a demand for a phase shift mask for a display device, which is manufactured using a phase shift mask blank having no light shielding film formed on a phase shift film, has an excellent pattern cross-sectional shape and excellent CD uniformity, and has a fine pattern formed thereon.
For example, patent document 1 proposes a phase shift mask blank for a display device having a phase shift film in which 2 or more thin films are laminated on a transparent substrate. The respective films constituting the phase shift film have different compositions, but each contains a substance that can be etched by the same etching liquid, and have different etching rates due to the different compositions. In patent document 1, the etching rate of each thin film constituting the phase shift film is adjusted so that the cross section of the edge portion where the phase shift film pattern is formed significantly is inclined when the phase shift film is patterned.
Patent document 1 also proposes a phase shift mask blank for a display device, in which a functional film including one or more films necessary for a transfer pattern represented by a light shielding film, a semi-transmissive film, an etching stopper film, and a hard mask film is disposed on the upper or lower portion of a phase reversal film.
Prior art literature
Patent literature
Patent document 1: japanese patent laid-open publication No. 2014-26681
Disclosure of Invention
Problems to be solved by the invention
The phase shift film used in the phase shift mask for display device proposed in the past is not designed in consideration of the influence of reflection of laser drawing light used in patterning of a resist film for forming a phase shift film pattern on the resist film, and therefore, the film surface reflectance of the phase shift film to the laser drawing light exceeds 20%. As a result, standing waves are generated in the resist film, and the CD uniformity of the resist film pattern is degraded, and the CD uniformity of the phase shift film pattern formed by patterning the resist film pattern as a mask may not satisfy the value required in recent years.
The phase shift film used in the phase shift mask for display device proposed in the past is not designed in consideration of the influence of reflection from the optical system of the exposure device, the surface film attached to the phase shift mask, and reflection from the display device substrate. Therefore, there are the following problems: when a phase shift mask for a display device is used and a pattern formed on the phase shift mask is transferred, diffusion (flare) of a transferred pattern due to reflected light from a display device substrate occurs, and there is a risk that transfer accuracy is deteriorated or a CD error of the transferred pattern transferred onto the display device substrate occurs.
Accordingly, the present invention has been made in view of the above-described problems, and an object of the present invention is to provide a phase shift mask blank for forming a phase shift mask for a display device, which has a film surface reflectance for light in a wavelength range of 350nm to 436nm used as laser drawing light and a back surface reflectance for light in a wavelength range of 365nm to 436nm used as exposure light, thereby having an excellent pattern cross-sectional shape and excellent CD uniformity, and forming a fine pattern, thereby improving transfer accuracy, and a method for manufacturing a phase shift mask using the same. Further, the present invention is directed to a method for manufacturing a high-resolution and high-definition display device, which uses a phase shift mask for a display device having an excellent pattern cross-sectional shape and excellent CD uniformity, and which has a fine pattern formed, thereby improving transfer accuracy, and which does not cause CD errors.
Means for solving the problems
The present inventors have made intensive studies to achieve the above object, and as a result, have obtained the following findings: by forming the phase shift film in at least 3 layers and designing the composition and film thickness of each layer constituting the phase shift film, it is possible to satisfy the predetermined optical characteristics required for the phase shift film as the transmittance and phase difference of the exposure light, and it is also possible to reduce the film surface reflectance of the phase shift film for light in the wavelength range of 350nm to 436nm and the back surface reflectance for light in the wavelength range of 365nm to 436 nm.
The present invention has been made based on this knowledge, and has the following configuration.
(constitution 1)
A phase shift mask blank comprising a phase shift film on a transparent substrate,
the phase shift film is composed of at least one of a metal-based material containing 1 or more metals and at least one selected from the group consisting of oxygen, nitrogen, and carbon, or a metal silicide-based material containing 1 or more metals, silicon, and at least one selected from the group consisting of oxygen, nitrogen, and carbon,
the phase shift film has a phase shift layer having mainly a function of adjusting transmittance and phase difference with respect to exposure light, an antireflection layer disposed on an upper side of the phase shift layer having mainly a function of reducing reflectance with respect to light incident from the phase shift film side, and an intermediate layer disposed between the phase shift layer and the antireflection layer,
the intermediate layer is a metal-based material having a metal content higher than that of the antireflection layer, or a metal silicide-based material having a total content higher than that of the metal content of the antireflection layer or the total content of the metal and silicon of the antireflection layer,
By the laminated structure of the phase shift layer, the intermediate layer, and the antireflection layer, the phase shift film has given optical characteristics for transmittance and phase difference of exposure light,
the phase shift film has a film surface reflectance with respect to light incident from the phase shift film side of
The wavelength range of 350nm to 436nm is 15% or less, and the back surface reflectance of the phase shift film with respect to light incident from the transparent substrate side is 20% or less in the wavelength range of 365nm to 436 nm.
(constitution 2)
The phase shift mask blank according to the above configuration 1, wherein the phase shift film is made of a material that can be etched by the same etchant.
(constitution 3)
The phase shift mask blank according to the above constitution 1 or 2, wherein the metal is chromium.
(constitution 4)
The phase shift mask blank according to the above configuration 3, wherein the phase shift layer and the antireflection layer are made of a chromium-based material containing chromium, oxygen and nitrogen, wherein the chromium is 30 to 70 atomic%, the oxygen is 20 to 60 atomic%, and the nitrogen is 0.4 to 30 atomic%, the nitrogen content of the phase shift layer is the same as or higher than the nitrogen content of the antireflection layer, the oxygen content of the antireflection layer is higher than the oxygen content of the phase shift layer,
The intermediate layer contains chromium and carbon, the content of chromium is 55 to 90 atomic percent, the content of carbon is 10 to 45 atomic percent, and the content of chromium in the intermediate layer is higher than the content of chromium in the phase shift layer and the antireflection layer.
(constitution 5)
The phase shift mask blank according to the above constitution 3 or 4, wherein the phase shift layer comprises chromium nitride or chromium nitride,
the anti-reflection layer comprises chromium (III) oxide bonded by chromium and oxygen.
(constitution 6)
The phase shift mask blank according to any one of the above configurations 3 to 5, wherein the intermediate layer is made of a chromium-based material further containing oxygen,
the phase shift layer, the intermediate layer, and the anti-reflection layer comprise chromium (III) oxide bonded with chromium and oxygen.
(constitution 7)
The phase shift mask blank according to the above configuration 1 or 2, wherein the phase shift layer is made of a metal silicide material containing at least one of oxygen and nitrogen, and the antireflection layer is made of a metal material containing at least one of oxygen and nitrogen.
(constitution 8)
The phase shift mask blank according to the above configuration 7, wherein the metal silicide material is a molybdenum silicide material, a zirconium silicide material, a titanium silicide material, or a molybdenum zirconium silicide material.
(constitution 9)
The phase shift mask blank according to the above configuration 1, wherein one or both of the phase shift layer, the intermediate layer, and the antireflection layer are made of a material having etching selectivity to the other layers.
(constitution 10)
The phase shift mask blank according to the above configuration 9, wherein the phase shift layer and the intermediate layer are made of a material containing a chromium-based material, and the antireflection layer is made of a metal-based material having etching selectivity to the phase shift layer and the intermediate layer.
(constitution 11)
The phase shift mask blank according to the above configuration 10, wherein the antireflection layer is made of a titanium-based material containing titanium and any one of oxygen and nitrogen.
(constitution 12)
The phase shift mask blank according to any one of the above configurations 1 to 11, wherein a light shielding film pattern is provided between the transparent substrate and the phase shift film.
(constitution 13)
The phase shift mask blank according to the above configuration 12, wherein the back surface reflectance of the light shielding film pattern with respect to the light incident from the transparent substrate side is 20% or less in a wavelength range of 365nm to 436 nm.
(constitution 14)
The phase shift mask blank according to any one of the above configurations 1 to 11, wherein the phase shift film has a light shielding film thereon, and the light shielding film has a film surface reflectance of 15% or less in a wavelength range of 350nm to 436 nm.
(constitution 15)
A method of fabricating a phase shift mask, the method comprising:
forming a resist film on the phase shift film of the phase shift mask blank of any one of the above configurations 1 to 8, 12, and 13, and forming a resist film pattern on the resist film by a drawing process and a developing process; and
and etching the phase shift film using the resist film pattern as a mask to form a phase shift film pattern on the transparent substrate.
(constitution 16)
A method of fabricating a phase shift mask, the method comprising:
forming a resist film on the phase shift film of the phase shift mask blank according to any one of the above configurations 9 to 13, and forming a resist film pattern on the resist film by a drawing process using a laser beam and a developing process;
etching the anti-reflection layer using the resist film pattern as a mask to form an anti-reflection layer pattern; and
and etching the intermediate layer and the phase shift layer using the anti-reflection layer pattern as a mask, thereby forming a phase shift film pattern on the transparent substrate.
(constitution 17)
A method of fabricating a phase shift mask, the method comprising:
Forming a resist film on the light shielding film of the phase shift mask blank according to the above configuration 14, and forming a resist film pattern on the resist film by a drawing process and a developing process;
etching the light shielding film using the resist film pattern as a mask to form a light shielding film pattern on the phase shift film; and
and etching the phase shift film using the light shielding film pattern as a mask, thereby forming a phase shift film pattern on the transparent substrate.
(constitution 18)
A method of manufacturing a display device, the method comprising:
a step of placing the phase shift mask obtained by the method for manufacturing a phase shift mask according to any one of the above configurations 15 to 17 on a mask stage of an exposure apparatus; and
and a step of irradiating the phase shift mask with exposure light and transferring the phase shift film pattern to a resist film formed on a display device substrate.
(constitution 19)
The method for manufacturing a display device according to the above constitution 18, wherein the exposure light is a composite light including light having a plurality of wavelengths selected from a wavelength range of 313nm to 436 nm.
ADVANTAGEOUS EFFECTS OF INVENTION
As described above, the phase shift mask blank according to the present invention is a phase shift mask blank comprising a phase shift film on a transparent substrate, the phase shift film being made of at least one of a metal material containing 1 or more metals and at least one selected from oxygen, nitrogen and carbon, or a metal silicide material containing 1 or more metals, silicon and at least one selected from oxygen, nitrogen and carbon, the phase shift film having a phase shift layer having a function of adjusting transmittance and a phase difference with respect to exposure light, an antireflection layer disposed on an upper side of the phase shift layer and having a function of reducing reflectance with respect to light incident from the phase shift film side, and an intermediate layer disposed between the phase shift layer and the antireflection layer, the intermediate layer is a metal-based material having a metal content higher than that of the antireflection layer, or a metal silicide-based material having a total content higher than that of the metal content of the antireflection layer or that of the metal and silicon of the antireflection layer, and the phase shift film has given optical characteristics for transmittance and retardation of exposure light by a laminated structure of the phase shift layer, the intermediate layer, and the antireflection layer, the film surface reflectance of the phase shift film for light incident from the phase shift film side is 15% or less in a wavelength range of 350nm to 436nm, and the back surface reflectance of the phase shift film for light incident from the transparent substrate side is 20% or less in a wavelength range of 365nm to 436 nm. Therefore, using the phase shift mask blank, a phase shift mask having excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern formed therein can be manufactured so that transfer accuracy is improved. In addition, by using the phase shift mask, a high-resolution and high-definition display device which does not cause CD errors can be manufactured.
Drawings
Fig. 1 is a schematic diagram showing a film constitution of a phase shift mask blank.
Fig. 2 is a schematic diagram showing another film configuration of the phase shift mask blank.
Fig. 3 is a schematic diagram showing another film configuration of the phase shift mask blank.
Fig. 4 is a film surface reflectance spectrum of the phase shift film of the phase shift mask blank of examples 1, 2, and comparative example 1.
Fig. 5 is a back surface reflectance spectrum of the phase shift film of the phase shift mask blank of examples 1, 2, comparative example 1.
Fig. 6 is a graph showing the results of composition analysis of the phase shift mask blank of example 1 with respect to the phase shift film in the depth direction.
Symbol description
10 phase shift mask blank
20 transparent substrate
30 phase shift film
31 phase shift layer
32 antireflection layer
33 metal layer
40 shading film pattern
41 backside anti-reflection layer
42 light shielding layer
45 shading film
46 light shielding layer
47 surface anti-reflection layer
Detailed Description
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiment is one embodiment for embodying the present invention, and the present invention is not limited to this range. In the drawings, the same or equivalent portions are denoted by the same reference numerals, and description thereof may be simplified or omitted.
Embodiment 1 (embodiments 1-1, 1-2, 1-3)
A phase shift mask blank according to embodiment 1 will be described.
Fig. 1 is a schematic diagram showing a film structure of a phase shift mask blank 10 according to embodiment 1-1. The phase shift mask blank 10 has: a transparent substrate 20 transparent to exposure light, and a phase shift film 30 disposed on the transparent substrate 20. The transparent substrate 20 has a transmittance of 85% or more, preferably 90% or more, with respect to exposure light when no surface reflection is lost.
The phase shift film 30 is made of a metal-based material containing 1 or more metals and at least one selected from oxygen, nitrogen, and carbon, or a metal silicide-based material containing 1 or more metals, silicon, and at least one selected from oxygen, nitrogen, and carbon.
Examples of the metal contained in the metal-based material include typical metals such as transition metals including chromium (Cr), zr (zirconium), molybdenum (Mo), tantalum (Ta), tungsten (W), and titanium (Ti), and aluminum (Al).
Examples of the metal silicide material include: nitride of metal silicide, oxide of metal silicide, oxidized nitride of metal silicide, carbonized nitride of metal silicide, oxidized carbonized nitride of metal silicide, and oxidized carbonized nitride of metal silicide. Examples of the metal contained in the metal silicide material include the transition metal and typical metals described above.
The phase shift film 30 has, in order from the transparent substrate 20 side, a phase shift layer 31, a metal layer 33 as an intermediate layer, and an antireflection layer 32.
As described in detail in the embodiment, the phase shift film 30 may be formed of a metal-based material for each of the phase shift layer 31, the antireflection layer 32, and the metal layer 33 (embodiments 1 and 2), or may be formed of a metal-based material for one or both of the phase shift layer 31, the antireflection layer 32, and the metal layer 33, and a metal silicide-based material for the other layers (embodiment 3).
The phase shift layer 31 is disposed on the main surface of the transparent substrate 20. The phase shift layer 31 has a function of adjusting transmittance and phase difference of exposure light. In the phase shift film 30, the phase shift layer 31 is the layer having the thickest film thickness than the film thicknesses of the antireflection layer 32 and the metal layer 33. The content of each element constituting the phase shift layer 31, the metal layer 33, and the antireflection layer 32 described later is a value measured by X-ray photoelectron spectroscopy (XPS, ESCA).
The phase shift layer 31 is made of a metal material or a metal silicide material.
When the phase shift film 30 is entirely made of a chromium (Cr) based material, the phase shift layer 31 is preferably made of a chromium (Cr) based material containing chromium (Cr) oxygen (O) and nitrogen (N), and the average content of each element is as follows: chromium 30 to 70 atomic percent, oxygen 20 to 60 atomic percent, and nitrogen 0.4 to 30 atomic percent. The phase shift layer 31 contains chromium nitride in which chromium and nitrogen are bonded in a bonding state (chemical state) of the components constituting the phase shift layer 31, and particularly preferably contains chromium nitride (CrN) or chromium nitride (Cr) 2 N). In addition, the phase shift layer 31 may also haveChromium-based material containing at least one of carbon (C) and fluorine (F). For example, as a material for forming the phase shift layer 31, crON, crOCN, crFCON can be given.
In the case where the metal constituting the metal silicide material of the phase shift film 30 includes molybdenum (Mo), zirconium (Zr), and titanium (Ti), the phase shift layer 31 is composed of a molybdenum silicide material containing molybdenum (Mo), silicon (Si), nitrogen (N), and/or oxygen (O), a zirconium silicide material containing zirconium (Zr), silicon (Si), nitrogen (N), and/or oxygen (O), or a titanium silicide material containing titanium (Ti), silicon (Si), nitrogen (N), and/or oxygen (O). In the case of a molybdenum silicide material, the average content of each element is preferably as follows: molybdenum (Mo) is 5 to 20 atomic percent, silicon (Si) is 15 to 45 atomic percent, nitrogen (N) is 0 to 75 atomic percent, and oxygen (O) is 0 to 45 atomic percent. In the case of the zirconium silicide material, the average content of each element is preferably as follows: zirconium (Zr) is 5 to 35 atomic percent, silicon (Si) is 5 to 45 atomic percent, nitrogen (N) is 0 to 70 atomic percent, and oxygen (O) is 0 to 70 atomic percent. In the case of a titanium silicide material, the average content of each element is preferably as follows: titanium (Ti) is 5 to 30 atomic%, silicon (Si) is 10 to 45 atomic%, nitrogen (N) is 0 to 70 atomic%, and oxygen (O) is 0 to 60 atomic%. The phase shift layer 31 may be made of a molybdenum silicide material containing carbon (C) or a zirconium silicide material containing carbon (C).
The phase shift layer 31 may be formed by a sputtering method.
The anti-reflection layer 32 is disposed on the upper side of the phase shift layer 31. The antireflection layer 32 mainly has a function of reducing the reflectance with respect to light incident from the phase shift film 30 side (i.e., the opposite side of the antireflection layer 32 from the transparent substrate 20 side). The antireflection layer 32 is a layer whose film thickness is adjusted by reducing the reflectance of the phase shift film 30 based on the interference effect of the reflection at the interface between the metal layer 33 and the antireflection layer 32 and the reflection at the surface of the antireflection layer 32.
The antireflection layer 32 is made of a metal material or a metal silicide material.
When the entire phase shift film 30 is made of a chromium (Cr) based material, the antireflection layer 32 is made of a chromium (Cr) based material containing chromium (Cr), oxygen (O), and nitrogen (N), and the average content of the respective elements is as follows: chromium is 30-70 primaryThe content of the oxygen is 20 to 60 atomic percent, and the content of the nitrogen is 0.4 to 30 atomic percent. The antireflection layer 32 contains chromium oxide in which chromium and oxygen are bonded in a bonding state (chemical state) of the components constituting the antireflection layer 32, and particularly preferably contains mainly chromium (III) oxide (Cr 2 O 3 ). The antireflection layer 32 may be made of a chromium-based material containing at least one of carbon (C) and fluorine (F). For example, as a material for forming the antireflection layer 32, crON, crOCN, crFON can be given. In this case, from the viewpoints of the effect of reducing the reflectance of light incident from the phase shift film side (the surface side of the antireflection layer 32) and the formation of an excellent pattern cross-sectional shape by wet etching as a whole of the phase shift film 30, the average content of nitrogen (N) contained in the phase shift layer 31 is set to be equal to or higher than the average content of nitrogen (N) contained in the antireflection layer 32, and the average content of oxygen (O) contained in the antireflection layer 32 is set to be higher than the average content of oxygen (O) contained in the phase shift layer 31. In addition, from the viewpoint of the effect of reducing the film surface reflectance, the average content of oxygen (O) contained in the antireflection layer 32 is preferably at least 1 atom% or more, more preferably 5 atom% or more, than the average content of oxygen (O) contained in the phase shift layer 31.
In the case where the metal constituting the metal silicide material of the phase shift film 30 includes molybdenum (Mo), zirconium (Zr), and titanium (Ti), the antireflection layer 32 is preferably made of a titanium material containing titanium (Ti), nitrogen (N), and oxygen (O), or a titanium material containing titanium (Ti) and oxygen (O), and the average content of the elements is as follows: titanium (Ti) 15 to 45 atom%, nitrogen (N) 20 to 50 atom%, and oxygen (O) 15 to 65 atom%. In the case of the metal silicide material constituting the phase shift film 30, the antireflection layer 32 may be composed of a molybdenum silicide material containing molybdenum (Mo), silicon (Si), nitrogen (N), and oxygen (O), a molybdenum silicide material containing molybdenum (Mo), silicon (Si), and oxygen (O), a zirconium silicide material containing zirconium (Zr), silicon (Si), nitrogen (N), and oxygen (O), a zirconium silicide material containing zirconium (Zr), silicon (Si), and oxygen (O), a titanium silicide material containing titanium (Ti), silicon (Si), nitrogen (N), and oxygen (O), or a titanium silicide material containing titanium (Ti), silicon (Si), and oxygen (O), but in order to secure adhesion to a resist film (not shown) formed on the surface, it is preferable to perform surface treatment such as HMDS (hexamethyldisilazane ).
The antireflection layer 32 may be formed by a sputtering method.
The metal layer 33 is arranged between the phase shift layer 31 and the anti-reflection layer 32. The metal layer 33 has a function of adjusting the transmittance for exposure light, and also has a function of reducing the reflectance for light incident from the phase shift film 30 side in combination with the antireflection layer 32. In addition, in combination with the phase shift layer, the function of reducing the reflectance with respect to light incident from the transparent substrate 20 side is provided.
The metal layer 33 is made of a metal-based material having an average content of metal higher than that of the metal of the antireflection layer 32, or a metal silicide-based material having an overall average content higher than that of the metal of the antireflection layer 32 and silicon.
When the phase shift film 30 is entirely made of a chromium (Cr) based material, or when the metal of the metal silicide based material constituting the phase shift film 30 includes molybdenum (Mo), zirconium (Zr), and titanium (Ti), the metal layer 33 contains chromium (Cr) and carbon (C), and the average content of the elements is as follows: the average content of chromium in the metal layer 33 is higher than the average content of chromium in the phase shift layer 31 and the antireflection layer 32, and the content of chromium (Cr) is 55 to 90 atomic% and the content of carbon (C) is 10 to 45 atomic%. When the entire phase shift film 30 is etched with the same etchant, the metal layer 33 can be suppressed from having a tapered cross-sectional shape by setting the average content of carbon (C) to 10 atomic% or more. Further, by setting the average content of carbon (C) contained in the metal layer 33 to 45 atomic% or less, the cross-sectional shape of the metal layer 33 can be suppressed from becoming tapered. By setting the average content of carbon (C) contained in the metal layer 33 to the above-described appropriate range, a pattern can be formed on the metal layer 33 by an appropriate mask process. The metal layer 33 may further include a chromium-based material containing at least one of nitrogen (N), oxygen (O), and fluorine (F). For example, as a material for forming the metal layer 33, crC, crCN, crCO, crCF, crCON can be given. Wherein the metal layer 33 preferably contains chromium Chromium-based material of (Cr), carbon (C) and oxygen (O). Further, from the viewpoint of obtaining an excellent pattern cross-sectional shape by wet etching in the form of a bonding state (chemical state) of the components constituting the phase shift layer 31, the antireflection layer 32, and the metal layer 33, it is further preferable that chromium (III) oxide (Cr 2 O 3 )。
In addition, when the metal constituting the metal-based material of the phase shift film 30 includes titanium (Ti) and the metal constituting the metal-based material includes molybdenum (Mo), zirconium (Zr), and titanium (Ti), the metal layer 33 is composed of a molybdenum-based silicide material containing molybdenum (Mo), silicon (Si), carbon (C), and/or nitrogen (N), a zirconium-based silicide material containing zirconium (Zr), silicon (Si), carbon (C), and/or nitrogen (N), and a titanium-based silicide material containing titanium (Ti), silicon (Si), carbon (C), and/or nitrogen (N). In the case of a molybdenum silicide material, the average content of each element is preferably as follows: molybdenum (Mo) is 5 to 20 atomic percent, silicon (Si) is 15 to 70 atomic percent, carbon (C) is 0 to 20 atomic percent, and nitrogen (N) is 0 to 30 atomic percent. In the case of the zirconium silicide material, the average content of each element is preferably as follows: zirconium (Zr) is 5 to 35 atomic percent, silicon (Si) is 5 to 70 atomic percent, carbon (C) is 0 to 20 atomic percent, and nitrogen (N) is 0 to 20 atomic percent. In the case of a titanium silicide material, the average content of each element is preferably as follows: titanium (Ti) 5 to 35 atom%, silicon (Si) 5 to 70 atom%, carbon (C) 0 to 20 atom%, and nitrogen (N) 0 to 20 atom%. The average content of molybdenum silicide, zirconium silicide, and titanium silicide contained in the metal layer 33 are higher than those contained in the phase shift layer 31 and the antireflection layer 32. The metal layer 33 may be a molybdenum silicide material, a zirconium silicide material, or a titanium silicide material containing at least one of carbon (C), nitrogen (N), and oxygen (O). For example, as a material for forming the metal layer 33, moSiC, moSiN, moSiCN, moSiCO, moSiCON, zrSiC, zrSiN, zrSiCN, zrSiCO, zrSiCON, tiSiC, tiSiN, tiSiCN, tiSiCO, tiSiCON can be given.
Since the sheet resistance of the phase shift film 30 is reduced by providing the metal layer 33, charging of the phase shift mask blank and the phase shift mask can be prevented. If the metal layer 33 is not provided, the foreign matter is likely to adhere because the electricity generated when the phase shift mask blank and the phase shift mask are moved in and out of the case is not discharged and the electricity is accumulated in the phase shift mask blank and the phase shift mask. In addition, when a phase shift mask is formed with a small pattern, electricity is transferred from the pattern to the pattern, which is liable to cause electrostatic breakdown.
The metal layer 33 may be formed by a sputtering method.
The metal layer 33 preferably has an extinction coefficient higher than that of the antireflection layer 32 in a wavelength range of 350nm to 436 nm. Further, it is preferable to have an extinction coefficient higher than that of the antireflection layer 32 in a wavelength range of 313nm to 436 nm.
The difference between the extinction coefficient of the metal layer 33 and the extinction coefficient of the antireflection layer 32 is preferably 1.5 to 3.5, more preferably 1.8 to 3.5. When the difference in extinction coefficient is 1.5 to 3.5, the reflectance of the interface between the metal layer 33 and the antireflection layer 32 in the above wavelength range (the wavelength range of 350nm to 436nm, or the wavelength range of 313nm to 436 nm) can be improved, and therefore, the antireflection effect can be further exhibited, which is preferable.
The metal layer 33 preferably has an extinction coefficient higher than that of the phase shift layer 31 in a wavelength range of 350nm to 436 nm. In addition, it is preferable to have an extinction coefficient higher than that of the phase shift layer 31 in a wavelength range of 313nm to 436 nm.
The extinction coefficient can be measured using an n & k multi-functional thin film analyzer, an ellipsometer, or the like.
When the metal layer 33 and the antireflection layer 32 are made of a chromium-based material, the metal layer 33 has a higher average chromium (Cr) content (at%) than the average chromium (Cr) content (at%) of the antireflection layer 32.
The difference between the average Cr content of the metal layer 33 and the average Cr content of the antireflection layer 32 is preferably 10 to 80 atomic%, more preferably 15 to 80 atomic%. When the difference in average Cr content is 10 to 80 atomic%, the reflectance of the interface between the metal layer 33 and the antireflection layer 32 in the above wavelength range (the wavelength range of 350 to 436nm or the wavelength range of 313 to 436 nm) can be improved, and therefore, the antireflection effect can be further exhibited, which is preferable. The etching rate of the metal layer 33 can be adjusted by adding nitrogen (N), oxygen (O), carbon (C), and fluorine (F) to chromium (Cr) to prepare a chromium-based material. For example, the wet etching rate can be reduced by containing carbon (C) and fluorine (F) in chromium (Cr), and the wet etching rate can be accelerated by containing nitrogen (N) and oxygen (O) in chromium (Cr). By setting the chromium-based material to which the above element is added in consideration of the wet etching rate of the phase shift layer 31 and the antireflection layer 32 formed above and below the metal layer 33, the cross-sectional shape of the phase shift film 30 after etching can be improved.
The metal layer 33 has a higher average chromium (Cr) content than that of the phase shift layer 31.
The phase shift layer 31, the metal layer 33, and the antireflection layer 32 preferably have refractive indices of 2.0 or more in the wavelength range of 350nm to 436nm, respectively. If the refractive index is 2.0 or more, the film thickness of the necessary phase shift film 30 can be reduced to obtain desired optical characteristics (transmittance and phase difference). Therefore, the phase shift mask manufactured using the phase shift mask blank 10 having the phase shift film 30 can have a phase shift film pattern having an excellent pattern cross-sectional shape and an excellent CD uniformity.
The refractive index can be measured using an n & k multifunctional thin film analyzer, ellipsometer, or the like.
The phase shift film 30 has predetermined optical characteristics for transmittance and phase difference of exposure light by the laminated structure of the phase shift layer 31, the metal layer 33, and the antireflection layer 32.
Any of the phase shift layer 31, the metal layer 33, and the antireflection layer 32 may be made of a material that can be etched with the same etchant, and one or both of the phase shift layer 31, the metal layer 33, and the antireflection layer 32 may be made of a material that has etching selectivity to other layers.
The transmittance of the phase shift film 30 to exposure light satisfies a value necessary as the phase shift film 30. The transmittance of the phase shift film 30 is as follows: the light of a predetermined wavelength (hereinafter referred to as a representative wavelength) included in the exposure light is preferably 1% to 70%, more preferably 2% to 60%, and even more preferably 3% to 50%. That is, when the exposure light is a composite light including light in a wavelength range of 313nm or more and 436nm or less, the phase shift film 30 has the above-described transmittance for light of a representative wavelength included in the wavelength range. For example, when the exposure light is a composite light including j-line (wavelength: 313 nm), i-line (wavelength: 365 nm), h-line (wavelength: 405 nm), and g-line (wavelength: 436 nm), the phase shift film 30 has the above-described transmittance for any light among the j-line, i-line, h-line, and g-line.
The phase difference of the phase shift film 30 with respect to the exposure light satisfies a value necessary as the phase shift film 30. The phase difference of the phase shift film 30 is as follows: the representative wavelength included in the exposure light is preferably 160 ° to 200 °, more preferably 170 ° to 190 °. Due to this property, the phase of the light of the representative wavelength included in the exposure light can be changed by 160 ° to 200 °. Therefore, a phase difference of 160 to 200 ° occurs between the light of the representative wavelength transmitted through the phase shift film 30 and the light of the representative wavelength transmitted through the transparent substrate 20 only. That is, when the exposure light is a composite light including light in a wavelength range of 313nm to 436nm, the phase shift film 30 has the above-described phase difference with respect to light of a representative wavelength included in the wavelength range. For example, when the exposure light is a composite light including j, i, h, and g lines, the phase shift film 30 has the above-described phase difference for any light of the j, i, h, and g lines.
The transmittance and the phase difference of the phase shift film 30 can be controlled by adjusting the respective compositions and thicknesses of the phase shift layer 31, the metal layer 33, and the antireflection layer 32 constituting the phase shift film 30. Therefore, in this embodiment, the composition and thickness of each of the phase shift layer 31, the metal layer 33, and the antireflection layer 32 are adjusted so that the transmittance and the phase difference of the phase shift film 30 have the above-described optical characteristics. The transmittance of the phase shift film 30 is mainly affected by the composition and thickness of the phase shift layer 31 and the metal layer 33. The refractive index of the phase shift film 30 is mainly affected by the composition and thickness of the phase shift layer 31.
The transmittance and the phase difference can be measured using a phase shift measuring device or the like.
The film surface reflectance of the phase shift film 30 with respect to the light incident from the phase shift film 30 side is 15% or less in the wavelength range of 350nm to 436 nm. The wavelength range of 313nm to 436nm is preferably 22.5% or less. That is, the film surface reflectance of the phase shift film 30 with respect to the light incident from the phase shift film 30 side is preferably 15% or less in the wavelength range of 350nm to 436nm, and 22% or less even when the wavelength range is enlarged to 313nm to 436 nm. When the film surface reflectance of the phase shift film 30 is 15% or less in the wavelength range of 350nm to 436nm, the film surface reflectance of the laser drawing light is reduced, and thus a phase shift mask having excellent CD uniformity can be formed. When the film surface reflectance of the phase shift film 30 is 22.5% or less in the wavelength range of 313nm to 436nm, the film surface reflectance with respect to exposure light is reduced, and therefore, when transferring the pattern formed on the phase shift mask, diffusion (flare) of the transferred pattern due to reflection light from the display device substrate can be prevented. The film surface reflectance of the phase shift film 30 is preferably 20% or less, more preferably 15% or less at 313nm to 436 nm.
The range of variation in the film surface reflectance of the phase shift film 30 is preferably 9% or less, more preferably 8.5% or less in the wavelength range of 350nm to 436nm, and is preferably 12.5% or less, more preferably 12% or less in the wavelength range of 313nm to 436 nm. That is, the range of variation in the film surface reflectance of the phase shift film 30 is 9% or less, more preferably 8.5% or less in the wavelength range of 350nm to 436nm, and is preferably 12.5% or less, more preferably 12% or less when the wavelength range is enlarged to 313nm to 436 nm.
The phase shift film 30 has a back reflection rate of 20% or less in a wavelength range of 365nm to 436nm and a wavelength range of 20% or less in a wavelength range of 313nm to 436nm with respect to light incident from the transparent substrate 20 side. By setting the back surface reflectance of the phase shift film 30 to the above range, the back surface reflectance of the phase shift film 30 with respect to the exposure light is reduced, and therefore, when transferring the pattern formed on the phase shift mask, deterioration in transfer accuracy due to the reflected light with the optical system of the exposure machine can be suppressed. In addition to the requirement of the back surface reflectance of the phase shift film 30, when the film surface reflectance of the phase shift film 30 is 20% or less in the wavelength range of 350nm to 436nm, the influence of the reflection with the optical system of the exposure machine and the reflection with the surface film attached to the phase shift mask and the display device substrate can be reduced, and therefore, a phase shift mask in which the transfer accuracy becomes good and the CD error transferred to the transfer pattern formed on the display device substrate can be prevented can be formed.
The range of variation in the back surface reflectance of the phase shift film 30 is preferably 18% or less, more preferably 16% or less in the wavelength range of 365nm to 436nm, and is preferably 18% or less, more preferably 16% or less in the wavelength range of 313nm to 436 nm. That is, the range of variation in the film surface reflectance of the phase shift film 30 is preferably 9% or less, more preferably 8.5% or less in the wavelength range of 350nm to 436nm, and is preferably 12.5% or less, more preferably 12% or less when the wavelength range is enlarged to 313nm to 436 nm.
The film surface reflectance, the back surface reflectance, and the fluctuation range of the film surface reflectance and the back surface reflectance of the phase shift film 30 can be controlled by adjusting the refractive index, the extinction coefficient, and the thickness of each of the phase shift layer 31, the metal layer 33, and the antireflection layer 32 constituting the phase shift film 30. Since the extinction coefficient and the refractive index can be controlled by adjusting the composition, in this embodiment, the composition and thickness of each of the phase shift layer 31, the metal layer 33, and the antireflection layer 32 are adjusted so that the film surface reflectance, the back surface reflectance, and the fluctuation range thereof of the phase shift film 30 have the above-described physical properties. The film surface reflectance, the back surface reflectance, and the fluctuation range of the film surface reflectance of the phase shift film 30 are mainly affected by the composition and the thickness of the metal layer 33 and the antireflection layer 32, respectively.
The film surface reflectance and the back surface reflectance can be measured using a spectrophotometer or the like. The range of variation in the reflectance of the film surface is determined from the difference between the maximum reflectance and the minimum reflectance in the wavelength range of 350nm to 436nm or 313nm to 436 nm.
The phase shift layer 31 may be formed of a single film having a uniform composition, may be formed of a plurality of films having different compositions, or may be formed of a single film having a composition that continuously changes in the thickness direction. The same applies to the metal layer 33 and the antireflection layer 32.
In addition, a composition gradient region in which a composition gradient is continuously generated in each element constituting the phase shift layer 31, the metal layer 33, and the antireflection layer 32 may be provided at the interface between the phase shift layer 31 and the metal layer 33 and the interface between the metal layer 33 and the antireflection layer 32.
Fig. 2 is a schematic diagram showing another film configuration of the phase shift mask blank 10 in embodiment 1-2. As shown in fig. 2, the phase shift mask blank 10 may have a light shielding film pattern 40 between the transparent substrate 20 and the phase shift film 30. The phase shift film 30 in embodiment 1-2 is the same as that in embodiment 1-1, and the description thereof is omitted.
When the phase shift mask blank 10 includes the light shielding film pattern 40, the light shielding film pattern 40 is disposed on the main surface of the transparent substrate 20. The light shielding film pattern 40 has a function of shielding exposure light from passing therethrough.
The material forming the light shielding film pattern 40 is not particularly limited as long as it has a function of shielding the exposure light from passing through. A back surface antireflection layer 41 for reducing the back surface reflectance of the light shielding film pattern 40 to light incident from the transparent substrate 20 side may be formed on the transparent substrate 20 side of the light shielding film pattern 40 as needed. In this case, the light shielding film pattern 40 has a structure including a back surface antireflection layer 41 and a light shielding layer 42 having a function of shielding exposure light from transmitting from the transparent substrate 20 side. Examples of the material of the light shielding film pattern include a metal material such as a chromium material and a metal silicide material. Examples of the chromium-based material include chromium (Cr), and chromium-based materials containing chromium (Cr) and at least one selected from carbon (C) and nitrogen (N). Further, a chromium-based material containing chromium (Cr) and at least one selected from oxygen (O) and fluorine (F), or a chromium-based material containing chromium (Cr) and at least one selected from carbon (C) and nitrogen (N), and further containing at least one selected from oxygen (O) and fluorine (F), may be mentioned. For example, as a material for forming the light shielding film pattern 40, cr, crC, crN, crCN, crO, crON, crCO, crCON is given.
Examples of the metal silicide material include metal silicide, metal silicide nitride, metal silicide oxide, metal silicide nitride oxide, metal silicide carbide nitride, metal silicide carbide oxide carbide, and metal silicide oxide carbide nitride. Examples of the metal contained in the metal silicide material include the transition metal and typical metals described above.
When the light shielding film pattern 40 includes the back surface antireflection layer 41, the back surface antireflection layer 41 preferably has a characteristic of 20% or less in a wavelength range of 365nm to 436 nm. The back surface antireflection layer 41 preferably has a characteristic of 20% or less in a wavelength range of 313nm to 436 nm.
The light shielding film pattern 40 may be formed by patterning a light shielding film formed by a sputtering method by etching.
In the portion where the phase shift film 30 and the light shielding film pattern 40 are stacked, the optical density for exposure light is preferably 3 or more, more preferably 3.5 or more.
The optical concentration may be measured using a spectrophotometer, an OD tester, or the like.
The light shielding film pattern 40 may be formed of a single film having a uniform composition, may be formed of a plurality of films having different compositions, or may be formed of a single film having a composition that continuously changes in the thickness direction.
The material of the light shielding film pattern 40 may be a material having etching selectivity to the phase shift film 30 (the phase shift layer 31, the metal layer 33, and the antireflection layer 32), or may be a material not having etching selectivity.
Next, fig. 3 is a schematic diagram showing another film configuration of the phase shift mask blank 10 in embodiments 1 to 3. As shown in fig. 3, the phase shift mask blank 10 may have a transparent substrate 20, a phase shift film 30, and a light shielding film 45. The light shielding film 45 may be formed of a single film having a uniform composition, may be formed of a plurality of films having different compositions, or may be formed of a single film having a composition that continuously changes in the thickness direction. The phase shift film 30 in embodiment 1-3 is the same as that in embodiment 1-1, and the description thereof is omitted. The material forming the light shielding film 45 is not particularly limited as long as it has a function of shielding the exposure light from passing through. The surface antireflection layer 47 for reducing the film surface reflectance of the light shielding film 45 with respect to the incident light may be formed on the surface side of the light shielding film 45 as necessary. In this case, the light shielding film 45 has a structure including a light shielding layer 46 having a function of shielding the exposure light from the phase shift film 30 side, and a surface antireflection layer 47. For example, as a material of the light shielding film 45, the same material as the light shielding film pattern 40 described above can be used. When the light shielding film 45 includes the surface antireflection layer 47, the surface antireflection layer 47 preferably has a characteristic of 20% or less in a wavelength range of 365nm to 436 nm. Further, it is preferable that the surface antireflection layer 47 has a characteristic of 22.5% or less in a wavelength range of 313nm to 436 nm. The light shielding layer 46 and the surface antireflection layer 47 may be single layers, or may have a multilayer structure in which at least one of them is a multilayer structure.
The light shielding film 45 may be formed by a sputtering method.
In embodiments 1 to 3, the material of the light shielding film 45 may be a material having etching selectivity to the phase shift film 30 (the phase shift layer 31, the metal layer 33, and the antireflection layer 32), or may be a material having no etching selectivity. In consideration of the manufacturing process of the phase shift mask, the material of the light shielding film 45 is preferably a material having etching selectivity to the phase shift film 30.
In the phase shift mask blank 10 according to embodiments 1 to 2 and embodiments 1 to 3, other functional films may be formed between the phase shift film 30 and the light shielding film pattern 40, between the phase shift film 30 and the light shielding film 45, and on the light shielding film 45, as required. Examples of the functional film include an etching stopper film and an etching mask film.
The phase shift mask blank 10 according to embodiment 1-1 or embodiment 1-2 may have a resist film on the phase shift film 30, and the phase shift mask blank 10 according to embodiment 1-3 may have a resist film on the light shielding film 45.
Next, a method for manufacturing the phase shift mask blank 10 according to the above embodiments 1-1 and 1-2 will be described. The phase shift mask blank 10 can be manufactured by performing the following preparation process and phase shift film forming process.
Next, each step will be described in detail.
1. Preparation step
In the preparation step, the transparent substrate 20 is first prepared. The material of the transparent substrate 20 is not particularly limited as long as it is a material having transparency to the exposure light used. Examples thereof include synthetic quartz glass, soda lime glass, and alkali-free glass.
In the case of manufacturing the phase shift mask blank 10 including the light shielding film pattern 40 according to embodiment 1 to 2, a light shielding film made of, for example, a chromium-based material is formed on the transparent substrate 20 by sputtering. Then, a resist film pattern is formed on the light shielding film, and the light shielding film is etched using the resist film pattern as a mask to form a light shielding film pattern 40. Then, the resist film pattern is peeled off. In the case where the light shielding film pattern 40 has a function of reducing the back surface reflectance with respect to light incident from the transparent substrate 20 side, the light shielding film is formed by forming the back surface antireflection layer 41 formed of, for example, chromium oxide containing chromium and oxygen on the transparent substrate 20 by a sputtering method, and forming the light shielding layer 42 of a chromium-based material containing chromium on the back surface antireflection layer 41. Then, a resist film pattern is formed on the light shielding film, and the light shielding film is etched using the resist film pattern as a mask, thereby forming a light shielding film pattern 40. Then, the resist film pattern is peeled off, and the light shielding film pattern 40 is obtained on the transparent substrate 20.
2. Phase shift film formation step
In the phase shift film forming step, the phase shift film 30 formed of a metal material or a metal silicide material is formed on the transparent substrate 20 by a sputtering method. Here, in the case where the light shielding film pattern 40 is formed on the transparent substrate 20, the phase shift film 30 is formed to cover the light shielding film pattern 40.
The phase shift film 30 may be formed as follows: a phase shift layer 31 is formed on the main surface of the transparent substrate 20, a metal layer 33 is formed on the phase shift layer 31, and an antireflection layer 32 is formed on the metal layer 33. The case where the phase shift film 30 is formed of a chromium-based material will be described below. In the case where the phase shift film 30 is formed of another metal material or metal silicide material, the phase shift film may be formed by a sputtering method in the same manner by adjusting the material of the sputtering target and the sputtering atmosphere.
The phase shift layer 31 may be formed using a sputtering target containing chromium or a chromium-based material, for example, in a sputtering gas atmosphere composed of a mixed gas of an inert gas containing at least one selected from helium, neon, argon, krypton, and xenon and an active gas containing at least one selected from oxygen, nitrogen, nitric oxide, nitrogen dioxide, carbon dioxide, hydrocarbon, and fluorine-containing gas. Examples of the hydrocarbon gas include: methane gas, butane gas, propane gas, styrene gas, and the like. As the sputtering target, a chromium-based material such as chromium oxide, chromium nitride, chromium oxynitride, and chromium oxynitride carbide can be used in addition to the chromium metal.
Similarly, the metal layer 33 may be formed using a sputtering target containing chromium or a chromium-based material in, for example, the following sputtering gas atmosphere: a sputtering gas atmosphere composed of an inert gas including at least one selected from helium, neon, argon, krypton, and xenon; or a sputtering gas atmosphere composed of a mixed gas of an inert gas containing at least one selected from helium, neon, argon, krypton, and xenon and an active gas containing at least one selected from oxygen, nitrogen, nitric oxide, nitrogen dioxide, carbon dioxide, hydrocarbon, and fluorine-containing gas. Examples of the hydrocarbon gas include: methane gas, butane gas, propane gas, styrene gas, and the like. As the sputtering target, a chromium-based material such as chromium oxide, chromium nitride, chromium oxynitride, and chromium oxynitride carbide can be used in addition to the chromium metal.
Similarly, the antireflection layer 32 may be formed using a sputtering target containing chromium or a chromium-based material, in a sputtering gas atmosphere composed of, for example, a mixed gas of an inert gas containing at least one selected from helium, neon, argon, krypton, and xenon and an active gas containing at least one selected from oxygen, nitrogen, nitric oxide, nitrogen dioxide, carbon dioxide, hydrocarbon, and fluorine-containing gas. Examples of the hydrocarbon gas include: methane gas, butane gas, propane gas, styrene gas, and the like. As the sputtering target, a chromium-based material such as chromium oxide, chromium nitride, chromium oxynitride, and chromium oxynitride carbide can be used in addition to the chromium metal.
When the phase shift layer 31, the metal layer 33, and the antireflection layer 32 are formed, the composition and thickness of each of the phase shift layer 31, the metal layer 33, and the antireflection layer 32 are adjusted so that the transmittance and the phase difference of the phase shift film 30 have the above-described predetermined optical characteristics, and the film surface reflectance, the back surface reflectance, and the fluctuation range of the reflectance and the back surface reflectance of the phase shift film 30 have the above-described predetermined physical properties and optical characteristics. The composition of each of the phase shift layer 31, the metal layer 33, and the antireflection layer 32 can be controlled by the composition and flow rate of sputtering gas, and the like. The thickness of each of the phase shift layer 31, the metal layer 33, and the antireflection layer 32 can be controlled by sputtering power, sputtering time, and the like. In the case where the sputtering apparatus is a linear sputtering apparatus, the thickness of each of the phase shift layer 31, the metal layer 33, and the antireflection layer 32 may be controlled by the conveyance speed of the substrate.
In the case where the phase shift layer 31 is formed of a single film having a uniform composition or is formed of a plurality of films, the above-described film formation process is performed 1 time or a plurality of times without changing the composition and flow rate of the sputtering gas.
When the phase shift layer 31 is formed of a plurality of films having different compositions, the above-described film formation process may be performed a plurality of times, the material of the sputtering target may be changed, the above-described film formation process may be performed a plurality of times, or a combination thereof may be performed a plurality of times, depending on the film formation process.
For example, in the case where the phase shift layer 31 is formed of a single film whose composition continuously varies in the thickness direction, the composition and flow rate of the sputtering gas are changed and the above-described film formation process is performed only 1 time. The same applies to the formation of the metal layer 33 and the formation of the antireflection layer 32. In the case of performing the film forming process a plurality of times, the sputtering power applied to the sputtering target can be reduced. When the composition of at least one of the metal layer 33 and the antireflection layer 32 is different from that of the phase shift layer 31, if the composition is different from that of a nonmetal such as C, N, O, the film may be formed as follows: the above-described film formation process is performed by changing the composition and flow rate of the sputtering gas in accordance with the film formation process. In the case where the composition is different from that of the metal (Cr, si, zr), the target must be changed. In this case, a plurality of targets having different compositions may be set in advance, and the positions of the targets to be discharged may be changed according to the target composition.
The phase shift layer 31, the metal layer 33, and the antireflection layer 32 are preferably formed continuously by taking out the transparent substrate 20 from the apparatus without exposure to the atmosphere using an in-line sputtering apparatus. By continuously forming the film without taking out the film from the apparatus, unwanted surface oxidation and surface carbonization of each layer can be prevented. Unwanted surface oxidation and surface carbonization of the respective layers may change the reflectivity of laser light used for drawing a resist film formed on the phase shift film 30 and exposure light used for transferring a phase shift film pattern to a resist film formed on a display device substrate, and may change the etching rates of oxidized portions and carbonized portions.
When the phase shift mask blank 10 having the resist film is manufactured, the resist film is formed on the phase shift film.
In the phase shift mask blank 10 according to embodiment 1-1, the phase shift film 30 formed of a metal material or a metal silicide material provided on the transparent substrate 20 has the phase shift layer 31, the antireflection layer 32, and the metal layer 33 provided between the phase shift layer 31 and the antireflection layer 32, the metal layer 33 has a chromium average content higher than that of the antireflection layer 32, the transmittance and the phase difference of the phase shift film 30 for exposure light satisfy predetermined optical characteristics necessary for the phase shift film 30, the film surface reflectance of the phase shift film 30 is 15% or less in a wavelength range of 350nm to 436nm, and the back surface reflectance of the phase shift film 30 is 20% or less in a wavelength range of 365nm to 436 nm. Therefore, using the phase shift mask blank 10, a phase shift mask having excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern formed therein can be manufactured so that transfer accuracy is good.
Next, a method for manufacturing the phase shift mask blank 10 according to embodiments 1 to 3 will be described. The method for manufacturing the phase shift mask blank 10 according to embodiments 1 to 3 described above is the same as the "1. Preparation step" and the "2. Phase shift film forming step", and the description thereof is omitted, and the light shielding film forming step is described below.
3. Light shielding film formation step
In the light shielding film forming step, the light shielding film 45 made of a metal or metal silicide material is formed on the phase shift film 30 by sputtering.
The light shielding film 45 is formed as follows: a light shielding layer 46 is formed on the phase shift film 30, and a surface antireflection layer 47 is formed on the light shielding layer 46 as needed. The case where the phase shift film 30 is a metal silicide material and the light shielding film 45 is formed of a chromium material will be described below. Note that, in the case where the light shielding film 45 is formed of a metal silicide material when the phase shift film 30 is a metal material (for example, a chromium material), and in the case where the phase shift film 30 and the light shielding film 45 are formed of a material having etching selectivity between the phase shift film 30 and the light shielding film 45 (for example, a metal silicide material) when the phase shift film 30 and the light shielding film 45 are metal materials (for example, a chromium material), the phase shift film can be formed by adjusting the material of the sputtering target and the sputtering atmosphere by the same sputtering method.
The light shielding layer 46 can be formed using a sputtering target containing chromium or a chromium-based material, for example, in a sputtering gas atmosphere composed of a mixed gas of an inert gas containing at least one selected from helium, neon, argon, krypton, and xenon and an active gas containing at least one selected from oxygen, nitrogen, nitric oxide, nitrogen dioxide, carbon dioxide, hydrocarbon, and fluorine-containing gas. Examples of the hydrocarbon gas include: methane gas, butane gas, propane gas, styrene gas, and the like. As the sputtering target, a chromium-based material such as chromium oxide, chromium nitride, chromium oxynitride, and chromium oxynitride carbide can be used in addition to the chromium metal.
Similarly, the surface antireflection layer 47 may be formed using a sputtering target containing chromium or a chromium-based material, for example, in a sputtering gas atmosphere composed of a mixed gas of an inert gas containing at least one selected from helium, neon, argon, krypton, and xenon and an active gas containing at least one selected from oxygen, nitrogen, nitric oxide, nitrogen dioxide, carbon dioxide, hydrocarbon, and fluorine-containing gas. Examples of the hydrocarbon gas include: methane gas, butane gas, propane gas, styrene gas, and the like. As the sputtering target, a chromium-based material such as chromium oxide, chromium nitride, chromium oxynitride, and chromium oxynitride carbide can be used in addition to the chromium metal.
When the light shielding layer 46 and the surface antireflection layer 47 are formed, the composition and thickness of each of the light shielding layer 46 and the surface antireflection layer 47 are adjusted so that the light shielding film 45 has the above-described physical properties and optical characteristics (in the combination of the phase shift film 30 and the light shielding film 45, the optical concentration is 3.0 or more, and the film surface reflectance of the light shielding film 45 is 15% or less in the wavelength range of 350nm to 436 nm). The composition of each of the light shielding layer 46 and the surface antireflection layer 47 of the light shielding film 45 can be controlled by the composition of sputtering gas, the flow rate, and the like. The thickness of each of the light shielding layer 46 and the surface antireflection layer 47 can be controlled by sputtering power, sputtering time, or the like. In the case where the sputtering apparatus is a linear sputtering apparatus, the thickness of each of the light shielding layer 46 and the surface antireflection layer 47 may be controlled according to the conveyance speed of the substrate.
Embodiment 2 (embodiments 2-1 and 2-2)
In embodiment 2, a method of manufacturing a phase shift mask will be described. Embodiment 2-1 is a method for manufacturing a phase shift mask using the phase shift mask blank of embodiments 1-1 and 1-2. Embodiment 2-2 is a method for manufacturing a phase shift mask using the phase shift mask blank of embodiment 1-3. The method for manufacturing a phase shift mask according to embodiment 2-1 uses the phase shift mask blanks according to embodiments 1-1 and 1-2, and includes the following step of forming a resist film pattern (resist film pattern forming step) and step of forming a phase shift film pattern (phase shift film pattern forming step); the method for manufacturing a phase shift mask according to embodiment 2-2 uses the phase shift mask blank according to embodiment 1-3, and includes the following resist film pattern forming step, light shielding film pattern forming step (light shielding film pattern forming step), and phase shift film pattern forming step.
Hereinafter, each step will be described in detail.
Method for manufacturing phase shift mask of embodiment 2-1
1. Resist film pattern formation step
In the resist film pattern forming step, first, a resist film is formed on the phase shift film 30 of the phase shift mask blank 10 according to embodiments 1-1 and 1-2. When the phase shift mask blank 10 includes a resist film on the phase shift film 30, the resist film is not formed. The resist film material to be used is not particularly limited as long as it is a material that is photosensitive to laser light having any wavelength selected from the wavelength range of 350nm to 436nm, which will be described later. In addition, the resist film may be of any of positive type and negative type.
Then, a given pattern is drawn on the resist film using laser light having an arbitrary wavelength selected from the wavelength range of 350nm to 436 nm. As a pattern drawn on the resist film, a line and space (line and space) pattern and a hole (hole) pattern can be given.
Then, the resist film is developed with a given developer, and a resist film pattern is formed on the phase shift film 30.
2. Phase shift film pattern formation step
In the phase shift film pattern forming step, first, the phase shift film 30 is etched using the resist film pattern as a mask to form a phase shift film pattern. The etching medium (etching solution, etching gas) for etching the phase shift film 30 is not particularly limited as long as it is a medium capable of etching the phase shift layer 31, the metal layer 33, and the antireflection layer 32 constituting the phase shift film 30, respectively. For example, when the phase shift layer 31, the metal layer 33, and the antireflection layer 32 constituting the phase shift film 30 are each made of a chromium-based material containing chromium (Cr), an etching solution containing ammonium cerium nitrate and perchloric acid, and an etching gas made of a mixed gas of chlorine and oxygen are given. In addition, the phase shift layer 31, the metal layer 33, and the antireflection layer 32 constituting the phase shift film 30 are each made of a metal silicide material In this case, an etching solution containing at least one fluorine compound selected from hydrofluoric acid, fluorosilicic acid and ammonium bifluoride, and at least one oxidizing agent selected from hydrogen peroxide, nitric acid and sulfuric acid; an etching solution comprising hydrogen peroxide, ammonium fluoride, and at least one oxidizing agent selected from phosphoric acid, sulfuric acid, nitric acid; CF (compact flash) 4 Gas, CHF 3 Gas, SF 6 Fluorine-containing gases such as gas; oxygen (O) is mixed with the gas 2 ) And the etching gas is obtained.
Then, the resist film pattern is peeled off using a resist peeling liquid or by polishing.
In the case where 1 or 2 layers among the phase shift layer 31, the metal layer 33, and the antireflection layer 32 are made of a material having etching selectivity to other layers, desired etching can be performed by changing the etching medium according to the layers.
According to the method for manufacturing a phase shift mask of embodiment 2-1, a phase shift mask having excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern formed therein can be manufactured so that transfer accuracy is improved.
Method for manufacturing phase shift mask of embodiment 2-2
1. Step 1 of Forming resist film Pattern
In the 1 st resist film pattern forming step, first, a resist film is formed on the light shielding film 45 of the phase shift mask blank 10 of embodiments 1 to 3. When the light shielding film 45 is provided with a resist film, the phase shift mask blank 10 does not have a resist film. The resist film material to be used is not particularly limited as long as it is a material that is photosensitive to laser light having any wavelength selected from the wavelength range of 350nm to 436nm, which will be described later. In addition, the resist film may be of any of positive type and negative type.
Then, a given pattern is drawn on the resist film using laser light having an arbitrary wavelength selected from the wavelength range of 350nm to 436 nm. Examples of the pattern drawn on the resist film include line and space patterns and perforation patterns.
Then, the resist film is developed with a given developer, and a 1 st resist film pattern is formed on the light shielding film 45.
2. A mask pattern forming step (1 st light shielding film pattern forming step) for forming a phase shift film pattern
In the mask pattern forming step, the light shielding film 45 is etched using the 1 st resist film pattern as a mask, thereby forming a mask pattern for forming a phase shift film pattern. The etching medium (etching solution, etching gas) for etching the light shielding film 45 is not particularly limited as long as it is a medium capable of etching the light shielding layer 46 and the surface antireflection layer 47 constituting the light shielding film 45, respectively. For example, when the light shielding layer 46 and the surface antireflection layer 47 constituting the light shielding film 45 are each made of a chromium-based material containing chromium (Cr), an etching solution containing ceric ammonium nitrate and perchloric acid and an etching gas made of a mixed gas of chlorine and oxygen are given. When the light shielding layer 46 and the surface antireflection layer 47 constituting the light shielding film 45 are each made of a metal silicide material, an etching solution containing at least one fluorine compound selected from hydrofluoric acid, fluorosilicic acid and ammonium bifluoride, and at least one oxidizing agent selected from hydrogen peroxide, nitric acid and sulfuric acid; an etching solution comprising hydrogen peroxide, ammonium fluoride, and at least one oxidizing agent selected from phosphoric acid, sulfuric acid, nitric acid; CF (compact flash) 4 Gas, CHF 3 Gas, SF 6 Fluorine-containing gases such as gas; oxygen (O) is mixed with the gas 2 ) And the etching gas is obtained.
Then, the resist film pattern is peeled off using a resist peeling liquid or by polishing.
3. Phase shift film pattern formation step
In the phase shift film pattern forming step, the phase shift film 30 is etched using the mask pattern (1 st light shielding film pattern) as a mask to form a phase shift film pattern. The etching medium (etching solution, etching gas) for etching the phase shift film 30 is not particularly limited as long as it is a medium capable of etching the phase shift layer 31, the metal layer 33, and the antireflection layer 32 constituting the phase shift film 30, respectively. The etching medium is the same as that of embodiment 2-1, and the description thereof is omitted.
4. Step 2 of Forming resist film Pattern
The 2 nd resist film pattern forming step is a step for forming a predetermined light shielding film pattern on the phase shift film pattern, and is a step for forming a 2 nd resist film pattern on the 1 st light shielding film pattern (the above-mentioned mask pattern). A resist film is formed so as to cover the phase shift film pattern and the 1 st light shielding film pattern obtained in the above step.
Then, a given pattern is drawn on the resist film using laser light having an arbitrary wavelength selected from the wavelength range of 350nm to 436 nm. Examples of the pattern drawn on the resist film include line and space patterns and perforation patterns.
Then, the resist film is developed with a given developer, and a 2 nd resist film pattern is formed on the 1 st light shielding film pattern.
5. Light shielding film pattern forming step
The 1 st light shielding film pattern is etched using the 2 nd resist film pattern as a mask, and a light shielding film pattern is formed on the phase shift film pattern. The etching medium (etching solution, etching gas) for etching the 1 st light shielding film pattern is the same as the etching medium for etching the light shielding film 45 described above, and the description thereof is omitted.
Then, the 2 nd resist film pattern is peeled off using a resist peeling liquid or by polishing.
According to the method for manufacturing a phase shift mask of embodiment 2-2, a phase shift mask having a light shielding film pattern formed on a phase shift film pattern, which has an excellent pattern cross-sectional shape and excellent CD uniformity, and which has a fine pattern formed, can be manufactured so that transfer accuracy is good.
Embodiment 3
In embodiment 3, a method for manufacturing a display device will be described. The display device is manufactured by performing the following mask mounting process and pattern transfer process.
Hereinafter, each step will be described in detail.
1. Mounting step
In the mounting step, the phase shift mask manufactured in embodiments 2-1 and 2-2 is mounted on a mask stage of an exposure apparatus. Here, the phase shift mask is disposed opposite to a resist film formed on a display device substrate via a projection optical system of an exposure device.
2. Pattern transfer process
In the pattern transfer step, exposure light is irradiated to the phase shift mask, and the phase shift film pattern is transferred to a resist film formed on the display device substrate. The exposure light is a composite light including light having a plurality of wavelengths selected from the wavelength range of 313nm to 436nm, or monochromatic light selected by filtering out a certain wavelength range from the wavelength range of 313nm to 436nm with a filter or the like. For example, the exposure light is a composite light including i line, h line, and g line, a mixed light including j line, i line, h line, and g line, or a monochromatic light of i line. When the composite light is used as the exposure light, the exposure light intensity can be increased to improve productivity, and thus the manufacturing cost of the display device can be reduced.
Further, since the phase shift mask has a back surface reflectance of 365 to 436nm and a wavelength range of 20% or less, an influence on reflection on the exposure device side can be suppressed, and thus a resist film formed on a display device substrate can be transferred with high accuracy. In addition, in the phase shift mask in which the film surface reflectance of the phase shift film is 22.5% or less in the wavelength range of 313nm to 436nm, diffusion (flare) of a transfer pattern due to reflected light from the display device substrate side can be prevented, and further, highly accurate pattern transfer can be performed to a resist film formed on the display device substrate.
The phase shift mask blank according to embodiment 1 and the phase shift mask manufactured by the method for manufacturing a phase shift mask according to embodiment 2 are preferably used as a phase shift mask blank for projection exposure and a phase shift mask for equivalent exposure. In particular, the resist composition can be used in an exposure environment of projection exposure in which the aperture Number (NA) is equal to or less than 0.06 to 0.15.
According to the method for manufacturing a display device of embodiment 3, a high-resolution and high-definition display device which does not generate a CD error can be manufactured.
Examples
Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. The following examples are merely examples of the present invention, and the present invention is not limited thereto.
The phase shift mask blanks of examples 1 to 5 and comparative example 1 include: a transparent substrate, and a phase shift film disposed on the transparent substrate. As the transparent substrate, a synthetic quartz glass substrate having a size of 800mm×920mm and a thickness of 10mm was used.
Examples 1 to 5 and comparative example 1 will be described in detail below.
Example 1
The phase shift film in the phase shift mask blank of example 1 is composed of a phase shift layer, a metal layer, and an antireflection layer disposed in this order from the transparent substrate side, and a composition gradient region is formed at the interface between the phase shift layer and the metal layer and at the interface between the metal layer and the antireflection layer (see fig. 6).
The phase shift mask blank of example 1 was manufactured in the following manner.
First, a synthetic quartz glass substrate as a transparent substrate was prepared. Both main surfaces of the transparent substrate are mirror polished. Both main surfaces of the transparent substrates prepared in examples 2 to 5 and comparative example 1 were mirror polished in the same manner.
Next, the transparent substrate was loaded into a line sputtering apparatus. The sputtering chamber is provided in the linear sputtering apparatus.
Then, a sputtering power of 2.7kW was applied to a chromium target disposed in a sputtering chamber, and argon (Ar) and nitrogen (N) were supplied to the chamber 2 )、CO 2 Gas and oxygen (O) 2 ) Is introduced into the sputtering chamber, and the transparent substrate is conveyed at a speed of 200 mm/min. Here, ar is 35sccm, N 2 35sccm, CO 2 13sccm, O 2 The mixed gas was introduced into the sputtering chamber at a flow rate of 10 sccm. When the transparent substrate passes near the chromium target, a phase shift layer made of a chromium-based material (CrCON) containing Cr, C, O, and N is formed on the transparent substrate.
Next, a sputtering power of 0.6kW was applied to the chromium targetArgon (Ar) and CH 4 The mixed gas of the gases (CH is contained in the concentration of 4% in argon (Ar)) 4 A mixed gas of gases) was introduced into the sputtering chamber while conveying the transparent substrate at a speed of 400 mm/min. When the transparent substrate passes near the chromium target, a metal layer made of a chromium-based material (CrC) containing Cr and C is formed on the phase shift layer.
Then, sputtering power of 3.3kW was applied to the chromium target, and argon (Ar) and nitrogen (N) 2 )、CO 2 Gas and oxygen (O) 2 ) Is introduced into the sputtering chamber, and the transparent substrate is conveyed at a speed of 400 mm/min. When the transparent substrate passes near the chromium target, an antireflection layer made of a chromium-based material (CrCON) containing Cr, C, O, and N is formed on the metal layer. Here, ar is 35sccm, N 2 35sccm, CO 2 13sccm, O 2 The mixed gas was introduced into the sputtering chamber at a flow rate of 9 sccm.
Next, the phase shift film including the phase shift layer, the metal layer, and the antireflection layer was removed from the linear sputtering apparatus, and cleaned.
The phase shift layer, the metal layer, and the antireflection layer were formed continuously in the linear sputtering apparatus, without exposing the transparent substrate to the atmosphere by taking it out of the linear sputtering apparatus.
Since the phase shift film of example 1, which is composed of the phase shift layer, the metal layer, and the antireflection layer, was formed in a linear sputtering apparatus, a composition gradient region was formed in which the composition of the elements constituting each layer was continuously inclined at the interface between the phase shift layer and the metal layer and the interface between the metal layer and the antireflection layer.
The composition in the depth direction of the phase shift film of example 1 was measured by X-ray photoelectron spectroscopy (ESCA), and the result is shown in fig. 6.
The phase shift layer is made of a chromium-based material containing chromium (Cr), oxygen (O), nitrogen (N), and carbon (C), and the average content of each element is Cr:49.8 atomic percent, O:40.0 atomic percent, N:8.2 atomic%, C:2.0 atomic percent. The metal layer is made of a chromium-based material containing chromium (Cr), carbon (C), and oxygen (O), and the average content of each element is Cr:69.9 atomic percent, C:22.7 atomic percent, O:7.4 atomic percent. The antireflection layer is made of a chromium-based material containing chromium (Cr), oxygen (O), nitrogen (N), and carbon (C), and the average content of each element is Cr:48.5 atomic percent, O:47.4 atomic percent, N:3.7 atomic%, C:0.4 atomic percent. In addition, there is a composition gradient region in which each element continuously decreases or increases between the phase shift layer and the metal layer, and between the metal layer and the antireflection layer.
The bonding state (chemical state) of the elements was evaluated from the spectra of Cr, O, and N in each layer. As a result, it was confirmed that the phase shift layer mainly contains chromium nitride (CrN) and chromium (III) oxide (Cr 2 O 3 )。
It was also confirmed that the bonding state (chemical state) of the elements constituting the metal layer mainly contained chromium (Cr), and chromium (III) oxide was also present (Cr 2 O 3 )。
It was also confirmed that the bonding state (chemical state) of the elements constituting the antireflection layer mainly contained chromium (III) oxide (Cr 2 O 3 ) There are also chromium nitride (CrN) and chromium nitride (Cr) 2 N)。
The phase shift film had a transmittance of 4.9% for 365nm light and a phase difference of 187 ° by the above 3-layer structure.
The transmittance and the retardation were measured using MPM-100 (trade name) manufactured by Lasertec. The measurements were carried out in the same manner as in examples 2 to 5 and comparative example 1.
Curve a in fig. 4 shows a film surface reflectance spectrum of the phase shift film of the phase shift mask blank of example 1. Curve a in fig. 5 shows the back side reflectance spectrum of the phase shift film of the phase shift mask blank of example 1.
As can be seen from fig. 4, the film surface reflectance of the phase shift film was 13.3% at a wavelength of 313nm, 9.6% at 350nm, 8.3% at a wavelength of 365nm, 7.1% at a wavelength of 405nm, 7.3% at a wavelength of 413nm, and 8.1% at a wavelength of 436 nm. The range of variation in the film surface reflectance of the phase shift film was 2.5% in the wavelength range of 350nm to 436nm, 1.2% in the wavelength range of 365nm to 436nm, and 6.2% in the wavelength range of 313nm to 436 nm.
As can be seen from fig. 5, the back surface reflectance of the phase shift film was 9.7% at a wavelength of 313nm, 8.8% at 350nm, 9.0% at a wavelength of 365nm, 12.3% at a wavelength of 405nm, 13.2% at a wavelength of 413nm, and 16.1% at a wavelength of 436 nm. The range of variation in the film surface reflectance of the phase shift film was 7.3% in the wavelength range of 350nm to 436nm, 7.1% in the wavelength range of 365nm to 436nm, and 7.3% in the wavelength range of 313nm to 436 nm.
Thus, the film surface reflectance of the phase shift film is 15% or less in the wavelength range of 350nm to 436nm and the back surface reflectance of the phase shift film is 20% or less in the wavelength range of 365nm to 436nm, and therefore, a phase shift mask having an excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern formed thereon can be manufactured using the phase shift mask blank, so that the transfer accuracy is excellent.
The film surface reflectance and the back surface reflectance were measured using SolidSpec-3700 (trade name) manufactured by Shimadzu corporation. The measurements were carried out in the same manner as in examples 2 to 5 and comparative example 1.
Using the phase shift mask blank described above, a phase shift mask was manufactured in the following manner.
First, a resist film made of a novolak-type positive photoresist is formed on the phase shift film of the phase shift mask blank.
Then, a given pattern was drawn on the resist film using a laser plotter with a laser light having a wavelength of 413 nm.
Then, the resist film is developed with a given developer, and a resist film pattern is formed on the phase shift film.
Then, the phase shift film is etched using the resist film pattern as a mask, thereby forming a phase shift film pattern. The phase shift layer, the metal layer, and the antireflection layer constituting the phase shift film are each formed of a chromium-based material containing chromium (Cr). Thus, the phase shift layer, the metal layer, and the anti-reflection layer may be etched by the same etching solution. Here, as an etching solution for etching the phase shift film, an etching solution containing ceric ammonium nitrate and perchloric acid is used.
Then, the resist film pattern is peeled off using a resist peeling liquid.
In the phase shift mask manufactured using the phase shift mask blank, although a small amount of corrosion occurs in the metal layer located at the center in the film thickness direction of the phase shift mask, the metal layer is corroded to such an extent that the mask characteristics are not affected.
The cross section of the phase shift film pattern of the phase shift mask was observed using an electron microscope (JSM 7401F (trade name) manufactured by japan electronics corporation). The measurements were carried out in the same manner as in examples 2 to 3 and comparative example 1.
The phase shift mask manufactured using the phase shift mask blank described above was excellent in that the phase shift film pattern had a CD deviation (CD uniformity) of 70 nm. The CD bias (CD uniformity) is the width of the line and gap patterns (width of line pattern: 2.0 μm, width of gap pattern: 2.0 μm) off the target.
The CD bias of the phase shift film pattern of the phase shift mask was measured using SIR8000 manufactured by Seiko Instruments nanotechnologies. The measurements were carried out in the same manner as in examples 2 to 5 and comparative example 1.
The phase shift mask has excellent pattern cross-sectional shape, excellent CD uniformity, good transfer accuracy, low film surface reflectivity and back surface reflectivity of the phase shift film pattern to exposure light, and low back surface reflectivity of the phase shift film pattern, so that a display device can be manufactured without generating CD error and with high resolution and high definition by using the phase shift mask. In the pattern transfer step using the phase shift mask in the manufacturing process of the display device, the exposure light is a composite light including j lines, i lines, h lines, and g lines, and the exposure light is a projection exposure of an equivalent exposure having an aperture Number (NA) of 0.1.
Example 2
The phase shift film in the phase shift mask blank of example 2 is composed of a phase shift layer, a metal layer, and an antireflection layer arranged in this order from the transparent substrate side.
The phase shift layer, the metal layer, and the antireflection layer in the phase shift mask blank of example 2 were formed under the following film formation conditions.
For the phase shift layer, except for the phase shift layer having a phase shift of 35sccm according to Ar, N 2 35sccm, CO 2 100sccm, O 2 A phase shift layer made of a chromium-based material (CrON) containing Cr, O, and N was formed on a transparent substrate in the same manner as in example 1, except that a mixed gas was introduced into the sputtering chamber at a flow rate of 35 sccm.
Next, a metal layer made of a chromium-based material (CrC) containing Cr and C was formed on the phase shift layer in the same manner as in example 1, except that a sputtering power of 0.5kW was applied to the chromium target disposed in the sputtering chamber.
Next, the antireflection layer was not limited to Ar of 35sccm and N 2 35sccm, CO 2 100sccm, O 2 An antireflection layer made of a chromium-based material (CrON) containing Cr, O, and N was formed on the metal layer in the same manner as in example 1 except that a mixed gas was introduced into the sputtering chamber at a flow rate of 35 sccm.
As a result of measuring the composition in the depth direction of the phase shift film of example 2 by X-ray photoelectron spectroscopy (ESCA), the phase shift layer was mainly composed of a chromium-based material containing chromium (Cr), oxygen (O), and nitrogen (N), and the average content of each element was Cr:45.5 atomic%, O:53.8 atomic percent, N:0.6 atomic%, C:0.1 atomic percent. The metal layer is made of a chromium-based material containing chromium (Cr), carbon (C), and oxygen (O), and the average content of each element is Cr:74.7 atomic%, C:15.8 atomic percent, O:8.8 atomic percent, N:0.7 atomic percent. The antireflection layer is mainly composed of a chromium-based material containing chromium (Cr), oxygen (O), and nitrogen (N), and the average content ratio of each element is Cr:44.4 atomic percent, O:55.0 atomic percent, N:0.5 atomic%, C:0.1 atomic percent. In addition, there is a composition gradient region in which each element continuously decreases or increases between the phase shift layer and the metal layer, and between the metal layer and the antireflection layer.
The bonding state (chemical state) of the elements was evaluated from the spectra of Cr, O, and N in each layer. Its knotIt was confirmed that the phase shift layer mainly contains chromium nitride (Cr 2 N) is also present with chromium (III) oxide (Cr 2 O 3 ) And chromium (VI) oxide (CrO) 3 )。
It was also confirmed that the bonding state (chemical state) of the elements constituting the metal layer mainly contained chromium (Cr), and chromium (III) oxide was also present (Cr 2 O 3 )。
It was also confirmed that the bonding state (chemical state) of the elements constituting the antireflection layer mainly contained chromium (III) oxide (Cr 2 O 3 )。
The phase shift film had a transmittance of 4.9% for 365nm light and a phase difference of 187 ° by the above 3-layer structure.
Curve b in fig. 4 shows the film surface reflectance spectrum of the phase shift film of the phase shift mask blank of example 2. Curve b in fig. 5 shows the back side reflectance spectrum of the phase shift film of the phase shift mask blank of example 2.
As can be seen from fig. 4, the film surface reflectance of the phase shift film was 21% at a wavelength of 313nm, 14.7% at 350nm, 12.8% at a wavelength of 365nm, 10.2% at a wavelength of 405nm, 9.8% at a wavelength of 413nm, and 9.0% at a wavelength of 436 nm. The range of variation in the film surface reflectance of the phase shift film was 5.7% in the wavelength range of 350nm to 436nm, 3.8% in the wavelength range of 365nm to 436nm, and 12.0% in the wavelength range of 313nm to 436 nm.
As can be seen in fig. 5, the back surface reflectance of the phase shift film was 7.5% at a wavelength of 313nm, 8.3% at 350nm, 9.8% at a wavelength of 365nm, 14.9% at a wavelength of 405nm, 15.9% at a wavelength of 413nm, and 18.2% at a wavelength of 436 nm. The range of variation in the film surface reflectance of the phase shift film was 9.9% in the wavelength range of 350nm to 436nm, 8.3% in the wavelength range of 365nm to 436nm, and 11.0% in the wavelength range of 313nm to 436 nm.
Thus, the film surface reflectance of the phase shift film is 15% or less in the wavelength range of 350nm to 436nm and the back surface reflectance of the phase shift film is 20% or less in the wavelength range of 365nm to 436nm, and therefore, a phase shift mask having an excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern formed thereon can be manufactured using the phase shift mask blank, so that the transfer accuracy is excellent.
The film surface reflectance and the back surface reflectance were measured using SolidSpec-3700 (trade name) manufactured by Shimadzu corporation.
As in the above-described embodiment, a phase shift mask was manufactured using the phase shift mask blank of embodiment 2. The resulting phase shift mask was excellent in that the CD deviation (CD uniformity) of the phase shift film pattern was 65 nm. The CD bias (CD uniformity) is the width of the line and gap patterns (width of line pattern: 2.0 μm, width of gap pattern: 2.0 μm) off the target.
The phase shift mask has excellent pattern cross-sectional shape, excellent CD uniformity, good transfer accuracy, low film surface reflectivity of the phase shift film pattern to exposure light, and low back surface reflectivity of the phase shift film pattern, so that a display device having high resolution and high definition without CD error can be manufactured by using the phase shift mask. In the pattern transfer step using the phase shift mask in the manufacturing process of the display device, the exposure light is a composite light including j lines, i lines, h lines, and g lines, and the exposure light is a projection exposure of an equivalent exposure having an aperture Number (NA) of 0.1.
Example 3
The phase shift film in the phase shift mask blank of example 3 is composed of a phase shift layer, a metal layer, and an antireflection layer arranged in this order from the transparent substrate side. In the phase shift mask blank of example 3, the phase shift layer and the metal layer (intermediate layer) are made of molybdenum silicide material, and the antireflection layer is made of titanium material having etching selectivity to the phase shift layer and the metal layer.
The phase shift layer, the metal layer, and the antireflection layer in the phase shift mask blank of example 3 were formed under the following film formation conditions.
For the phase shift layer, a sputtering power of 6.0kW was applied to a molybdenum silicide target (Mo: si=1:4), while argon (Ar) and oxygen (O 2 ) And nitrogen (N) 2 ) Introducing into a sputtering chamber, and forming a film on a transparent substrate, wherein the film comprises Mo,A phase shift layer (film thickness: 100 nm) formed of a molybdenum silicide material (MoSiON) of Si, O and N. Here, the flow rate of the gas introduced into the sputtering chamber is as follows: argon (Ar) was 50sccm, oxygen (O) 2 ) 40sccm, nitrogen (N) 2 ) 50sccm.
For the metal layer (interlayer), argon (Ar) and nitrogen (N) were supplied with a sputtering power of 1.5kW to (Mo: si=1:4) 2 ) A metal layer (intermediate layer) made of a molybdenum silicide material (MoSiN) containing Mo, si, and N was formed on a transparent substrate while being introduced into a sputtering chamber (film thickness: 30 nm). Here, the flow rate of the gas introduced into the sputtering chamber is as follows: argon (Ar) was 60sccm and nitrogen (N) 2 ) 40sccm.
The antireflection layer was subjected to sputtering power of 2.0kW for a titanium target, and argon (Ar) and oxygen (O) 2 ) And nitrogen (N) 2 ) An antireflection layer (film thickness: 60 nm). Here, the flow rate of the gas introduced into the sputtering chamber is as follows: argon (Ar) was 100sccm and oxygen (O) 2 ) 60sccm, nitrogen (N) 2 ) 60sccm.
As a result of measuring the composition in the depth direction of the phase shift film of example 3 by X-ray photoelectron spectroscopy (ESCA), the phase shift layer was Mo:10 atomic percent, si:40 atomic percent, O:25 atomic percent, N:25 atomic percent, the metal layer (intermediate layer) is Mo:15 atomic percent, si:60 atomic percent, N:25 atomic percent of the antireflection layer is Ti:50.5 atomic percent, O:40.5 atomic percent, N:9.0 atomic%. In addition, there is a composition gradient region in which each element continuously decreases or increases between the phase shift layer and the metal layer, and between the metal layer and the antireflection layer.
The phase shift film had a transmittance of 6.60% for 365nm light and a phase difference of 183.3 ° by having the above-described 3-layer structure.
The film surface reflectance of the phase shift film was 7.60% at a wavelength of 313nm, 0.79% at 350nm, 0.05% at 365nm, 4.34% at 405nm, 5.53% at 413nm, and 8.74% at 436 nm. The range of variation in the film surface reflectance of the phase shift film was 8.69% in the wavelength range of 350nm to 436nm, 8.69% in the wavelength range of 365nm to 436nm, and 8.69% in the wavelength range of 313nm to 436 nm.
The back surface reflectance of the phase shift film was 12.52% at a wavelength of 313nm, 15.87% at 350nm, 17.36% at 365nm, 19.17% at 405nm, 19.07% at 413nm, and 18.10% at 436 nm. The range of variation in the film surface reflectance of the phase shift film was 3.30% in the wavelength range of 350nm to 436nm, 1.81% in the wavelength range of 365nm to 436nm, and 6.65% in the wavelength range of 313nm to 436 nm.
Thus, the film surface reflectance of the phase shift film is 15% or less in the wavelength range of 350nm to 436nm and the back surface reflectance of the phase shift film is 20% or less in the wavelength range of 365nm to 436nm, and therefore, a phase shift mask having an excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern formed thereon can be manufactured using the phase shift mask blank, so that the transfer accuracy is excellent.
The film surface reflectance and the back surface reflectance were measured using SolidSpec-3700 (trade name) manufactured by Shimadzu corporation.
Using the phase shift mask blank described above, a resist film pattern was formed on the phase shift film in the same manner as in example 1. Then, the antireflective layer made of the titanium-based material was wet etched using the resist film pattern as a mask with an etching solution obtained by diluting a mixed solution of ammonium bifluoride and hydrogen peroxide with pure water to form a pattern on the antireflective layer. Further, the phase shift layer and the metal layer made of a molybdenum silicide material are wet etched with an etching solution obtained by diluting a mixed solution of ammonium bifluoride and hydrogen peroxide with pure water to form a pattern on the phase shift layer and the metal layer. By this wet etching, the resist film pattern remaining on the antireflection layer is also removed. Thus, a phase shift mask is manufactured by forming a phase shift film pattern on the phase shift layer, the metal layer, and the anti-reflection layer.
The CD deviation (CD uniformity) of the phase shift film pattern of the obtained phase shift mask was 58.0nm, which was good. CD bias (CD uniformity) is the off-target line and gap pattern (width of line pattern:
Width of gap pattern 2.0 μm: 2.0 μm).
The phase shift mask has excellent pattern cross-sectional shape, excellent CD uniformity, good transfer accuracy, and low film surface reflectivity of the phase shift film pattern to exposure light, so that a display device having high resolution and high definition without generating CD error can be manufactured by using the phase shift mask. In the pattern transfer step using the phase shift mask in the manufacturing process of the display device, the exposure light is a composite light including j lines, i lines, h lines, and g lines, and the exposure light is a projection exposure of an equivalent exposure having an aperture Number (NA) of 0.1.
Further, since the phase shift mask is composed of a molybdenum silicide material as the phase shift layer and a metal layer (intermediate layer) as well as a titanium material as the antireflection layer, the phase shift mask can improve adhesion to a resist film, and is advantageous in forming a fine pattern.
Comparative example 1.
The phase shift film in the phase shift mask blank of comparative example 1 was composed of only the phase shift layer (CrOCN, film thickness 122 nm). The phase shift mask blank of comparative example 1 is different from the phase shift mask blank of the above-described embodiment in that the phase shift film does not have a metal layer and an antireflection layer.
The phase shift layer in the phase shift mask blank of comparative example 1 was formed under the following film forming conditions.
For the phase shift layer, argon (Ar) and nitrogen (N) were supplied to a chromium target disposed in a sputtering chamber with a sputtering power of 3.5kW 2 ) And CO 2 The mixed gas of the gases was introduced into the sputtering chamber, and the transparent substrate was conveyed at a speed of 200 mm/min. When the transparent substrate passed near the chromium target, a phase shift layer having a film thickness of 122nm and formed of CrOCN was formed on the main surface of the transparent substrate. Here, ar is 46sccm and N 2 Is 32sccm, CO 2 A mixed gas was introduced into the sputtering chamber at a flow rate of 18.5 sccm.
The composition in the depth direction of the phase shift film of comparative example 1 was measured by X-ray photoelectron spectroscopy (ESCA). The phase shift film is uniform in the depth direction, cr:44 atomic%, C:8 atomic percent, O:30 atomic percent, N:18 atomic%.
The phase shift film had a transmittance of 4.5% for 365nm light and a phase difference of 181 ° by the above-mentioned 1-layer structure.
Curve c in fig. 4 shows the film surface reflectance spectrum of the phase shift film of the phase shift mask blank of comparative example 1. Curve c in fig. 5 shows the back side reflectance spectrum of the phase shift film of the phase shift mask blank of comparative example 1.
As can be seen from fig. 4, the film surface reflectance of the phase shift film was 21.0% at a wavelength of 313nm, 23.9% at 350nm, 24.0% at a wavelength of 365nm, 25.1% at a wavelength of 405nm, 25.3% at a wavelength of 413nm, and 26.0% at a wavelength of 436 nm. The range of variation in the film surface reflectance of the phase shift film was 2.1% in the wavelength range of 350nm to 436nm, 2.0% in the wavelength range of 365nm to 436nm, and 12.0% in the wavelength range of 313nm to 436 nm.
As can be seen in fig. 5, the back surface reflectance of the phase shift film was 7.5% at a wavelength of 313nm, 17.1% at 350nm, 17.9% at a wavelength of 365nm, 19.9% at a wavelength of 405nm, 20.2% at a wavelength of 413nm, and 20.3% at a wavelength of 436 nm. The range of variation in the film surface reflectance of the phase shift film was 3.2% in the wavelength range of 350nm to 436nm, 2.4% in the wavelength range of 365nm to 436nm, and 11.0% in the wavelength range of 313nm to 436 nm.
Using the phase shift mask blank described above, a phase shift mask was manufactured in the same manner as in example 1.
The phase shift mask pattern section of the phase shift mask manufactured using the phase shift mask blank described above is vertical.
The CD deviation of the phase shift film pattern of the phase shift mask manufactured using the phase shift mask blank described above was 90nm, and did not reach the level required for the phase shift mask for manufacturing a high resolution, high definition display device.
The phase shift mask has an excellent pattern cross-sectional shape, but since the film surface reflectance of the phase shift film exceeds 15% in the wavelength range of 350nm to 436nm, the CD variation is large (CD uniformity is poor), and since the film surface reflectance of the phase shift film pattern against exposure light is high and the back surface reflectance of the phase shift film pattern is also higher than in the examples, a high resolution and high definition display device which does not generate CD errors cannot be manufactured using the phase shift mask. In the pattern transfer step using the phase shift mask in the manufacturing process of the display device, the exposure light is a composite light including j lines, i lines, h lines, and g lines, and the exposure light is a projection exposure of an equivalent exposure having an aperture Number (NA) of 0.1.
Example 4.
The phase shift mask blank of example 4 is a phase shift mask blank in which a light shielding film is formed on the phase shift film of example 3.
After a phase shift film was formed on a transparent substrate in the same manner as in example 3, a light shielding film was formed under the following film formation conditions. The light shielding film has a structure including a light shielding layer and a surface antireflection layer from the phase shift film side, the light shielding layer is formed as a laminated structure of a lower light shielding layer and an upper light shielding layer, and the surface antireflection layer is formed as a laminated structure of a 1 st surface antireflection layer and a 2 nd surface antireflection layer.
For the lower light shielding layer, argon (Ar) and nitrogen (N) were supplied to a sputtering power of 1.5kW to a chromium target disposed in a sputtering chamber 2 ) The mixed gas of (2) was introduced into a sputtering chamber, and a transparent substrate was conveyed at a conveying speed of 400 mm/min, whereby a lower light shielding layer made of CrN containing Cr and N was formed. In the case where Ar is 65sccm and N 2 The mixed gas was introduced into the sputtering chamber at a flow rate of 15 sccm.
Then, a sputtering power of 8.5kW was applied to a chromium target disposed in a sputtering chamber, and argon (Ar) and CH were used as the sputtering power 4 Mixed gas Ar/CH of gas 4 (4.9%) gas was introduced into the sputtering chamber, and the transparent substrate was conveyed at a conveying speed of 400 mm/min, and an upper light shielding layer made of CrC containing Cr and C was formed on the lower light shielding layer. Ar/CH as a mixed gas 4 (4.9%) was introduced into the sputtering chamber at a flow rate of 31 sccm.
Then, sputtering power of 1.5kW was applied to a chromium target disposed in a sputtering chamber, and argon (Ar) and CH were used as the sputtering power 4 Ar/CH of mixed gas of gases 4 (5.5%) gas, nitrogen (N) 2 ) And oxygen (O) 2 ) While the transparent substrate was conveyed at a conveying speed of 400 mm/min, a 1 st surface antireflection layer made of CrCON containing Cr, C, O, and N was formed on the upper light shielding layer. In accordance with Ar/CH 4 (5.5%) at 31sccm, N 2 8sccm, O 2 The mixed gas was introduced into the sputtering chamber at a flow rate of 3 sccm.
Finally, a sputtering power of 1.95kW was applied to a chromium target disposed in a sputtering chamber, and the resultant was used as argon (Ar) and CH 4 Ar/CH of mixed gas of gases 4 (5.5%) gas, nitrogen (N) 2 ) And oxygen (O) 2 ) The mixed gas of (2) was introduced into a sputtering chamber, and a 2 nd surface antireflection layer formed of CrCON containing Cr, C, O, and N was formed on the 1 st surface antireflection layer while conveying the transparent substrate at a conveying speed of 400 mm/min, to obtain a phase shift mask blank. In accordance with Ar/CH 4 (5.5%) at 31sccm, N 2 8sccm, O 2 The mixed gas was introduced into the sputtering chamber at a flow rate of 3 sccm.
The film surface reflectance of the light shielding film of the phase shift mask blank in which the phase shift film and the light shielding film were formed on the transparent substrate was 17.2% at a wavelength of 313nm, 12.1% at a wavelength of 350nm, 11.0% at 365nm, 8.2% at a wavelength of 405nm, 7.5% at a wavelength of 413nm, and 8.4% at a wavelength of 436 nm. The optical concentration at 365nm in the laminated film of the phase shift film and the light shielding film is 4.0 or more. The back surface reflectance of the phase shift film in the phase shift mask blank was 12.5% at a wavelength of 313nm, 17.4% at a wavelength of 365nm, 19.2% at a wavelength of 405nm, and 18.1% at a wavelength of 436 nm.
Thus, the film surface reflectance of the phase shift film is 15% or less in the wavelength range of 350nm to 436nm, the film surface reflectance of the light shielding film is 15% or less in the wavelength range of 350nm to 436nm, and the back surface reflectance of the phase shift film is 20% or less in the wavelength range of 365nm to 436nm, and therefore, a phase shift mask having an excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern formed thereon can be manufactured using the phase shift mask blank, and the transfer accuracy is improved.
Using the phase shift mask blank described above, a phase shift mask was manufactured in the following manner. First, a 1 st resist film pattern is formed on a light shielding film, and then, the light shielding film is wet etched with an etching solution containing ceric ammonium nitrate and perchloric acid using the 1 st resist film pattern as a mask, and a mask pattern including the light shielding film pattern is formed on a phase shift film.
Next, the phase shift film is wet etched using the mask pattern as a mask with an etching solution obtained by diluting a mixed solution of ammonium bifluoride and hydrogen peroxide with pure water, thereby forming a phase shift film pattern. The resist film pattern remaining on the mask pattern may be removed by the wet etching solution.
Next, in order to form a light shielding film pattern in the center portion of the phase shift film pattern, a resist film is formed on the mask pattern and the phase shift film pattern, and a 2 nd resist film pattern is formed on the mask pattern in the same manner as described above. Then, the light shielding film was wet etched with an etching solution containing ceric ammonium nitrate and perchloric acid using the 2 nd resist film pattern as a mask, a light shielding film pattern was formed in the center portion on the phase shift film, and finally, the resist film pattern was peeled off with a resist peeling solution, thereby producing a phase shift mask.
The CD deviation (CD uniformity) of the phase shift film pattern of the obtained phase shift mask was 57.0nm, which was good. CD bias (CD uniformity) is the off-target line and gap pattern (width of line pattern:
width of gap pattern 2.0 μm: 2.0 μm).
The phase shift mask has excellent pattern cross-sectional shape, excellent CD uniformity, good transfer accuracy, low film surface reflectivity of the phase shift film pattern and the light shielding film pattern to exposure light, and low back surface reflectivity of the phase shift film pattern, so that a display device can be manufactured without generating CD error and with high resolution and high definition by using the phase shift mask. In the pattern transfer step using the phase shift mask in the manufacturing process of the display device, the exposure light is a composite light including j lines, i lines, h lines, and g lines, and the exposure light is a projection exposure of an equivalent exposure having an aperture Number (NA) of 0.1.
Example 5
The phase shift mask blank of example 5 is a phase shift mask blank in which a phase shift film is formed on a light shielding film pattern composed of a laminate film of a back side antireflection layer and a light shielding layer on a transparent substrate.
The back surface antireflection layer and the light shielding layer in the light shielding film pattern are obtained by forming and patterning a light shielding film under the following film forming conditions.
For the back surface antireflection layer, argon (Ar) and nitrogen (N) were supplied to a sputtering power of 4.0kW to a chromium target disposed in a sputtering chamber 2 ) And oxygen (O) 2 ) The mixed gas of (2) was introduced into a sputtering chamber, and a transparent substrate was conveyed at a conveying speed of 350 mm/min, whereby a back surface antireflection layer formed of CrON containing Cr, O and N was formed. The flow rate of the gas introduced into the sputtering chamber was as follows: argon (Ar) was 100sccm and nitrogen (N) 2 ) 45sccm, oxygen (O) 2 ) 25sccm.
Then, a sputtering power of 5.0kW was applied to a chromium target disposed in a sputtering chamber, and argon (Ar) and nitrogen (N) were simultaneously supplied 2 ) The transparent substrate was conveyed at a conveying speed of 200 mm/min while being introduced into the sputtering chamber, and a light shielding layer made of CrN containing Cr and N was formed on the back surface antireflection layer. The flow rate of the gas introduced into the sputtering chamber was as follows: argon (Ar) was 130sccm and nitrogen (N) 2 ) 30sccm.
The back surface reflectance of the light shielding film formed of the laminated film of the back surface antireflection layer and the light shielding layer formed on the transparent substrate was 10.4% at a wavelength of 313nm, 6.2% at a wavelength of 365nm, 4.7% at a wavelength of 405nm, and 4.8% at a wavelength of 436 nm.
Then, the light shielding film is etched and patterned, whereby a light shielding film pattern is formed on the transparent substrate.
Next, the phase shift film of example 1 was formed on the light shielding film pattern, and a phase shift mask blank was manufactured. The phase shift mask blank had optical characteristics similar to those of example 1, in which the film surface reflectance was 13.3% at 313nm, 9.6% at 350nm, 8.3% at 365nm, 7.1% at 405nm, 7.3% at 413nm and 8.1% at 436 nm. The range of variation in the film surface reflectance of the phase shift film was 2.5% in the wavelength range of 350nm to 436nm, 1.2% in the wavelength range of 365nm to 436nm, and 6.2% in the wavelength range of 313nm to 436 nm. The back surface reflectance of the phase shift film not having the light shielding film pattern formed thereon also had the same optical characteristics as in example 1, and the back surface reflectance was 9.7% at a wavelength of 313nm, 8.8% at 350nm, 9.0% at 365nm, 12.3% at 405nm, 13.2% at 413nm, and 16.1% at 436 nm. The range of variation in the film surface reflectance of the phase shift film was 7.3% in the wavelength range of 350nm to 436nm, 7.1% in the wavelength range of 365nm to 436nm, and 7.3% in the wavelength range of 313nm to 436 nm.
Thus, the film surface reflectance of the phase shift film is 15% or less in the wavelength range of 350nm to 436nm, the back surface reflectance of the light shielding film is 15% or less in the wavelength range of 350nm to 436nm, and the back surface reflectance of the phase shift film is 20% or less in the wavelength range of 365nm to 436nm, and therefore, a phase shift mask having an excellent pattern cross-sectional shape and excellent CD uniformity and having a fine pattern formed thereon can be manufactured using the phase shift mask blank, and the transfer accuracy is improved.
Further, a phase shift mask was produced using the phase shift mask blank in the same manner as in example 1. As a result, the CD deviation (CD uniformity) of the phase shift film pattern was 70nm, which was good.
The phase shift mask has excellent pattern cross-sectional shape, excellent CD uniformity, good transfer accuracy, low film surface reflectivity and back surface reflectivity of the phase shift film pattern to exposure light, and low back surface reflectivity of the phase shift film pattern, so that a display device can be manufactured without generating CD error and with high resolution and high definition by using the phase shift mask. In the pattern transfer step using the phase shift mask in the manufacturing process of the display device, the exposure light is a composite light including j lines, i lines, h lines, and g lines, and the exposure light is a projection exposure of an equivalent exposure having an aperture Number (NA) of 0.1.
As described above, the present invention is described in detail based on the embodiments and examples, but the present invention is not limited to these. It should be apparent to those skilled in the art having ordinary technical knowledge in the field that variations and modifications can be made within the technical spirit of the present invention.

Claims (13)

1. A phase shift mask blank comprising a phase shift film on a transparent substrate,
the phase shift film is composed of at least one of a metal-based material containing 1 or more metals and at least one selected from the group consisting of oxygen, nitrogen, and carbon, or a metal silicide-based material containing 1 or more metals, silicon, and at least one selected from the group consisting of oxygen, nitrogen, and carbon,
the phase shift film has a phase shift layer having mainly a function of adjusting transmittance and phase difference with respect to exposure light, an antireflection layer disposed on an upper side of the phase shift layer having mainly a function of reducing reflectance with respect to light incident from the phase shift film side, and an intermediate layer disposed between the phase shift layer and the antireflection layer,
the intermediate layer is a metal-based material having a metal content higher than that of the antireflection layer, or a metal silicide-based material having a total content higher than that of the metal content of the antireflection layer or the total content of the metal and silicon of the antireflection layer,
By the laminated structure of the phase shift layer, the intermediate layer, and the antireflection layer, the phase shift film has given optical characteristics for transmittance and phase difference of exposure light,
the film surface reflectance of the phase shift film for light incident from the phase shift film side is 22.5% or less in a wavelength range of 313nm to 436nm, and the back surface reflectance of the phase shift film for light incident from the transparent substrate side is 20% or less in a wavelength range of 313nm to 436 nm.
2. A phase shift mask blank comprising a phase shift film on a transparent substrate,
the phase shift film is composed of at least one of a metal-based material containing 1 or more metals and at least one selected from the group consisting of oxygen, nitrogen, and carbon, or a metal silicide-based material containing 1 or more metals, silicon, and at least one selected from the group consisting of oxygen, nitrogen, and carbon,
the phase shift film has a phase shift layer having mainly a function of adjusting transmittance and phase difference with respect to exposure light, an antireflection layer disposed on an upper side of the phase shift layer having mainly a function of reducing reflectance with respect to light incident from the phase shift film side, and an intermediate layer disposed between the phase shift layer and the antireflection layer,
The intermediate layer is a metal-based material having a metal content higher than that of the antireflection layer, or a metal silicide-based material having a total content higher than that of the metal content of the antireflection layer or the total content of the metal and silicon of the antireflection layer,
by the laminated structure of the phase shift layer, the intermediate layer, and the antireflection layer, the phase shift film has given optical characteristics for transmittance and phase difference of exposure light,
the film surface reflectance of the phase shift film for light incident from the phase shift film side is 22.5% or less in a wavelength range of 313nm to 436nm, and the back surface reflectance of the phase shift film for light incident from the transparent substrate side is 20% or less in a wavelength range of 365nm to 436 nm.
3. The phase shift mask blank according to claim 1 or 2, wherein a range of variation in film surface reflectance of the phase shift film is 12.5% or less in a wavelength range of 313nm to 436 nm.
4. The phase shift mask blank according to claim 1 or 2, wherein a range of variation in back reflectivity of the phase shift film is 18% or less in a wavelength range of 313nm to 436 nm.
5. The phase shift mask blank according to claim 1 or 2, wherein the phase shift film is composed of a material that can be etched with the same etchant.
6. The phase shift mask blank according to claim 1 or 2, wherein the metal silicide-based material constituting the phase shift film is any of a nitride of a metal silicide, an oxide of a metal silicide, an oxynitride of a metal silicide, a carbide of a metal silicide, an oxycarbide of a metal silicide, and an oxycarbide of a metal silicide.
7. The phase shift mask blank according to claim 6, wherein the metal silicide-based material is a molybdenum silicide-based material, a zirconium silicide-based material, a titanium silicide-based material, a molybdenum zirconium silicide-based material.
8. The phase shift mask blank according to claim 1 or 2, wherein the metal contained in the metal-based material constituting the phase shift film is any one of chromium (Cr), zr (zirconium), molybdenum (Mo), tantalum (Ta), tungsten (W), titanium (Ti), and aluminum (Al).
9. The phase shift mask blank according to claim 1 or 2, wherein a light shielding film having a film surface reflectance of 15% or less in a wavelength range of 350nm to 436nm is provided on the phase shift film.
10. A method of fabricating a phase shift mask, the method comprising:
a step of forming a resist film on the phase shift film of the phase shift mask blank according to any one of claims 1 to 8, and forming a resist film pattern on the resist film by a drawing process and a developing process; and
And etching the phase shift film using the resist film pattern as a mask to form a phase shift film pattern on the transparent substrate.
11. A method of fabricating a phase shift mask, the method comprising:
a step of forming a resist film on the light shielding film of the phase shift mask blank according to claim 9, and forming a resist film pattern on the resist film by a drawing process and a developing process;
etching the light shielding film using the resist film pattern as a mask to form a light shielding film pattern on the phase shift film; and
and etching the phase shift film using the light shielding film pattern as a mask, thereby forming a phase shift film pattern on the transparent substrate.
12. A method of manufacturing a display device, the method comprising:
a step of placing the phase shift mask obtained by the method for manufacturing a phase shift mask according to claim 10 or 11 on a mask stage of an exposure apparatus; and
and a step of irradiating the phase shift mask with exposure light and transferring the phase shift film pattern to a resist film formed on a display device substrate.
13. The method for manufacturing a display device according to claim 12, wherein the exposure light is a composite light including light of a plurality of wavelengths selected from a wavelength range of 313nm to 436 nm.
CN202311459935.1A 2017-01-16 2018-01-15 Phase shift mask blank, method for manufacturing phase shift mask using the same, and method for manufacturing display device Pending CN117518704A (en)

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Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6342205A (en) * 1986-08-07 1988-02-23 Nec Corp Oscillation circuit
JP3262302B2 (en) * 1993-04-09 2002-03-04 大日本印刷株式会社 Phase shift photomask, blank for phase shift photomask, and method of manufacturing the same
JPH10186632A (en) * 1996-10-24 1998-07-14 Toppan Printing Co Ltd Blank for halftone type phase shift mask and halftone type phase shift mask
JP2983020B1 (en) * 1998-12-18 1999-11-29 ホーヤ株式会社 Halftone type phase shift mask blank and halftone type phase shift mask
JP2001083687A (en) * 1999-09-09 2001-03-30 Dainippon Printing Co Ltd Halftone phase shift photomask and blank for halftone phase shift photomask for producing same
US6500587B1 (en) * 2001-02-02 2002-12-31 Advanced Micro Devices, Inc. Binary and attenuating phase-shifting masks for multiple wavelengths
JP2005092241A (en) * 2002-03-01 2005-04-07 Hoya Corp Method for producing halftone phase shift mask blank
JP2003322947A (en) * 2002-04-26 2003-11-14 Hoya Corp Halftone phase shifting mask blank and halftone phase shifting mask
JP4525893B2 (en) * 2003-10-24 2010-08-18 信越化学工業株式会社 Phase shift mask blank, phase shift mask and pattern transfer method
JP4784983B2 (en) * 2006-01-10 2011-10-05 Hoya株式会社 Halftone phase shift mask blank and halftone phase shift mask
JP5121020B2 (en) * 2008-09-26 2013-01-16 Hoya株式会社 Multi-tone photomask, photomask blank, and pattern transfer method
KR101282040B1 (en) 2012-07-26 2013-07-04 주식회사 에스앤에스텍 Phase shift blankmask and photomask using the flat pannel display
JP6138676B2 (en) * 2013-12-27 2017-05-31 Hoya株式会社 Phase shift mask blank, method for manufacturing the same, and method for manufacturing the phase shift mask
JP5743008B2 (en) * 2014-06-06 2015-07-01 信越化学工業株式会社 Photomask blank and manufacturing method thereof, photomask, optical pattern irradiation method, and halftone phase shift film design method
US10146123B2 (en) * 2014-12-26 2018-12-04 Hoya Corporation Mask blank, phase shift mask, method for manufacturing phase shift mask, and method for manufacturing semiconductor device
JP6322250B2 (en) * 2016-10-05 2018-05-09 Hoya株式会社 Photomask blank

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