JP2018116263A - Phase shift mask blank and method for manufacturing phase shift mask using the same, and method for manufacturing display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phase shift mask blank to be used for forming such a phase shift mask for a display device that has an excellent pattern cross-sectional profile and excellent CD uniformity, has a fine pattern formed therein and achieves good transfer accuracy.SOLUTION: The phase shift mask blank includes a phase shift film 30 on a transparent substrate 20, in which the phase shift film is made of a metal-based material or a metal silicide-based material. The phase shift film includes a phase shift layer 31, a reflectance reducing layer 32 disposed above the phase shift layer, and an intermediate layer disposed therebetween. The intermediate layer is made of a metal-based material having a higher metal content percentage than the metal content percentage of the reflectance reducing layer, or made of a metal silicide-based material having a higher total content percentage of metal and silicon than the total content percentage of the reflectance reducing layer. The phase shift film has a film surface reflectance of 15% or less in the wavelength range from 350 nm to 436 nm; and a back surface reflectance of the phase shift film with respect to light incident on the transparent substrate side is 20% or less in the wavelength range from 365 nm to 436 nm.SELECTED DRAWING: Figure 1

Description

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

  In recent years, as display devices such as FPD (Flat Panel Display) have been improved in resolution and definition, they have excellent pattern cross-sectional shape and excellent CD uniformity, and are used for display devices in which fine patterns are formed. There is a need for a phase shift mask.

  In addition, the cost of manufacturing a phase shift mask is required to be reduced due to the price reduction of display devices such as FPDs. In the case of a conventional phase shift mask blank in which a light shielding film is formed on a phase shift film, the light shielding film is etched using the resist film pattern as a mask to form a light shielding film pattern, and then the light shielding film pattern The phase shift film is etched by using the mask as a mask to form a phase shift film pattern, and then the resist film pattern is peeled off, and further, the light shielding film pattern is peeled off to produce a phase shift mask having the phase shift film pattern. . On the other hand, in the case of the phase shift mask blank in which the light-shielding film is not formed on the phase shift film, the process of forming the light-shielding film pattern on the phase shift film and the peeling process are unnecessary, and the manufacturing cost can be reduced.

  Corresponding to such a recent situation, manufactured using a phase shift mask blank in which a light-shielding film is not formed on the phase shift film, has an excellent pattern cross-sectional shape and excellent CD uniformity, There is a demand for a phase shift mask for a display device in which a fine pattern is formed.

For example, Patent Document 1 proposes a phase shift mask blank for a display device including a phase shift film having a configuration in which two or more thin films are stacked on a transparent substrate. The thin films constituting the phase shift film have different compositions, but both are made of materials that can be etched by the same etching solution, 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-sectional inclination of the edge portion of the phase shift film pattern is steep when the phase shift film is patterned.
In Patent Document 1, at least one of films necessary for a transfer pattern including a light-shielding film, a semi-transmissive film, an etching stopper film, and a hard mask film is formed above or below the phase inversion film. There has also been proposed a phase shift mask blank for a display device provided with a functional film including the same.

JP 2014-26281 A

The phase shift film used for the phase shift mask for the display device proposed in the past considers the influence on the resist film by the reflection of the laser drawing light used when patterning the resist film used to form the phase shift film pattern. Not designed. For this reason, the film surface reflectance of the phase shift film with respect to laser drawing light exceeds 20%. As a result, a standing wave is generated in the resist film, and accordingly, the CD uniformity of the resist film pattern is deteriorated. As a result, the phase shift film pattern formed by patterning using the resist film pattern as a mask. In some cases, the CD uniformity cannot satisfy a value required in recent years.
In addition, the phase shift film used for a phase shift mask for a display device that has been proposed in the past is affected by reflection from the optical system of the exposure machine and reflection from a pellicle or display device substrate attached to the phase shift mask. Not designed with consideration. For this reason, when transferring the pattern formed on the phase shift mask using the phase shift mask for the display device, blurring (flare) of the transfer pattern caused by the reflected light from the display device substrate occurs, There is a problem that there is a risk that transfer accuracy is deteriorated or a CD error of a transfer pattern transferred to the display device substrate occurs.

  For this reason, the present invention has been made in view of the above-mentioned problems, and the film surface reflectance with respect to light in the wavelength range of 350 nm to 436 nm used as laser drawing light and the wavelength of 365 nm to 436 nm used as exposure light. Display device having an excellent pattern cross-sectional shape and excellent CD uniformity, a fine pattern is formed, and transfer accuracy is good by including a phase shift film with reduced back-surface reflectance for light in the region An object of the present invention is to provide a phase shift mask blank used for forming a phase shift mask for use, and a method of manufacturing a phase shift mask using the same. Furthermore, by using a phase shift mask for a display device that has excellent pattern cross-sectional shape and excellent CD uniformity, a fine pattern is formed and transfer accuracy is good, no CD error occurs. An object is to provide a method for manufacturing a high-resolution, high-definition display device.

  The inventor diligently studied to achieve the above-described object, and constituted the phase shift film by at least three layers, and devised the composition and film thickness of each layer constituting the phase shift film, thereby making the phase with respect to the exposure light. While the transmittance and phase difference of the shift film satisfy predetermined optical characteristics required for the phase shift film, the film surface reflectivity of the phase shift film and the light in the wavelength range of 365 nm to 436 nm with respect to light in the wavelength range of 350 nm to 436 nm. It came to the knowledge that the back surface reflectance with respect to can be reduced.

  This invention is made | formed based on this knowledge, and has the following structures.

(Configuration 1)
A phase shift mask blank comprising a phase shift film on a transparent substrate,
The phase shift film is selected from one or more metals and a metal-based material containing at least one selected from oxygen, nitrogen, and carbon, or one or more metals, silicon, oxygen, nitrogen, and carbon. Composed of at least one of metal silicide-based materials containing at least one of
The phase shift film is arranged on the upper side of the phase shift layer mainly having a function of adjusting the transmittance and phase difference with respect to exposure light, and reflects light incident from the phase shift film side. A reflectance reduction layer mainly having a function of reducing the reflectance, and an intermediate layer disposed between the phase shift layer and the reflectance reduction layer,
The intermediate layer is a metal-based material having a metal content higher than the metal content of the reflectance reduction layer, or the metal content of the reflectance reduction layer or the metal of the reflectance reduction layer A metal silicide-based material having a total content higher than the total content of silicon,
Due to the laminated structure of the phase shift layer, the intermediate layer, and the reflectance reduction layer, the transmittance and phase difference of the phase shift film with respect to exposure light have predetermined optical characteristics,
The film surface reflectance of the phase shift film with respect to light incident from the phase shift film side is 15% or less in a wavelength region of 350 nm to 436 nm, and the phase shift with respect to light incident from the transparent substrate side. A phase shift mask blank, wherein the back surface reflectance of the film is 20% or less in a wavelength range of 365 nm to 436 nm.

(Configuration 2)
The phase shift mask blank according to Configuration 1, wherein the phase shift film is made of a material that can be etched with the same etchant.

(Configuration 3)
The phase shift mask blank according to Configuration 1 or 2, wherein the metal is chromium.

(Configuration 4)
The phase shift layer and the reflectance reduction layer are made of a chromium-based material containing chromium, oxygen, and nitrogen, and chromium is 30 to 70 atomic%, oxygen is 20 to 60 atomic%, and nitrogen is 0.4 to 30 atomic%, and the content of nitrogen contained in the phase shift layer is equal to or greater than the content of nitrogen contained in the reflectance reduction layer, and oxygen contained in the reflectance reduction layer The content of is greater than the content of oxygen contained in the phase shift layer,
The intermediate layer contains chromium and carbon, the chromium content is 55 to 90 atomic%, the carbon content is 10 to 45 atomic%, and the chromium content in the intermediate layer is the phase. The phase shift mask blank according to Configuration 3, wherein the phase shift mask blank is greater than the chromium content contained in the shift layer and the reflectance reduction layer.

(Configuration 5)
The phase shift mask according to Configuration 3 or 4, wherein the phase shift layer includes chromium mononitride or dichromium nitride, and the reflectance reduction layer includes chromium (III) oxide in which chromium and oxygen are combined. blank.

(Configuration 6)
The intermediate layer is further composed of a chromium-based material containing oxygen,
The phase shift mask according to any one of configurations 3 to 5, wherein the phase shift layer, the intermediate layer, and the reflectance reduction layer include chromium (III) oxide in which chromium and oxygen are combined. blank.

(Configuration 7)
The phase shift layer is made of a metal silicide-based material containing at least one of oxygen or nitrogen, and the reflectance reduction layer is made of a metal-based material containing at least one of oxygen or nitrogen. The phase shift mask blank according to Configuration 1 or 2, wherein:

(Configuration 8)
The phase shift mask blank according to 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.

(Configuration 9)
The phase shift mask according to Configuration 1, wherein one or two of the phase shift layer, the intermediate layer, and the reflectance reduction layer are made of a material having etching selectivity with respect to other layers. blank.

(Configuration 10)
The phase shift layer and the intermediate layer are made of a material made of a chromium-based material, and the reflectance reduction layer is made of a metal-based material having etching selectivity with the phase shift layer and the intermediate layer. A phase shift mask blank according to Configuration 9, wherein

(Configuration 11)
The phase shift mask blank according to Configuration 10, wherein the reflectance reduction layer is made of titanium and a titanium-based material containing any one of oxygen and nitrogen.

(Configuration 12)
The phase shift mask blank according to any one of configurations 1 to 11, further comprising a light-shielding film pattern between the transparent substrate and the phase shift film.
(Configuration 13)
13. The phase shift mask blank according to Configuration 12, wherein a back surface reflectance of the light-shielding film pattern with respect to light incident from the transparent substrate side is 20% or less in a wavelength region of 365 nm to 436 nm.
(Configuration 14)
The light-shielding film is provided on the phase shift film, and the film surface reflectance of the light-shielding film is 15% or less in a wavelength region of 350 nm to 436 nm. The described phase shift mask blank.

(Configuration 15)
A resist film is formed on the phase shift film of the phase shift mask blank according to any one of Configurations 1 to 8, 12, and 13, and a resist film pattern is formed on the resist film by a drawing process and a development process. Forming, 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;
A method of manufacturing a phase shift mask characterized by comprising:

(Configuration 16)
A resist film is formed on the phase shift film of the phase shift mask blank according to any one of Structures 9 to 13, and a resist film pattern is formed on the resist film by a drawing process using a laser beam and a development process. Forming a step;
Etching the reflectance reduction layer using the resist film pattern as a mask to form a reflectance reduction layer pattern;
Etching the intermediate layer and the phase shift layer using the reflectance reduction layer pattern as a mask to form a phase shift film pattern on the transparent substrate;
A method of manufacturing a phase shift mask characterized by comprising:
(Configuration 17)
Forming a resist film on the light-shielding film of the phase shift mask blank according to Configuration 14, and forming a resist film pattern on the resist film by a drawing process and a development 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;
Etching the phase shift film using the light shielding film pattern as a mask to form a phase shift film pattern on the transparent substrate;
A method of manufacturing a phase shift mask characterized by comprising:

(Configuration 18)
Placing the phase shift mask obtained by the method of manufacturing a phase shift mask according to any one of Structures 15 to 17 on a mask stage of an exposure apparatus;
Irradiating the phase shift mask with exposure light to transfer the phase shift film pattern to a resist film formed on a display device substrate;
A method for manufacturing a display device, comprising:

(Configuration 19)
19. The method for manufacturing a display device according to Configuration 18, wherein the exposure light is composite light including light having a plurality of wavelengths selected from a wavelength range of 313 nm to 436 nm.

  As described above, the phase shift mask blank according to the present invention is a phase shift mask blank including a phase shift film on a transparent substrate, and the phase shift film includes at least one metal, oxygen, nitrogen, and carbon. Or at least one of a metal-based material containing at least one selected from the group consisting of one or more metals, silicon, and at least one selected from oxygen, nitrogen, and carbon. The phase shift film is disposed on the upper side of the phase shift layer mainly having a function of adjusting the transmittance and the phase difference with respect to the exposure light, and with respect to light incident from the phase shift film side. A reflectance reduction layer mainly having a function of reducing the reflectance, and an intermediate layer disposed between the phase shift layer and the reflectance reduction layer, the intermediate layer, It is a metal-based material having a metal content higher than the metal content of the emissivity reduction layer, or from the metal content of the reflectivity reduction layer or the total content of metal and silicon of the reflectivity reduction layer A metal silicide-based material having a high total content, wherein the phase shift layer, the intermediate layer, and the reflectance reduction layer have a laminated structure in which the transmittance and phase difference of the phase shift film with respect to exposure light are predetermined. The film surface reflectance of the phase shift film with respect to light incident from the phase shift film side is 15% or less in the wavelength range of 350 nm to 436 nm, and is incident from the transparent substrate side. The back surface reflectance of the phase shift film with respect to the emitted light is 20% or less in the wavelength range of 365 nm to 436 nm. For this reason, using this phase shift mask blank, it is possible to manufacture a phase shift mask having excellent pattern cross-sectional shape and excellent CD uniformity, in which a fine pattern is formed and transfer accuracy is good. . Further, by using this phase shift mask, a high-resolution and high-definition display device that does not cause a CD error can be manufactured.

It is a schematic diagram which shows the film | membrane structure of a phase shift mask blank. It is a schematic diagram which shows the other film | membrane structure of a phase shift mask blank. It is a schematic diagram which shows the other film | membrane structure of a phase shift mask blank. It is a film surface reflectance spectrum of the phase shift film of the phase shift mask blank in Examples 1 and 2 and Comparative Example 1. It is a back surface reflectance spectrum of the phase shift film of the phase shift mask blank in Examples 1 and 2 and Comparative Example 1. It is a graph which shows the composition analysis result of the depth direction with respect to the phase shift film of the phase shift mask blank in Example 1. FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the following embodiment is one form at the time of actualizing this invention, Comprising: This invention is not limited within the range. In the drawings, the same or equivalent parts may be denoted by the same reference numerals, and the description thereof may be simplified or omitted.

Embodiment 1 (Embodiments 1-1, 1-2, 1-3).
In the first embodiment, a phase shift mask blank will be described.

  FIG. 1 is a schematic diagram showing a film configuration of a phase shift mask blank 10 according to Embodiment 1-1. The phase shift mask blank 10 includes a transparent substrate 20 that is transparent to exposure light, and a phase shift film 30 that is 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 there is no surface reflection loss.

The phase shift film 30 is selected from one or more metals and a metal-based material containing at least one selected from oxygen, nitrogen, and carbon, or one or more metals, silicon, oxygen, nitrogen, and carbon. It is comprised with the metal silicide type | system | group material containing at least 1 selected.
Examples of the metal contained in the metal material include transition metals such as chromium (Cr), Zr (zirconium), molybdenum (Mo), tantalum (Ta), tungsten (W), titanium (Ti), aluminum (Al), and the like. The typical metal is mentioned.
Examples of the metal silicide-based material include metal silicide nitride, metal silicide oxide, metal silicide oxynitride, metal silicide carbonitride, metal silicide oxycarbide, and metal silicide oxycarbonitride. Is mentioned. Examples of the metal contained in the metal silicide material include the transition metals and typical metals described above.

The phase shift film 30 includes a phase shift layer 31, a metal layer 33 that is an intermediate layer, and a reflectance reduction layer 32 from the transparent substrate 20 side.
As will be described in detail in the embodiment, the phase shift film 30 may be formed of a metal material for all of the phase shift layer 31, the reflectance reduction layer 32, and the metal layer 33 (Examples 1 and 2). In addition, any one or two of the phase shift layer 31, the reflectance reduction layer 32, and the metal layer 33 may be formed of a metal material, and the other layers may be formed of a metal silicide material ( Example 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 mainly adjusting the transmittance and the phase difference with respect to the exposure light. The phase shift layer 31 is the thickest layer in the phase shift film 30 as compared with the film thickness of the reflectance reduction layer 32 and the metal layer 33. In addition, let the content rate of each element which comprises the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 mentioned later be 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 entire phase shift film 30 is composed of a chromium (Cr) -based material, the phase shift layer 31 is composed of a chromium-based material containing chromium (Cr), oxygen (O), and nitrogen (N). The average element content is preferably 30 to 70 atomic% for chromium, 20 to 60 atomic% for oxygen, and 0.4 to 30 atomic% for nitrogen. Further, the phase shift layer 31 includes chromium nitride in which chromium and nitrogen are bonded as a bonding state (chemical state) of components constituting the phase shift layer 31, and in particular, chromium mononitride (CrN) or dichromium nitride ( Preferably it contains Cr ₂ N). Furthermore, the phase shift layer 31 may have a chromium-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, and CrFCON can be cited.

When the metal of the metal silicide material constituting the phase shift film 30 includes molybdenum (Mo), zirconium (Zr), or titanium (Ti), the phase shift layer 31 includes molybdenum (Mo), silicon (Si ), Nitrogen (N) and / or oxygen (O), a molybdenum silicide-based material, and zirconium (Zr), silicon (Si), nitrogen (N) and / or oxygen (O) It is composed of a silicide material or a titanium silicide material containing titanium (Ti), silicon (Si), nitrogen (N) and / or oxygen (O). In the case of a molybdenum silicide-based material, the average content of each element is 5 to 20 atomic percent for molybdenum (Mo), 15 to 45 atomic percent for silicon (Si), 0 to 75 atomic percent for nitrogen (N), oxygen ( O) is preferably from 0 to 45 atomic%. In the case of a zirconium silicide-based material, the average content of each element is 5 to 35 atomic% for zirconium (Zr), 5 to 45 atomic% for silicon (Si), 0 to 70 atomic% for nitrogen (N), It is preferable that oxygen (O) is 0 to 70 atomic%. In the case of a titanium silicide-based material, the average content of each element is 5-30 atomic percent for titanium (Ti), 10-45 atomic percent for silicon (Si), 0-70 atomic percent for nitrogen (N), It is preferable that oxygen (O) is 0 to 60 atomic%. Furthermore, the phase shift layer 31 may have a molybdenum silicide-based material containing carbon (C) or a zirconium silicide-based material containing carbon (C).
The phase shift layer 31 can be formed by a sputtering method.

The reflectance reduction layer 32 is disposed on the upper side of the phase shift layer 31. The reflectance reduction layer 32 mainly has a function of reducing the reflectance with respect to light incident from the phase shift film 30 side (that is, the side opposite to the transparent substrate 20 side of the reflectance reduction layer 32). The thickness of the reflectance reduction layer 32 is adjusted in order to reduce the reflectance of the phase shift film 30 due to the interference effect due to the reflection at the interface between the metal layer 33 and the reflectance reduction layer 32 and the reflection from the surface of the reflectance reduction layer 32. It is a layer.
The reflectance reduction layer 32 is made of a metal material or a metal silicide material.

When the entire phase shift film 30 is composed of a chromium (Cr) -based material, the reflectance reduction layer 32 is composed of a chromium-based material containing chromium (Cr), oxygen (O), and nitrogen (N), The average content of each element is 30 to 70 atomic% for chromium, 20 to 60 atomic% for oxygen, and 0.4 to 30 atomic% for nitrogen. Further, the reflectance reduction layer 32 includes chromium oxide in which chromium and oxygen are combined as a binding state (chemical state) of components constituting the reflectance reduction layer 32, and in particular, chromium (III) oxide (Cr ₂ O ₃ ) is mainly included. Furthermore, the reflectance reduction layer 32 may have a chromium-based material containing at least one of carbon (C) and fluorine (F). For example, CrON, CrOCN, CrFON can be cited as a material for forming the reflectance reduction layer 32. In this case, from the viewpoint of reducing the reflectance with respect to light incident from the phase shift film side (surface side of the reflectance reduction layer 32) and forming an excellent pattern cross-sectional shape by wet etching as the entire phase shift film 30. The average content of nitrogen (N) contained in the phase shift layer 31 is the same as or more than the average content of nitrogen (N) contained in the reflectance reduction layer 32. The average content of oxygen (O) contained is greater than the average content of oxygen (O) contained in the phase shift layer 31. The average content of oxygen (O) contained in the reflectance reduction layer 32 is at least 1 atomic% or more, preferably 5 atomic% or more than the average content of oxygen (O) contained in the phase shift layer 31. Increasing the number is preferable in terms of the effect of reducing the film surface reflectance.

When the metal of the metal silicide material constituting the phase shift film 30 includes molybdenum (Mo), zirconium (Zr), or titanium (Ti), the reflectance reduction layer 32 includes titanium (Ti) and nitrogen (N ) And oxygen (O) and a titanium-based material containing titanium (Ti) and oxygen (O). The average content of each element is 15 to 15 for titanium (Ti). It is preferable that 45 atomic%, nitrogen (N) is 20 to 50 atomic%, and oxygen (O) is 15 to 65 atomic%. In the case of the metal silicide material constituting the phase shift film 30, the reflectance reduction layer 32 is a molybdenum silicide material containing molybdenum (Mo), silicon (Si), nitrogen (N), and oxygen (O). Molybdenum silicide-based material containing molybdenum (Mo), silicon (Si) and oxygen (O), zirconium silicide-based material containing zirconium (Zr), silicon (Si), nitrogen (N) and oxygen (O) Material, zirconium silicide material containing zirconium (Zr), silicon (Si) and oxygen (O), titanium silicide containing titanium (Ti), silicon (Si), nitrogen (N) and oxygen (O) It may be made of a titanium silicide material containing a titanium-based material, titanium (Ti), silicon (Si), and oxygen (O). That the resist film in order to secure the adhesion between the (not shown), it is preferable to perform surface treatment such as HMDS (hexamethyldisilazane).
The reflectance reduction layer 32 can be formed by a sputtering method.

The metal layer 33 is disposed between the phase shift layer 31 and the reflectance reduction layer 32. The metal layer 33 has a function of adjusting the transmittance with respect to the exposure light, and has a function of reducing the reflectance with respect to the light incident from the phase shift film 30 side in combination with the reflectance reduction layer 32. Further, in combination with the phase shift layer, it has a function of reducing the reflectance with respect to light incident from the transparent substrate 20 side.
The metal layer 33 is a metal-based material having an average metal content that is higher than the average metal content of the reflectance reduction layer 32, or the average content of the sum of the metal and silicon of the reflectance reduction layer 32. It is composed of a metal silicide-based material having a total average content rate higher than the rate.

When the entire phase shift film 30 is made of a chromium (Cr) -based material, or 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 each element is 55 to 90 atomic% of chromium (Cr) and carbon (C). The average content of chromium contained in the metal layer 33 is higher than the average content of chromium contained in the phase shift layer 31 and the reflectance reduction layer 32. When the entire phase shift film 30 is etched with the same etchant, by setting the average content of carbon (C) to 10 atomic% or more, it is possible to suppress the cross-sectional shape of the metal layer 33 from becoming a tapered shape. . Moreover, it can suppress that the cross-sectional shape of the metal layer 33 becomes a taper shape because the average content rate of carbon (C) contained in the metal layer 33 shall be 45 atomic% or less. By setting the average content of carbon (C) contained in the metal layer 33 in the appropriate range, a pattern can be formed in 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 cited. Among these, the metal layer 33 is preferably a chromium-based material containing chromium (Cr), carbon (C), and oxygen (O). Then, as a combined state (chemical state) of components constituting the phase shift layer 31, the reflectance reduction layer 32, and the metal layer 33, all of these layers are oxidized from the viewpoint of obtaining an excellent pattern cross-sectional shape by wet etching. More preferably, it contains chromium (III) (Cr ₂ O ₃ ).

Further, when the metal of the metal material constituting the phase shift film 30 includes titanium (Ti) and the metal of the metal silicide material includes molybdenum (Mo), zirconium (Zr), or titanium (Ti). The metal layer 33 is made of molybdenum silicide-based material containing molybdenum (Mo), silicon (Si), carbon (C) and / or nitrogen (N), zirconium (Zr), silicon (Si), Zirconium silicide-based material containing carbon (C) and / or nitrogen (N), and titanium silicide containing titanium (Ti) and silicon (Si) and carbon (C) and / or nitrogen (N) Consists of system materials. In the case of a molybdenum silicide-based material, the average content of each element is 5 to 20 atomic% for molybdenum (Mo), 15 to 70 atomic% for silicon (Si), 0 to 20 atomic% for carbon (C), nitrogen ( N) is preferably from 0 to 30 atomic%. In the case of a zirconium silicide-based material, the average content of each element is 5 to 35 atomic% for zirconium (Zr), 5 to 70 atomic% for silicon (Si), 0 to 20 atomic% for carbon (C), It is preferable that nitrogen (N) is 0 to 20 atomic%. In the case of a titanium silicide material, the average content of each element is 5 to 35 atomic% for titanium (Ti), 5 to 70 atomic% for silicon (Si), 0 to 20 atomic% for carbon (C), It is preferable that nitrogen (N) is 0 to 20 atomic%. The average content of molybdenum silicide contained in the metal layer 33, the average content of zirconium silicide, and the average content of titanium silicide are the average content of molybdenum silicide contained in the phase shift layer 31 and the reflectance reduction layer 32, and zirconium silicide. More than the average content of titanium silicide. Further, the metal layer 33 may be a molybdenum silicide material, a zirconium silicide material, or a titanium silicide material containing at least one of oxygen (O). For example, the material for forming the metal layer 33 includes MoSiC, MoSiN, MoSiCN, MoSiCO, MoSiCON, ZrSiC, ZrSiN, ZrSiCN, ZrSiCO, ZrSiCON, TiSiC, TiSiN, TiSiCN, TiSiCO, and TiSiCON.
By providing the metal layer 33, the sheet resistance of the phase shift film 30 is lowered, so that charge up of the phase shift mask blank and the phase shift mask can be prevented. When the metal layer 33 is not provided, since the electricity generated when the phase shift mask blank and the phase shift mask are taken in and out of the case does not escape and the electricity is stored in the phase shift mask blank and the phase shift mask, foreign matter is easily attached. Further, when a small pattern is formed on the phase shift mask, electricity jumps from pattern to pattern, and electrostatic breakdown is likely to occur.
The metal layer 33 can be formed by a sputtering method.

It is preferable that the metal layer 33 has an extinction coefficient higher than the extinction coefficient of the reflectance reduction layer 32 in a wavelength region of 350 nm to 436 nm. Further, it is preferable that the extinction coefficient is higher than the extinction coefficient of the reflectance reduction layer 32 in the wavelength region of 313 nm to 436 nm.
The difference between the extinction coefficient of the metal layer 33 and the extinction coefficient of the reflectance reduction layer 32 is preferably 1.5 to 3.5, and more preferably 1.8 to 3.5. When the difference in extinction coefficient is 1.5 to 3.5, the above wavelength range (the wavelength range of 350 nm to 436 nm or the wavelength range of 313 nm to 436 nm) of the interface between the metal layer 33 and the reflectance reduction layer 32. ), The reflectance can be increased, so that the effect of reducing the reflectance is further exhibited.
In addition, it is preferable that the metal layer 33 has an extinction coefficient higher than the extinction coefficient of the phase shift layer 31 in a wavelength range of 350 nm to 436 nm. Further, it is preferable that the extinction coefficient is higher than the extinction coefficient of the phase shift layer 31 in the wavelength range of 313 nm to 436 nm.
The extinction coefficient can be measured using an n & k analyzer or an ellipsometer.

When the metal layer 33 and the reflectance reduction layer 32 are made of a chromium-based material, the metal layer 33 contains a chromium (Cr) average content higher than the chromium (Cr) average content (atomic%) of the reflectance reduction layer 32. Rate (atomic%).
The difference between the Cr average content rate of the metal layer 33 and the Cr average content rate of the reflectance reduction layer 32 is preferably 10 to 80 atomic%, and more preferably 15 to 80 atomic%. When the difference in the average Cr content is 10 to 80 atomic%, the above wavelength range of the interface between the metal layer 33 and the reflectance reduction layer 32 (a wavelength range of 350 nm to 436 nm or a wavelength range of 313 nm to 436 nm) Since the reflectance in can be increased, the effect of reducing the reflectance is further exhibited, which is preferable. The etching rate of the metal layer 33 can be adjusted by adding chromium (Cr) to nitrogen (N), oxygen (O), carbon (C), and fluorine (F) to obtain a chromium-based material. . For example, by adding carbon (C) or fluorine (F) to chromium (Cr), the wet etching rate can be slowed down, and nitrogen (N) or oxygen (O) is included in chromium (Cr). Thus, the wet etching rate can be increased. In consideration of the wet etching rate with the phase shift layer 31 and the reflectance reduction layer 32 formed above and below the metal layer 33, a phase after etching is obtained by using a chromium-based material in which the above-described elements are added to chromium. The cross-sectional shape of the shift film 30 can be improved.
The metal layer 33 has a chromium (Cr) average content rate that is higher than the chromium (Cr) average content rate of the phase shift layer 31.

Each of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 preferably has a refractive index of 2.0 or more in a wavelength region of 350 nm to 436 nm. When the refractive index is 2.0 or more, the thickness of the phase shift film 30 necessary for obtaining desired optical characteristics (transmittance and phase difference) can be reduced. Therefore, the phase shift mask manufactured using the phase shift mask blank 10 provided with the phase shift film 30 can include a phase shift film pattern having excellent pattern cross-sectional shape and excellent CD uniformity.
The refractive index can be measured using an n & k analyzer or an ellipsometer.

Due to the laminated structure of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32, the transmittance and phase difference of the phase shift film 30 with respect to the exposure light have predetermined optical characteristics.
The phase shift film 30 may be made of a material that can be etched with the same etchant for any of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32. The phase shift layer 31, the metal layer 33, and One or two of the reflectance reduction layers 32 may be made of a material having etching selectivity with respect to other layers.

  The transmittance of the phase shift film 30 with respect to the exposure light satisfies a value necessary for the phase shift film 30. The transmittance of the phase shift film 30 is preferably 1% to 70%, more preferably 2% to 60% with respect to light having a predetermined wavelength included in the exposure light (hereinafter referred to as a representative wavelength). And more preferably 3% to 50%. That is, when the exposure light is composite light including light having a wavelength range of 313 nm to 436 nm, the phase shift film 30 has the above-described transmittance with respect to light having a representative wavelength included in the wavelength range. For example, when the exposure light is j-ray (wavelength: 313 nm), i-line (wavelength: 365 nm), h-line (wavelength: 405 nm) and g-line (wavelength: 436 nm), the phase shift film 30 is It has the transmittance described above for any of 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 for the phase shift film 30. The phase difference of the phase shift film 30 is preferably 160 ° to 200 °, and more preferably 170 ° to 190 ° with respect to the light having the representative wavelength included in the exposure light. Due to this property, the phase of the light having the representative wavelength contained in the exposure light can be changed by 160 ° to 200 °. For this reason, a phase difference of 160 to 200 ° is generated between the light with the representative wavelength transmitted through the phase shift film 30 and the light with the representative wavelength transmitted through only the transparent substrate 20. That is, when the exposure light is a composite light including light having a wavelength range of 313 nm or more and 436 nm or less, the phase shift film 30 has the above-described phase difference with respect to light having a representative wavelength included in the wavelength range. For example, when the exposure light is a composite light including j-line, i-line, h-line, and g-line, the phase shift film 30 has been described above for any of the j-line, i-line, h-line, and g-line. Has a phase difference.

The transmittance and phase difference of the phase shift film 30 can be controlled by adjusting the composition and thickness of each of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 constituting the phase shift film 30. . For this reason, in this embodiment, the composition of each of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 is set so that the transmittance and the phase difference of the phase shift film 30 have the predetermined optical characteristics described above. The thickness is adjusted. 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 amount measuring device or the like.

  The film surface reflectance of the phase shift film 30 with respect to light incident from the phase shift film 30 side is 15% or less in the wavelength region of 350 nm to 436 nm. Moreover, it is preferable that it is 22.5% or less in the wavelength range of 313 nm-436 nm. That is, the film surface reflectance of the phase shift film 30 with respect to light incident from the phase shift film 30 side is 15% or less in the wavelength range of 350 nm to 436 nm, and even if the wavelength range is expanded to 313 nm to 436 nm, 22% The following is preferable. When the film surface reflectance of the phase shift film 30 is 15% or less in the wavelength region of 350 nm to 436 nm, the film surface reflectance with respect to the laser drawing light is reduced, so that a phase shift mask having excellent CD uniformity is formed. be able to. Further, when the film surface reflectance of the phase shift film 30 is 22.5% or less in the wavelength region of 313 nm to 436 nm, the film surface reflectance with respect to the exposure light is reduced. When transferring, it is possible to prevent the transfer pattern from being blurred (flared) due to the reflected light from the display device substrate. The film surface reflectance of the phase shift film 30 is preferably 20% or less, more preferably 15% or less, in the range of 313 nm to 436 nm.

  The fluctuation range of the film surface reflectance of the phase shift film 30 is preferably 9% or less, more preferably 8.5% or less in the wavelength region of 350 nm to 436 nm. Moreover, it is preferable that it is 12.5% or less in the wavelength range of 313 nm-436 nm, More preferably, it is 12%. That is, the fluctuation range of 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 350 nm to 436 nm, even if the wavelength range is expanded to 313 nm to 436 nm. It is preferably 12.5% or less, and more preferably 12% or less.

  The back surface reflectance of the phase shift film 30 with respect to light incident from the transparent substrate 20 side is 20% or less in a wavelength region of 365 nm to 436 nm. Moreover, it is preferable that it is 20% or less also in the wavelength range of 313 nm-436 nm. By setting the back surface reflectivity of the phase shift film 30 within the above range, the back surface reflectivity for the exposure light of the phase shift film 30 is reduced. Therefore, when transferring the pattern formed on the phase shift mask, Deterioration of transfer accuracy due to reflected light from the optical system can be suppressed. In addition to the requirements for 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 region of 350 nm to 436 nm, reflection from the optical system of the exposure machine and phase shift Since the influence of reflection on the pellicle and the display device substrate attached to the mask can be reduced, a transfer accuracy is improved, and a phase shift mask that prevents a CD error of a transfer pattern transferred to the display device substrate can be formed. it can.

  The fluctuation range of 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 365 nm to 436 nm. Moreover, it is preferable that it is 18% or less in a wavelength range of 313 nm-436 nm, More preferably, it is 16%. That is, the fluctuation range of 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 350 nm to 436 nm, and the wavelength range is 313 nm to 436 nm. It is preferably 12.5% or less, more preferably 12% or less.

The film surface reflectivity, the back surface reflectivity, and the fluctuation width thereof of the phase shift film 30 are the refractive index and extinction coefficient of each of the phase shift layer 31, the metal layer 33, and the reflectivity reduction layer 32 constituting the phase shift film 30. And can be controlled by adjusting the thickness. Since the extinction coefficient and the refractive index can be controlled by adjusting the composition, in this embodiment, the film surface reflectance, the back surface reflectance, and the fluctuation width thereof of the phase shift film 30 are the predetermined values described above. The composition and thickness of each of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 are adjusted so as to have physical properties. Note that the film surface reflectance, the back surface reflectance, and the fluctuation range thereof of the phase shift film 30 are mainly affected by the composition and thickness of the metal layer 33 and the reflectance reduction layer 32.
The film surface reflectance and the back surface reflectance can be measured using a spectrophotometer or the like. The fluctuation range of the film surface reflectance is obtained from the difference between the maximum reflectance and the minimum reflectance in the wavelength range of 350 nm to 436 nm or 313 nm to 436 nm.

The phase shift layer 31 may be composed of a single film having a uniform composition, or may be composed of a plurality of films having different compositions, or the composition continuously changes in the thickness direction. It may be a case of a single film. The same applies to the metal layer 33 and the reflectance reduction layer 32.
In addition, each element constituting each phase shift layer 31, metal layer 33, and reflectance reduction layer 32 is continuously present at the interface between the phase shift layer 31 and the metal layer 33 and at the interface between the metal layer 33 and the reflectance reduction layer 32. You may have the composition inclination area | region where the composition inclination was carried out.

  FIG. 2 is a schematic diagram illustrating another film configuration of the phase shift mask blank 10 according to Embodiment 1-2. As shown in FIG. 2, the phase shift mask blank 10 may include a light shielding film pattern 40 between the transparent substrate 20 and the phase shift film 30. The phase shift film 30 in the embodiment 1-2 is the same as that in the embodiment 1-1, and the description 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 blocking film pattern 40 has a function of blocking the transmission of exposure light.
The material for forming the light-shielding film pattern 40 is not particularly limited as long as the material has a function of blocking the transmission of exposure light. If necessary, a back surface reflectance reduction layer 41 for reducing the back surface reflectance of the light shielding film pattern 40 with respect to light incident from the transparent substrate 20 side is formed on the transparent substrate 20 side of the light shielding film pattern 40. It doesn't matter. In this case, the light-shielding film pattern 40 includes a back surface reflectance reduction layer 41 and a light-shielding layer 42 having a function of shielding the exposure light from the transparent substrate 20 side. For example, examples of the material for the light-shielding film pattern include metal materials such as chromium materials and metal silicide materials. Examples of the chromium-based material include chromium (Cr) or a chromium-based material containing chromium (Cr) and at least one of carbon (C) and nitrogen (N). In addition, a chromium-based material containing chromium (Cr) and at least one of oxygen (O) and fluorine (F), or chromium (Cr), at least of carbon (C) and nitrogen (N) And a chromium-based material containing at least one of oxygen (O) and fluorine (F). For example, as a material for forming the light-shielding film pattern 40, Cr, CrC, CrN, CrCN, CrO, CrON, CrCO, and CrCON can be cited.

Metal silicide materials include metal silicide, metal silicide nitride, metal silicide oxide, metal silicide oxynitride, metal silicide oxynitride, metal silicide oxycarbide, and metal silicide oxycarbonitride Is mentioned. Examples of the metal contained in the metal silicide material include the transition metals and typical metals described above.
In addition, when the light-shielding film pattern 40 is provided with the back surface reflectance reduction layer 41, it is preferable that the back surface reflectance reduction layer 41 has a characteristic of 20% or less in a wavelength region of 365 nm to 436 nm. Furthermore, the back surface reflectance reduction layer 41 preferably has a characteristic of 20% or less in the wavelength range of 313 nm to 436 nm.
The light shielding film pattern 40 can 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 laminated, the optical density with respect to the exposure light is preferably 3 or more, and more preferably 3.5 or more.
The optical density can be measured using a spectrophotometer or an OD meter.

The light-shielding film pattern 40 may be composed of a single film having a uniform composition, or may be composed of a plurality of films having different compositions, and the composition is continuously in the thickness direction. It may be composed of a single film that changes.
The material of the light-shielding film pattern 40 may be a material having etching selectivity with respect to the phase shift film 30 (phase shift layer 31, metal layer 33, reflectance reduction layer 32) or not having etching selectivity. It may be a material.

Next, FIG. 3 is a schematic diagram illustrating another film configuration of the phase shift mask blank 10 according to Embodiment 1-3. As shown in FIG. 3, the phase shift mask blank 10 may include 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, or may be formed of a plurality of films having different compositions, or the composition continuously changes in the thickness direction. It may be a case of a single film. The phase shift film 30 in the embodiment 1-3 is the same as that in the embodiment 1-1, and the description is omitted. The material for forming the light-shielding film 45 is not particularly limited as long as the material has a function of blocking the transmission of exposure light. If necessary, a surface reflectance reduction layer 47 for reducing the film surface reflectance of the light shielding film 45 with respect to light incident on the surface side of the light shielding film 45 may be formed. In this case, the light-shielding film 45 includes a light-shielding layer 46 having a function of shielding the transmission of exposure light from the phase shift film 30 side and a surface reflectance reduction layer 47. For example, as the material of the light-shielding film 45, the same material as that of the above-described light-shielding film pattern 40 can be used. In addition, when the light-shielding film 45 includes the surface reflectance reduction layer 47, the surface reflectance reduction layer 47 preferably has a characteristic of 20% or less in a wavelength range of 365 nm to 436 nm. Further, the surface reflectance reduction layer 47 preferably has a characteristic of 22.5% or less in the wavelength region of 313 nm to 436 nm. The light shielding layer 46 and the surface reflectance reduction layer 47 may each be a single layer, or at least one of them may have a plurality of laminated structures.
The light shielding film 45 can be formed by a sputtering method.

In Embodiment 1-3, the material of the light-shielding film 45 may be a material having etching selectivity with respect to the phase shift film 30 (phase shift layer 31, metal layer 33, reflectance reduction layer 32). A material having no etching selectivity may be used. Considering the manufacturing process of the phase shift mask, the light shielding film 45 is preferably made of a material having etching selectivity with respect to the phase shift film 30.
In the phase shift mask blank 10 of the embodiment 1-2 or the embodiment 1-3, the phase shift film 30 and the light shielding film are interposed between the phase shift film 30 and the light shielding film pattern 40 as necessary. Another functional film can be formed on the light-shielding film 45. Examples of the functional film include an etching stopper film and an etching mask film.

  In addition, the phase shift mask blank 10 of Embodiment 1-1 or Embodiment 1-2 may be provided with a resist film on the phase shift film 30, or the phase shift of Embodiment 1-3. The mask blank 10 may include a resist film on the light shielding film 45.

Next, a method for manufacturing the phase shift mask blank 10 of the above-described Embodiments 1-1 and 1-2 will be described. The phase shift mask blank 10 is manufactured by performing the following preparation process and phase shift film formation process.
Hereinafter, each process will be described in detail.

1. Preparation Step In the preparation step, first, the transparent substrate 20 is prepared. The material of the transparent substrate 20 is not particularly limited as long as it is a material having translucency with respect to the exposure light to be used. Examples thereof include synthetic quartz glass, soda lime glass, and alkali-free glass.
When manufacturing the phase shift mask blank 10 provided with the light-shielding film pattern 40 of Embodiment 1-2, after that, the light-shielding film which consists of chromium materials, for example is formed on the transparent substrate 20 by sputtering method. Thereafter, 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 the light shielding film pattern 40. Thereafter, the resist film pattern is peeled off. When 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, for example, chromium oxide containing chromium and oxygen is formed on the transparent substrate 20 by sputtering. A light-shielding film is formed by forming a back-surface reflectance reduction layer 41 made of the above and a light-shielding layer 42 of a chromium-based material containing chromium on the back-surface reflectance reduction layer 41. Thereafter, 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 the light shielding film pattern 40. Thereafter, the resist film pattern is peeled off to obtain the light-shielding film pattern 40 on the transparent substrate 20.

2. Phase Shift Film Forming Step In the phase shift film forming step, a phase shift film 30 made of a metal material or a metal silicide material is formed on the transparent substrate 20 by sputtering. Here, when the light-shielding film pattern 40 is formed on the transparent substrate 20, the phase shift film 30 is formed so as to cover the light-shielding film pattern 40.

  The phase shift film 30 is formed by forming a phase shift layer 31 on the main surface of the transparent substrate 20, forming a metal layer 33 on the phase shift layer 31, and forming a reflectance reduction layer 32 on the metal layer 33. It is formed by doing. Hereinafter, a case where the phase shift film 30 is formed of a chromium-based material will be described. Even when the phase shift film 30 is formed of another metal-based material or a metal silicide-based material, it can be similarly formed by a sputtering method by adjusting the material of the sputtering target and the sputtering atmosphere.

  The phase shift layer 31 is formed by using a sputtering target containing chromium or a chromium-based material, for example, an inert material containing at least one selected from the group consisting of helium gas, neon gas, argon gas, krypton gas, and xenon gas. A sputtering gas comprising a mixed gas of a gas and an active gas containing at least one selected from the group consisting of oxygen gas, nitrogen gas, nitrogen monoxide gas, nitrogen dioxide gas, carbon dioxide gas, hydrocarbon gas, and fluorine gas Done in an atmosphere. Examples of the hydrocarbon gas include methane gas, butane gas, propane gas, and styrene gas. As the sputtering target, chromium-based materials such as chromium oxide, chromium nitride, chromium oxynitride, chromium oxynitride chromium carbide, etc. can be used in addition to chromium metal.

  Similarly, the formation of the metal layer 33 includes, for example, at least one selected from the group consisting of helium gas, neon gas, argon gas, krypton gas, and xenon gas using a sputtering target containing chromium or a chromium-based material. A sputtering gas atmosphere made of an inert gas, or an inert gas containing at least one selected from the group consisting of helium gas, neon gas, argon gas, krypton gas and xenon gas, and oxygen gas, nitrogen gas, nitrogen monoxide gas, It is performed in a sputtering gas atmosphere made of a mixed gas with an active gas containing at least one selected from the group consisting of nitrogen dioxide gas, carbon dioxide gas, hydrocarbon gas, and fluorine gas. Examples of the hydrocarbon gas include methane gas, butane gas, propane gas, and styrene gas. As the sputtering target, chromium-based materials such as chromium oxide, chromium nitride, chromium oxynitride, chromium oxynitride chromium carbide, etc. can be used in addition to chromium metal.

  Similarly, the reflectance reduction layer 32 is formed by using a sputtering target containing chromium or a chromium-based material, for example, at least one selected from the group consisting of helium gas, neon gas, argon gas, krypton gas, and xenon gas. A mixed gas of an inert gas containing oxygen and an active gas containing at least one selected from the group consisting of oxygen gas, nitrogen gas, nitrogen monoxide gas, nitrogen dioxide gas, carbon dioxide gas, hydrocarbon gas, and fluorine gas Is performed in a sputtering gas atmosphere. Examples of the hydrocarbon gas include methane gas, butane gas, propane gas, and styrene gas. As the sputtering target, chromium-based materials such as chromium oxide, chromium nitride, chromium oxynitride, chromium oxynitride chromium carbide, etc. can be used in addition to chromium metal.

  When the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 are formed, the composition and thickness of each of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 are determined by the transmittance of the phase shift film 30. The phase difference has the above-mentioned predetermined optical characteristics, and the film surface reflectance, the back surface reflectance, and the fluctuation range thereof of the phase shift film 30 are adjusted to have the above-described predetermined physical properties / optical characteristics. . The composition of each of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 can be controlled by the composition and flow rate of the sputtering gas. The thickness of each of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 can be controlled by sputtering power, sputtering time, and the like. Further, when the sputtering apparatus is an in-line type sputtering apparatus, the thickness of each of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 can be controlled also by the transport speed of the substrate.

When the phase shift layer 31 is formed of a single film having a uniform composition or a plurality of films, the above-described film formation process is performed only once or a plurality of times without changing the composition and flow rate of the sputtering gas. Do.
When the phase shift layer 31 is composed of a plurality of films having different compositions, the above-described film formation process is performed a plurality of times by changing the composition and flow rate of the sputtering gas for each film formation process. Perform multiple times, or a combination thereof.
For example, when the phase shift layer 31 is formed of a single film whose composition changes continuously in the thickness direction, the above-described film forming process is performed only once while changing the composition and flow rate of the sputtering gas. The same applies to the formation of the metal layer 33 and the formation of the reflectance reduction layer 32. When the film forming process is performed a plurality of times, the sputtering power applied to the sputtering target can be reduced. Even when the composition of at least one of the metal layer 33 and the reflectance reduction layer 32 is different from that of the phase shift layer 31, if the different composition is a non-metallic composition such as C, N, and O, the above-described film forming process is performed. A film can be formed by changing the composition and flow rate of the sputtering gas for each film forming process. In addition, when a different composition is a metal (Cr, Si, Zr), the change of a target is needed. In this case, a plurality of targets having different compositions are set in advance, and the position of the target to be discharged is changed depending on the target composition.

  It is preferable that the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 are continuously formed using an in-line type sputtering apparatus without taking the transparent substrate 20 out of the apparatus and exposing it to the atmosphere. By continuously forming the film without taking it out of the apparatus, unintended surface oxidation and surface carbonization of each layer can be prevented. Unintentional surface oxidation or surface carbonization of each layer transfers the phase shift film pattern to the laser beam used when drawing the resist film formed on the phase shift film 30 or the resist film formed on the display device substrate. There is a possibility that the reflectance with respect to the exposure light used at the time may be changed, or the etching rate of the oxidized portion or the carbonized portion may be changed.

  In addition, when manufacturing the phase shift mask blank 10 provided with a resist film, next, a resist film is formed on a phase shift film.

  In the phase shift mask blank 10 according to Embodiment 1-1, the phase shift film 30 made of a metal material or a metal silicide material provided on the transparent substrate 20 includes a phase shift layer 31 and a reflectance reduction layer 32. And a metal layer 33 provided between the phase shift layer 31 and the reflectance reduction layer 32 and having an average chromium content higher than the average chromium content of the reflectance reduction layer 32, and exposure. While the transmittance and phase difference of the phase shift film 30 with respect to light satisfy predetermined optical characteristics required for the phase shift film 30, the film surface reflectance of the phase shift film 30 is 15% or less in the wavelength range of 350 nm to 436 nm. And the back surface reflectance of the phase shift film 30 is 20% or less in the wavelength region of 365 nm to 436 nm. For this reason, a phase shift mask having excellent pattern cross-sectional shape and excellent CD uniformity, a fine pattern is formed, and transfer accuracy is good using this phase shift mask blank 10. it can.

  Next, the manufacturing method of the phase shift mask blank 10 in Embodiment 1-3 is demonstrated. The manufacturing method of the phase shift mask blank 10 of the embodiment 1-3 described above is the same as the above-mentioned “1. preparation step” and “2. phase shift film formation step”, and thus the description thereof is omitted. The light shielding film forming step will be described.

3. Light-shielding film forming step In the light-shielding film forming step, a 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 by depositing a light shielding layer 46 on the phase shift film 30 and, if necessary, a surface reflectance reduction layer 47 on the light shielding layer 46. In the following, a case where the phase shift film 30 is made of a metal silicide material and the light shielding film 45 is made of a chromium material will be described. When the phase shift film 30 is a metal material (for example, chromium material), the light shielding film 45 is formed of a metal silicide material, or the phase shift film 30 and the light shielding film 45 are a metal material. (E.g., a chromium-based material), a material having an etching selectivity between the phase shift film 30 and the light-shielding film 45 (e.g., a metal silicide-based material) can also be used as a sputtering target material. By adjusting the sputtering atmosphere, it can be similarly formed by a sputtering method.

  The light shielding layer 46 is formed by using a sputtering target containing chromium or a chromium-based material, for example, an inert gas containing at least one selected from the group consisting of helium gas, neon gas, argon gas, krypton gas, and xenon gas. And a sputter gas atmosphere comprising a mixed gas of oxygen gas, nitrogen gas, nitrogen monoxide gas, nitrogen dioxide gas, carbon dioxide gas, hydrocarbon gas, and active gas selected from the group consisting of fluorine gas Done in Examples of the hydrocarbon gas include methane gas, butane gas, propane gas, and styrene gas. As a sputtering target, chromium-based materials such as chromium oxide, chromium nitride, chromium carbide, chromium oxynitride, chromium oxide carbide, chromium nitride carbide, chromium oxynitride chromium carbide and the like can be used in addition to chromium metal.

Similarly, the film formation of the surface reflectivity reducing layer 47 is performed using a sputtering target containing chromium or a chromium-based material, for example, at least selected from the group consisting of helium gas, neon gas, argon gas, krypton gas, and xenon gas. Mixing of an inert gas containing one kind and an active gas containing at least one kind selected from the group consisting of oxygen gas, nitrogen gas, nitrogen monoxide gas, nitrogen dioxide gas, carbon dioxide gas, hydrocarbon gas, and fluorine gas It is performed in a sputtering gas atmosphere made of gas. Examples of the hydrocarbon gas include methane gas, butane gas, propane gas, and styrene gas. As a sputtering target, chromium-based materials such as chromium oxide, chromium nitride, chromium carbide, chromium oxynitride, chromium oxide carbide, chromium nitride carbide, chromium oxynitride chromium carbide and the like can be used in addition to chromium metal.
When the light shielding layer 46 and the surface reflectance reduction layer 47 are formed, the composition and thickness of each of the light shielding layer 46 and the surface reflectance reduction layer 47 are the same as the optical density and the film surface reflectance of the light shielding film 45 described above. Predetermined physical properties and optical characteristics (in the combination of the phase shift film 30 and the light-shielding film 45, the optical density is 3.0 or more and the film surface reflectance of the light-shielding film 45 is 15 in the wavelength region of 350 nm to 436 nm. % Or less). The compositions of the light shielding layer 46 and the surface reflectance reduction layer 47 of the light shielding film 45 can be controlled by the composition and flow rate of the sputtering gas. The thicknesses of the light shielding layer 46 and the surface reflectance reduction layer 47 can be controlled by the sputtering power, the sputtering time, and the like. Further, when the sputtering apparatus is an in-line type sputtering apparatus, the thicknesses of the light shielding layer 46 and the surface reflectance reduction layer 47 can be controlled also by the substrate transport speed.

Embodiment 2 (Embodiments 2-1, 2-2).
In the second embodiment, a method for manufacturing a phase shift mask will be described. The embodiment 2-1 is a method of manufacturing a phase shift mask using the phase shift mask blank of the embodiments 1-1 and 1-2. The embodiment 2-2 is a method of manufacturing a phase shift mask using the phase shift mask blank of the embodiment 1-3. The manufacturing method of the phase shift mask of Embodiment 2-1 uses the phase shift mask blank of Embodiment 1-1, 1-2, and forms the following resist film patterns (resist film pattern formation process) And a step of forming a phase shift film pattern (phase shift film pattern formation step), and the method of manufacturing the phase shift mask of the embodiment 2-2 uses the phase shift mask blank of the embodiment 1-3. And a resist film pattern forming step, a step of forming a light-shielding film pattern (light-shielding film pattern forming step), and a phase shift film pattern forming step.
Hereinafter, each process will be described in detail.

Manufacturing method of phase shift mask of embodiment 2-1. Resist film pattern forming step In the resist film pattern forming step, first, a resist film is formed on the phase shift film 30 of the phase shift mask blank 10 of the embodiments 1-1 and 1-2. However, when the phase shift mask blank 10 is provided with 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. What is necessary is just to be sensitive to laser light having any wavelength selected from the wavelength range of 350 nm to 436 nm described later. Further, the resist film may be either a positive type or a negative type.
Thereafter, a predetermined pattern is drawn on the resist film using laser light having any wavelength selected from a wavelength range of 350 nm to 436 nm. Examples of the pattern drawn on the resist film include a line and space pattern and a hole pattern.
Thereafter, the resist film is developed with a predetermined developer to form a resist film pattern on the phase shift film 30.

2. Phase Shift Film Pattern Forming 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 can etch each of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 constituting the phase shift film 30. Not limited. For example, when each of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 constituting the phase shift film 30 is made of a chromium-based material containing chromium (Cr), ceric ammonium nitrate and perchlorine Examples thereof include an etching solution containing an acid and an etching gas composed of a mixed gas of chlorine gas and oxygen gas. Further, when each of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 constituting the phase shift film 30 is made of a metal silicide material, hydrofluoric acid, hydrosilicofluoric acid, and fluorine are used. An etching solution containing at least one fluorine compound selected from ammonium hydride and at least one oxidizing agent selected from hydrogen peroxide, nitric acid, and sulfuric acid, hydrogen peroxide, ammonium fluoride, phosphoric acid, An etching solution containing at least one oxidant selected from sulfuric acid and nitric acid, a fluorine-based gas such as CF ₄ gas, CHF ₃ gas, and SF ₆ gas, and an etching gas in which O ₂ gas is mixed with these gases Can be mentioned.
Thereafter, the resist film pattern is stripped using a resist stripping solution or by ashing.
When one or two of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 are made of a material having etching selectivity with respect to other layers, the etching medium is changed according to the layer. Thus, desired etching can be performed.

  According to the manufacturing method of the phase shift mask of this embodiment 2-1, the phase shift mask has excellent pattern cross-sectional shape and excellent CD uniformity, a fine pattern is formed, and transfer accuracy is good. Can be manufactured.

Manufacturing method of phase shift mask of embodiment 2-2 First Resist Film Pattern Forming Step In the first 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 Embodiment 1-3. However, when the phase shift mask blank 10 is provided with a resist film on the light shielding film 45, the resist film is not formed. The resist film material to be used is not particularly limited. What is necessary is just to be sensitive to laser light having any wavelength selected from the wavelength range of 350 nm to 436 nm described later. Further, the resist film may be either a positive type or a negative type.
Thereafter, a predetermined pattern is drawn on the resist film using laser light having any wavelength selected from a wavelength range of 350 nm to 436 nm. Examples of the pattern drawn on the resist film include a line and space pattern and a hole pattern.
Thereafter, the resist film is developed with a predetermined developer to form a first resist film pattern on the light-shielding film 45.

2. Mask pattern forming process for forming phase shift film pattern (first light-shielding film pattern forming process)
In the mask pattern forming step, the light-shielding film 45 is etched using the first resist film pattern as a mask to form 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 each of the light-shielding layer 46 and the surface reflectance reduction layer 47 constituting the light-shielding film 45 can be etched. For example, when each of the light shielding layer 46 and the surface reflectance reduction layer 47 constituting the light shielding film 45 is made of a chromium-based material containing chromium (Cr), it contains ceric ammonium nitrate and perchloric acid. Examples thereof include an etching solution and an etching gas composed of a mixed gas of chlorine gas and oxygen gas. Further, when each of the light shielding layer 46 and the surface reflectance reduction layer 47 constituting the light shielding film 45 is made of a metal silicide material, it is made of hydrofluoric acid, hydrosilicofluoric acid, and ammonium hydrogen fluoride. Etching solution containing at least one selected fluorine compound and at least one oxidizing agent selected from hydrogen peroxide, nitric acid, and sulfuric acid, hydrogen peroxide, ammonium fluoride, phosphoric acid, sulfuric acid, nitric acid Examples thereof include an etching solution containing at least one selected oxidizing agent, a fluorine-based gas such as CF ₄ gas, CHF ₃ gas, and SF ₆ gas, and an etching gas obtained by mixing these gases with O ₂ gas.
Thereafter, the resist film pattern is stripped using a resist stripping solution or by ashing.

3. Phase Shift Film Pattern Forming Step In the phase shift film pattern forming step, the phase shift film 30 is etched using the mask pattern (first light-shielding film pattern) described above 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 can etch each of the phase shift layer 31, the metal layer 33, and the reflectance reduction layer 32 constituting the phase shift film 30. Not limited. Since the etching medium is the same as that in Embodiment 2-1, the description is omitted.

4). Second resist film pattern forming step The second resist film pattern forming step is for forming a predetermined light-shielding film pattern on the phase shift film pattern, and is performed on the first light-shielding film pattern (the mask pattern described above). 2 is a step of forming a resist film pattern. A resist film is formed so as to cover the phase shift film pattern and the first light-shielding film pattern obtained in the above steps.
Thereafter, a predetermined pattern is drawn on the resist film using laser light having any wavelength selected from a wavelength range of 350 nm to 436 nm. Examples of the pattern drawn on the resist film include a line and space pattern and a hole pattern.
Thereafter, the resist film is developed with a predetermined developer to form a second resist film pattern on the first light-shielding film pattern.

5. Light-shielding film pattern forming step The first light-shielding film pattern is etched using the second resist film pattern as a mask to form a light-shielding film pattern on the phase shift film pattern. Since the etching medium (etching solution, etching gas) for etching the first light-shielding film pattern is the same as the etching medium for etching the light-shielding film 45 described above, description thereof is omitted.
Thereafter, the second resist film pattern is stripped using a resist stripping solution or by ashing.
According to the method of manufacturing the phase shift mask of the embodiment 2-2, the phase shift mask has a light shielding film pattern formed on the phase shift film pattern, and has an excellent pattern cross-sectional shape and excellent CD uniformity. And a phase shift mask in which a fine pattern is formed and transfer accuracy is good.

Embodiment 3 FIG.
In Embodiment 3, a method for manufacturing a display device will be described. The display device is manufactured by performing the following mask placement process and pattern transfer process.
Hereinafter, each process will be described in detail.

1. Placement Step In the placement step, the phase shift mask manufactured in Embodiments 2-1 and 2-2 is placed on the mask stage of the exposure apparatus. Here, the phase shift mask is disposed so as to face the resist film formed on the display device substrate via the projection optical system of the exposure apparatus.

2. Pattern Transfer Process In the pattern transfer process, the phase shift mask is irradiated with exposure light, and the phase shift film pattern is transferred to a resist film formed on the display device substrate. The exposure light is composite light including light of a plurality of wavelengths selected from the wavelength range of 313 nm to 436 nm, or monochromatic light selected by cutting a wavelength range from the wavelength range of 313 nm to 436 nm with a filter or the like. For example, the exposure light is composite light including i-line, h-line and g-line, mixed light including j-line, i-line, h-line and g-line, or i-line monochromatic light. When composite light is used as exposure light, the exposure light intensity can be increased to increase the throughput, so that the manufacturing cost of the display device can be reduced.
Furthermore, since it is a phase shift mask in which the back surface reflectance of the phase shift film is 20% or less in the wavelength range of 365 to 436 nm, the influence of reflection on the exposure apparatus side can be suppressed, and it is formed on the display device substrate. High-accuracy pattern transfer can be performed on the resist film. Further, in the phase shift mask in which the film surface reflectance of the phase shift film is 22.5% or less in the wavelength region of 313 nm to 436 nm, the transfer pattern blurring (flare) due to the reflected light from the display device substrate side is caused. Furthermore, highly accurate pattern transfer can be performed on the resist film formed on the display device substrate.
The above-described phase shift mask blank of the first embodiment and the phase shift mask manufactured by the method of manufacturing the phase shift mask of the second embodiment are the same as the phase shift mask blank and the phase shift mask for projection exposure of equal magnification exposure. Are preferably used. In particular, it is preferably used in an exposure environment of projection exposure with the same magnification exposure having a numerical aperture (NA) of 0.06 to 0.15.

  According to the display device manufacturing method of the third embodiment, it is possible to manufacture a high-resolution and high-definition display device that does not cause a CD error.

  Hereinafter, based on an Example and a comparative example, this invention is demonstrated more concretely. The following examples are merely examples of the present invention and do not limit the present invention.

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. A synthetic quartz glass substrate having a size of 800 mm × 920 mm and a thickness of 10 mm was used as the transparent substrate.
Hereinafter, Examples 1 to 5 and Comparative Example 1 will be described in detail.

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 a reflectance reduction layer arranged in order from the transparent substrate side, and further, an interface between the phase shift layer and the metal layer, A composition gradient region is formed at the interface between the metal layer and the reflectance reduction layer (see FIG. 6).

The phase shift mask blank of Example 1 was manufactured by the following method.
First, a synthetic quartz glass substrate, which is a transparent substrate, was prepared. Both main surfaces of the transparent substrate are mirror-polished. Both main surfaces of the transparent substrate prepared in Examples 2 to 5 and Comparative Example 1 are similarly mirror-polished.
Next, the transparent substrate was carried into an in-line type sputtering apparatus. A sputtering chamber is provided in the in-line type sputtering apparatus.
Next, a sputtering power of 2.7 kW was applied to the chromium target placed in the sputtering chamber, and a mixed gas of Ar gas, N ₂ gas, CO ₂ gas, and O ₂ gas was introduced into the sputtering chamber, and 200 mm / The transparent substrate was conveyed at a speed of minutes. Here, the mixed gas, Ar is 35 sccm, _{N 2} is 35 sccm, CO ₂ is 13 sccm, _{O 2} was introduced into the sputtering chamber so as to 10sccm flow. When the transparent substrate passed near the chromium target, a phase shift layer made of a chromium-based material (CrCON) containing Cr, C, O, and N was formed on the transparent substrate.

Next, a sputtering power of 0.6 kW is applied to the chromium target, and a mixed gas of Ar gas and CH ₄ gas (a mixed gas containing CH ₄ gas at a concentration of 4% in Ar gas is put into the sputtering chamber). While being introduced, the transparent substrate was conveyed at a speed of 400 mm / min.When the transparent substrate passed near the chromium target, a metal layer made of a chromium-based material (CrC) containing Cr and C was formed on the phase shift layer. A film was formed.
Next, a sputtering power of 3.3 kW is applied to the chromium target, and a transparent substrate is introduced at a rate of 400 mm / min while introducing a mixed gas of Ar gas, N ₂ gas, CO ₂ gas, and O ₂ gas into the sputtering chamber. Was transported. When the transparent substrate passed near the chromium target, a reflectance reduction layer made of a chromium-based material (CrCON) containing Cr, C, O, and N was formed on the metal layer. Here, the mixed gas, Ar is 35 sccm, _{N 2} is 35 sccm, CO ₂ is 13 sccm, _{O 2} was introduced into the sputtering chamber so that the flow rate of 9 sccm.
Next, the transparent substrate on which the phase shift film composed of the phase shift layer, the metal layer, and the reflectance reduction layer was formed was taken out from the in-line type sputtering apparatus and cleaned.
In addition, the film formation of the phase shift layer, the film formation of the metal layer, and the film formation of the reflectance reduction layer are continuously performed in the in-line type sputtering apparatus without being exposed to the atmosphere by taking the transparent substrate out of the in-line type sputtering apparatus. I went there.

Since the phase shift film composed of the phase shift layer, the metal layer, and the reflectance reduction layer of Example 1 is formed by an in-line type sputtering apparatus, the interface between the phase shift layer and the metal layer, the metal layer and the reflection A composition gradient region in which the elements constituting each layer are continuously compositionally gradient is formed at the interface with the rate reduction layer.
The result of having measured the composition of the depth direction about the phase shift film | membrane of Example 1 by the X ray photoelectron spectroscopy (ESCA) is shown in FIG.
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 atoms. %, O: 40.0 atomic%, N: 8.2 atomic%, and C: 2.0 atomic%. The metal layer is made of a chromium-based material containing chromium (Cr), carbon (C), and oxygen (O). The average content of each element is Cr: 69.9 atomic%, C: They were 22.7 atomic% and O: 7.4 atomic%. Furthermore, the reflectance reduction 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. 0.5 atomic%, O: 47.4 atomic%, N: 3.7 atomic%, and C: 0.4 atomic%. Moreover, between the phase shift layer and the metal layer, and between the metal layer and the reflectance reduction layer, there were composition gradient regions in which each element was continuously reduced or increased.

Moreover, the bonding state (chemical state) of the elements was evaluated from the Cr, O, and N spectra of each layer. As a result, it was confirmed that the phase shift layer mainly contains chromium mononitride (CrN) and further chromium oxide (III) (Cr ₂ O ₃ ) was present.
Further, the bonding state of elements constituting the metal layer (chemical state) were mainly comprises chromium (Cr), it confirmed that the addition of chromium oxide (III) _(Cr 2 _{O 3)} is present.
Further, the bonding state (chemical state) of the elements constituting the reflectance reduction layer mainly includes chromium oxide (III) (Cr ₂ O ₃ ), and chromium mononitride (CrN) and dichromium nitride (Cr ₂ N) are included. It was confirmed that it existed.

The phase shift film had a transmittance of 4.9% for 365 nm light and a phase difference of 187 ° due to the three-layer structure described above.
The transmittance and the phase difference were measured using MPM-100 (trade name) manufactured by Lasertec. The same measurement was performed in Examples 2 to 5 and Comparative Example 1.

Curve a in FIG. 4 shows the film surface reflectance spectrum of the phase shift film of the phase shift mask blank of Example 1. A curve a in FIG. 5 shows a back surface reflectance spectrum of the phase shift film of the phase shift mask blank of Example 1.
As seen in FIG. 4, the phase shift film has a film surface reflectance of 13.3% at a wavelength of 313 nm, 9.6% at 350 nm, and 8.3% at a wavelength of 365 nm, It was 7.1% at a wavelength of 405 nm, 7.3% at a wavelength of 413 nm, and 8.1% at a wavelength of 436 nm. In the phase shift film, the fluctuation range of the film surface reflectance is 2.5% in the wavelength region of 350 nm to 436 nm, 1.2% in the wavelength region of 365 nm to 436 nm, and 313 nm to 436 nm. In the wavelength band, it was 6.2%.

As seen in FIG. 5, the phase shift film has a back surface reflectance of 9.7% at a wavelength of 313 nm, 8.8% at 350 nm, 9.0% at a wavelength of 365 nm, and 405 nm. And 12.3% at a wavelength of 413 nm, and 16.1% at a wavelength of 436 nm. In the phase shift film, the fluctuation range of the film surface reflectance is 7.3% in the wavelength region of 350 nm to 436 nm, 7.1% in the wavelength region of 365 nm to 436 nm, and 313 nm to 436 nm. In the wavelength region, it was 7.3%.
Thus, the film surface reflectance of the phase shift film is 15% or less in the wavelength region of 350 nm to 436 nm, and the back surface reflectance of the phase shift film is 20% or less in the wavelength region of 365 nm to 436 nm. Therefore, by using this phase shift mask blank, a phase shift mask having excellent pattern cross-sectional shape and excellent CD uniformity, a fine pattern is formed, and transfer accuracy is good. Can do.
The film surface reflectance and the back surface reflectance were measured using SolidSpec-3700 (trade name) manufactured by Shimadzu Corporation. The same measurement was performed in Examples 2 to 5 and Comparative Example 1.

A phase shift mask was manufactured by the following method using the phase shift mask blank described above.
First, a resist film made of a novolac positive photoresist was formed on the phase shift film of the above-described phase shift mask blank.
Thereafter, a predetermined pattern was drawn on the resist film using a laser beam with a wavelength of 413 nm by a laser drawing machine.
Thereafter, the resist film was developed with a predetermined developer to form a resist film pattern on the phase shift film.

Thereafter, the phase shift film was etched using the resist film pattern as a mask to form a phase shift film pattern. Each of the phase shift layer, the metal layer, and the reflectance reduction layer constituting the phase shift film is formed of a chromium-based material containing chromium (Cr). For this reason, a phase shift layer, a metal layer, and a reflectance reduction layer can be etched with the same etching solution. Here, an etching solution containing ceric ammonium nitrate and perchloric acid was used as an etching solution for etching the phase shift film.
Thereafter, the resist film pattern was stripped using a resist stripping solution.

In the phase shift film pattern cross section of the phase shift mask manufactured using the above-described phase shift mask blank, a slight biting occurs in the metal layer located at the center in the film thickness direction of the phase shift film pattern. The mask characteristics were not affected.
In addition, the phase shift film pattern cross section of the phase shift mask was observed using an electron microscope (JSM7401F (trade name) manufactured by JEOL Ltd.). The same measurement was performed in Examples 2 to 3 and Comparative Example 1.

The CD variation (CD uniformity) of the phase shift film pattern of the phase shift mask manufactured using the above-described phase shift mask blank was 70 nm, which was favorable. The CD variation (CD uniformity) is a deviation width from a target line and space pattern (line pattern width: 2.0 μm, space pattern width: 2.0 μm).
The CD variation in the phase shift film pattern of the phase shift mask was measured using SIR8000 manufactured by Seiko Instruments Nano Technology. The same measurement was performed in Examples 2 to 5 and Comparative Example 1.

  The above-described phase shift mask has excellent pattern cross-sectional shape, excellent CD uniformity, good transfer accuracy, and has low film surface reflectance and back surface reflectance of the phase shift film pattern with respect to exposure light. Since the back surface reflectance of the film pattern is also low, when a display device was manufactured using the above-described phase shift mask, a high-resolution and high-definition display device in which no CD error occurred could be manufactured. The pattern transfer process using the phase shift mask in the manufacturing process of the display device is a projection exposure of the same magnification exposure with a numerical aperture (NA) of 0.1, and the exposure light is j-line, i-line, and h-line. And composite light including g-line.

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 a reflectance reduction layer arranged in this order from the transparent substrate side.
The phase shift layer, metal layer, and reflectance reduction layer in the phase shift mask blank of Example 2 were formed under the following film formation conditions.
The phase shift layer, as a mixed gas, Ar is 35 sccm, _{N 2} is 35 sccm, except that the CO ₂ is 100 sccm, _{O 2} was introduced into the sputtering chamber so that the flow rate of 35 sccm, the transparent substrate in the same manner as in Example 1 A phase shift layer made of a chromium-based material (CrON) containing Cr, O, and N was formed thereon.
Next, the metal layer is a chromium-based material (CrC) containing Cr and C on the phase shift layer in the same manner as in Example 1 except that a sputtering power of 0.5 kW is applied to the chromium target disposed in the sputtering chamber. A metal layer consisting of
Next, the reflectance reduction layer is the same as in Example 1 except that the mixed gas is introduced into the sputtering chamber so that the flow rate of Ar is 35 sccm, N ₂ is 35 sccm, CO ₂ is 100 sccm, and O ₂ is 35 sccm. Then, a reflectance reduction layer made of a chromium-based material (CrON) containing Cr, O, and N was formed on the metal layer.

  As a result of measuring the composition in the depth direction by X-ray photoelectron spectroscopy (ESCA) with respect to the phase shift film of Example 2, the phase shift layer is mainly composed of chromium (Cr), oxygen (O), and nitrogen (N). The average content of each element is Cr: 45.5 atomic%, O: 53.8 atomic%, N: 0.6 atomic%, C: 0.1 atomic% there were. The metal layer is made of a chromium-based material containing chromium (Cr), carbon (C), and oxygen (O). The average content of each element is Cr: 74.7 atomic%, C: They were 15.8 atomic%, O: 8.8 atomic%, and N: 0.7 atomic%. Further, the reflectance reduction layer is mainly composed of a chromium-based material containing chromium (Cr), oxygen (O), and nitrogen (N), and the average content of each element is Cr: 44.4 atoms. %, O: 55.0 atomic%, N: 0.5 atomic%, and C: 0.1 atomic%. Moreover, between the phase shift layer and the metal layer, and between the metal layer and the reflectance reduction layer, there were composition gradient regions in which each element was continuously reduced or increased.

Moreover, the bonding state (chemical state) of the elements was evaluated from the Cr, O, and N spectra of each layer. As a result, it is confirmed that the phase shift layer mainly contains dichromium nitride (Cr ₂ N), and further contains chromium oxide (III) (Cr ₂ O ₃ ) and chromium oxide (VI) (CrO ₃ ). did it.
Further, the bonding state of elements constituting the metal layer (chemical state) were mainly comprises chromium (Cr), it confirmed that the addition of chromium oxide (III) _(Cr 2 _{O 3)} is present.
Further, the bonding state of elements constituting the reflectivity reducing layer (chemical state) was confirmed to contain mainly chromium (III) oxide and (Cr 2 _{O 3).}
The phase shift film had a transmittance of 4.9% for light of 365 nm and a phase difference of 187 ° due to the three-layer structure described above.

A curve b in FIG. 4 shows a film surface reflectance spectrum of the phase shift film of the phase shift mask blank of Example 2. A curve b in FIG. 5 shows a back surface reflectance spectrum of the phase shift film of the phase shift mask blank of Example 2.
As shown in FIG. 4, the phase shift film has a film surface reflectance of 21% at a wavelength of 313 nm, 14.7% at 350 nm, 12.8% at a wavelength of 365 nm, and 405 nm. It was 10.2% at the wavelength, 9.8% at the 413 nm wavelength, and 9.0% at the 436 nm wavelength. In the phase shift film, the fluctuation range of the film surface reflectance is 5.7% in the wavelength range of 350 nm to 436 nm, 3.8% in the wavelength range of 365 nm to 436 nm, and 313 nm to 436 nm. In the wavelength region, it was 12.0%.

  As seen in FIG. 5, the phase shift film has a back surface reflectance of 7.5% at a wavelength of 313 nm, 8.3% at 350 nm, 9.8% at a wavelength of 365 nm, and 405 nm. The wavelength was 14.9%, the wavelength of 413 nm was 15.9%, and the wavelength of 436 nm was 18.2%. In the phase shift film, the fluctuation range of the film surface reflectance is 9.9% in the wavelength range of 350 nm to 436 nm, 8.3% in the wavelength range of 365 nm to 436 nm, and 313 nm to 436 nm. In the wavelength region, it was 11.0%.

Thus, the film surface reflectance of the phase shift film is 15% or less in the wavelength region of 350 nm to 436 nm, and the back surface reflectance of the phase shift film is 20% or less in the wavelength region of 365 nm to 436 nm. Therefore, by using this phase shift mask blank, a phase shift mask having excellent pattern cross-sectional shape and excellent CD uniformity, a fine pattern is formed, and transfer accuracy is good. Can do.
The film surface reflectance and the back surface reflectance were measured using SolidSpec-3700 (trade name) manufactured by Shimadzu Corporation.
A phase shift mask was manufactured using the phase shift mask blank of Example 2 in the same manner as in the above-described Example. The CD variation (CD uniformity) of the phase shift film pattern of the obtained phase shift mask was 65 nm, which was good. The CD variation (CD uniformity) is a deviation width from a target line and space pattern (line pattern width: 2.0 μm, space pattern width: 2.0 μm).

  The phase shift mask described above has excellent pattern cross-sectional shape, excellent CD uniformity, good transfer accuracy, and low film surface reflectance of the phase shift film pattern with respect to exposure light, and the back surface of the phase shift film pattern. Since the reflectance is also low, when a display device is manufactured using the above-described phase shift mask, a high-resolution and high-definition display device in which no CD error occurs can be manufactured. The pattern transfer process using the phase shift mask in the manufacturing process of the display device is a projection exposure of the same magnification exposure with a numerical aperture (NA) of 0.1, and the exposure light is j-line, i-line, and h-line. And composite light including g-line.

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 a reflectance reduction 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 reflectance reduction layer is made of a titanium material having etching selectivity with respect to the phase shift layer and metal layer. Configured.

The phase shift layer, metal layer, and reflectance reduction layer in the phase shift mask blank of Example 3 were formed under the following film formation conditions.
The phase shift layer applies 6.0 kW of sputtering power to a molybdenum silicide target (Mo: Si = 1: 4), and introduces Ar gas, O ₂ gas, and N ₂ gas into the sputtering chamber, while on the transparent substrate. A phase shift layer (film thickness: 100 nm) made of a molybdenum silicide-based material (MoSiON) containing Mo, Si, O, and N was formed. Here, the Ar gas was introduced into the sputtering chamber at a flow rate of 50 sccm, O ₂ gas was 40 sccm, and N ₂ gas was 50 sccm.
The metal layer (intermediate layer) applied Mo and Si on the transparent substrate while applying a sputtering power of 1.5 kW to (Mo: Si = 1: 4) and introducing Ar gas and N ₂ gas into the sputtering chamber. A metal layer (intermediate layer) (film thickness: 30 nm) made of a molybdenum silicide-based material (MoSiN) containing N was formed. Here, Ar gas was introduced into the sputtering chamber at a flow rate of 60 sccm and N ₂ gas at a flow rate of 40 sccm.
The reflectance reduction layer is a titanium-based titanium layer containing Ti, O, and N on the metal layer while applying a sputtering power of 2.0 kW to the titanium target and introducing Ar gas, O ₂ gas, and N ₂ gas into the sputtering chamber. A reflectance reduction layer (film thickness: 60 nm) made of a material (TiON) was formed. Here, Ar gas was introduced into the sputtering chamber at a flow rate of 100 sccm, O ₂ gas was 60 sccm, and N ₂ gas was 60 sccm.

  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%, Si: 40 atomic%, O: 25 atomic%. N: 25 atomic%, metal layer (intermediate layer) is Mo: 15 atomic%, Si: 60 atomic%, N: 25 atomic%, reflectance reduction layer is Ti: 50.5 atomic%, O: 40 It was 0.5 atomic% and N: 9.0 atomic%. Moreover, between the phase shift layer and the metal layer, and between the metal layer and the reflectance reduction layer, there were composition gradient regions in which each element was continuously reduced or increased.

  The phase shift film had a transmittance of 6.60% for light of 365 nm and a phase difference of 183.3 ° due to the above-described three-layer structure.

The phase shift film has a film surface reflectance of 7.60% at a wavelength of 313 nm, 0.79% at 350 nm, 0.05% at a wavelength of 365 nm, and 4.34% at a wavelength of 405 nm. And 5.53% at a wavelength of 413 nm and 8.74% at a wavelength of 436 nm. The phase shift film has a fluctuation range of the film surface reflectance of 8.69% in the wavelength region of 350 nm to 436 nm, 8.69% in the wavelength region of 365 nm to 436 nm, and 313 nm to 436 nm. In the wavelength band, it was 8.69%.
The phase shift film has a back surface reflectance of 12.52% at a wavelength of 313 nm, 15.87% at 350 nm, 17.36% at a wavelength of 365 nm, and 19.17% at a wavelength of 405 nm. Yes, 19.07% at a wavelength of 413 nm, and 18.10% at a wavelength of 436 nm. In the phase shift film, the fluctuation range of the film surface reflectance is 3.30% in the wavelength range of 350 nm to 436 nm, 1.81% in the wavelength range of 365 nm to 436 nm, and 313 nm to 436 nm. In the wavelength region, it was 6.65%.
Thus, the film surface reflectance of the phase shift film is 15% or less in the wavelength region of 350 nm to 436 nm, and the back surface reflectance of the phase shift film is 20% or less in the wavelength region of 365 nm to 436 nm. Therefore, by using this phase shift mask blank, a phase shift mask having excellent pattern cross-sectional shape and excellent CD uniformity, a fine pattern is formed, and transfer accuracy is good. Can do.
The film surface reflectance and the back surface reflectance were measured using SolidSpec-3700 (trade name) manufactured by Shimadzu Corporation.

  A resist film pattern was formed on the phase shift film by the same method as in Example 1 using the above-described phase shift mask blank. Then, using the resist film pattern as a mask, the reflectance reduction layer composed of a titanium-based material is wet-etched with an etching solution obtained by diluting a mixed solution of ammonium hydrogen fluoride and hydrogen peroxide with pure water, and the reflectance A pattern was formed on the reduction layer. Further, the phase shift layer and the metal layer made of molybdenum silicide-based material are wet-etched with an etchant obtained by diluting a mixed solution of ammonium hydrogen fluoride and hydrogen peroxide with pure water to form the phase shift layer and the metal layer. A pattern was formed. The resist film pattern remaining on the reflectance reduction layer was also removed by this wet etching. Thus, the phase shift mask was manufactured by forming the phase shift film pattern in the phase shift layer, the metal layer, and the reflectance reduction layer.

The CD variation (CD uniformity) of the phase shift film pattern of the obtained phase shift mask was 58.0 nm, which was favorable. The CD variation (CD uniformity) is a deviation width from a target line and space pattern (line pattern width: 2.0 μm, space pattern width: 2.0 μm).
The above-described phase shift mask has an excellent pattern cross-sectional shape, excellent CD uniformity, good transfer accuracy, and the film surface reflectance of the phase shift film pattern with respect to exposure light is low, and thus a display device was manufactured. However, using the above-described phase shift mask, a high-resolution and high-definition display device in which no CD error occurs can be manufactured. The pattern transfer process using the phase shift mask in the manufacturing process of the display device is a projection exposure of the same magnification exposure with a numerical aperture (NA) of 0.1, and the exposure light is j-line, i-line, and h-line. And composite light including g-line.
In addition, this phase shift mask has a phase shift layer and a metal layer (intermediate layer) made of a molybdenum silicide material and a reflectance reduction layer made of a titanium material. This can be improved and is advantageous for forming a fine pattern.

Comparative Example 1
The phase shift film in the phase shift mask blank of Comparative Example 1 is composed of only a 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 example in that the phase shift film does not include a metal layer and a reflectance reduction layer.
The phase shift layer in the phase shift mask blank of Comparative Example 1 was formed under the following film formation conditions.
The phase shift layer applies a sputtering power of 3.5 kW to a chromium target disposed in the sputtering chamber, and introduces a mixed gas of Ar gas, N ₂ gas, and CO ₂ gas into the sputtering chamber, and reaches 200 mm / min. The transparent substrate was conveyed at a speed. When the transparent substrate passed near the chromium target, a phase shift layer having a film thickness of 122 nm made of CrOCN was formed on the main surface of the transparent substrate. Here, the mixed gas was introduced into the sputtering chamber so that the flow rates of Ar were 46 sccm, N ₂ was 32 sccm, and CO ₂ was 18.5 sccm.
For the phase shift film of Comparative Example 1, the composition in the depth direction was measured by X-ray photoelectron spectroscopy (ESCA). The phase shift film was uniform in the depth direction, and was Cr: 44 atomic%, C: 8 atomic%, O: 30 atomic%, and N: 18 atomic%.

  The phase shift film had a transmittance of 4.5% with respect to light of 365 nm and a phase difference of 181 ° due to the single-layer structure described above.

A curve c in FIG. 4 shows a film surface reflectance spectrum of the phase shift film of the phase shift mask blank of Comparative Example 1. A curve c in FIG. 5 shows a back surface reflectance spectrum of the phase shift film of the phase shift mask blank of Comparative Example 1.
As seen in FIG. 4, the phase shift film has a film surface reflectance of 21.0% at a wavelength of 313 nm, 23.9% at a wavelength of 350 nm, and 24.0% at a wavelength of 365 nm, It was 25.1% at a wavelength of 405 nm, 25.3% at a wavelength of 413 nm, and 26.0% at a wavelength of 436 nm. In the phase shift film, the fluctuation range of the film surface reflectance is 2.1% in the wavelength region of 350 nm to 436 nm, 2.0% in the wavelength region of 365 nm to 436 nm, and 313 nm to 436 nm. In the wavelength region, it was 12.0%.
As seen in FIG. 5, the phase shift film has a back surface reflectance of 7.5% at a wavelength of 313 nm, 17.1% at 350 nm, 17.9% at a wavelength of 365 nm, and 405 nm. The wavelength was 19.9%, the wavelength of 413 nm was 20.2%, and the wavelength of 436 nm was 20.3%. Further, in the phase shift film, the fluctuation range of the film surface reflectance is 3.2% in the wavelength range of 350 nm to 436 nm, 2.4% in the wavelength range of 365 nm to 436 nm, and 313 nm to 436 nm. In the wavelength region, it was 11.0%.

  A phase shift mask was manufactured by the same method as in Example 1 using the above-described phase shift mask blank.

  The phase shift film pattern cross section of the phase shift mask manufactured using the above-described phase shift mask blank was vertical.

  The CD variation of the phase shift film pattern of the phase shift mask manufactured using the above-described phase shift mask blank is 90 nm, which is a level required for the phase shift mask used for manufacturing a high-resolution, high-definition display device. It was not reached.

  The above-described phase shift mask has an excellent pattern cross-sectional shape. However, since the film surface reflectance of the phase shift film exceeds 15% in the wavelength region of 350 nm to 436 nm, the CD variation is large (CD In addition, the film surface reflectance of the phase shift film pattern with respect to the exposure light is high, and the back surface reflectance of the phase shift film pattern is also higher than in the embodiment. A high-resolution, high-definition display device that does not cause errors could not be manufactured. The pattern transfer process using the phase shift mask in the manufacturing process of the display device is a projection exposure of the same magnification exposure with a numerical aperture (NA) of 0.1, and the exposure light is j-line, i-line, and h-line. And composite light including g-line.

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.
A phase shift film was formed on the transparent substrate in the same manner as in Example 3 above, and then a light-shielding film was formed under the following film formation conditions. The light-shielding film includes a light-shielding layer and a surface reflectance reduction layer from the phase shift film side. The light-shielding layer has a laminated structure of a lower light-shielding layer and an upper light-shielding layer, and the surface reflectance reduction layer is a first surface reflection layer. A laminated structure of the rate reduction layer and the second surface reflectance reduction layer was formed.
The lower light-shielding layer applies a 1.5 kW sputtering power to a chromium target placed in the sputtering chamber, and introduces a mixed gas of Ar gas and N ₂ gas into the sputtering chamber at a transfer speed of 400 mm / min. A lower light shielding layer made of CrN containing Cr and N was formed. The mixed gas was introduced into the sputtering chamber so that the flow rate was 65 sccm for Ar and 15 sccm for N ₂ .

Next, a sputtering power of 8.5 kW is applied to the chromium target disposed in the sputtering chamber on the lower light shielding layer, and Ar / CH ₄ (4.9%) gas, which is a mixed gas of Ar gas and CH ₄ gas. Was introduced into the sputtering chamber, the transparent substrate was transported at a transport speed of 400 mm / min, and an upper light shielding layer made of CrC containing Cr and C was formed. Note that Ar / CH ₄ (4.9%), which is a mixed gas, was introduced into the sputtering chamber so as to have a flow rate of 31 sccm.
Next, a sputtering power of 1.5 kW is applied to the chromium target disposed in the sputtering chamber on the upper light shielding layer, and Ar / CH ₄ (5.5%) gas, which is a mixed gas of Ar gas and CH ₄ gas. 1st surface reflectance reduction which consists of CrCON containing Cr, C, O, and N by carrying a transparent substrate at a conveyance speed of 400 mm / min while introducing a mixed gas of N ₂ gas and O ₂ gas into the sputtering chamber Layers were deposited. The mixed gas was introduced into the sputtering chamber so that Ar / CH ₄ (5.5%) had a flow rate of 31 sccm, N ₂ was 8 sccm, and O ₂ was 3 sccm.

Finally, the first surface reflectivity reducing layer, a sputtering power of 1.95kW chromium target disposed in a sputtering chamber is applied, Ar gas and _{CH 4} Ar / CH ₄ is a mixed gas of the gas (5. 5%) A transparent substrate is transported at a transport speed of 400 mm / min while introducing a mixed gas of gas, N ₂ gas, and O ₂ gas into the sputtering chamber, and a second composed of CrCON containing Cr, C, O, and N A surface reflectance reducing layer was formed to obtain a phase shift mask blank. The mixed gas was introduced into the sputtering chamber so that Ar / CH ₄ (5.5%) had a flow rate of 31 sccm, N ₂ was 8 sccm, and O ₂ was 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 are formed on the transparent substrate is 17.2% at a wavelength of 313 nm, 12.1% at a wavelength of 350 nm, and 365 nm. 11.0%, 8.2% at a wavelength of 405 nm, 7.5% at a wavelength of 413 nm, and 8.4% at a wavelength of 436 nm. The optical density at 365 nm in the laminated film of the phase shift film and the light shielding film was 4.0 or more. Further, the reflectance of the back surface of the phase shift film in this phase shift mask blank is 12.5% at a wavelength of 313 nm, 17.4% at a wavelength of 365 nm, 19.2% at a wavelength of 405 nm, and 18 at a wavelength of 436 nm. It was 1%.

  Thus, the film surface reflectance of the phase shift film is 15% or less in the wavelength region of 350 nm to 436 nm, and the film surface reflectance of the light-shielding film is 15% or less in the wavelength region of 350 nm to 436 nm. Furthermore, since the back surface reflectance of the phase shift film is 20% or less in the wavelength range of 365 nm to 436 nm, an excellent pattern cross-sectional shape and excellent CD uniformity can be obtained using this phase shift mask blank. It is possible to manufacture a phase shift mask having a fine pattern and good transfer accuracy.

A phase shift mask was manufactured by the following method using the phase shift mask blank described above. First, a first resist film pattern was formed on the light shielding film. Then, using the first resist film pattern as a mask, the light shielding film is wet-etched with an etchant containing ceric ammonium nitrate and perchloric acid, and a mask pattern made of the light shielding film pattern is formed on the phase shift film. Formed.
Next, using the mask pattern as a mask, the phase shift film was wet-etched with an etchant obtained by diluting a mixed solution of ammonium hydrogen fluoride and hydrogen peroxide with pure water to form a phase shift film pattern. The resist film pattern remaining on the mask pattern was also removed by this wet etching solution.

Next, in order to form a light-shielding film pattern at the center of the above-described phase shift film pattern, a resist film is formed on the mask pattern and the phase shift film pattern, and the second resist is formed on the mask pattern in the same manner as described above. A film pattern was formed. Then, using the second resist film pattern as a mask, the light-shielding film is wet-etched with an etchant containing ceric ammonium nitrate and perchloric acid to form a light-shielding film pattern at the center on the phase shift film Finally, the resist film pattern was stripped using a resist stripper to manufacture a phase shift mask.
The CD variation (CD uniformity) of the phase shift film pattern of the obtained phase shift mask was 57.0 nm, which was favorable. The CD variation (CD uniformity) is a deviation width from a target line and space pattern (line pattern width: 2.0 μm, space pattern width: 2.0 μm).

  The above-described phase shift mask has excellent pattern cross-sectional shape, excellent CD uniformity, good transfer accuracy, and the film surface reflectance of the phase shift film pattern and the light-shielding film pattern with respect to exposure light is low. Since the back surface reflectance of the shift film pattern is also low, when a display device was manufactured using the above-described phase shift mask, a high-resolution and high-definition display device in which no CD error occurred could be manufactured. The pattern transfer process using the phase shift mask in the manufacturing process of the display device is a projection exposure of the same magnification exposure with a numerical aperture (NA) of 0.1, and the exposure light is j-line, i-line, and h-line. And composite light including g-line.

Example 5 FIG.
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 laminated film of a back surface reflectance reduction layer and a light shielding layer on a transparent substrate.
The back-surface reflectance reduction layer and the light shielding layer in the above-described light shielding film pattern are formed by patterning a light shielding film under the following film formation conditions.
The back surface reflectance reduction layer applies a sputtering power of 4.0 kW to a chromium target disposed in the sputtering chamber, and introduces a mixed gas of Ar gas, N ₂ gas, and O ₂ gas into the sputtering chamber, and 350 mm / min. The transparent substrate was transported at a transport speed of 1, and a back surface reflectance reduction layer made of CrON containing Cr, O, and N was formed. Ar was introduced into the sputtering chamber so that the flow rate was 100 sccm, N ₂ was 45 sccm, and O ₂ was 25 sccm.

Next, a sputtering power of 5.0 kW is applied to the chromium target disposed in the sputtering chamber on the back surface reflectance reduction layer, and a mixed gas of Ar gas and N ₂ gas is introduced into the sputtering chamber, and 200 mm / min. The transparent substrate was transported at a transport speed of 1, and a light shielding layer made of CrN containing Cr and N was formed. Ar was introduced into the sputtering chamber so that the flow rate was 130 sccm and N ₂ was 30 sccm.
As described above, the back-surface reflectance of the light-shielding film composed of the laminated film of the back-surface reflectance reduction layer and the light-shielding layer formed on the transparent substrate is 10.4% at the wavelength of 313 nm, 6.2% at the wavelength of 365 nm, It was 4.7% at a wavelength of 405 nm and 4.8% at a wavelength of 436 nm.
And the light-shielding film pattern was formed on the transparent substrate by patterning the light-shielding film mentioned above by an etching.

  Next, the phase shift film of Example 1 was formed on the light-shielding film pattern to manufacture a phase shift mask blank. The film surface reflectance of the phase shift film of this phase shift mask blank has the same optical characteristics as in Example 1. The film surface reflectance is 13.3% at a wavelength of 313 nm, and 9% at 350 nm. 0.6% at a wavelength of 365 nm, 7.1% at a wavelength of 405 nm, 7.3% at a wavelength of 413 nm, and 8.1% at a wavelength of 436 nm. In the phase shift film, the fluctuation range of the film surface reflectance is 2.5% in the wavelength region of 350 nm to 436 nm, 1.2% in the wavelength region of 365 nm to 436 nm, and 313 nm to 436 nm. In the wavelength band, it was 6.2%. Further, the back surface reflectance of the phase shift film on which the light-shielding film pattern is not formed has the same optical characteristics as in Example 1, and the back surface reflectance is 9.7% at a wavelength of 313 nm, which is 350 nm. 8.8% at a wavelength of 365 nm, 9.0% at a wavelength of 365 nm, 12.3% at a wavelength of 405 nm, 13.2% at a wavelength of 413 nm, and 16.1% at a wavelength of 436 nm. It was. In the phase shift film, the fluctuation range of the film surface reflectance is 7.3% in the wavelength region of 350 nm to 436 nm, 7.1% in the wavelength region of 365 nm to 436 nm, and 313 nm to 436 nm. In the wavelength region, it was 7.3%.

Thus, the film surface reflectance of the phase shift film is 15% or less in the wavelength region of 350 nm to 436 nm, and the back surface reflectance of the light-shielding film pattern is 15% or less in the wavelength region of 350 nm to 436 nm. Since the back surface reflectance of the phase shift film is 20% or less in the wavelength region of 365 nm to 436 nm, this phase shift mask blank is used to have excellent pattern cross-sectional shape and excellent CD uniformity, A phase shift mask having a pattern and good transfer accuracy can be manufactured.
Further, similarly to Example 1 described above, a phase shift mask was manufactured using this phase shift mask blank. As a result, the CD variation (CD uniformity) of the phase shift film pattern was good at 70 nm.

  The above-described phase shift mask has excellent pattern cross-sectional shape, excellent CD uniformity, good transfer accuracy, and has low film surface reflectance and back surface reflectance of the phase shift film pattern with respect to exposure light. Since the back surface reflectance of the film pattern is also low, when a display device was manufactured using the above-described phase shift mask, a high-resolution and high-definition display device in which no CD error occurred could be manufactured. The pattern transfer process using the phase shift mask in the manufacturing process of the display device is a projection exposure of the same magnification exposure with a numerical aperture (NA) of 0.1, and the exposure light is j-line, i-line, and h-line. And composite light including g-line.

  As mentioned above, although this invention was demonstrated in detail based on embodiment and an Example, this invention is not limited to this. It is obvious that those having ordinary knowledge in the relevant field can make modifications and improvements within the technical idea of the present invention.

10 phase shift mask blank, 20 transparent substrate, 30 phase shift film,
31 phase shift layer, 32 reflectance reduction layer, 33 metal layer,
40 light-shielding film pattern, 41 back surface reflectance reduction layer, 42 light shielding layer 45 light shielding film, 46 light shielding layer, 47 surface reflectance reduction layer.

Claims (19)

A phase shift mask blank comprising a phase shift film on a transparent substrate,
The phase shift film is selected from one or more metals and a metal-based material containing at least one selected from oxygen, nitrogen, and carbon, or one or more metals, silicon, oxygen, nitrogen, and carbon. Composed of at least one of metal silicide-based materials containing at least one of
The phase shift film is arranged on the upper side of the phase shift layer mainly having a function of adjusting the transmittance and phase difference with respect to exposure light, and reflects light incident from the phase shift film side. A reflectance reduction layer mainly having a function of reducing the reflectance, and an intermediate layer disposed between the phase shift layer and the reflectance reduction layer,
The intermediate layer is a metal-based material having a metal content higher than the metal content of the reflectance reduction layer, or the metal content of the reflectance reduction layer or the metal of the reflectance reduction layer A metal silicide-based material having a total content higher than the total content of silicon,
Due to the laminated structure of the phase shift layer, the intermediate layer, and the reflectance reduction layer, the transmittance and phase difference of the phase shift film with respect to exposure light have predetermined optical characteristics,
The film surface reflectance of the phase shift film with respect to light incident from the phase shift film side is 15% or less in a wavelength region of 350 nm to 436 nm, and the phase shift with respect to light incident from the transparent substrate side. A phase shift mask blank, wherein the back surface reflectance of the film is 20% or less in a wavelength range of 365 nm to 436 nm.   2. The phase shift mask blank according to claim 1, wherein the phase shift film is made of a material that can be etched with the same etchant.   The phase shift mask blank according to claim 1, wherein the metal is chromium. The phase shift layer and the reflectance reduction layer are made of a chromium-based material containing chromium, oxygen, and nitrogen, and chromium is 30 to 70 atomic%, oxygen is 20 to 60 atomic%, and nitrogen is 0.4 to 30 atomic%, and the content of nitrogen contained in the phase shift layer is equal to or greater than the content of nitrogen contained in the reflectance reduction layer, and oxygen contained in the reflectance reduction layer The content of is greater than the content of oxygen contained in the phase shift layer,
The intermediate layer contains chromium and carbon, the chromium content is 55 to 90 atomic%, the carbon content is 10 to 45 atomic%, and the chromium content in the intermediate layer is the phase. 4. The phase shift mask blank according to claim 3, wherein the phase shift mask blank is greater than a chromium content contained in the shift layer and the reflectance reduction layer. 5. 5. The phase shift according to claim 3, wherein the phase shift layer includes chromium mononitride or dichromium nitride, and the reflectance reduction layer includes chromium (III) oxide in which chromium and oxygen are combined. Mask blank. The intermediate layer is further composed of a chromium-based material containing oxygen,
6. The phase shift according to claim 3, wherein the phase shift layer, the intermediate layer, and the reflectance reduction layer include chromium (III) oxide in which chromium and oxygen are combined. Mask blank.   The phase shift layer is made of a metal silicide-based material containing at least one of oxygen or nitrogen, and the reflectance reduction layer is made of a metal-based material containing at least one of oxygen or nitrogen. The phase shift mask blank according to claim 1, wherein the phase shift mask blank is provided.   8. The phase shift mask blank according to claim 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.   2. The phase shift according to claim 1, wherein one or two of the phase shift layer, the intermediate layer, and the reflectance reduction layer are made of a material having etching selectivity with respect to another layer. Mask blank.   The phase shift layer and the intermediate layer are made of a material made of a chromium-based material, and the reflectance reduction layer is made of a metal-based material having etching selectivity with the phase shift layer and the intermediate layer. The phase shift mask blank according to claim 9.   The phase shift mask blank according to claim 10, wherein the reflectance reduction layer is made of titanium and a titanium-based material containing any one of oxygen and nitrogen.   The phase shift mask blank according to any one of claims 1 to 11, further comprising a light-shielding film pattern between the transparent substrate and the phase shift film.   The phase shift mask blank according to claim 12, wherein a back surface reflectance of the light-shielding film pattern with respect to light incident from the transparent substrate side is 20% or less in a wavelength region of 365 nm to 436 nm.   The light shielding film is provided on the phase shift film, and the film surface reflectance of the light shielding film is 15% or less in a wavelength region of 350 nm to 436 nm. The phase shift mask blank described in 1. A resist film is formed on the phase shift film of the phase shift mask blank according to any one of claims 1 to 8, 12, and 13, and a resist film pattern is formed on the resist film by a drawing process and a development process. Forming a step;
Etching the phase shift film using the resist film pattern as a mask to form a phase shift film pattern on the transparent substrate;
A method of manufacturing a phase shift mask characterized by comprising: A resist film is formed on the phase shift film of the phase shift mask blank according to claim 9, and a resist film is formed on the resist film by a drawing process using a laser beam and a development process. Forming a pattern;
Etching the reflectance reduction layer using the resist film pattern as a mask to form a reflectance reduction layer pattern;
Etching the intermediate layer and the phase shift layer using the reflectance reduction layer pattern as a mask to form a phase shift film pattern on the transparent substrate;
A method of manufacturing a phase shift mask characterized by comprising: Forming a resist film on the light-shielding film of the phase shift mask blank according to claim 14, and forming a resist film pattern on the resist film by a drawing process and a development 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;
Etching the phase shift film using the light shielding film pattern as a mask to form a phase shift film pattern on the transparent substrate;
A method of manufacturing a phase shift mask characterized by comprising: Placing the phase shift mask obtained by the method of manufacturing a phase shift mask according to any one of claims 15 to 17 on a mask stage of an exposure apparatus;
Irradiating the phase shift mask with exposure light to transfer the phase shift film pattern to a resist film formed on a display device substrate;
A method for manufacturing a display device, comprising:   19. The method for manufacturing a display device according to claim 18, wherein the exposure light is a composite light including light having a plurality of wavelengths selected from a wavelength range of 313 nm to 436 nm.

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