JP2020020868A - Phase shift mask blank, phase shift mask and method for manufacturing phase shift mask - Google Patents

Abstract

To provide a phase shift mask blank, a phase shift mask and a method for manufacturing a phase shift mask, by which a blank defect can be corrected while suppressing reduction in characteristics of a phase shift mask.SOLUTION: The phase shift mask blank includes a light-transmitting substrate that transmits light at a predetermined wavelength, and a phase shift film disposed on the light-transmitting substrate. The phase shift film has an underlay phase shift film disposed on the light-transmitting substrate, and an overlay phase shift film disposed on the underlay phase shift film. The overlay phase shift film can be etched by fluorine-based dry etching and has durability against oxygen-based dry etching. The underlay phase shift film can be etched by oxygen-based dry etching and has durability against fluorine-based dry etching. The light-transmitting substrate has durability against oxygen-based dry etching.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a phase shift mask blank, a phase shift mask, and a method for manufacturing a phase shift mask, and more particularly, to manufacturing a semiconductor integrated circuit, a color filter for a CCD (charge coupled device), an LCD (liquid display device), a magnetic head, and the like. The present invention relates to a phase shift mask used for the above.

  In recent years, with the miniaturization of semiconductor elements, high resolution is also required for projection exposure. Thus, in the field of photomasks, a phase shift method has been developed as a technique for improving the resolution of a transfer pattern. The principle of the phase shift method is to adjust the phase difference between the phase of the transmitted light passing through the phase shift portion adjacent to the opening and the phase of the transmitted light passing through the opening to be approximately 180 °. The light intensity at the boundary between the aperture and the opening is weakened (phase shift effect), and as a result, the resolution of the transfer pattern is improved. A photomask using this principle is generally called a phase shift mask.

  A phase shift mask blank used for a phase shift mask has a structure in which a phase shift film and a light shielding film are sequentially laminated on a light transmitting substrate such as a quartz substrate. The thickness and composition of the phase shift film are adjusted so as to obtain desired phase difference and transmittance. When the phase difference is 175 degrees to 180 degrees and the transmittance is 5% to 7%, the film thickness is 60 nm. It is mainly formed of a single-layer film or a multi-layer film of an 80 nm MoSi-based material. The thickness and composition of the light-shielding film are adjusted so that the OD value (optical density) combined with the phase shift film becomes a desired value, and the OD value combined with the above-described phase shift film is 2.8. In the above case, the mainstream is a single-layer film or a multi-layer film of a chromium-based material having a thickness of 40 nm to 60 nm.

As a method of forming a pattern of a phase shift mask, a resist film is formed on a light shielding film of a phase shift mask blank, a pattern is drawn on the resist film by a laser beam or an electron beam, and is developed to form a resist pattern. The light-shielding film is etched using the resist pattern as a mask to form a light-shielding film pattern, the phase-shift film is etched using the light-shielding film pattern as a mask, and the resist film and the light-shielding film are removed to form a pattern of the phase-shift film. The method of forming is common.
In a phase shift mask requiring high-precision pattern formation, dry etching using gas plasma is mainly used for etching. In general, dry etching of a chromium-based material light-shielding film is performed by oxygen-containing chlorine-based dry etching (Cl / O system), and dry etching of a MoSi-based phase shift film is performed by fluorine-based dry etching (F system). is there.

Dry etching of the phase shift film made of MoSi-based material is performed by fluorine-based dry etching (F-based), but the underlying quartz substrate is also etched by fluorine-based dry etching. At this time, there is a problem that the dug amount of the quartz substrate varies depending on the pattern and position of the phase shift film, and the variation changes the phase difference due to the phase shift mask.
In order to solve this problem, a method of forming an etching stopper film having resistance to fluorine-based dry etching (F-based) between the phase shift film and the quartz substrate is considered. According to this method, when etching the phase shift film, it is possible to hardly damage the underlying quartz substrate such as digging.

Materials containing aluminum, silicon, and oxygen have been proposed as materials for the etching stopper film (for example, see Patent Documents 1 and 2). By forming these materials on a quartz substrate to a thickness of about 3 nm to 10 nm, an etching stopper having an etching resistance to oxygen-containing chlorine-based dry etching (Cl / O-based) and fluorine-based dry etching (F-based). It can be a membrane.
On the other hand, a defect called a blank defect may occur in the mask blank during the manufacturing process. The types of blank defects are generally uneven defects generated at the interface between the phase shift film and the translucent substrate, cavities generated inside the phase shift film, and foreign substances mixed into the phase shift film.

  The phase shift mask blank having the etching stopper film made of the above-mentioned material containing aluminum, silicon and oxygen has the etching stopper film removed on the quartz substrate at the opening of the phase shift film pattern by the final phase shift mask. It remains without being. Therefore, when a blank defect occurs on the quartz substrate or inside the etching stopper film, the etching stopper film hinders the removal of the blank defect in the repair process in principle.

WO 2016/185941 International Publication No. WO 2017/0382313

The etching stopper film is removed from the quartz substrate at the opening of the phase shift film pattern to expose the quartz substrate at the opening of the phase shift film pattern. This makes it possible to remove the blank defect in the repair process. However, according to this method, when removing the etching stopper film, not only the etching stopper film but also other layers constituting the phase shift mask may be etched to damage other layers. If the other layers are damaged, the characteristics of the phase shift mask may be degraded.
The present invention has been made in view of the above circumstances, and a phase shift mask blank, a phase shift mask, and a phase shift mask that enable correction of a blank defect while suppressing deterioration in characteristics of the phase shift mask It is an object of the present invention to provide a method for producing the same.

  A phase shift mask blank according to one embodiment of the present invention includes: a light-transmitting substrate that transmits light of a preset wavelength; and a phase-shift film provided on the light-transmitting substrate. Has a lower layer phase shift film provided on the translucent substrate, and an upper layer phase shift film provided on the lower layer phase shift film, and the upper layer phase shift film can be etched by fluorine-based dry etching. And has resistance to oxygen-based dry etching, the lower phase shift film can be etched by oxygen-based dry etching, and has resistance to fluorine-based dry etching, and the light-transmitting substrate is And has resistance to oxygen-based dry etching.

  A phase shift mask according to one embodiment of the present invention is a light-transmitting substrate that transmits light of a predetermined wavelength, and a phase-shift film pattern provided on the light-transmitting substrate and having a predetermined shape. Wherein the phase shift film pattern includes a lower phase shift film provided on the translucent substrate, and an upper phase shift film provided on the lower phase shift film. The shift film can be etched by fluorine-based dry etching, and has resistance to oxygen-based dry etching, and the lower layer phase shift film can be etched by oxygen-based dry etching, and is resistant to fluorine-based dry etching. The light-transmitting substrate has resistance to oxygen-based dry etching.

  A method of manufacturing a phase shift mask according to one embodiment of the present invention is a method of manufacturing a phase shift mask using the above-described phase shift mask blank, wherein a light-shielding film provided on the upper phase shift film is Performing at least one type of dry etching selected from oxygen-containing chlorine-based dry etching, non-oxygen-containing chlorine-based dry etching, and fluorine-based etching to form a pattern having a predetermined shape on the light-shielding film; Performing a fluorine-based dry etching on the upper phase shift film to form a pattern having a predetermined shape on the upper phase shift film; and performing an oxygen-based dry etching on the lower phase shift film. Forming a pattern of a predetermined shape on the lower phase shift film.

  According to the present invention, it is possible to provide a phase shift mask blank, a phase shift mask, and a method of manufacturing a phase shift mask that can correct a blank defect while suppressing a decrease in characteristics of the phase shift mask.

FIG. 2 is a schematic sectional view showing a phase shift mask blank according to the first embodiment of the present invention. FIG. 6 is a schematic sectional view showing a phase shift mask blank according to a second embodiment of the present invention. FIG. 3 is a schematic cross-sectional view illustrating a configuration example of a phase shift mask according to an embodiment of the present invention. It is a section schematic diagram showing in order a manufacturing method of a phase shift mask using a phase shift mask blank concerning a 1st embodiment of the present invention. It is a section schematic diagram showing in order a manufacturing method of a phase shift mask using a phase shift mask blank concerning a 2nd embodiment of the present invention in order. FIG. 9 is a schematic cross-sectional view showing a manufacturing process in which the light-shielding film is damaged when the lower phase shift film contains chromium. FIG. 4 is a schematic cross-sectional view showing a manufacturing process in which a residue of the lower phase shift film is generated when the lower phase shift film contains tantalum or molybdenum. FIG. 7 is a schematic cross-sectional view showing a manufacturing process in which an undercut occurs in the lower phase shift film when the lower phase shift film contains chromium.

  Hereinafter, embodiments for implementing the present invention (hereinafter, embodiments) will be described with reference to the drawings. In the following description of the drawings, the same portions are denoted by the same reference numerals. However, the drawings are schematic and do not accurately reflect the actual dimensional ratios or the number of patterns. Further, the embodiments described below exemplify configurations for embodying the technical idea of the present invention, and the technical idea of the present invention is as follows. It is not something to be done. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

  A phase shift mask blank according to an embodiment of the present invention includes a substrate (hereinafter, a translucent substrate) transparent to a wavelength of exposure light (hereinafter, an exposure wavelength) transmitted through the phase shift mask blank, and a translucent substrate. A phase shift film provided thereon; and a light shielding film provided on the phase shift film. The exposure wavelength is, for example, 200 nm or less. The phase shift film has a function of giving a predetermined amount of phase change to exposure light transmitted through the phase shift film. The phase shift film has a lower phase shift film and an upper phase shift film provided on the lower phase shift film.

The lower phase shift film has resistance to fluorine-based dry etching (F-based) and non-oxygen-containing chlorine-based dry etching (Cl-based), and can be etched by oxygen-based dry etching (O-based). Here, fluorine-based dry etching (F-based) refers to dry etching using a fluorine-based gas. Examples of the fluorine-based gas include CF ₄ , C ₂ F ₆ , SF _6, and a gas further mixed with an inert gas such as a nitrogen gas or a helium gas. Non-oxygen-containing chlorine-based dry etching (Cl-based) refers to dry etching using a chlorine-based gas that does not contain oxygen. Examples of the non-oxygen-containing chlorine-based gas include Cl ₂ , HCl, BCl ₂ , and CCl ₄ . Oxygen-based dry etching (O-based) refers to dry etching using an oxygen-based gas. O ₂ is exemplified as the oxygen-based gas. The upper phase shift film has resistance to oxygen-based dry etching (O-based) and can be etched by fluorine-based dry etching (F-based). In the present embodiment, the lower phase shift film contains ruthenium (Ru).

Examples of the phase shift mask blank according to the embodiment of the present invention include a first embodiment and a second embodiment described below.
FIG. 1 is a schematic sectional view showing a configuration example of the phase shift mask blank according to the first embodiment of the present invention. As shown in FIG. 1, the phase shift mask blank 10 according to the first embodiment includes a translucent substrate 11 transparent to an exposure wavelength, a lower phase shift film 12 provided on the translucent substrate 11, , An upper phase shift film 13 provided on the lower phase shift film 12, and a light shielding film 14 provided on the upper phase shift film 13. The lower phase shift film 12 and the upper phase shift film 13 form the phase shift film 2.

FIG. 2 is a schematic sectional view showing a configuration example of a phase shift mask blank according to a second embodiment of the present invention. As shown in FIG. 2, the phase shift mask blank 20 according to the second embodiment includes a light-transmitting substrate 11 transparent to an exposure wavelength, and a lower phase-shift film 12 provided on the light-transmitting substrate 11. An upper phase shift film 13 provided on the lower phase shift film 12, a light shielding film 14 provided on the upper phase shift film 13, and a hard mask film 15 provided on the light shielding film 14.
Here, there is no particular limitation on the material of the light-transmitting substrate 11. The translucent substrate 11 is made of, for example, quartz glass, calcium fluoride (CaF ₂ ), or aluminosilicate glass.

  The lower phase shift film 12 is made of ruthenium alone or a ruthenium compound having a ruthenium content of 50 atomic% or more and less than 100%. Specifically, the lower phase shift film 12 is preferably made of ruthenium alone or a compound of ruthenium and at least one material selected from nitrogen, boron, carbon, oxygen, niobium and zirconium. Further, the lower phase shift film 12 prevents a decrease in resistance to fluorine-based dry etching (F-based) and non-oxygen-containing chlorine-based dry etching (Cl-based) and prevents deterioration in workability in oxygen-based dry etching (O-based). For this reason, it is preferable that tantalum and molybdenum are not contained, and the ruthenium content is 50 atomic% or more.

The lower phase shift film 12 preferably does not contain chromium in order to prevent a decrease in resistance to oxygen-containing chlorine-based dry etching (Cl / O-based) and a deterioration in workability in oxygen-based dry etching (O-based). . The thickness of the lower phase shift film 12 is preferably 2 nm or more and 20 nm or less, particularly preferably 5 nm or more and 15 nm or less in order to achieve both sufficient etching resistance and transparency to exposure light.
The upper layer phase shift film 13 is a silicon oxide film, a silicon nitride film, or a silicon oxynitride film, or a silicon and transition metal oxide film, a silicon and transition metal nitride film, or a silicon and transition metal oxynitride film. Consists of The upper phase shift film 13 is a single-layer film, a multi-layer film, or a gradient film, and the transmittance and the phase difference with respect to the exposure wavelength are adjusted by appropriately selecting the composition and the film thickness. The gradient film is a film in which the composition ratio of the material forming the gradient film changes continuously in the thickness direction of the gradient film. As the transition metal, molybdenum, titanium, vanadium, cobalt, nickel, zirconium, niobium, and hafnium are preferable.

  The value of the transmittance of the phase shift film 2 in which the lower phase shift film 12 and the upper phase shift film 13 are combined is 3% or more and 100% or more with respect to the transmittance of the light transmitting substrate 1 when the final phase shift mask is completed. It is as follows. The transmittance of the phase shift film 2 can be appropriately selected from the optimum transmittance according to a desired wafer pattern. For example, the transmittance is 5% or more and 40% or less. Note that a phase shift mask having a transmittance of 100% is also called a CPL (Chromeless Phase Lithography). The value of the phase difference of the phase shift film 2 including the lower layer phase shift film 12 and the upper layer phase shift film 13 is 170 ° or more and 190 ° or less, especially 175 ° or more and 180 ° or less when the final phase shift mask is completed. It is preferred that

Here, the phase difference of the phase shift film 2 refers to the exposure light transmitted through the phase shift film 2 and the portion where the phase shift film 2 is removed (for example, an opening 2h of a phase shift film pattern 2p described later). This is the phase difference from the exposure light. The phase difference of the phase shift film 2 is determined by the amount of phase change of the exposure light passing through the phase shift film 2.
The lower phase shift film 12 has resistance to fluorine-based dry etching (F-based). In a later-described manufacturing process of the phase shift mask 100, the upper phase shift film 13 is etched, but at this time, the lower phase shift film 12 is not etched (or almost not etched). Thereafter, the lower phase shift film 12 is removed by oxygen-based dry etching (O-based) in which the translucent substrate 11 is not etched (or almost not etched). As a result, a phase shift film pattern 2p described later is formed.

  The composition of the upper phase shift film 13 changes depending on the combination of desired transmittance and phase difference. For example, in the phase shift film 2 in which the upper phase shift film 13 and the lower phase shift film 12 are combined, the composition of the upper phase shift film 13 is adjusted so that the transmittance is 10% and the phase difference is 180 degrees. The composition of the upper phase shift film 13 is a silicon-silicon oxide film, a silicon-silicon nitride film, a silicon-silicon oxynitride film, or an oxide film of silicon and a transition metal (for example, molybdenum), and a nitride of silicon and a transition metal. In the case of a film, an oxynitride film of silicon and a transition metal, silicon is 20 to 60 atomic%, particularly 30 to 50 atomic%, and molybdenum is 0 to 20 atomic%, particularly 0 at% or more. 10 atomic% or less, oxygen is 0 atomic% to 20 atomic%, particularly 0 atomic% to 10 atomic%, and nitrogen is 30 atomic% to 80 atomic%, particularly 40 atomic% to 70 atomic%. preferable. Thereby, the upper phase shift film 13 can realize resistance to oxygen-based dry etching (O-based), workability to fluorine-based dry etching (F-based), and resistance to various chemical cleaning.

The upper phase shift film 13 also has resistance to oxygen-containing chlorine-based dry etching (Cl / O-based) and non-oxygen-containing chlorine-based dry etching (Cl-based) used for removing the light-shielding film 14. Here, oxygen-containing chlorine-based dry etching (Cl / O-based) refers to dry etching using an oxygen-containing chlorine-based gas. Examples of the oxygen-containing chlorine-based gas include a gas obtained by mixing a chlorine gas and an oxygen gas, and a gas obtained by further mixing an inert gas such as a nitrogen gas and a helium gas. When the upper phase shift film 13 is a multilayer film or a gradient film, it has strong resistance to oxygen-containing chlorine-based dry etching (Cl / O-based) and non-oxygen-containing chlorine-based dry etching (Cl-based). It is preferable to form a silicon-based compound film having a small (or no) content of a transition metal on the outermost surface. Specifically, it is preferable to form SiO ₂ or SiON on the outermost surface of the upper phase shift film 13.

On the other hand, the thickness of the light-shielding film 14 also changes depending on the transmittance of the phase shift film 2 including the upper phase shift film 13 and the lower phase shift film 12. Adjustment is made so that the total amount of the phase shift film 2 and the phase shift film 2 becomes 2.5 or more, more preferably 2.8 or more. For example, when the transmittance of the phase shift film 2 is 10%, the thickness of the light-shielding film 14 is preferably from 20 nm to 65 nm, particularly preferably from 30 nm to 60 nm.
Further, the light shielding film 14 may have a function as an antireflection layer. In this case, to suppress the reflectance with respect to the exposure wavelength to, for example, 45% or less, particularly 30% or less, is to reduce the multiple reflection between the phase shift mask 100 (see FIG. 3 described later) and the projection exposure surface during exposure. It is preferable in suppressing. Further, it is preferable that the reflectance for the wavelength (for example, 257 nm) of the light used for the reflection inspection of the phase shift mask blanks 10 and 20 and the phase shift mask 100 be, for example, 30% or less, in order to detect a defect with high accuracy. In order to increase the effect of the antireflection layer, there is a method of increasing the gas content on the surface side of the light-shielding film 14 to have a higher refractive index and a lower extinction coefficient.

  The light-shielding film 14 is a single-layer film containing chromium alone, chromium and at least one selected from nitrogen, oxygen, and carbon, or a multilayer film or a gradient film thereof. The light-shielding film 14 has a chromium content of 30 atomic% or more and 100 atomic% or less, particularly 35 atomic% or more and 65 atomic% or less, and oxygen of 0 atomic% or more and 60 atomic% or less, particularly 10 atomic% or more and 60 atomic% or less. The nitrogen content is 0 atomic% or more and 50 atomic% or less, especially 0 atomic% or more and 30 atomic% or less, and the carbon content is 0 atomic% or more and 30 atomic% or less, particularly 0 atomic% or more and 20 atomic% or less. preferable. Thus, the light-shielding film 14 has resistance to fluorine-based dry etching (F-based) and oxygen-based dry etching (O-based), workability to oxygen-containing chlorine-based dry etching (Cl / O-based), and an effect as an antireflection layer. , And resistance to various chemical cleanings can be realized.

  Alternatively, the light-shielding film 14 is a single-layer film made of a tantalum compound and containing at least one selected from nitrogen, boron, oxygen, and carbon, or a multi-layer film or a gradient film thereof. It is a film as a component. The composition of the light-shielding film 14 is such that tantalum is 50 atomic% or more and 100 atomic% or less, particularly 60 atomic% or more and 90 atomic% or less, nitrogen is 0 atomic% or more and 70 atomic% or less, particularly 10 atomic% or more and 60 atomic% or less. %, Oxygen is 0 atom% or more and 10 atom% or less, especially 0 atom% or more and 5 atom% or less, carbon is 0 atom% or more and 20 atom% or less, especially 0 atom% or more and 10 atom% or less, boron Is preferably at least 0 atomic% and at most 20 atomic%, particularly preferably at least 0 atomic% and at most 10 atomic%. Thereby, the light-shielding film 14 is resistant to oxygen-containing chlorine-based dry etching (Cl / O-based) and oxygen-based dry etching (O-based), workability to non-oxygen-containing chlorine-based dry etching (Cl-based), and various chemicals. Resistance to washing can be realized.

The hard mask film 15 is a single-layer film containing silicon and at least one selected from oxygen and nitrogen, or a multilayer film or a gradient film thereof. The thickness of the hard mask film 15 is preferably 2 nm or more and 30 nm or less, and particularly preferably 20 nm or less in order to reduce damage to the resist during dry etching of the hard mask film and to realize a thinner resist. Further, the thickness of the hard mask film 15 is preferably 3 nm or more in order to prevent pinholes during film formation and loss of the film during etching or cleaning.
The composition of the hard mask film 15 is such that silicon is at least 20 at% and at most 60 at%, particularly at least 30 at% and at most 50 at%, oxygen is at least 0 at% and at most 80 at%, particularly 0 at% to 70 at%, It is preferable that nitrogen is 0 to 80 atomic%, particularly 0 to 70 atomic%. Accordingly, the hard mask film 15 has resistance to oxygen-containing chlorine-based dry etching (Cl / O-based) and oxygen-based dry etching (O-based), workability to fluorine-based dry etching (F-based), and cleaning for various chemicals. Resistance can be realized.

Alternatively, the hard mask film 15 is a single-layer film containing chromium alone or chromium and one or more selected from oxygen, nitrogen, and carbon, or a multilayer film or a gradient film thereof. The thickness of the hard mask film 15 is preferably 2 nm or more and 30 nm or less, and particularly preferably 20 nm or less in order to reduce damage to the resist when dry etching the hard mask film 15 and to realize a thinner resist. Further, the thickness of the hard mask film 15 is preferably 3 nm or more in order to prevent pinholes during film formation and loss of the film during etching or cleaning.
The composition of the hard mask film 15 is such that chromium is 30 at% to 100 at%, particularly 50 at% to 100 at%, oxygen is 0 at% to 50 at%, especially 0 at% to 40 at%, It is preferable that nitrogen is 0 to 50 atomic%, particularly 0 to 40 atomic%, and carbon is 0 to 30 atomic%, particularly 0 to 20 atomic%. Thereby, the hard mask film 15 is resistant to fluorine-based dry etching (F-based), non-oxygen-containing chlorine-based dry etching (Cl-based) and oxygen-based dry etching (O-based), and oxygen-containing chlorine-based dry etching (Cl / O)) and resistance to various chemical cleaning.

  The above-mentioned lower phase shift film 12, upper phase shift film 13, light-shielding film 14, and hard mask film 15 can all be formed by a known method. As a method for easily obtaining a film having excellent homogeneity, a sputter film forming method is preferably mentioned, but the present invention does not need to be limited to the sputter film forming method.

The target and the sputtering gas are selected according to the film composition. For example, as a method for forming a film containing chromium, a target containing chromium is used, only an inert gas such as an argon gas, only a reactive gas such as oxygen, or a mixture of an inert gas and a reactive gas is used. A method of performing reactive sputtering in a gas can be used. The flow rate of the sputtering gas may be adjusted according to the film characteristics, and may be constant during the film formation, or when the amount of oxygen or nitrogen is to be changed in the thickness direction of the film, the amount is changed according to the desired composition. You may. Further, the power applied to the target, the distance between the target and the substrate, and the pressure in the film formation chamber may be adjusted. Also, for example, in the formation of a film containing silicon and metal, as the target, a target whose content ratio of silicon and metal is adjusted may be used alone, or a silicon target, a metal target, and silicon and metal. A plurality of targets may be appropriately selected from the targets consisting of.
The phase shift mask according to the embodiment of the present invention is obtained by patterning or removing each film of the above-described phase shift mask blanks 10 and 20 into a desired pattern.

  Next, a phase shift mask and a method of manufacturing the phase shift mask according to the embodiment of the present invention will be specifically described. FIG. 3 is a schematic sectional view showing a configuration example of the phase shift mask according to the embodiment of the present invention. As shown in FIG. 3, the phase shift mask 100 according to the embodiment includes a translucent substrate 11, a phase shift film pattern 2p provided on the translucent substrate 11, and a phase shift film pattern 2p provided on the phase shift film pattern 2p. Light-shielding film 14p. The phase shift film pattern 2p is a film in which a pattern having a preset shape (hereinafter, a predetermined shape) is formed on the phase shift film 2. The phase shift film pattern 2p includes a lower phase shift film 12p and an upper phase shift film 13p on which a pattern having a predetermined shape is formed. The pattern of the lower phase shift film 12p and the pattern of the upper phase shift film 13p have the same shape (or substantially the same shape). The light-shielding film 14p is a film in which a pattern having a predetermined shape is formed on the light-shielding film 14. The phase shift mask 100 has a first region R1 and a second region R2 located around the first region R1. The second region R2 is, for example, an outer peripheral region of the phase shift mask 100. The light-shielding film 14p is arranged in the second region R2. Thus, the outer peripheral area of the phase shift mask 100 becomes a light-shielding area that blocks exposure light. For the phase shift mask 100, for example, exposure light having a wavelength of 200 nm or less is applied.

  4A to 4G are schematic cross-sectional views sequentially showing a method for manufacturing the phase shift mask according to the first embodiment of the present invention. FIGS. 4A to 4G sequentially show a manufacturing method using the phase shift mask blank 10 shown in FIG. As shown in FIG. 4A, the manufacturing apparatus applies a resist film on the light-shielding film 14 of the phase shift mask blank 10, paints the resist film, and then performs a developing process to form a resist pattern 16. I do. Next, as shown in FIG. 4B, the manufacturing apparatus performs oxygen-containing chlorine-based dry etching (Cl / O-based) on the light shielding film 14 partially covered with the resist pattern 16, The light shielding film 14 is patterned. As a result, the manufacturing apparatus forms the light-shielding film 14p having a pattern having substantially the same shape as the resist pattern 16.

  Next, as shown in FIG. 4C, the manufacturing apparatus peels off the remaining resist pattern 16 and cleans the phase shift mask blank from which the resist pattern 16 has been removed. Next, as shown in FIG. 4D, the manufacturing apparatus performs a fluorine-based dry etching (F-based) on the upper phase shift film 13 partially covered with the light shielding film 14p, The shift film 13 is patterned. Thus, the manufacturing apparatus forms the upper phase shift film 13p having a pattern having substantially the same shape as the light-shielding film 14p. Next, as shown in FIG. 4E, the manufacturing apparatus performs oxygen-based dry etching (O-based) on the lower phase shift film 12 partially covered by the light shielding film 14p and the upper phase shift film 13p. To pattern the lower phase shift film 12. Thus, the manufacturing apparatus forms the lower phase shift film 12p having a pattern substantially the same as the shape of the upper phase shift film 13p.

Next, as shown in FIG. 4F, the manufacturing apparatus applies a resist film on the translucent substrate 1, draws the resist film, and then performs a developing process to form a resist pattern 17. . The resist pattern 17 has a shape exposing the first region R1 and covering the second region R2.
Next, as shown in FIG. 4G, the manufacturing apparatus performs oxygen-containing chlorine-based dry etching (Cl / O-based) on the light-shielding film 14p that is not covered with the resist pattern 17, to form a first region. The light-shielding film 14p of R1 is removed. Thereafter, the manufacturing apparatus peels off the remaining resist pattern 17 and cleans the phase shift mask blank from which the resist pattern 17 has been removed. Thus, the phase shift mask 100 shown in FIG. 3 is completed. In the completed phase shift mask 100, the light-shielding film 14p remains without being removed in the second region R2.

  5A to 5H are schematic sectional views sequentially showing a method for manufacturing a phase shift mask according to the second embodiment of the present invention. FIGS. 5A to 5H sequentially show a manufacturing method using the phase shift mask blank 20 shown in FIG. As shown in FIG. 5A, the manufacturing apparatus applies a resist film on the hard mask film 15 of the phase shift mask blank 20, draws the resist film, performs a developing process thereafter, and forms the resist pattern 16 Form. Next, as shown in FIG. 5B, the manufacturing apparatus performs a fluorine-based dry etching (F-based) on the hard mask film 15 partially covered with the resist 15 is patterned. Thus, the manufacturing apparatus forms the hard mask film 15p having a pattern having substantially the same shape as the resist pattern 16.

  Next, as shown in FIG. 5C, the manufacturing apparatus peels off the remaining resist pattern 16 and cleans the phase shift mask blank from which the resist pattern 16 has been removed. Next, as shown in FIG. 5D, the manufacturing apparatus performs oxygen-containing chlorine-based dry etching (Cl / O-based) on the light-shielding film 14 partially covered with the hard mask film 15p. Then, the light shielding film 14 is patterned. Thus, the manufacturing apparatus forms the light-shielding film 14p having a pattern having substantially the same shape as the hard mask film 15p. Next, as shown in FIG. 5E, the manufacturing apparatus performs a fluorine-based dry etching (F-based) on the upper phase shift film 13 partially covered with the hard mask film 15p and the light-shielding film 14p. Then, the upper phase shift film 13 is patterned. Thus, the manufacturing apparatus forms the upper phase shift film 13p having a pattern having substantially the same shape as the light-shielding film 14p. In the process of forming the upper phase shift film 13p, the hard mask film 15p is removed by etching.

Subsequent steps are the same as those of the manufacturing method according to the first embodiment. That is, as shown in FIG. 5F, the manufacturing apparatus performs oxygen-based dry etching (O-based) on the lower phase shift film 12 partially covered with the light shielding film 14p and the upper phase shift film 13p. Then, the lower phase shift film 12 is patterned. Thus, the manufacturing apparatus forms the lower phase shift film 12p having a pattern substantially the same as the shape of the upper phase shift film 13p.
Next, as shown in FIG. 5G, the manufacturing apparatus applies a resist film on the translucent substrate 1, draws the resist film, and then performs a developing process to form a resist pattern 17. . The resist pattern 17 has a shape exposing the first region R1 and covering the second region R2.

  Next, as shown in FIG. 5H, the manufacturing apparatus performs oxygen-containing chlorine-based dry etching (Cl / O-based) on the light-shielding film 14p that is not covered with the resist pattern 17, thereby forming the first region. The light-shielding film 14p of R1 is removed. Thereafter, the manufacturing apparatus peels off the remaining resist pattern 17 and cleans the phase shift mask blank from which the resist pattern 17 has been removed. Thus, the phase shift mask 100 shown in FIG. 3 is completed. In the completed phase shift mask 100, the light-shielding film 14p remains without being removed in the second region R2.

  In the steps of FIG. 4A and FIG. 5A, a positive resist or a negative resist can be used as a material of the resist film, but an electron beam lithography for forming a high-precision pattern can be used. It is preferable to use a chemically amplified resist. The thickness of the resist film is, for example, in a range from 50 nm to 300 nm. In particular, when manufacturing a phase shift mask that requires formation of a fine pattern, it is necessary to reduce the thickness of the resist film so as not to increase the aspect ratio of the resist pattern 16 in order to prevent pattern collapse. Pattern collapse means that the resist pattern collapses. When the pattern collapses, it hinders the formation of the lower layer pattern. Examples of the pattern collapse include a case where the resist pattern is peeled off from the base surface, a case where the resist pattern is broken in the middle of the pattern, and the like.

The thickness of the resist film is preferably 150 nm or less in combination with the hard mask film 15. On the other hand, the lower limit of the thickness of the resist film is determined by comprehensively considering conditions such as the etching resistance of the resist material to be used, and is preferably 60 nm or more. When a chemically amplified resist film for electron beam writing is used as the resist film, the energy density of the electron beam at the time of writing is in the range of 10 to 150 μC / cm ² . After the writing, the resist film is subjected to a heating process and a developing process to obtain a resist pattern 16.
In the step of FIG. 5B, the condition of the fluorine-based dry etching (F-based) for patterning the hard mask film 15 may be a known condition used when dry-etching a silicon-based compound film. As the fluorine-based gas, CF ₄ , C ₂ F ₆ or SF ₆ may be used, and a gas further mixed with an inert gas such as a nitrogen gas or a helium gas may be used as needed. Since the light-shielding film 14, which is the lower layer of the hard mask film 15, has resistance to fluorine-based dry etching (F-based), it remains without being removed or patterned in this step.

In the steps of FIGS. 4B and 5D, the condition of oxygen-containing chlorine-based dry etching (Cl / O-based) for patterning the light-shielding film 14 is used when the chromium compound film is dry-etched. It may be a known one. As the oxygen-containing chlorine-based gas, a mixture of a chlorine gas and an oxygen gas may be used, and if necessary, a mixture of an inert gas such as a nitrogen gas and a helium gas may be used. The upper phase shift film 13, which is the lower layer of the light-shielding film 14, has resistance to oxygen-containing chlorine-based dry etching (Cl / O-based), and thus remains without being removed or patterned in this step.
In the steps of FIGS. 4C and 5C, the resist pattern 16 can be peeled and removed by dry etching, but is generally wet-peeled with a peeling liquid.

Further, in the step of FIG. 5E, the condition of the fluorine-based dry etching (F-type) for removing the hard mask film 15p, and in the steps of FIG. 4D and FIG. The condition of the fluorine-based dry etching (F-based) for patterning may be a known condition used for dry-etching a silicon-based compound film. As the fluorine-based gas, CF ₄ , C ₂ F ₆ or SF ₆ may be used, and if necessary, a mixture of an inert gas such as a nitrogen gas or a helium gas may be used. Since the lower phase shift film 12 has resistance to fluorine-based dry etching (F-based), the translucent substrate 1 is not dug. Therefore, in the phase shift mask 100, a phase difference error does not occur due to the pattern dependence of the substrate digging amount or the mask position dependence. In the phase shift mask 100, a more uniform phase difference can be realized in all patterns and all portions of the mask.

If the lower phase shift film 12 contains tantalum or molybdenum having low resistance to fluorine-based dry etching (F type), the lower phase shift film 12 may be damaged in the present process, such as film reduction or the like. There is a possibility that the phase shift film 12 is removed. In this case, the phase difference of the phase shift mask is not uniform.
In the steps of FIGS. 4E and 5F, oxygen gas is used for oxygen-based dry etching (O-based) for patterning the lower phase shift film 12, and if necessary, argon gas or helium gas is used. Alternatively, a mixture of an inert gas such as the above may be used. Since the light-shielding film 14p, the upper phase shift film 13p, and the light-transmitting substrate 1 have resistance to oxygen-based dry etching (O-based), they remain without being removed or patterned in this step.
The lower phase shift film 12 contains ruthenium. When the lower phase shift film 12 contains chromium, tantalum, or molybdenum instead of ruthenium, the light-shielding film is reduced in thickness in the steps of FIG. 4E and FIG. Residue may be generated.

  FIG. 6 is a schematic cross-sectional view showing a manufacturing process in which the light-shielding film is damaged when the lower phase shift film contains chromium. If the lower phase shift film contains chromium, it becomes difficult to process the lower phase shift film by oxygen-based dry etching (O-based). The etching of the lower phase shift film containing chromium must be performed by oxygen-containing chlorine-based dry etching (Cl / O-based). As shown in FIG. 6, when oxygen-containing chlorine-based dry etching (Cl / O-based) is performed on the lower phase shift film 120 containing chromium, the lower phase shift film 120 is etched and the light shielding film 14p is also etched. And causes a problem of a decrease in optical density (OD value). For example, as shown by the dotted line in FIG. 6, the light-shielding film 14p may be damaged by a dry etching of oxygen-containing chlorine (Cl / O-based) such as a decrease in film thickness.

  FIG. 7 is a schematic cross-sectional view showing a manufacturing process in which a residue of the lower phase shift film is generated when the lower phase shift film contains tantalum or molybdenum. If the lower phase shift film contains tantalum or molybdenum, it becomes difficult to process the lower phase shift film by oxygen-based dry etching (O-based). The etching of the lower phase shift film containing tantalum or molybdenum needs to be performed by non-oxygen-containing chlorine-based dry etching (Cl-based). Here, the outermost surface of the lower phase shift film containing tantalum or molybdenum is oxidized when the lower phase shift film is formed to form an oxide film. As shown in FIG. 7, when the non-oxygen-containing chlorine-based dry etching (Cl-based) is performed on the lower phase shift film 121 containing tantalum or molybdenum, the etching processability is deteriorated due to the presence of the oxide film, and the residue 121r May occur.

In the steps of FIGS. 4F and 5G, the drawing method may use laser drawing, which is less accurate than electron beam drawing. In this case, the manufacturing apparatus obtains the resist pattern 17 by applying a resist film, performing laser drawing, and then performing a developing process.
4 (g) and FIG. 5 (h), the conditions of the oxygen-containing chlorine-based dry etching (Cl / O-based) for removing the light-shielding film 14p are known in the art which have been used for removing the chromium compound film. It is good. As the oxygen-containing chlorine-based gas, a mixture of a chlorine gas and an oxygen gas may be used, and if necessary, a mixture of an inert gas such as a nitrogen gas and a helium gas may be used. Since the upper phase shift film has resistance to oxygen-containing chlorine-based dry etching (Cl / O-based), it remains without being removed or patterned in this step.
If the lower phase shift film contains chromium, whose resistance to oxygen-containing chlorine-based dry etching (Cl / O-based) is deteriorated, the lower phase shift film is formed in the steps of FIGS. 4 (g) and 5 (h). An undercut may occur in the shift film.

  FIG. 8 is a schematic cross-sectional view showing a manufacturing process in which an undercut occurs in the lower phase shift film when the lower phase shift film contains chromium. If the lower phase shift film contains chromium, the lower phase shift film is isotropically etched by oxygen-containing chlorine-based dry etching (Cl / O-based). As a result, as shown in FIG. 8, an undercut 122uc occurs in the lower phase shift film 122 containing chromium, and the line pattern of the lower phase shift film 122 becomes thinner than the upper phase shift film 13p. The undercut 122uc of the lower phase shift film 122 leads to peeling or falling of the upper phase shift film 13p, and there is a possibility that the resolution and the element characteristics are deteriorated.

The resist pattern 17 after the steps of FIG. 4 (g) and FIG. 5 (h) can be removed by dry etching, but is generally wet-peeled with a remover.
In the embodiment of the present invention, an inspection (hereinafter, defect inspection) for inspecting a product for a defect is performed at any stage of FIGS. 4 (a) to 4 (g) and FIGS. 5 (a) to 5 (h). Good. The defect inspection is, for example, an appearance inspection. When a defect is detected in the area of the opening 2h of the phase shift film pattern 2p in the defect inspection, a step of correcting the defect may be added. There are various methods for repairing the defect depending on the type and size of the defect. However, in the case of a black defect in which a part of the upper phase shift film 13p is larger than a desired size, a fluorine-based gas is supplied to the defective portion. A correction method for removing only a defective portion by etching with high accuracy by irradiating an electron beam is performed. Here, in the step shown in FIG. 4D, the lower phase shift film 12 covers the region of the opening 2h. The lower layer phase shift film 12 contains ruthenium and has resistance to fluorine-based dry etching (F-based). Therefore, the lower phase shift film 12 prevents the translucent substrate 11 from being damaged when correcting the electron beam. This enables more accurate correction.

  As described above, the phase shift mask blanks 10 and 20 according to the embodiment of the present invention include the translucent substrate 11 that transmits exposure light having a preset wavelength (hereinafter, a predetermined wavelength), and the translucent substrate. And a phase shift film 2 provided on the substrate 11. The predetermined wavelength is, for example, 200 nm or less. The phase shift film 2 has a lower layer phase shift film 12 provided on the light transmitting substrate 11 and an upper layer phase shift film 13 provided on the lower layer phase shift film 12. The upper phase shift film 13 can be etched by fluorine-based dry etching (F-based) and has resistance to oxygen-based dry etching (O-based). The lower phase shift film 12 can be etched by oxygen-based dry etching (O-based) and has resistance to fluorine-based dry etching (F-based). The translucent substrate 11 has resistance to oxygen-based dry etching (O-based).

  Here, “etchable by fluorine-based dry etching (F-based) and resistant to oxygen-based dry etching (O-based)” means that the etching rate by fluorine-based dry etching (F-based) is high. The etching rate by oxygen-based dry etching (O-based) is sufficiently small, which means that etching is not or almost not performed by oxygen-based dry etching (O-based). Similarly, “etchable by oxygen-based dry etching (O-based) and resistant to fluorine-based dry etching (F-based)” means that the etching rate by oxygen-based dry etching (F-based) is high. That is, the etching rate by the fluorine-based dry etching (F-based) is sufficiently small, which means that the etching is not performed (or almost not etched) by the fluorine-based dry etching (F-based). In the present embodiment, “having resistance” means that it is not etched (or almost not etched).

  According to this, when the upper layer phase shift film 13 is processed by fluorine-based dry etching (F system), the lower layer phase shift film 12 is not etched (or almost not etched), and the light-transmitting substrate 11 is There is no exposure to fluorine-based dry etching (F-based). Further, in the oxygen-based dry etching (O-based) used for processing the lower layer phase shift film 12, the light transmitting substrate 11 is not etched (or almost not etched). Therefore, in etching the phase shift film 2 including the upper phase shift film 13 and the lower phase shift film 12, damage to the light transmitting substrate 11 is suppressed. The digging amount of the translucent substrate 11 can be reduced to zero (or almost zero).

Thus, the phase shift mask 100 manufactured from the phase shift mask blanks 10 and 20 can prevent the phase difference of the exposure light from being changed due to the variation in the amount of digging of the translucent substrate 11. The phase shift mask 100 can eliminate the phase difference change depending on the shape of the phase shift film pattern 2p and the position in the surface of the light transmitting substrate 11.
According to the phase shift mask blanks 10 and 20, the lower phase shift film 12 can be removed by oxygen-based dry etching (O-based). Therefore, it is possible to remove a blank defect generated inside the lower phase shift film 12 and to correct a blank defect generated on the light transmitting substrate 11.

  Further, according to the phase shift mask blanks 10 and 20, the light transmitting substrate 11, the upper phase shift film 13, and the light shielding film 14 are not subjected to oxygen-based dry etching (O-based) used for processing the lower layer phase shift film 12. Has a resistance, and in particular, can greatly increase the etching selectivity with respect to the light transmitting substrate 11 (the etching rate of the lower phase shift film 12 divided by the etching rate of the light transmitting substrate 11). It is. Therefore, by sufficiently performing over-etching of the lower phase shift film 12 (etching that is extended after the etching time for removing the film), it is possible to reduce the omission failure of the lower phase shift film 12. This is also advantageous for the quality of the phase shift mask 100. A phase shift mask blank capable of correcting a blank defect while suppressing a decrease in characteristics can be provided.

Further, the lower phase shift film 12 may contain ruthenium. According to this, a film that can be etched by oxygen-based dry etching (O-based) and has resistance to fluorine-based dry etching (F-based) can be realized as the lower phase shift film 12.
Further, lower phase shift film 12 may be composed of ruthenium alone or a ruthenium compound having a ruthenium content of 50 atomic% or more and less than 100 atomic%. According to this, a film that can be etched by oxygen-based dry etching (O-based) and has resistance to fluorine-based dry etching (F-based) can be realized as the lower phase shift film 12.

Further, the thickness of lower phase shift film 12 may be not less than 2 nm and not more than 20 nm. According to this, the lower phase shift film 12 can achieve both sufficient etching resistance to fluorine-based dry etching (F-based) and transparency to exposure light.
The upper phase shift film 13 contains silicon and may contain one or more atoms selected from molybdenum, titanium, vanadium, cobalt, nickel, zirconium, niobium, hafnium, nitrogen, oxygen and carbon. . According to this, a film which can be etched by fluorine-based dry etching (F-based) and has resistance to oxygen-based dry etching (O-based) can be realized as the upper phase shift film 13.

  Further, the phase shift mask blanks 10 and 20 may further include a light shielding film 14 provided on the upper phase shift film 13. The light-shielding film 14 can be etched by one or more types of dry etching selected from oxygen-containing chlorine-based dry etching (Cl / O-based), non-oxygen-containing chlorine-based dry etching (Cl-based), and fluorine-based dry etching, and It may have resistance to fluorine-based dry etching (F-based) and oxygen-based dry etching (O-based). The upper phase shift film 13 may have resistance to oxygen-containing chlorine-based dry etching (Cl / O-based) and non-oxygen-containing chlorine-based dry etching (Cl-based). The lower phase shift film 12 may have resistance to oxygen-containing chlorine-based dry etching (Cl / O-based) and non-oxygen-containing chlorine-based dry etching (Cl-based).

  Here, it is possible to perform etching by one or more types of dry etching selected from oxygen-containing chlorine-based dry etching (Cl / O-based), non-oxygen-containing chlorine-based dry etching (Cl-based), and fluorine-based dry etching. Resists dry etching (F-based) and oxygen-based dry etching (O-based). "Oxygen-containing chlorine-based dry etching (Cl / O-based), non-oxygen-containing chlorine-based dry etching (Cl-based) The etching rate of fluorine-based dry etching (F-based) or the etching rate of oxygen-based dry etching (O-based) is sufficiently higher than the etching rate of one or more types of dry etching selected from the group consisting of fluorine-based dry etching and fluorine-based dry etching. Small, fluorine-based dry etching (F-based) or oxygen-based dry etching ( System) are not in etched (or means substantially not etched) that.

  According to this, since the light shielding film 14 blocks the exposure light, a light shielding region (for example, the second region R2) can be provided in the phase shift mask blanks 10 and 20. Further, when the light shielding film 14 is processed by one or more types of dry etching selected from oxygen-containing chlorine-based dry etching (Cl / O-based), non-oxygen-containing chlorine-based dry etching (Cl-based) and fluorine-based dry etching. In addition, the upper phase shift film 13 and the lower phase shift film 12 are not etched (or almost not etched). Further, when the upper phase shift film 13 is processed by the fluorine-based dry etching (F-based) and when the lower phase shift film 12 is processed by the oxygen-based dry etching (O-based), the light shielding film 14p is etched. Not (or almost not etched). Thus, the manufacturing apparatus can sequentially dry-etch the upper phase shift film 13 and the lower phase shift film 12 using the light shielding film 14p as a mask.

  The phase shift mask 100 according to the embodiment of the present invention is manufactured from the phase shift mask blanks 10 and 20 described above. The phase shift mask 100 includes a translucent substrate 11 that transmits exposure light of a predetermined wavelength (for example, 200 nm or less), and a phase shift film pattern 2p provided on the translucent substrate 11 and having a predetermined shape. . The phase shift film pattern 2p has a lower phase shift film 12p provided on the translucent substrate 11, and an upper phase shift film 13p provided on the lower phase shift film 12p. The upper phase shift film 13p can be etched by fluorine-based dry etching (F-based) and has resistance to oxygen-based dry etching (O-based). The lower phase shift film 12p can be etched by oxygen-based dry etching (O-based) and has resistance to fluorine-based dry etching (F-based). The translucent substrate 11 has resistance to oxygen-based dry etching (O-based). According to this, it is possible to provide a phase shift mask capable of correcting a blank defect while suppressing a decrease in characteristics.

The lower phase shift film 12p may contain ruthenium. According to this, a film which can be etched by oxygen-based dry etching (O-based) and has resistance to fluorine-based dry etching (F-based) can be realized as the lower phase shift film 12p.
The lower layer phase shift film 12p may be composed of ruthenium alone or a ruthenium compound having a ruthenium content of 50 atomic% or more and less than 100 atomic%. According to this, a film which can be etched by oxygen-based dry etching (O-based) and has resistance to fluorine-based dry etching (F-based) can be realized as the lower phase shift film 12p.

The thickness of the lower phase shift film 12p may be 2 nm or more and 20 nm or less. According to this, the lower phase shift film 12p can achieve both sufficient etching resistance to fluorine-based dry etching (F-based) and transparency to exposure light.
The upper phase shift film 13p contains silicon and may contain one or more atoms selected from molybdenum, titanium, vanadium, cobalt, nickel, zirconium, niobium, hafnium, nitrogen, oxygen and carbon. According to this, a film which can be etched by fluorine-based dry etching (F-based) and has resistance to oxygen-based dry etching (O-based) can be realized as the upper phase shift film 13p.

  The phase shift mask 100 may further include a light shielding film 14p provided on the upper phase shift film 13p. The light-shielding film 14p can be etched by one or more types of dry etching selected from oxygen-containing chlorine-based dry etching (Cl / O-based), non-oxygen-containing chlorine-based dry etching (Cl-based), and fluorine-based dry etching, and It may have resistance to fluorine-based dry etching (F-based) and oxygen-based dry etching (O-based). The upper phase shift film 13p may have resistance to oxygen-containing chlorine-based dry etching (Cl / O-based) and non-oxygen-containing chlorine-based dry etching (Cl-based). The lower phase shift film 12 may have resistance to oxygen-containing chlorine-based dry etching (Cl / O-based) and non-oxygen-containing chlorine-based dry etching (Cl-based).

  According to this, since the light shielding film 14p shields the exposure light, a light shielding region (for example, the second region R2) can be provided in the phase shift mask 100. Further, when manufacturing the phase shift mask 100, the manufacturing apparatus sequentially dry-etches the upper phase shift film 13 and the lower phase shift film 12 using the light shielding film 14p as a mask, thereby forming the upper phase shift film 13 and the lower phase shift film. 12 can be formed.

  The method for manufacturing the phase shift mask according to the embodiment of the present invention is a method for manufacturing the phase shift mask 100 using the phase shift mask blanks 10 and 20. (Cl / O-based), one or more types of dry etching selected from non-oxygen-containing chlorine-based dry etching (Cl-based) and fluorine-based etching to form a pattern of a predetermined shape on the light shielding film 14; A step of performing a fluorine-based dry etching (F-based) on the upper phase shift film 13 to form a pattern of a predetermined shape on the upper phase shift film 13; System) to form a pattern of a predetermined shape on the lower phase shift film 12. According to this, it is possible to provide a method of manufacturing a phase shift mask capable of correcting a blank defect while suppressing a decrease in characteristics.

  Hereinafter, embodiments of the present invention will be described more specifically with reference to Examples, but the present invention is not limited to the following Examples.

(Example 1)
A lower phase shift film made of ruthenium was formed with a thickness of 5 nm on a quartz substrate by using an ion sputtering apparatus. Ruthenium was used as the target, and xenon was used as the sputtering gas. When the composition of this lower phase shift film was analyzed by ESCA, Ru = 100 (atomic% ratio).
An upper phase shift film made of silicon and nitrogen was formed with a thickness of 60 nm on the lower phase shift film using a DC sputtering apparatus. Silicon was used as a target, and argon and nitrogen were used as sputtering gases. When the composition of the upper phase shift film was analyzed by ESCA, Si: N was 43:57 (atomic% ratio).

A lower light-shielding film made of chromium and nitrogen was formed to a thickness of 30 nm on the upper phase shift film using a DC sputtering apparatus. Chromium was used as the target, and argon and nitrogen were used as the sputtering gas. When the composition of this lower light-shielding film was analyzed by ESCA, Cr: N = 90: 10 (atomic% ratio).
An upper light-shielding film made of chromium, oxygen, and nitrogen was formed to a thickness of 20 nm on the lower light-shielding film using a DC sputtering apparatus. Chromium was used as a target, and argon, oxygen, and nitrogen were used as sputtering gases. When the composition of this upper light-shielding film was analyzed by ESCA, it was Cr: O: N = 45: 45: 10 (atomic% ratio). The optical density (OD value) at the exposure wavelength (193 nm) of an ArF excimer laser obtained by combining the upper light-shielding film, the lower light-shielding film, the upper phase shift film, and the lower phase shift film was measured by a spectrophotometer. 3.0.

In this manner, a lower phase shift film made of ruthenium, an upper phase shift film made of silicon and nitrogen, a lower light-shielding film made of chromium and nitrogen, and an upper light-shielding film made of chromium, oxygen and nitrogen are laminated on a quartz substrate. A phase shift mask blank was obtained.
Next, a negative chemically amplified electron beam resist is spin-coated on the upper light-shielding film at a film thickness of 200 nm, an electron beam is drawn at a dose of 35 μC / cm ² , heat treatment is performed at 110 ° C. for 10 minutes, and paddle development is performed. For 90 seconds to form a resist pattern.
Next, the upper light-shielding film and the lower light-shielding film were continuously patterned using a dry etching apparatus. The etching gas used was chlorine, oxygen and helium, the gas pressure was set to 5 mTorr, the ICP power was set to 400 W, and the bias power was set to 40 W. Overetching was performed 100%. Next, the resist pattern was stripped and washed with sulfuric acid and water.

Next, the upper phase shift film was patterned using a dry etching apparatus. The etching gas used was CF ₄ and oxygen, the gas pressure was set to 5 mTorr, the ICP power was set to 400 W, and the bias power was set to 20 W. Overetching was performed 50%. After the dry etching, no damage was caused to the lower phase shift film by the dry etching.
Next, the lower phase shift film was patterned using a dry etching apparatus. The etching gas used was oxygen and helium, the gas pressure was set to 5 mTorr, the ICP power was set to 400 W, and the bias power was set to 40 W. Overetching was performed 100%. After the dry etching, no damage was caused to the upper light-shielding film by the dry etching.

Next, a positive resist film was spin-coated, and writing was performed with a laser writing apparatus. Thereafter, development was performed to form a resist pattern.
Next, the upper light-shielding film and the lower light-shielding film were continuously removed using a dry etching apparatus. The etching gas used was chlorine, oxygen and helium, the gas pressure was 10 mTorr, the ICP power was 500 W, and the bias power was 10 W. Overetching was performed 200%. After this dry etching process, no undercut in which the line pattern of the lower phase shift film was thinner than the upper phase shift film did not occur.

Next, the resist pattern was peeled and washed by sulfuric acid water washing to obtain a phase shift mask. When the transmittance and the phase difference of this phase shift mask were measured by MPM193 manufactured by Lasertec, the transmittance of the phase shift film portion with respect to the transmittance of the quartz substrate at the exposure wavelength of ArF excimer laser (193 nm) was 11%, and the phase difference was 11%. Was 180 degrees. When the amount of phase difference change in the mask plane of this phase shift mask was measured, a phase shift film that could be processed by fluorine dry etching (F system) on a quartz substrate without interposing another film was used. It was confirmed that it was improved by 70% over the shift mask. In addition, when a plurality of such phase shift masks were manufactured and the probability of occurrence of a defect in the opening of the phase shift film pattern was investigated by a defect inspection, the phase shift mask obtained by laminating an etching stopper containing aluminum on a quartz substrate was found. The improvement was 3%, and it was confirmed that the improvement was 5% compared to a phase shift mask in which a lower layer phase shift film containing tantalum or molybdenum was laminated on a quartz substrate.
Next, when trying to correct the defect on the quartz substrate detected by the defect inspection, a repair machine using a contact-type needle, a repair machine using gas and electron beam, or a repair machine using laser, It was confirmed that the correction could be made so as not to affect the resist dimensions on the wafer substrate after the wafer exposure.

(Example 2)
A lower phase shift film made of ruthenium and nitrogen was formed to a thickness of 10 nm on a quartz substrate by using an ion sputtering apparatus. The target used was ruthenium, and the sputtering gas used was xenon and nitrogen. When the composition of this lower phase shift film was analyzed by ESCA, Ru: N = 90: 10 (atomic% ratio).
Using a DC sputtering apparatus, an upper phase shift film made of silicon, oxygen and nitrogen was formed on this lower phase shift film to a thickness of 65 nm. Silicon was used as a target, and argon, oxygen, and nitrogen were used as sputtering gases. When the composition of this upper phase shift film was analyzed by ESCA, Si: O: N = 30: 50: 20 (atomic% ratio).

A lower light-shielding film made of chromium and nitrogen was formed to a thickness of 30 nm on the upper phase shift film using a DC sputtering apparatus. Chromium was used as the target, and argon and nitrogen were used as the sputtering gas. When the composition of this lower light-shielding film was analyzed by ESCA, Cr: N = 90: 10 (atomic% ratio).
An upper light-shielding film made of chromium, oxygen, and nitrogen was formed to a thickness of 20 nm on the lower light-shielding film using a DC sputtering apparatus. Chromium was used as a target, and argon, oxygen, and nitrogen were used as sputtering gases. When the composition of this upper light-shielding film was analyzed by ESCA, it was Cr: O: N = 45: 45: 10 (atomic% ratio). The optical density (OD value) at the exposure wavelength (193 nm) of an ArF excimer laser obtained by combining the upper light-shielding film, the lower light-shielding film, the upper phase shift film, and the lower phase shift film was measured by a spectrophotometer. 3.0.

An etching mask film made of silicon and oxygen was formed with a thickness of 10 nm on the upper light-shielding film by using a DC sputtering device. Silicon was used as a target, and argon and oxygen were used as sputtering gases. When the composition of this etching mask film was analyzed by ESCA, Si: O = 33: 67 (atomic% ratio).
Thus, on the quartz substrate, the lower phase shift film made of ruthenium and nitrogen, the upper phase shift film made of silicon, oxygen, and nitrogen, the lower light-shielding film made of chromium and nitrogen, and the upper light-shielded film made of chromium, oxygen, and nitrogen A phase shift mask blank in which a film and an etching mask film composed of silicon and oxygen were laminated was obtained.

Next, a negative chemically amplified electron beam resist is spin-coated on the etching mask film with a film thickness of 150 nm, an electron beam is drawn at a dose of 35 μC / cm ² , heat treatment is performed at 110 ° C. for 10 minutes, and paddle development is performed. For 90 seconds to form a resist pattern.
Next, the etching mask film was patterned using a dry etching apparatus. The etching gas used was CF ₄ and oxygen, the gas pressure was set to 5 mTorr, the ICP power was set to 400 W, and the bias power was set to 20 W. Overetching was performed 100%. Next, the resist pattern was stripped and washed with sulfuric acid and water.

Next, the upper light-shielding film and the lower light-shielding film were continuously patterned using a dry etching apparatus. The etching gas used was chlorine, oxygen and helium, the gas pressure was 5 mTorr, the ICP power was 400 W, and the bias power was 40 W. Overetching was performed 100%.
Next, the upper phase shift film was patterned and the etching mask film was removed using a dry etching apparatus. The etching gas used was CF ₄ and oxygen, the gas pressure was set to 5 mTorr, the ICP power was set to 400 W, and the bias power was set to 20 W. Overetching was performed on the upper phase shift film by 50%. After the dry etching, no damage was caused to the lower phase shift film by the dry etching.

Next, the lower phase shift film was patterned using a dry etching apparatus. The etching gas used was oxygen and helium, the gas pressure was set to 5 mTorr, the ICP power was set to 400 W, and the bias power was set to 40 W. Overetching was performed 100%. After the dry etching, no damage was caused to the upper light-shielding film by the dry etching.
Next, a positive resist film was spin-coated, and writing was performed with a laser writing apparatus. Thereafter, development was performed to form a resist pattern.
Next, the upper light-shielding film and the lower light-shielding film were continuously removed using a dry etching apparatus. The etching gas used was chlorine, oxygen and helium, the gas pressure was set to 10 mTorr, the ICP power was set to 500 W, and the bias power was set to 10 W. Overetching was performed 200%. After this dry etching process, no undercut in which the line pattern of the lower phase shift film was thinner than the upper phase shift film did not occur.

Next, the resist pattern was peeled and washed by sulfuric acid water washing to obtain a phase shift mask. When the transmittance and the phase difference of this phase shift mask were measured by MPM193 manufactured by Lasertec, the transmittance of the phase shift film portion with respect to the transmittance of the quartz substrate at the exposure wavelength of ArF excimer laser (193 nm) was 11%, and the phase difference was 11%. Was 180 degrees. When the amount of phase difference change in the mask plane of this phase shift mask was measured, a phase shift film that could be processed by fluorine dry etching (F system) on a quartz substrate without interposing another film was used. It was confirmed that it was improved by 70% over the shift mask. In addition, when a plurality of such phase shift masks were manufactured and the probability of occurrence of a defect in the opening of the phase shift film pattern was investigated by a defect inspection, the phase shift mask obtained by laminating an etching stopper containing aluminum on a quartz substrate was found. The improvement was 3%, and it was confirmed that the improvement was 5% compared to a phase shift mask in which a lower layer phase shift film containing tantalum or molybdenum was laminated on a quartz substrate.
Next, when trying to correct the defect on the quartz substrate detected by the defect inspection, a repair machine using a contact-type needle, a repair machine using gas and electron beam, or a repair machine using laser, It was confirmed that the correction could be made so as not to affect the resist dimensions on the wafer substrate after the wafer exposure.

(Example 3)
A lower phase shift film made of ruthenium and boron was formed with a thickness of 10 nm on a quartz substrate by using an ion sputtering apparatus. Ruthenium was used as the target, and xenon and boron were used as the sputtering gas. When the composition of this lower phase shift film was analyzed by ESCA, Ru: B = 70: 30 (atomic% ratio).
An upper phase shift film made of silicon, molybdenum, oxygen, and nitrogen was formed to a thickness of 70 nm on the lower phase shift film using a DC sputtering apparatus using two targets. Molybdenum and silicon were used as targets, and argon, oxygen, and nitrogen were used as sputtering gases. When the composition of this upper phase shift film was analyzed by ESCA, Si: Mo: O: N was 20: 10: 25: 45 (atomic% ratio).

Using a DC sputtering apparatus, a light-shielding film made of tantalum and nitrogen was formed to a thickness of 30 nm on the upper phase shift film. Tantalum was used as a target, and argon and nitrogen were used as sputtering gases. When the composition of this light-shielding film was analyzed by ESCA, tantalum: N = 70: 30 (atomic% ratio). Further, the optical density (OD value) at an exposure wavelength (193 nm) of an ArF excimer laser obtained by combining the light-shielding film, the upper phase shift film and the lower phase shift film with a spectrophotometer was 3.0. Was.
An etching mask film made of chromium and nitrogen was formed with a thickness of 10 nm on the light-shielding film using a DC sputtering device. Chromium was used as the target, and argon and nitrogen were used as the sputtering gas. When the composition of this light-shielding film was analyzed by ESCA, Cr: N = 90: 10 (atomic% ratio).

Thus, a lower phase shift film made of ruthenium and boron, an upper phase shift film made of silicon, molybdenum, oxygen, and nitrogen, a light-shielding film made of tantalum and nitrogen, and an etching mask film made of chromium and nitrogen on a quartz substrate Was obtained to obtain a phase shift mask blank.
Next, a negative chemically amplified electron beam resist is spin-coated on the etching mask film with a film thickness of 150 nm, an electron beam is drawn at a dose of 35 μC / cm ² , heat treatment is performed at 110 ° C. for 10 minutes, and paddle development is performed. For 90 seconds to form a resist pattern.

Next, the etching mask film was patterned using a dry etching apparatus. The etching gas used was chlorine, oxygen and helium, the gas pressure was 5 mTorr, the ICP power was 400 W, and the bias power was 40 W. Overetching was performed 100%. Next, the resist pattern was stripped and washed with sulfuric acid and water.
Next, the light-shielding film was patterned using a dry etching apparatus. The etching gas used was chlorine and helium, the gas pressure was 5 mTorr, the ICP power was 400 W, and the bias power was 40 W. Overetching was performed 100%.

Next, the upper phase shift film was patterned using a dry etching apparatus. The etching gas used was CF ₄ and oxygen, the gas pressure was set to 5 mTorr, the ICP power was set to 400 W, and the bias power was set to 20 W. Overetching was performed 50%. After the dry etching, no damage was caused to the lower phase shift film by the dry etching.
Next, the lower phase shift film was patterned using a dry etching apparatus. The etching gas used was oxygen and helium, the gas pressure was set to 5 mTorr, the ICP power was set to 400 W, and the bias power was set to 40 W. Overetching was performed 100%.

Next, the etching mask film was removed using a dry etching apparatus. The etching gas used was chlorine, oxygen and helium, the gas pressure was set to 10 mTorr, the ICP power was set to 500 W, and the bias power was set to 10 W. Overetching was performed 200%. After this dry etching process, no undercut in which the line pattern of the lower phase shift film was thinner than the upper phase shift film did not occur.
Next, a positive resist film was spin-coated, and writing was performed with a laser writing apparatus. Thereafter, development was performed to form a resist pattern.
Next, the light-shielding film was removed using a dry etching apparatus. The etching gas used was chlorine and helium, the gas pressure was 10 mTorr, the ICP power was 500 W, and the bias power was 10 W. Overetching was performed 200%. After this dry etching process, no undercut in which the line pattern of the lower phase shift film was thinner than the upper phase shift film did not occur.

Next, the resist pattern was peeled and washed by sulfuric acid water washing to obtain a phase shift mask. When the transmittance and the phase difference of this phase shift mask were measured by MPM193 manufactured by Lasertec, the transmittance of the phase shift film portion with respect to the transmittance of the quartz substrate at the exposure wavelength of ArF excimer laser (193 nm) was 12%, and the phase difference was 12%. Was 180 degrees. When the amount of phase difference change in the mask plane of this phase shift mask was measured, a phase shift film that could be processed by fluorine dry etching (F system) on a quartz substrate without interposing another film was used. It was confirmed that it was improved by 70% over the shift mask. In addition, when a plurality of such phase shift masks were manufactured and the probability of occurrence of a defect in the opening of the phase shift film pattern was investigated by a defect inspection, the phase shift mask obtained by laminating an etching stopper containing aluminum on a quartz substrate was found. The improvement was 3%, and it was confirmed that the improvement was 5% compared to a phase shift mask in which a lower layer phase shift film containing tantalum or molybdenum was laminated on a quartz substrate.
Next, when trying to correct the defect on the quartz substrate detected by the defect inspection, a repair machine using a contact-type needle, a repair machine using gas and electron beam, or a repair machine using laser, It was confirmed that the correction could be made so as not to affect the resist dimensions on the wafer substrate after the wafer exposure.

(Example 4)
A lower phase shift film made of ruthenium and niobium was formed to a thickness of 5 nm on a quartz substrate by using an ion sputtering apparatus. The target used was ruthenium-niobium, and the sputtering gas used was xenon and nitrogen. When the composition of this lower phase shift film was analyzed by ESCA, Ru: Nb = 85: 15 (atomic% ratio).
An upper phase shift film made of silicon, molybdenum, oxygen and nitrogen was formed to a thickness of 68 nm on the lower phase shift film using a DC sputtering apparatus using two targets. Molybdenum and silicon were used as targets, and argon, oxygen, and nitrogen were used as sputtering gases. When the composition of this upper phase shift film was analyzed by ESCA, Si: Mo: O: N = 40: 8: 7: 45 (atomic% ratio).

Using a DC sputtering device, a lower light-shielding film made of chromium, nitrogen, and carbon was formed to a thickness of 25 nm on the upper phase shift film. Chromium was used as the target, and argon, nitrogen and carbon were used as the sputtering gas. When the composition of this lower light-shielding film was analyzed by ESCA, it was found that Cr: N: C = 85: 10: 5 (atomic% ratio).
An upper light-shielding film made of chromium, oxygen, and nitrogen was formed to a thickness of 15 nm on the lower light-shielding film using a DC sputtering apparatus. Chromium was used as a target, and argon, oxygen, and nitrogen were used as sputtering gases. When the composition of this upper light-shielding film was analyzed by ESCA, it was Cr: O: N = 45: 45: 10 (atomic% ratio). Further, the optical density (OD value) at the exposure wavelength (193 nm) of an ArF excimer laser obtained by combining the upper light-shielding film, the lower light-shielding film, the upper phase shift film, and the lower phase shift film was measured by a spectrophotometer. 3.0.

An etching mask film made of silicon and oxygen was formed with a thickness of 10 nm on the upper light-shielding film by using a DC sputtering device. Silicon was used as a target, and argon and oxygen were used as sputtering gases. When the composition of this etching mask film was analyzed by ESCA, Si: O = 33: 67 (atomic% ratio).
Thus, a lower phase shift film made of ruthenium and niobium, an upper phase shift film made of silicon, molybdenum, oxygen, and nitrogen, a lower light-shielding film made of chromium, nitrogen, and carbon, chromium, oxygen, and nitrogen are formed on a quartz substrate. A phase shift mask blank in which an upper light-shielding film made of and an etching mask film made of silicon and oxygen is laminated.

Next, a negative chemically amplified electron beam resist is spin-coated on the etching mask film with a film thickness of 150 nm, an electron beam is drawn at a dose of 35 μC / cm ² , heat treatment is performed at 110 ° C. for 10 minutes, and paddle development is performed. For 90 seconds to form a resist pattern.
Next, the etching mask film was patterned using a dry etching apparatus. The etching gas used was CF ₄ and oxygen, the gas pressure was set to 5 mTorr, the ICP power was set to 400 W, and the bias power was set to 20 W. Overetching was performed 100%. Next, the resist pattern was stripped and washed with sulfuric acid and water.

Next, the upper light-shielding film and the lower light-shielding film were continuously patterned using a dry etching apparatus. The etching gas used was chlorine, oxygen and helium, the gas pressure was 5 mTorr, the ICP power was 400 W, and the bias power was 40 W. Overetching was performed 100%.
Next, the upper phase shift film was patterned and the etching mask film was removed using a dry etching apparatus. The etching gas used was CF ₄ and oxygen, the gas pressure was set to 5 mTorr, the ICP power was set to 400 W, and the bias power was set to 20 W. Overetching was performed on the upper phase shift film by 50%. After the dry etching, no damage was caused to the lower phase shift film by the dry etching.

Next, the lower phase shift film was patterned using a dry etching apparatus. The etching gas used was oxygen and helium, the gas pressure was set to 5 mTorr, the ICP power was set to 400 W, and the bias power was set to 40 W. Overetching was performed 100%. After the dry etching, no damage was caused to the upper light-shielding film by the dry etching.
Next, a positive resist film was spin-coated, and writing was performed with a laser writing apparatus. Thereafter, development was performed to form a resist pattern.
Next, the upper light-shielding film and the lower light-shielding film were continuously removed using a dry etching apparatus. The etching gas used was chlorine, oxygen and helium, the gas pressure was set to 10 mTorr, the ICP power was set to 500 W, and the bias power was set to 10 W. Overetching was performed 200%. After this dry etching process, no undercut in which the line pattern of the lower phase shift film was thinner than the upper phase shift film did not occur.

Next, the resist pattern was peeled and washed by sulfuric acid water washing to obtain a phase shift mask. When the transmittance and the phase difference of this phase shift mask were measured by MPM193 manufactured by Lasertec, the transmittance of the phase shift film portion was 4% of the transmittance of the quartz substrate at the exposure wavelength of ArF excimer laser (193 nm), and the phase difference was 4%. Was 180 degrees. When the amount of phase difference change in the mask plane of this phase shift mask was measured, a phase shift film that could be processed by fluorine dry etching (F system) on a quartz substrate without interposing another film was used. It was confirmed that it was improved by 70% over the shift mask. In addition, when a plurality of such phase shift masks were manufactured and the probability of occurrence of a defect in the opening of the phase shift film pattern was investigated by a defect inspection, the phase shift mask obtained by laminating an etching stopper containing aluminum on a quartz substrate was found. The improvement was 3%, and it was confirmed that the improvement was 5% compared to a phase shift mask in which a lower layer phase shift film containing tantalum or molybdenum was laminated on a quartz substrate.
Next, when trying to correct the defect on the quartz substrate detected by the defect inspection, a repair machine using a contact-type needle, a repair machine using gas and electron beam, or a repair machine using laser, It was confirmed that the correction could be made so as not to affect the resist dimensions on the wafer substrate after the wafer exposure.

(Modification)
Various modifications of the embodiment of the present invention are possible. For example, in a modified example of the embodiment, the light shielding films 14 and 14p may contain ruthenium. The light-shielding films 14 and 14p may be composed of ruthenium alone or a ruthenium compound having a ruthenium content of 50 atomic% or more and less than 100 atomic%. In this case, lower phase shift films 12 and 12p may contain chromium. The lower layer phase shift films 12 and 12p may be a single layer film containing chromium alone or chromium and at least one selected from nitrogen, oxygen and carbon.

With such a configuration, the light-shielding film 14 can be processed by oxygen-based dry etching (O-based) to form the light-shielding film 14p having a pattern. Further, the upper phase shift film 13, which is the base of the light-shielding films 14, 14p, has resistance to oxygen-based dry etching (O-based). Therefore, when processing the light shielding film 14, the upper phase shift film 13 is not etched (or almost not etched). Therefore, when processing the light shielding film 14, damage to the upper phase shift film 13 is suppressed. Thereby, the possibility that a defect occurs in the opening 2h of the phase shift film pattern 2p can be reduced. When the light-shielding film 14 contains ruthenium, it is preferable to use a hard mask composed of a silicon oxide film (SiO ₂ ) for patterning. This makes it possible to pattern the light-shielding film 14 into a predetermined shape while preventing the hard mask from being damaged.

  In the present invention, since the composition, thickness and layer structure of the phase shift mask blank and the manufacturing process and conditions of the phase shift mask using the same are selected within an appropriate range, for example, a logic device of 28 nm or less or 30 nm It is possible to provide a phase shift mask in which a fine pattern is formed with high precision, corresponding to the following memory device manufacturing.

2 ... Phase shift film 2p ... Phase shift film pattern 10, 20 ... Phase shift mask blank 11 ... Transparent substrate (substrate transparent to exposure wavelength)
12 ... Lower phase shift film 12p ... (predetermined pattern formed) Lower phase shift film 13 ... Upper phase shift film 13p ... (predetermined pattern formed) upper phase Shift film 14 ... Light-shielding film 14p ... Light-shielding film 15 (on which a pattern of a predetermined shape is formed) 15 ... Hard mask films 16, 17 ... Resist pattern 100 ... Phase shift mask

Claims (13)

A translucent substrate that transmits light of a preset wavelength,
A phase shift film provided on the translucent substrate,
The phase shift film,
A lower phase shift film provided on the translucent substrate,
And an upper phase shift film provided on the lower phase shift film,
The upper phase shift film can be etched by fluorine-based dry etching, and has resistance to oxygen-based dry etching,
The lower phase shift film can be etched by oxygen-based dry etching, and has resistance to fluorine-based dry etching,
A phase shift mask blank, wherein the translucent substrate has resistance to oxygen-based dry etching.   The phase shift mask blank according to claim 1, wherein the lower phase shift film contains ruthenium.   3. The phase shift mask blank according to claim 2, wherein the lower phase shift film is made of ruthenium alone or a ruthenium compound having a ruthenium content of 50 at% or more and less than 100 at%.   4. The phase shift mask blank according to claim 2, wherein the thickness of the lower phase shift film is 2 nm or more and 20 nm or less. 5.   The upper layer phase shift film contains silicon, and contains one or more atoms selected from molybdenum, titanium, vanadium, cobalt, nickel, zirconium, niobium, hafnium, nitrogen, oxygen and carbon. 5. The phase shift mask blank according to any one of 4. A light shielding film provided on the upper layer phase shift film,
The light-shielding film can be etched by one or more types of dry etching selected from oxygen-containing chlorine-based dry etching, non-oxygen-containing chlorine-based dry etching, and fluorine-based dry etching. Resistant to
The upper phase shift film has resistance to oxygen-containing chlorine-based dry etching and non-oxygen-containing chlorine-based dry etching,
The phase shift mask blank according to any one of claims 1 to 5, wherein the lower phase shift film has resistance to oxygen-containing chlorine-based dry etching and non-oxygen-containing chlorine-based dry etching. A translucent substrate that transmits light of a preset wavelength,
A phase shift film pattern provided on the light-transmitting substrate and having a preset shape,
The phase shift film pattern,
A lower phase shift film provided on the translucent substrate,
An upper phase shift film provided on the lower phase shift film,
The upper phase shift film can be etched by fluorine-based dry etching, and has resistance to oxygen-based dry etching,
The lower phase shift film can be etched by oxygen-based dry etching, and has resistance to fluorine-based dry etching,
The phase shift mask, wherein the light-transmitting substrate has resistance to oxygen-based dry etching.   The phase shift mask according to claim 7, wherein the lower phase shift film contains ruthenium.   9. The phase shift mask according to claim 8, wherein the lower phase shift film is made of ruthenium alone or a ruthenium compound having a ruthenium content of 50 at% or more and less than 100 at%.   10. The phase shift mask according to claim 8, wherein the thickness of the lower phase shift film is 2 nm or more and 20 nm or less.   The upper phase shift film contains silicon, and contains at least one atom selected from molybdenum, titanium, vanadium, cobalt, nickel, zirconium, niobium, hafnium, nitrogen, oxygen and carbon. 11. The phase shift mask according to any one of items 10 to 10. A light shielding film provided on the upper layer phase shift film,
The light-shielding film can be etched by one or more types of dry etching selected from oxygen-containing chlorine-based dry etching, non-oxygen-containing chlorine-based dry etching, and fluorine-based dry etching. Resistant to
The upper phase shift film has resistance to oxygen-containing chlorine-based dry etching and non-oxygen-containing chlorine-based dry etching,
The phase shift mask according to any one of claims 7 to 11, wherein the lower phase shift film has resistance to oxygen-containing chlorine-based dry etching and non-oxygen-containing chlorine-based dry etching. A method for manufacturing a phase shift mask using the phase shift mask blank according to any one of claims 1 to 6,
The light-shielding film provided on the upper phase shift film is subjected to one or more types of dry etching selected from oxygen-containing chlorine-based dry etching, non-oxygen-containing chlorine-based dry etching, and fluorine-based etching, to thereby provide the light-shielding film. Forming a pattern of a preset shape on the film;
Performing a fluorine-based dry etching on the upper phase shift film to form a pattern having a predetermined shape on the upper phase shift film;
Performing oxygen-based dry etching on the lower phase shift film to form a pattern having a predetermined shape on the lower phase shift film.

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