A reflective mask blank for EUV lithography includes: a substrate; a multilayer reflective film for reflecting EUV light; and a phase shift film for shifting a phase of EUV light, the multilayer reflective film and the phase shift film formed on or above the substrate in this order. The phase shift film includes a layer 1 including ruthenium (Ru) and at least one selected from the group consisting of oxygen (O) and nitrogen (N). Among diffraction peaks derived from the phase shift film observed at 2θ: from 20° to 50° by out-of-plane XRD method, a peak having the highest intensity has a half value width FWHM of 1.0° or more.

A mask blank wherein damage to a light semitransmissive film due to dry etching for removing a light shielding film is inhibited. Mask blank 100 has a light semitransmissive film 2 and light shielding film 4 laminated on a main surface of a transparent substrate 1. Film 2 can be dry etched with a fluorine-based gas. Film 4 has laminated lower layer 41 and upper layer 42. Lower layer 41 contained tantalum and id substantially free from hafnium, zirconium, and oxygen. Upper layer 42 contains tantalum and one or more of hafnium and zirconium and is substantially free from oxygen excluding the surface layer of the upper layer 42. Between the light semitransmissive film 2 and lower layer 41 is an etching stopper film 3 having etch selectivity with respect to the lower layer 41 in dry etching with an etching gas containing the chlorine-based gas and no oxygen gas.

A mask blank wherein damage to a light semitransmissive film due to dry etching for removing a light shielding film is inhibited. Mask blank 100 has a light semitransmissive film 2 and light shielding film 4 laminated on a main surface of a transparent substrate 1. Film 2 can be dry etched with a fluorine-based gas. Film 4 has laminated lower layer 41 and upper layer 42. Lower layer 41 contained tantalum and id substantially free from hafnium, zirconium, and oxygen. Upper layer 42 contains tantalum and one or more of hafnium and zirconium and is substantially free from oxygen excluding the surface layer of the upper layer 42. Between the light semitransmissive film 2 and lower layer 41 is an etching stopper film 3 having etch selectivity with respect to the lower layer 41 in dry etching with an etching gas containing the chlorine-based gas and no oxygen gas.

Provided is a mask blank including an etching stopper. The mask blank has a structure where an etching stopper film and a thin film for pattern formation are stacked in this order on a transparent substrate, in which the thin film is formed of a material containing silicon, the etching stopper film is formed of a material containing hafnium, aluminum, and oxygen, and an oxygen deficiency ratio of the etching stopper film is 6.4% or less.

Provided is a mask blank including an etching stopper. The mask blank has a structure where an etching stopper film and a thin film for pattern formation are stacked in this order on a transparent substrate, in which the thin film is formed of a material containing silicon, the etching stopper film is formed of a material containing hafnium, aluminum, and oxygen, and an oxygen deficiency ratio of the etching stopper film is 6.4% or less.

A reflective mask blank includes a substrate and, on or above the substrate in order, a reflective layer for reflecting EUV light, a protective layer for protecting the reflective layer, and an absorbent layer for absorbing EUV light. The absorbent layer has a reflectance for a wavelength of 13.53 nm of from 2.5% to 10%. A film thickness d of the absorbent layer satisfies a relationship of:

[00001]$d_{MAX}-\left(i\times 6+1\right)\mathrm{nm}\le d\le d_{MAX}-\left(i\times 6-1\right)\mathrm{nm}$

where the integer i is 0 or 1, and d.sub.MAX is represented by:

[00002]$d_{MAX}\left(\mathrm{nm}\right)=\frac{13.53}{2n\cos 6°}\left\{\mathrm{INT}\left(\frac{0.58}{1-n}\right)+\frac{1}{2\pi }\left({\tan }^{-1}\left(\frac{-k}{1-n}\right)+0.64\right)\right\}$

where n is a refractive index of the absorbent layer, k is an absorption coefficient of the absorbent layer, and INT(x) is a function of returning an integer value obtained by truncating a decimal part.

A blankmask for EUV lithography includes a substrate, a reflective layer, a capping layer, and a phase shift layer. The phase shift layer is made of a material containing ruthenium (Ru) and chromium (Cr), and a total content of ruthenium (Ru) and chromium (Cr) is 50 to 100 at %. The phase shift layer may further contain boron (B) or nitrogen (N). The phase shift layer of the present invention has a high relative reflectance (relative reflectance with respect to a reflectance of the reflective layer under the phase shift layer) with respect to a tantalum (Ta)-based phase shift layer and has a phase shift amount of 170 to 230°. It is possible to obtain excellent resolution when finally manufacturing a pattern of 7 nm or less by using a photomask manufactured using such a blankmask.

A blankmask for EUV lithography includes a substrate, a reflective layer, a capping layer, and a phase shift layer. The phase shift layer is made of a material containing ruthenium (Ru) and chromium (Cr), and a total content of ruthenium (Ru) and chromium (Cr) is 50 to 100 at %. The phase shift layer may further contain boron (B) or nitrogen (N). The phase shift layer of the present invention has a high relative reflectance (relative reflectance with respect to a reflectance of the reflective layer under the phase shift layer) with respect to a tantalum (Ta)-based phase shift layer and has a phase shift amount of 170 to 230°. It is possible to obtain excellent resolution when finally manufacturing a pattern of 7 nm or less by using a photomask manufactured using such a blankmask.

The present invention provides a photomask blank which exhibits high adhesion of a resist film to a film containing chromium, and which is capable of achieving good resolution limit and good CD linearity during the formation of an assist pattern of a line pattern, said assist pattern supplementing the resolution of the main pattern of a photomask. A photomask blank (511) according to the present invention is provided, on a substrate, with: a film (21) to be processed; and, sequentially from the far side from the substrate, a first layer (311) which contains oxygen and nitrogen, while having a chromium content of 40% by atom or less, an oxygen content of 50% by atom or more, a nitrogen content of 10% by atom or less and a thickness of 6 nm or less, a second layer (312) which contains oxygen, nitrogen and carbon, while having a chromium content of 40% by atom or less, an oxygen content of 30% by atom or more, a nitrogen content of 17% by atom or more, a carbon content of 13% by atom or less and a thickness of 46 nm or more, and a third layer (313) which contains oxygen and nitrogen, while having a chromium content of 50% by atom or more, an oxygen content of 20% by atom or less and a nitrogen content of 30% by atom or more.

The present invention provides a photomask blank which exhibits high adhesion of a resist film to a film containing chromium, and which is capable of achieving good resolution limit and good CD linearity during the formation of an assist pattern of a line pattern, said assist pattern supplementing the resolution of the main pattern of a photomask. A photomask blank (511) according to the present invention is provided, on a substrate, with: a film (21) to be processed; and, sequentially from the far side from the substrate, a first layer (311) which contains oxygen and nitrogen, while having a chromium content of 40% by atom or less, an oxygen content of 50% by atom or more, a nitrogen content of 10% by atom or less and a thickness of 6 nm or less, a second layer (312) which contains oxygen, nitrogen and carbon, while having a chromium content of 40% by atom or less, an oxygen content of 30% by atom or more, a nitrogen content of 17% by atom or more, a carbon content of 13% by atom or less and a thickness of 46 nm or more, and a third layer (313) which contains oxygen and nitrogen, while having a chromium content of 50% by atom or more, an oxygen content of 20% by atom or less and a nitrogen content of 30% by atom or more.