A mask blank glass substrate having a maximum value of a circularly averaged power spectral density of 1,000 nm.sup.4 or less at a spatial frequency of 0.1 μm.sup.−1 or more and 20 μm.sup.−1 or less, the maximum value being obtained by measuring a surface morphology of a region of 10 μm×10 μm with an atomic force microscope.

In an imprint mold-forming synthetic quartz glass substrate (1) of rectangular shape having dimensions L1 and L2 with L1≥L2, a circular region is delineated on the substrate back surface by a circle of radius R with L2−2R≥10 mm. When approximation analysis is performed from the 1st to 8th term in the Zernike polynomials on the circular region, a coefficient of the 4th term is equal to or greater than −(2R/100,000×1) μm.

In an imprint mold-forming synthetic quartz glass substrate (1) of rectangular shape having dimensions L1 and L2 with L1≥L2, a circular region is delineated on the substrate back surface by a circle of radius R with L2−2R≥10 mm. When approximation analysis is performed from the 1st to 8th term in the Zernike polynomials on the circular region, a coefficient of the 4th term is equal to or greater than −(2R/100,000×1) μm.

A multilayered-reflective-film-provided substrate includes: a substrate; a multilayered reflective film provided on the substrate; and a protective film provided on the multilayered reflective film, in which the protective film includes ruthenium (Ru) and at least one additive material selected from aluminum (Al), yttrium (Y), zirconium (Zr), rhodium (Rh), and hafnium (Hf), and a content of the additive material is 5% or more by atom and less than 50% by atom.

A reflective mask blank includes a multilayer reflective film, a first thin film, and a second thin film in this order on a main surface of a substrate, a relative reflectance R.sub.2 of the second thin film with respect to a reflectance of the multilayer reflective film in the light of 13.5 nm wavelength is 3% or more, and an extinction coefficient k.sub.1 of the first thin film in the light of 13.5 nm wavelength and a thickness d.sub.1 [nm] of the first thin film satisfy a relationship of (Formula 1).

21.5?k.sub.1.sup.2?d.sub.1.sup.2?52.5?k.sub.1?d.sub.1+32.1>R.sub.2(Formula 1)

A mask blank glass substrate having a maximum value of a circularly averaged power spectral density of 1,000 nm.sup.4 or less at a spatial frequency of 0.1 m.sup.1 or more and 20 m.sup.1 or less, the maximum value being obtained by measuring a surface morphology of a region of 10 m10 m with an atomic force microscope.

Disclosed is a mask blank substrate for use in lithography, wherein the main surface on which the transfer pattern of the substrate is formed has a root mean square roughness (Rms) of not more than 0.15 nm obtained by measuring an area of 1 m1 m with an atomic force microscope, and has a power spectrum density of not more than 10 nm.sup.4 at a spatial frequency of not less than 1 m.sup.1.

A hard mask film 2 provided on substrate 1 is formed by tin-containing chromium-containing material. In the chromium-containing material including tin, which forms the hard mask film 2, the etching resistance to fluorine-containing dry etching is equal to or higher than the etching resistance of the tin-free chromium-containing material, and it shows a significantly high etching rate as compared with a chromium-containing material free of tin under conditions for chlorine-containing dry etching. As a result, the time for chlorine-containing dry etching is shortened, and damage to a resist pattern is reduced. Thus, high-precision pattern transfer can be performed. The present invention provides a novel technique for increasing etching process-ability by increasing a dry-etching rate of a hard mask film made of a chromium-containing material while assuring a hard mask function of the hard mask film.

Disclosed is a mask blank substrate for use in lithography, wherein the main surface on which the transfer pattern of the substrate is formed has a root mean square roughness (Rms) of not more than 0.15 nm obtained by measuring an area of 1 m1 m with an atomic force microscope, and has a power spectrum density of not more than 10 nm.sup.4 at a spatial frequency of not less than 1 m.sup.1.