Abstract: A reflective mask blank includes a substrate, a multilayered reflection film configured to reflect EUV rays, a protection film configured to protect the multilayered reflection film, and an absorption film configured to absorb the EUV rays in this order. The protection film contains Rh as a main component. The multilayered reflection film includes an uppermost layer that is closest to the protection film in the multilayered reflection film and contains Si and N. In the uppermost layer, an element ratio (N/Si) of N to Si is greater than 0.00 and less than 1.50, and an element ratio (O/Si) of O to Si is 0.00 or greater and less than 0.44.

Abstract: A reflective mask blank includes a substrate; a multilayer reflective film that reflects EUV light; a protection film that protects the multilayer reflective film; and an absorption film that absorbs the EUV light, in this order. The protection film contains 50 at % or more of Rh. When a band-shaped gray scale image parallel to an interface between the protection film and the multilayer reflective film is obtained by imaging a cross section of the protection film with a transmission electron microscope (TEM) and a luminance profile of the gray scale image in a longitudinal direction of the gray scale image is created, a number of peaks of the luminance profile per 100 nm in the longitudinal direction of the gray scale image is 50 or more.

Abstract: A method for producing a reflective mask blank, includes: forming a reflective multilayer film on or above a substrate by using an ion beam sputtering apparatus and a process gas, the ion beam sputtering apparatus accelerating an ion generated by applying a voltage to a grid, and causing the ion to collide with a target to perform sputtering, the process gas including at least one inert gas selected from He, Ne, Ar, Kr, Xe, Rn, and N2 as an ion source, in which a product of an effective area (cm2) of the grid and a flow rate (sccm) of the process gas supplied to the ion beam sputtering apparatus during film formation is 3600 (cm2·sccm) or less.

Abstract: A reflective mask blank includes a substrate; a multilayer reflective film that reflects EUV light; a protection film that protects the multilayer reflective film; and an absorption film that absorbs the EUV light, in this order. The protection film contains 50 at % or more of Rh. When a band-shaped gray scale image parallel to an interface between the protection film and the multilayer reflective film is obtained by imaging a cross section of the protection film with a transmission electron microscope (TEM) and a luminance profile of the gray scale image in a longitudinal direction of the gray scale image is created, a number of peaks of the luminance profile per 100 nm in the longitudinal direction of the gray scale image is 50 or more.