Reflective mask blank for euv lithography and process for its production

Abstract

To provide a process for producing an EUV mask blank, whereby the deformation of a substrate due to film stress in a Mo/Si multilayer reflective film can be reduced, and the change with time of the film stress in the Mo/Si multilayer reflective film can be reduced. A process for producing a reflective mask blank for EUVL, which comprises forming a multilayer reflective film for reflecting EUV light on a film-forming surface of a substrate, then forming an absorber layer for absorbing EUV light, on the multilayer reflective film, to produce a reflective mask blank for EUV lithography, wherein the multilayer reflective film is a Mo/Si multilayer reflective film, the uppermost layer of the multilayer reflective film is a Si film, and after forming the absorber layer, the substrate on which the absorber layer is formed is subjected to heating treatment at a temperature of from 110 to 170° C.

Dependencies are inferred from the claim text.