REFLECTIVE MASK BLANK FOR EUV LITHOGRAPHY AND PRODUCTION METHOD THEREOF

摘要

Provided is a EUV mask blank production method with which deformation of a substrate due to a film stress in a Mo/Si multilayer reflective film can be mitigated, and temporal changes in the film stress in the Mo/Si multilayer reflective film can be mitigated. In this production method of the reflective mask blank for EUVL, after a multilayer reflective film for reflecting EUV light is formed on a film-formation surface of a substrate, an absorber layer for absorbing the EUV light is formed on the multilayer reflective film in order to produce a reflective mask blank for EUVL. In the production method of the reflective mask blank for EUVL, the multilayer reflective film is an Mo/Si multilayer reflective film, the topmost layer of the Mo/Si multilayer reflective film is an Si film, and after the absorber layer is formed, the substrate with the absorber layer is thermally treated at a temperature of between 110 and 170°C.