Multilayer reflective film coated substrate, manufacturing method thereof, reflective mask blank, and reflective mask

摘要

A multilayer reflective film coated substrate includes a multilayer under film comprised of Mo/Si alternately-layered films and a multilayer reflective film comprised of Mo/Si alternately-layered films for reflecting exposure light. The multilayer under film and the multilayer reflective film are formed on a substrate in this order. Given that a cycle length of the multilayer under film is d bottom (unit: nm) and a cycle length of the multilayer reflective film is d top (unit: nm), a relationship of a formula (1) is satisfied when d bottom>d top, the formula (1) given by <?in-line-formulae description="In-line Formulae" end="lead"?>(n+ 0.15 )xd top<=d bottom<=(n+ 0.9 )xd top<?in-line-formulae description="In-line Formulae" end="tail"?> where n is a natural number equal to or greater than 1.