Reflective mask blank for EUV lithography and process for its production, as well as substrate with reflective layer for such mask blank and process for its production

摘要

Process for producing a substrate with reflective layer for EUVL, which comprises forming a reflective layer for reflecting EUV light on a substrate, wherein the reflective layer is a multilayer reflective film having a low refractive index layer and a high refractive index layer alternately stacked plural times by a sputtering method, and depending upon the in-plane distribution of the peak reflectivity of light in the EUV wavelength region in a radial direction from the center of the substrate at the surface of the multilayer reflective film, at least one layer among the respective layers constituting the multilayer reflective film is made to be a reflectivity distribution correction layer having a thickness distribution provided in a radial direction from the center of the substrate, to suppress the in-plane distribution of the peak reflectivity of light in the EUV wavelength region in a radial direction from the center of the substrate.

主权项

1. A process for producing a substrate with reflective layer for EUV lithography (EUVL), which comprises forming a reflective layer for reflecting EUV light on a substrate, wherein the reflective layer is a multilayer reflective film having a low refractive index layer and a high refractive index layer alternately stacked plural times by a sputtering method, and depending upon the in-plane distribution of the peak reflectivity of light in the EUV wavelength region in a radial direction from the center of the substrate at the surface of the multilayer reflective film, at least one layer among the respective layers constituting the multilayer reflective film is made to be a reflectivity distribution correction layer having a thickness distribution provided in a radial direction from the center of the substrate, to suppress and reduce the in-plane distribution of the peak reflectivity of light in the EUV wavelength region in a radial direction from the center of the substrate.