Patent ID: 7436490

Claim:
An exposure apparatus for exposing a substrate to a pattern of an original by use of extreme ultraviolet light, said apparatus comprising: a blaze type diffraction grating disposed so that light from a plasma light source is incident thereon; and an optical system configured to direct extreme ultraviolet light diffracted by said blaze type diffraction grating and having largest diffraction intensity to at least one of the original and the substrate; wherein said blaze type diffraction grating has a blaze angle which is set so that extreme ultraviolet light of a diffraction order having largest diffraction intensity is diffracted in a direction which is between diffraction lights of consecutive diffraction orders, which lights are in a wavelength region other than the extreme ultraviolet light, and wherein the diffraction order of the extreme ultraviolet light having largest diffraction intensity differs from the consecutive orders of the lights in the wavelength region other than the extreme ultraviolet light.