US Patent 7105255 EUV reflection mask and lithographic process using the same

An invention of lithography process using an improved reflection mask is provided for extreme ultraviolet (EUV) lithography. In the process an incident EUV is transmitted onto the reflection mask at a grazing incident angle. Therefore a reflected EUV develops a pattern image to a photo resist layer on the surface of the wafer, wherein the shape of the pattern image is dependent on the shape of a plurality of reflective regions on the surface of the reflection mask. Specially, the improved reflection mask is more easily fabricated. The surface roughness and the defects of the reflection mask are also more easily controlled. The improved EUV lithography process is more efficient and cheap.