Patent Number: 7,713,666

Title: Reflective mask blank for EUV lithography

Abstract: To provide a reflective mask blank for EUV lithography having an absorber layer which has a low reflectance in a wavelength region of EUV light or light for inspection of a pattern and which is easy to control to have a desired layer composition and thickness. A reflective mask blank for EUV lithography, which comprises a substrate, and a reflective layer to reflect EUV light and an absorber layer to absorb EUV light, formed in this order on the substrate, wherein the absorber layer contains tantalum (Ta) and hafnium (Hf), and in the absorber layer, the content of Hf is from 20 to 60 at. % and the content of Ta is from 40 to 80 at. %.

Inventors: Hayashi; Kazuyuki (Chiyoda-ku, JP), Kadowaki; Kazuo (Chiyoda-ku, JP), Sugiyama; Takashi (Chiyoda-ku, JP)

Assignee: Asahi Glass Company, Limited

International Classification: G03F 1/00 (20060101)

Expiration Date: 5/11/12018