US Patent Issued to AGC on May 20 for "Reflective mask blank, reflective mask, method of manufacturing reflective mask blank, and method of manufacturing reflective mask" (Japanese Inventors)

ALEXANDRIA, Va., June 16 -- United States Patent no. 12,306,530, issued on May 20, was assigned to AGC Inc. (Tokyo).

"Reflective mask blank, reflective mask, method of manufacturing reflective mask blank, and method of manufacturing reflective mask" was invented by Takuma Kato (Tokyo), Daijiro Akagi (Tokyo), Takeshi Okato (Tokyo), Ryusuke Oishi (Fukushima, Japan) and Yusuke Ono (Fukushima, Japan).

According to the abstract* released by the U.S. Patent & Trademark Office: "A reflective mask blank includes a substrate; a multilayer reflective film that reflects EUV light; a protection film that protects the multilayer reflective film; and an absorption film that absorbs the EUV light, in this order. The protection film contains 50 at % or m...