US Patent Issued to S&S TECH on Feb. 3 for "Phase shift blankmask and photomask for EUV lithography" (South Korean Inventors)

ALEXANDRIA, Va., Feb. 3 -- United States Patent no. 12,541,144, issued on Feb. 3, was assigned to S&S TECH Co. Ltd. (Daegu-si, South Korea).

"Phase shift blankmask and photomask for EUV lithography" was invented by Yong-Dae Kim (Daegu, South Korea), Jong-Hwa Lee (Daegu, South Korea) and Chul-Kyu Yang (Daegu, South Korea).

According to the abstract* released by the U.S. Patent & Trademark Office: "Disclosed is a blankmask for EUV lithography, including a reflective film, a capping film and a phase shift film which are sequentially formed on a substrate. The phase shift film includes a first layer containing niobium (Nb) and chrome (Cr), and a second layer containing tantalum (Ta) and silicon (Si). In the first layer, the content of niobium...