ALEXANDRIA, Va., May 12 -- United States Patent no. 12,625,429, issued on May 12, was assigned to SHIN-ETSU CHEMICAL Co. LTD. (Tokyo).
"Resist composition and pattern forming process" was invented by Jun Hatakeyama (Joetsu, Japan) and Masahiro Fukushima (Joetsu, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A resist composition comprising a base polymer comprising repeat units having a salt structure consisting of a sulfonic acid anion bonded to a polymer backbone and a sulfonium cation having an acid labile group of aromatic group-containing cyclic secondary or tertiary ester type as the acid generator exhibits a high sensitivity and reduced LWR or improved CDU."
The patent was filed on Jan. 31, 202...