ALEXANDRIA, Va., Aug. 5 -- United States Patent no. 12,699,318, issued on Aug. 4, was assigned to SHIN-ETSU CHEMICAL Co. LTD. (Tokyo).
"Onium salt, resist composition, and patterning process" was invented by Masahiro Fukushima (Joetsu, Japan), Jun Hatakeyama (Joetsu, Japan), Tomomi Watanabe (Joetsu, Japan) and Kazuhiro Katayama (Joetsu, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "Provided is a novel onium salt used for a resist composition that has high sensitivity and excellent resolution, improved LWR and CDU, and that can inhibit collapse of a resist pattern for both of positive-type and negative-type resists in lithography: an onium salt represented by the following general formula (1), wherein ...