ALEXANDRIA, Va., Oct. 28 -- United States Patent no. 12,451,364, issued on Oct. 21, was assigned to HITACHI HIGH-TECH Corp. (Tokyo).
"Plasma processing method" was invented by Kenta Nakajima (Tokyo), Toru Ito (Tokyo) and Fumiyoshi Ofuji (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "A plasma processing method for uniformly removing a processing target film in a lateral direction even when a depth of a trench is increased, in particular, a method for plasma-etching a tungsten film of a stacked film formed by alternately stacking an insulating film and the tungsten film. The method includes: a first depositing step of depositing a film; a first etching step of etching after the first depositing step; a ...