ALEXANDRIA, Va., July 30 -- United States Patent no. 12,374,528, issued on July 29, was assigned to HITACHI HIGH-TECH Corp. (Tokyo).
"Plasma processing apparatus" was invented by Haixiang Huang (Tokyo) and Kenichi Kuwahara (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "A plasma processing apparatus for controlling a length of a first output duration of a microwave power and a length of a second output duration to obtain a desired etching rate distribution of a wafer, in which one cycle of pulse modulation includes a first output duration of a microwave output and a second output duration having a finite value smaller than the first output, and an OFF duration. An etching rate distribution is a concave...