US Patent Issued to Tokyo Electron on March 11 for "Plasma processing apparatus and plasma processing method" (Japanese Inventor)

ALEXANDRIA, Va., March 12 -- United States Patent no. 12,249,487, issued on March 11, was assigned to Tokyo Electron Ltd. (Tokyo).

"Plasma processing apparatus and plasma processing method" was invented by Chishio Koshimizu (Miyagi, Japan).

According to the abstract* released by the U.S. Patent & Trademark Office: "In a plasma processing apparatus, a radio-frequency power supply adjusts frequencies of radio-frequency power in each bias cycle of electrical bias energy. The radio-frequency power supply uses a reference time series of frequencies of the radio-frequency power in each bias cycle. The radio-frequency power supply repeats using a changed time series of frequencies of the radio-frequency power in each bias cycle to increase a deg...