Patent ID: 9666414
Date: 2017-05-30
CPC Classifications: C23C,H01J,H01L

Claim:
1. A plasma etch chamber, comprising: a chuck to support a workpiece during an etching process; a first showerhead disposed above the chuck to distribute a first feed gas into the first chamber region, wherein the chuck and the first showerhead form a first RF coupled electrode pair to capacitively energize a first plasma of the first feed gas within a first chamber region between the first showerhead and the chuck; a secondary electrode disposed above and electrically isolated from the first showerhead, opposite the chuck, wherein the secondary electrode and the first showerhead form a second RF coupled electrode pair to capacitively discharge a second plasma of a second feed gas within a second chamber region between the first showerhead and the secondary electrode, and wherein the second RF coupled electrode pair is independently operable from the first RF coupled electrode pair; and a controller to alternately energize the first and second plasmas during the etching process by alternately powering the first and second RF coupled electrode pairs automatically.