Patent ID: 8083961

Claim:
A method of etching a thin film on a substrate using a plasma processing system having a ballistic electron beam, comprising: disposing said substrate on a substrate holder in said plasma processing system; coupling direct current (DC) power to an electrode within said plasma processing system in order to create said ballistic electron beam from secondary electrons generated from ions bombarding said electrode during plasma generation; coupling alternating current (AC) power to said electrode having DC power coupled thereto and to said substrate holder, in order to form plasma in said plasma processing system; modulating two or more of a frequency, a duty cycle and an amplitude of said AC power to said electrode having DC power coupled thereto in order to control uniformity of the ions bombarding said electrode and thereby adjust the spatial distribution of said secondary electrons emitted from said electrode and the electron beam flux for said ballistic electron beam; and etching the thin film with the plasma and the ballistic electron beam having an adjusted spatial distribution of electron beam flux.