Methods and devices for the limitation of the plasma region - etching in order to achieve a precise shape of the substrate surfaces

摘要

A reactor 10 having a vacuum housing 30 which encloses a plasma chamber 14 is used to perform local plasma assisted chemical etching on an etchable substrate 12. The chamber 14 is movable and is sized according to the removal material footprint desired. An rf driven electrode 22 and rf driven gas diffuser 22 have the same diameter as the chamber 14. The substrate 12 is mounted on a substrate holder 44 which also acts as the other electrode. The holder 44 is mounted on an X-Y positioning table 46. A reactive gas is flowed into the chamber with rf power so as to break the reactive gas into a plasma. The plasma chamber 14 which locally confines the plasma may be scanned over the substrate surface while the gap between the chamber and the substrate is varied to yield a desired etch profile.