US Patent 7879187 Plasma etching apparatus

The present invention relates to a plasma etching apparatus, which comprises a chamber, a substrate support disposed inside the chamber to support a substrate, a shield disposed with a gap on the substrate such that plasma is not generated therein while allowing an edge portion of the substrate to be exposed, an antenna disposed at a position on an outer wall of the chamber to apply plasma-generating power to an area between the edge portion of the substrate and an inner wall of the chamber, and a bias-applying unit for applying bias to the substrate support. According to the present invention, the shield and the substrate support prevent plasma from being generated at other portions of a substrate except an edge portion of the substrate. Inductively coupled plasma is employed to generate plasma with high density, thereby removing a thin film and particles remained at the edge portion of the substrate. In addition, by means of the discharging of inductively coupled plasma, it is possible to improve an etching rate at the edge portion of the substrate and to adjust the profile of an etching process at a low processing pressure.