Abstract: This invention relates to a plasma etching system, which includes a lower flange and a spaced upper flange; a chamber wall mounted between the flanges to form a closed etching chamber; a grounded wafer support plate disposed in said chamber for receiving thereon a wafer to be processed; an electrical insulating element interposed between the chamber wall and the support plate; a sintered or sintered-like porous electrode plate mounted in the chamber in spaced relationship with respect to the wafer; said plate having a gas inlet for receiving a supply of etching gas; circuitry for applying an excitation voltage to this plate, and said chamber having a gas outlet leading to a vacuum source.