Sputter etching apparatus having a second electrically floating electrode and magnet means

Claim 1

A sputter etching apparatus comprising: an evacuatible vacuum treatment chamber, a sputter etching electrode mounted in said chamber for supporting a substrate to be etched, means for evacuating said chamber, means for introducing an etching gas into said evacuated chamber, means for supplying electric power to said electrode for generating a plasms from said etching gas in said chamber, an opposite electrode mounted in said chamber in an electrically floating condition facing said sputter etching electrode for confining the plasma in the space formed between said opposite electrode and said sputter etching electrode, said opposite electrode being electrically insulated from contact with said chamber and from direct connection with said means for supplying electric power, and magnet means mounted in said chamber for generating a magnetic field which extends substantially perpendicularly to said opposite electrode and said sputter etching electrode and extends in an axial direction along a peripheral open region surrounding said space so that the plasma is confined in said space.