Etching of silicon dioxide selectively to silicon nitride and polysilicon

摘要: Silicon dioxide on a substrate is directionally etched using hydrogen halide plasma which created within an etch chamber. The method selectively etches silicon relative to polysilicon and nitride. A the combination of NH 3 NF gases or CF 4 O 2 mixed with H N are located An electrical field chamber causing gas mixture form plasma. negative charge at bottom attracts positively charged plasma, thereby etching in downward direction. result anisotropic product. also shown be effective non-selectively thermal deposited oxides, resulting similar rate for different types oxides.