Selective gas etching of silicon nitride on silicon - uses plasma produced by HF glow discharge in mixt. of perfluoro-propane and oxygen

摘要

In gas etching of a silicon nitride (I) layer on a Si semiconductor using a gas mixt. of a fluorocarbon cpd. (II) and oxygen in a plasma produced by H.F. glow discharge in a reactor, (II) is pefluoropropane and the press. of the gas mixt. is 0.5-1.5 torr. (I) can be etched selectively, without attacking the Si. (II) is mixed with a 5-20 vol.% oxygen and a 200-800 W discharge is used.