초록 ▼

BF3 based mixtures for selectively etching thin layers of silicon dioxide over silicon for use in the plasma etch process for integrated circuits manufacture is disclosed. In the process, when trace amounts of formaldehyde are added to the etch system the rate on oxide inceases markedly. The effect

BF3 based mixtures for selectively etching thin layers of silicon dioxide over silicon for use in the plasma etch process for integrated circuits manufacture is disclosed. In the process, when trace amounts of formaldehyde are added to the etch system the rate on oxide inceases markedly. The effect on the silicon is not substantial. The optional addition of an inert diluent gas did not substantially change these results.

대표청구항 ▼

A method of selectively etching silicon dioxide preferentially over silicon or polysilicon in an article containing a layer of silicon dioxide on an underlayer of silicon or polysilicon which comprises exposing said article to a plasma gas mixture discharge wherein the plasma comprises BF3 and forma

A method of selectively etching silicon dioxide preferentially over silicon or polysilicon in an article containing a layer of silicon dioxide on an underlayer of silicon or polysilicon which comprises exposing said article to a plasma gas mixture discharge wherein the plasma comprises BF3 and formaldehyde gas wherein the formaldehyde is derived by contacting the plasma gas with a source of formaldehyde and continuing said exposure until the silicon dioxide layer is penetrated. A plasma etch gas for selectively etching silicon dioxide against silicon comprising BF3 and formaldehyde where in the BF3 gas is preconditioned by contacting said gas with a source of formaldehyde.