The structure which was formed with the method of using the etching medicine and that etching medicine which possess the selectivity for the silicon dioxide which is on top of the silicon dioxide and nitriding silicon of non dope and is doped, and that.

摘要

The etching medicine which as for x integer of 2 or 5, as for y with integer of 1 or 4, as for x+y 6 is, consists of C₂ H _{xF y} etches silicon dioxide which are doped than non dope silicon dioxide and nitriding silicon selectively. Therefore, in the dry etching method which uses the etching medicine which consists of C₂ H _{xF y}, non dope silicon dioxide and nitriding silicon it can be used as the etching stop material. C₂ H _{xF y} can be used as a basic etching medicine, or as the additive of the other etching medicine and the mixed etching medicine. Being based on the etching medicine of this invention, and the method of this invention the semiconductor device which includes the structure which patterning is done (10) it disclosed. The silicon dioxide structure which concretely, most vertical side walls (34) possesses this invention and, is doped (24) with, the side wall (34) approaching, the semiconductor device which includes with the structure of non dope silicon dioxide and the nitriding silicon which it exposes (10) it consists of.