ISOLATING FILM FORMING METHOD OF SEMICONDUCTOR DEVICE

摘要

The method for preventing the crystal defect generation in the substrate and flattening the surface of the field oxide layer comprises steps; (a) forming the pad oxide, the 1st silicon nitride and oxide layers in sequence on the silicon substrate; (b) forming the trench mask after photoetching; (c) forming the polysilicon layer on the opening side wall of the trench mask; (d) forming the sloped trench by etching the polysilicon and the substrate; (e) forming the 2nd nitride and oxide layers in sequence and etching with the width greater than the oxide layer one to form the oxide layer on the opening side wall of the sloped trench; (f) injecting the channel stop ion after opening the silicon substrate by removing the 2nd nitride layer which is not coated by the oxide layer; and (g) forming the field oxide layer on the sloped trench.