MANUFACTURE OF SEMICONDUCTOR DEVICE

摘要

PURPOSE:To minimize the bird beak produced in case of selective oxidation perfectly preventing bird head production by a method wherein silicon nitride is left steadily on the side of opened silicon substrate. CONSTITUTION:As shown in the figure, the oxide film 14 is formed on the opened part of a n type semiconductor substrate by thermal oxidation. After entirely being formed by CVD processing, if the silicon nitride film 15 is entirely etched by dry etching with remarkable anisotropy, the opened bottom of n type semiconductor substrate and the silicon nitride film only formed on the silicon nitride 13 are exclusivey etched while the silicon nitride film 15 only formed on the side of opened part is left self-matchable. The effect of leaving silicon nitride film 15 on the side of opened n type semiconductor substrate 11 only is to prevent water or oxgen from being supplied in the lateral direction not to produce bird beak at all. The oxide film 17 is formed by selective oxidation in the figure preventing bird beak and bird head from being produced at all.