SEMICONDUCTOR DEVICE AND METHOD MANUFACTURING THE SAME

摘要

The present invention relates to a method for manufacturing a semiconductor device wherein the method comprises the step of sequentially forming n-type epitaxial layer, p-type epitaxial layer, and a first n+ region at the first surface of n+ type carbon silicon substrate; and the step of forming a trench penetrating the first n+ region and the p-type epitaxial layer and including a first part having a linear profile and elliptical second part wherein the step of forming the trench comprises the step of forming a photosensitive film pattern on the first n+ region; the step of forming the first part of the trench by forming a first trench through etching the first n+ region and p-type epitaxial layer by using the photosensitive film as a mask; the step of forming a buffer layer by using vitreous carbon on the first n+ region and the first trench after removing the photosensitive film pattern; the step of forming a buffer layer pattern by etching the buffer layer for the bottom of the first trench to be exposed; the step of forming a second trench by etching the bottom of the first trench by using the buffer layer pattern as mask; the step of forming the second part of the trench by isotropic etching the second trench; and the step of removing the buffer pattern.