Semiconductor Device and Manufacturing Method Thereof

Abstract

A semiconductor device includes: a substrate having a front and back surface. A main junction region, a terminal region and a field cut-off region are sequentially arranged in the substrate close to the front surface. A trench is formed in the terminal region near the field cut-off region, surrounded by field limiting rings. The junction depth of rings around the trench is greater than that of rings not surrounding it. By arranging trench structures in the terminal region, the depth of ion implantation can be increased, so that a larger junction depth can be formed subsequently. The larger junction depth can reduce a peak electric field strength on the surface; the peak electric field strength shifts from the surface to the inside of silicon; and the curvature radius of the terminal P-type implantation region is increased, thereby increasing the breakdown voltage of the terminal structure.

Dependencies are inferred from the claim text.