Patent ID: 8921933
Filing Date: 2014-12-30
Classification: H01L

Abstract:
1. A semiconductor structure, comprising: a substrate; a first doped region in the substrate, wherein the first doped region has a first conductivity type, the first doped region comprises: a sub-doped layer having the first conductivity type; and a buried doped layer under the sub-doped layer and having the first conductivity type; a second doped region in the sub-doped layer, wherein the second doped region has a second conductivity type opposite to the first conductivity type; a third doped region in the second doped region and having the first conductivity type; a buried doped region on a sidewall of the buried doped layer and having the second conductivity type; a first trench structure having a first gate structure; and a second trench structure, wherein the first gate structure and the second trench structure are respectively on different sides of the second doped region, a dopant concentration of a first portion of the buried doped layer adjacent to the first trench structure is smaller than a dopant concentration of a second portion of the buried doped layer far from the first trench structure, the first trench structure is extended into the first portion of the buried doped layer, the second trench structure is extended into the buried doped region adjacent to the second portion of the buried doped layer.