Patent ID: 8975691
Filing Date: 2015-03-10
Classification: H01L

Abstract:
1. A trenched power semiconductor device with enhanced breakdown voltage comprising: a substrate; at least two gate trenches, located in the substrate; a first dielectric layer, lining inner surfaces of the gate trenches; a first polysilicon structure, located in the gate trenches; at least a first trench, located between the neighboring gate trenches; a body region of a first conductive type, located between the gate trenches, and the first trench penetrating the body region to the substrate below the body region; a second polysilicon structure of the first conductive type, located in a lower portion of the first trench, wherein the second polysilicon structure is located under the body region, the upper surface of the second polysilicon structure is spaced from the lower surface of the body region with a predetermined distance and the second polysilicon structure is in contact with the portion of the substrate that is surrounding the first trench; a source region of a second conductive type, which is opposite to the first conductive type, located in an upper portion of the body region; at least a heavily doped region of the first conductive type, located in the body region; and a source metal layer, electrically connected to the heavily doped region and the source region.