Patent ID: 9502512
Filing Date: 2016-11-22
CPC Classification: H01L

Claim Text:
1. An edge terminal structure of a trench power semiconductor device, wherein the power semiconductor device is a trench power metal oxide semiconductor field effect transistor and comprises an active area and an edge terminal area, the edge terminal structure comprising: a first conductive-type substrate; a first conductive-type epitaxial layer formed on the first conductive-type substrate, wherein a trench being located in a surface of the first conductive-type epitaxial layer in the edge terminal area beside the active area; a first electrode located on the surface of the first conductive-type epitaxial layer; a second electrode located on a back of the first conductive-type substrate; a first field plate disposed on a sidewall of the trench and extending toward a tail of the trench, wherein the first field plate comprises at least an L-shaped electric-plate, a gate insulation layer below the L-shaped electric-plate, and the first electrode on the L-shaped electric-plate; and a second field plate comprising a portion of the first electrode and at least an insulation layer between the portion of the first electrode and the first conductive-type epitaxial layer, wherein the second field plate is free of the L-shaped electric-plate, the insulation layer covers the tail of the trench and further extends to completely cover the L-shaped electric-plate of the first field plate.