Patent ID: 7956411
Filing Date: 2011-06-07
Classification: H01L

Abstract:
1. A trench gate field effect transistor, comprising: a trench extending into a semiconductor region; a conductive electrode disposed in the trench, the conductive electrode being insulated from the semiconductor region by a dielectric layer, the conductive electrode including a conductive liner lining the dielectric layer along opposite sidewalls of the trench, the conductive liner having tapered edges such that a thickness of the conductive liner gradually increases from a top surface of the conductive electrode to a point in lower half of the conductive electrode, the conductive electrode further including a conductive fill material filling a center portion of the trench and sandwiched by the conductive liner; a drift region of a first conductivity type in the semiconductor region; a body region of a second conductivity type extending over the drift region; and source regions of the first conductivity type in the body region adjacent the trench.