Patent ID: 6222232
Filing Date: 2001-04-24
Classification: H01L

Abstract:
A MOS technology power device comprising:a semiconductor substrate,a semiconductor layer of a first conductivity type superimposed over the semiconductor substrate,an insulated gate layer covering the semiconductor layer,a plurality of substantially rectilinear elongated openings parallel to each other in said insulated gate layer, each said opening including a first edge and a second edge,a respective plurality of elongated body stripes of a second conductivity type formed in said semiconductor layer under said elongated openings,source regions of the first conductivity type included in said body stripes, anda metal layer covering the insulated gate layer and contacting the body stripes and the source regions through said elongated openings,wherein each said body stripe comprises first portions and second portions, said first portions being substantially aligned with the first edge of the respective elongated opening and extending under the second edge of said elongated opening to form a channel region, each said first portion including said source region extending substantially from a longitudinal axis of symmetry of said respective elongated opening to said second edge of the elongated opening, and said second portions, longitudinally intercalated with said first portions and having a top view of a wave shape form, substantially aligned with the second edge of the elongated opening and extending under the first edge of the elongated opening to form a channel region, each said second portion including said source region extending substantially from said longitudinal axis of symmetry to said first edge of the elongated opening, said first portions and said second portions of the body stripes being respectively aligned in a direction transversal to said longitudinal axis,wherein said insulated gate layer comprises an oxide layer covering the semiconductor layer, a conductive gate layer covering the oxide layer and an insulating layer covering the conductive gate layer for the insulation thereof from the metal layer, the oxide layer comprising first oxide layer portions having a first thickness and extending over the channel regions of the first and second portions of the body stripes to an intermediate point between adjacent elongated openings, and second oxide layer portions having a second thickness and extending from said intermediate point to the edges of the adjacent elongated openings, wherein the first thickness and the second thickness have two different values,wherein said oxide layer at each end defines at least part of respective adjacent rectilinear elongated openings, and said metal layer fills said openings extending to contact ends of adjacently disposed oxide layerswherein said metal layer is continuous and extends uninterrupted from one opening, over said insulating layer, and to an adjacent opening.