Patent ID: 8198154
Filing Date: 2012-06-12
Classification: H01L

Abstract:
1. A method for forming a semiconductor device comprising: a) providing a start material comprising a semiconductor substrate and a semiconductor epitaxial layer disposed on top of the substrate, wherein the substrate and epitaxial layer are of opposite conductivity types; b) forming a drift layer at a top portion of the epitaxial layer, wherein the drift layer has the same conductivity type as the substrate; c) depositing a nitride layer on top of a surface of the semiconductor epitaxial layer; d) etching the nitride layer at non-active region; e) forming field oxide regions in drift-drain extension regions; f) forming a drain contact trench in the drift layer and the epitaxial layer; g) forming insulating spacers along sidewalls of the drain contact trench; h) filling the drain contact trench with an electrically conductive drain plug; i) forming a gate dielectric layer on top of the drift layer; j) forming a conductive gate on top of the gate dielectric layer; k) forming a body region at a top portion of the epitaxial layer, so that a portion of the body region is under the gate; l) implanting dopants into a top portion of the drift layer to form a source region and a top drain contact, wherein the source region and the top drain contact have the same conductivity type as the substrate; and m) forming an electrically conductive drain strap on top of the drain plug.