Metal-oxide-semiconductor device having improved performance and reliability

Abstract

A method for forming a MOS device includes the steps of forming a gate proximate an upper surface of a semiconductor layer, the semiconductor layer including a substrate of a first conductivity type and a second layer of a second conductivity type; forming first and second source/drain regions of the second conductivity type in the second layer proximate the upper surface of the second layer, the first source/drain region being spaced laterally from the second source/drain region, the gate being formed at least partially between the first and second source/drain regions; and forming at least one electrically conductive trench in the second layer between the gate and the second source/drain region, the trench being formed proximate the upper surface of the semiconductor layer and extending substantially vertically through the second layer to the substrate. The step of forming the trench includes the steps of forming an insulating layer substantially lining sidewalls of the trench, and substantially filling the trench with an electrically conductive material.