Patent ID: 6521497
Filing Date: 2003-02-18
Classification: H01L

Abstract:
A method of making a heavy body structure for a trenched DMOS transistor comprising:providing a semiconductor substrate; forming a plurality of trenches into the substrate; implanting a first dopant at a first energy and dosage into the substrate, to form a doped well; implanting, into said well and between adjacent trenches, a second dopant at a second energy and dosage to form a first doped portion of a heavy body; and implanting, into said well and between adjacent trenches, a third dopant at a third energy and dosage to form a second doped portion of said heavy body, wherein the first portion of the heavy body is deeper than the second portion of the heavy body, and wherein said dosage of said second dopant has a doping concentration that is greater than said dosage of said third dopant.