Patent ID: 8349691
Filing Date: 2013-01-08
Classification: H01L

Abstract:
1. A method of forming a power metal-oxide-semiconductor field effect transistor (MOSFET), comprising: forming an epitaxial layer of a first conductivity type on a substrate of the first conductivity type; forming a body layer of a second conductivity type in the epitaxial layer; forming a plurality of mask patterns on the substrate; forming a plurality of trenches in the body layer and in a portion of the epitaxial layer between the mask patterns; forming a first oxide layer on surfaces of the trenches; forming a first conductive layer in the trenches; performing a trimming process to the mask patterns for reducing a line width of each of the mask patterns, so as to form trimmed mask patterns; forming two source regions of the first conductivity type in the body layer beside each of the trenches by using the trimmed mask patterns as a mask; forming a plurality of dielectric patterns on the first conductive layer and between the trimmed mask patterns; and removing the trimmed mask patterns, wherein a surface of the first conductive layer is no higher than a surface of the body layer.