Patent ID: 9735266
Date: 2017-08-15
CPC Classifications: H01L

Claim:
1. A trench metal oxide semiconductor field effect transistor (MOSFET) comprising: an epitaxial layer over a substrate; a plurality of trenches in the epitaxial layer, wherein the plurality of trenches includes a first trench and a second trench, wherein a depth of the first trench is different from a depth of the second trench, and the second trench is adjacent to the first trench; a self-aligned source contact between the first trench and the second trench; a heavily-doped region in the epitaxial layer, wherein the self-aligned source contact is connected to the heavily-doped region; a source region surrounding the self-aligned source contact, wherein the source region is convex-shaped, the source region is separated from the heavily-doped region, and the self-aligned source contact is connected to the source region; and a first gate structure in the first trench, the first gate structure comprising: