Patent ID: 9698055
Date: 2017-07-04
CPC Classifications: H01L

Claim:
1. A method, comprising: etching a semiconductor substrate to form a semiconductor strip, wherein trenches are formed in the semiconductor substrate, and wherein the trenches are on opposite sidewalls of the semiconductor strip; forming a spacer on a sidewall of the semiconductor strip; using the spacer as an etching mask to extend the trenches down into the semiconductor substrate, wherein the semiconductor substrate is etched; filling a dielectric material into the trenches; planarizing the dielectric material to form insulation regions in the trenches; and recessing the insulation regions, wherein after the recessing, top surfaces of the insulation regions are lower than a top surface of the semiconductor strip; after recessing the insulation regions, an upper portion of the semiconductor strip lies above a top surface of the insulation regions, and wherein the upper portion of the semiconductor strip includes the top surface, a first sidewall portion and a second sidewall portion, wherein: