Patent ID: 9099324
Filing Date: 2015-08-04
Classification: H01L

Abstract:
1. A method for fabricating a semiconductor device, the method comprising: forming a trench in a semiconductor substrate, the trench having a sidewall and a bottom surface; performing at least one etch and epitaxy process on the sidewall and the bottom surface of the trench, the etch and epitaxy process comprising: etching out a portion of the sidewall of the trench and a portion of the bottom surface of the trench; and forming an epitaxial layer conformal to the remaining portion of the sidewall and the remaining portion of the bottom surface; and filling the trench with a dielectric material to form a trench isolation, wherein the operation of forming the epitaxial layer comprises: forming a doped epitaxial layer on the remaining portion of the sidewall and the remaining portion of the bottom surface; and forming an undoped epitaxial layer on the doped epitaxial layer.