Semiconductor device with trench isolation

摘要

A semiconductor device includes a semiconductor substrate and a trench isolation. The trench isolation is located in the semiconductor substrate, and includes an epitaxial layer and a dielectric material. The epitaxial layer is in a trench of the semiconductor and is peripherally enclosed thereby, in which the epitaxial layer is formed by performing etch and epitaxy processes. The etch and epitaxy process includes etching out a portion of a sidewall of the trench and a portion of a bottom surface of the trench and forming the epitaxial layer conformal to the remaining portion of the sidewall and the remaining portion of the bottom surface. The dielectric material is peripherally enclosed by the epitaxial layer.

主权项

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.