SILICON RECESS ETCH AND EPITAXIAL DEPOSIT FOR SHALLOW TRENCH ISOLATION (STI)

摘要

Some embodiments of the present disclosure relate to a method. In this method, a semiconductor substrate, which has an active region disposed in the semiconductor substrate, is received. A shallow trench isolation (STI) structure is formed to laterally surround the active region. An upper surface of the active region bounded by the STI structure is recessed to below an upper surface of the STI structure. The recessed upper surface extends continuously between inner sidewalls of the STI structure and leaves upper portions of the inner sidewalls of the STI structure exposed. A semiconductor layer is epitaxially grown on the recessed surface of the active region between the inner sidewalls of the STI structure. A gate dielectric is formed over the epitaxially-grown semiconductor layer. A conductive gate electrode is formed over the gate dielectric.

主权项

1. A semiconductor device, comprising:
a semiconductor substrate including an active region; a shallow trench isolation (STI) structure laterally surrounding the active region, wherein the semiconductor substrate includes an upper surface circumscribing outer sidewalls of the STI structure and a recessed surface circumscribed by inner sidewalls of the STI structure, the recessed surface having a height that is less than that of the upper surface, as measured from a bottom surface of the semiconductor substrate; and an epitaxial silicon region contacting the recessed surface and exhibiting an absence of germanium.