FINFET WITH A SILICON GERMANIUM ALLOY CHANNEL AND METHOD OF FABRICATON THEREOF

摘要

A gate cavity is formed exposing a portion of a silicon fin by removing a sacrificial gate structure that straddles the silicon fin. An epitaxial silicon germanium alloy layer is formed within the gate cavity and on the exposed portion of the silicon fin. Thermal mixing or thermal condensation is performed to convert the exposed portion of the silicon fin into a silicon germanium alloy channel portion which is laterally surrounded by silicon fin portions. A functional gate structure is formed within the gate cavity providing a finFET structure having a silicon germanium alloy channel portion which is laterally surrounded by silicon fin portions.

主权项

1. A method of forming a semiconductor structure comprising:
forming a sacrificial gate structure straddling a portion of a silicon fin; forming a dielectric material over said silicon fin and having a topmost surface that is coplanar with a topmost surface of said sacrificial gate structure; removing said sacrificial gate structure to provide a gate cavity exposing a portion of said silicon fin; converting said exposed portion of said silicon fin into a silicon germanium alloy channel portion, wherein said converting said exposed portion of said silicon fin into said silicon germanium alloy channel portion comprises epitaxially depositing a silicon germanium alloy layer within said gate cavity and directly on said exposed portion of said silicon fin, and performing a thermal condensation process; and providing a functional gate structure in said gate cavity and in direct contact with said silicon germanium alloy channel portion.