SOURCE/DRAIN STRUCTURE OF SEMICONDUCTOR DEVICE

摘要

The present invention relates to a semiconductor device. An exemplary structure of a field-effect transistor includes a substrate which includes a main surface and a cavity under the main surface; a gate laminate which is placed on the main surface of the substrate; a spacer which is placed close to one lateral surface of the gate laminate; a shallow trench isolation (STI) region which is placed on the lateral surface of the gate laminate wherein the STI region is within the substrate; and a source/drain (S/D) structure which is distributed between the gate laminate and the STI region. The S/D structure includes: a stress-strain material which is placed in the cavity wherein the lattice constant of the stress-strain material is different from the lattice constant of the substrate; and an S/D extension unit which is placed between the substrate and the stress-strain material wherein the S/D extension unit extends under the spacer and includes a part vertical to the main surface.