Patent ID: 11908952
Assignee: SAMSUNG ELECTRONICS CO., LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H  B | IPC B  H

Claim 11:
12. A semiconductor device, comprising:
a substrate;
a channel on the substrate;
a gate electrode on the channel; and
source/drain structures on opposing sides of the gate electrode, the source/drain structures each comprising a first epitaxial layer and a second epitaxial layer having different compositions from each other,
wherein the second epitaxial layer is in a center region of each of the source/drain structures,
wherein the first epitaxial layer surrounds a bottom surface and both side surfaces of the second epitaxial layer,
wherein the side surfaces of the second epitaxial layer each comprise first portions that are inclined so that a width of the second epitaxial layer decreases toward the substrate and second portions that are curved downwardly from upper portions of the first epitaxial layer and are connected to upper ends of the first portions, and
wherein the first epitaxial layer comprises outer side surfaces having substantially vertical portions.