Semiconductor device and manufacturing method thereof
A semiconductor device includes at least one semiconductor fin, a gate electrode, at least one gate spacer, and a gate dielectric. The semiconductor fin includes at least one recessed portion and at least one channel portion. The gate electrode is present on at least the channel portion of the semiconductor fin. The gate spacer is present on at least one sidewall of the gate electrode. The gate dielectric is present at least between the channel portion of the semiconductor fin and the gate electrode. The gate dielectric extends farther than at least one end surface of the channel portion of the semiconductor fin.
1. A semiconductor device, comprising:
a semiconductor fin;
a first epitaxial structure on a first side of a channel portion of the semiconductor fin;
a second epitaxial structure on a second side of the channel portion of the semiconductor fin opposite to the first side of the channel portion of the semiconductor fin; and
a gate dielectric overlying the channel portion of the semiconductor fin, wherein:
the channel portion of the semiconductor fin has a first length measured in a first direction extending from the first epitaxial structure to the second epitaxial structure,
the gate dielectric has a second length measured in the first direction, wherein the second length is different than the first length, and
the first epitaxial structure is in direct contact with a first surface of the gate dielectric facing the first direction.
2. The semiconductor device of claim 1 , wherein the second length is greater than the first length.
3. The semiconductor device of claim 1 , wherein the first epitaxial structure directly contacts a second surface of the gate dielectric perpendicular to the first surface.
4. The semiconductor device of claim 1 , comprising:
a gate spacer, wherein the first epitaxial structure directly contacts a surface of the gate spacer facing the channel portion.
5. The semiconductor device of claim 4 , wherein the first epitaxial structure contacts a second surface of the gate dielectric facing the channel portion.
6. The semiconductor device of claim 1 , wherein the first epitaxial structure underlies the gate dielectric.
7. The semiconductor device of claim 1 , comprising:
a gate spacer, wherein the gate dielectric underlies a first portion of the gate spacer and does not underlie a second portion of the gate spacer.
8. The semiconductor device of claim 1 , comprising:
a gate spacer, wherein no portion of the channel portion of the semiconductor fin underlies the gate spacer.
9. The semiconductor device of claim 1 , comprising:
a gate spacer, wherein the channel portion underlies a first portion of the gate spacer and does not underlie a second portion of the gate spacer.
10. The semiconductor device of claim 1 , comprising:
a gate spacer, wherein:
a first portion of the first epitaxial structure underlying the gate dielectric has a first width, and
a second portion of the first epitaxial structure underlying the gate spacer has a second width different than the first width.
11. A semiconductor device, comprising:
a semiconductor fin;
a first epitaxial structure on a first side of a channel portion of the semiconductor fin;
a second epitaxial structure on a second side of the channel portion of the semiconductor fin opposite to the first side of the channel portion of the semiconductor fin;
a gate dielectric overlying the channel portion of the semiconductor fin; and
a gate spacer, wherein:
a first portion of the first epitaxial structure underlying the gate dielectric has a first width, and
a second portion of the first epitaxial structure underlying the gate spacer has a second width different than the first width.
12. The semiconductor device of claim 11 , wherein the second width is greater than the first width.
13. The semiconductor device of claim 11 , wherein a first interface is defined where the channel portion of the semiconductor fin contacts the first epitaxial structure.
14. The semiconductor device of claim 13 , comprising:
a gate electrode, wherein the first interface underlies the gate electrode.
15. The semiconductor device of claim 13 , wherein the first interface underlies the gate spacer.
16. The semiconductor device of claim 13 , comprising:
a gate electrode, wherein:
a second interface is defined where the gate electrode contacts the gate spacer, and
the first interface underlies the second interface.
17. A semiconductor device, comprising:
a semiconductor fin;
a first epitaxial structure on a first side of a channel portion of the semiconductor fin;
a second epitaxial structure on a second side of the channel portion of the semiconductor fin opposite to the first side of the channel portion of the semiconductor fin;
a gate dielectric overlying the channel portion of the semiconductor fin; and
a gate spacer, wherein:
the gate dielectric has a first surface facing a first direction and directly contacting the first epitaxial structure,
the gate dielectric has a second surface facing a second direction perpendicular to the first direction and directly contacting the first epitaxial structure, and
the gate spacer has a first surface facing the first direction and directly contacting the first epitaxial structure.
18. The semiconductor device of claim 17 , wherein:
the channel portion of the semiconductor fin has a first length measured in the second direction,
the gate dielectric has a second length measured in the second direction, and
the second length is different than the first length.
19. The semiconductor device of claim 18 , wherein the second length is greater than the first length.
20. The semiconductor device of claim 17 , comprising:
a gate electrode, wherein the first epitaxial structure underlines the gate electrode.