FinFET device with epitaxial structures that wrap around the fins and the method of fabricating the same
A FinFET device is provided. The FinFET device includes a plurality of fin structures that protrude upwardly out of a dielectric isolation structure. The FinFET device also includes a plurality of gate structures that partially wrap around the fin structures. The fin structures each extend in a first direction, and the gate structures each extend in a second direction different from the first direction. An epitaxial structure is formed over at least a side surface of each of the fin structures. The epitaxial structure includes: a first epi-layer, a second epi-layer, or a third epi-layer. The epitaxial structure formed over each fin structure is separated from adjacent epitaxial structures by a gap. A silicide layer is formed over each of the epitaxial structures. The silicide layer at least partially fills in the gap. Conductive contacts are formed over the silicide layer.
1. A semiconductor device, comprising:
a first epitaxial structure;
a first silicide layer located on the first epitaxial structure;
a second epitaxial structure; and
a second silicide layer located on the second epitaxial structure;
wherein a gap separates the first silicide layer from the second silicide layer, and wherein the first epitaxial structure and the second epitaxial structure each comprise a first layer and a second layer.
2. The semiconductor device of claim 1 , wherein the semiconductor device comprises one or more FinFET transistors.
3. The semiconductor device of claim 2 , wherein the first epitaxial structure and the second epitaxial structure comprise source/drains of the one or more FinFET transistors.
4. The semiconductor device of claim 1 , further comprising:
a first semi-conductive fin over which the first epitaxial structure is located;
a second semi-conductive fin over which the second epitaxial structure is located; and
a dielectric isolation structure located between the first semi-conductive fin and the second semi-conductive fin.
5. The semiconductor device of claim 4 , further comprising: a gate located over the first semi-conductive fin and over the second semi-conductive fin.
6. The semiconductor device of claim 5 , wherein the gate contains a high-k gate dielectric and a metal gate electrode.
7. The semiconductor device of claim 5 , wherein:
the gate comprises an elongated structure that extends in a first direction; and
the first silicide layer is separated from the second silicide layer in the first direction.
8. The semiconductor device of claim 7 , wherein the first semi-conductive fin and the second semi-conductive fin each extend in a second direction different from the first direction.
9. The semiconductor device of claim 1 , wherein the first epitaxial structure and the second epitaxial structure each contain silicon germanium.
10. The semiconductor device of claim 9 , wherein:
the first layer and the second layer have different germanium contents.
11. The semiconductor device of claim 10 , wherein the second layer is located conformally on the first layer.
12. The semiconductor device of claim 1 , further comprising: a metal-containing contact located on an upper surface and side surfaces of the first silicide layer and the second silicide layer.
13. A semiconductor device, comprising:
a first epitaxial structure;
a first silicide layer formed on an upper surface and side surfaces of the first epitaxial structure;
a second epitaxial structure;
a second silicide layer formed on an upper surface and side surfaces of the second epitaxial structure; and
a metal component that is in direct contact with the first silicide layer and the second silicide layer, wherein at least a portion of the metal component is disposed between the first silicide layer and the second silicide layer;
wherein the first epitaxial structure and the second epitaxial structure each include at least a first layer and a second layer, the first layer and the second layer having different material compositions.
14. The semiconductor device of claim 13 , further comprising:
a first semi-conductive fin over which the first epitaxial structure is located;
a second semi-conductive fin over which the second epitaxial structure is located;
a dielectric isolation structure disposed between the first semi-conductive fin and the second semi-conductive fin; and
a high-k metal gate that partially wraps around the first semi-conductive fin and the second semi-conductive fin;
wherein:
the high-k metal gate extends in a first direction;
the first semi-conductive fin and the second semi-conductive fin each extend in a second direction different from the first direction; and
the portion of the metal component separates the first silicide layer from the second silicide layer in the first direction.
15. The semiconductor device of claim 13 , wherein:
the second layer is formed conformally on the first layer.
16. A method, comprising:
forming a first semi-conductive fin and forming a second semi-conductive fin;
epitaxially growing a first epitaxial structure over the first semi-conductive fin and epitaxially growing a second epitaxial structure over the second semi-conductive fin, wherein the first epitaxial structure and the second epitaxial structure are separated by a gap, wherein the epitaxially growing comprises epitaxially growing at least a first layer and a second layer that contains a different material than the first layer;
forming a first silicide layer on the first epitaxial structure and forming a second silicide layer on the second epitaxial structure, wherein the first silicide layer and the second silicide layer partially reduce, but do not completely eliminate, the gap; and
forming one or more conductive contacts over the first and second silicide layer, including in the gap.
17. The method of claim 16 , wherein the first layer and the second layer have different germanium contents.
18. The method of claim 17 , wherein the epitaxially growing comprises growing the second layer conformally on the first layer.
19. The method of claim 16 , wherein:
the first silicide layer is formed on an upper surface and side surfaces of the first epitaxial structure; and
the second silicide layer is formed on an upper surface and side surfaces of the second epitaxial structure.
20. The method of claim 16 , further comprising: forming an elongated gate structure over the first semi-conductive fin and the second semi-conductive fin, the elongated gate structure extending in a first direction, wherein the first epitaxial structure and the second epitaxial structure are separated in the first direction.