Semiconductor device and manufacturing method thereof
A semiconductor device includes an isolation layer disposed over a substrate, first and second fin structures, a gate structure, a source/drain structure. The first fin structure and the second fin structure are both disposed over the substrate, and extend in a first direction in plan view. The gate structure is disposed over parts of the first and second fin structures, and extends in a second direction crossing the first direction in plan view. A first void is formed in the source/drain structure.
1. A semiconductor device comprising:
an isolation insulating layer disposed over a substrate;
a first fin structure and a second fin structure, both disposed over the substrate, the first and second fin structures extending in a first direction in plan view;
a source/drain structure;
a first void formed in the source/drain structure; and
a second void formed in the source/drain structure and located above the first void.
2. The semiconductor device of claim 1 , wherein:
the source/drain structure includes a first epitaxial layer and a second epitaxial layer disposed on the first epitaxial layer,
the first epitaxial layer has a first V-shape, and
the first void is formed by the second epitaxial layer at a bottom of the first V-shape.
3. The semiconductor device of claim 2 , wherein the second void is formed by the second epitaxial layer above the first void.
4. The semiconductor device of claim 3 , wherein a third void is formed by the second epitaxial layer above the second void.
5. The semiconductor device of claim 2 , wherein the source/drain structure further includes a third epitaxial layer disposed on the second epitaxial layer.
6. The semiconductor device of claim 5 , wherein:
the second epitaxial layer has a second V-shape, and
the second void is formed by the third epitaxial layer at a bottom of the second V-shape.
7. The semiconductor device of claim 6 , wherein a third void is formed by the third epitaxial layer above the second void.
8. A semiconductor device comprising:
a first fin structure and a second fin structure;
a source/drain structure; and
a first void formed in the source/drain structure, wherein:
the source/drain structure includes a first epitaxial layer and a second epitaxial layer disposed on the first epitaxial layer,
the first epitaxial layer has a first V-shape, and
the first void is formed by the second epitaxial layer at a bottom of the first V-shape.
9. The semiconductor device of claim 8 , wherein a second void is formed by the second epitaxial layer above the first void.
10. The semiconductor device of claim 9 , wherein a third void is formed by the second epitaxial layer above the second void.
11. The semiconductor device of claim 8 , wherein the source/drain structure further includes a third epitaxial layer disposed on the second epitaxial layer.
12. The semiconductor device of claim 8 , wherein:
the second epitaxial layer has a second V-shape, and
a second void is formed by the third epitaxial layer at a bottom of the second V-shape.
13. The semiconductor device of claim 12 , wherein a third void is formed by the third epitaxial layer above the second void.
14. A semiconductor device comprising:
a first fin structure, a second fin structure and a third fin structure, which protrude from an isolation insulating layer and are arranged such that the second fin structure is disposed between the first and third fin structures in a first direction in plan view;
a source/drain structure; and
lower voids formed in the source/drain structure, wherein:
the source/drain structure includes a first epitaxial layer and a second epitaxial layer disposed on the first epitaxial layer,
the first epitaxial layer has a first lower V-shape corresponding to an area between the first and second fin structures and a second lower V-shape corresponding to an area between the second and third fin structures, and
the lower voids includes a first lower void formed by the second epitaxial layer at a bottom of the first lower V-shape and a second lower void formed by the second epitaxial layer at a bottom of the second lower V-shape.
15. The semiconductor device of claim 14 , wherein the first and second lower voids are located at substantially a same first height.
16. The semiconductor device of claim 14 , further comprising middle voids formed in the second epitaxial layer,
wherein the middle voids includes a first middle void formed above the first lower void, and a second middle void formed above the second lower void.
17. The semiconductor device of claim 16 , wherein the first and second middle voids are located at substantially a same second height.
18. The semiconductor device of claim 14 , wherein the source/drain structure further includes a third epitaxial layer disposed on the second epitaxial layer.
19. The semiconductor device of claim 18 , wherein:
the second epitaxial layer has a first upper V-shape above the first lower V-shape and a second upper V-shape above the second lower V-shape,
middle voids are formed in the source/drain structure,
the middle voids include a first middle void formed by the third epitaxial layer at a bottom of the first upper V-shape and a second middle void formed by the third epitaxial layer at a bottom of the second upper V-shape.
20. The semiconductor device of claim 19 , wherein upper voids are formed by the third epitaxial layer above the middle voids.