Semiconductor device and method for fabricating the same
A semiconductor device includes a fin-shaped structure on a substrate, a gate structure on the fin-shaped structure and an interlayer dielectric (ILD) layer around the gate structure, and a single diffusion break (SDB) structure in the ILD layer and the fin-shaped structure. Preferably, the SDB structure includes a bottom portion and a top portion on the bottom portion, in which the top portion and the bottom portion include different widths.
1. A semiconductor device, comprising:
a fin-shaped structure on a substrate;
a gate structure on the fin-shaped structure and an interlayer dielectric (ILD) layer around the gate structure;
an epitaxial layer adjacent to the gate structure;
a single diffusion break (SDB) structure in the ILD layer and the fin-shaped structure, wherein the SDB structure comprises:
a bottom portion comprising a first width and a second width, wherein a top surface of the bottom portion is higher than a top surface of the epitaxial layer; and
a top portion on the bottom portion, wherein the top portion comprise a third width and a top surface of the bottom portion is higher than a top surface of the fin-shaped structure.
2. The semiconductor device of claim 1 , further comprising:
a first spacer around the gate structure;
a second spacer around the SDB structure; and
a contact etch stop layer (CESL) between the first spacer and the second spacer.
3. The semiconductor device of claim 2 , wherein the first spacer and the second spacer comprise different heights.
4. The semiconductor device of claim 2 , wherein the CESL is U-shaped.
5. The semiconductor device of claim 2 , wherein a top surface of the CESL adjacent to the second spacer is lower than a top surface of the CESL adjacent to the first spacer.
6. The semiconductor device of claim 1 , wherein a top surface of the bottom portion is even with a top surface of the gate structure.
7. The semiconductor device of claim 1 , wherein the SDB structure comprises:
a liner; and
a dielectric layer on the liner, wherein the liner and the dielectric layer comprise different material.
8. The semiconductor device of claim 1 , further comprising an air gap in the SDB structure.
9. The semiconductor device of claim 1 , wherein the fin-shaped structure is disposed extending along a first direction and the SDB structure is disposed extending along a second direction.
10. The semiconductor device of claim 9 , wherein the first direction is orthogonal to the second direction.