Semiconductor device having a gate on a fin-shaped structure and multi-layer single diffusion break (SDB) features
A method for fabricating a semiconductor device includes the steps of forming a fin-shaped structure on a substrate, forming a first trench and a second trench in the fin-shaped structure, forming a first dielectric layer in the first trench and the second trench, removing part of the first dielectric layer, forming a second dielectric layer in the first trench and the second trench to form a first single diffusion break (SDB) structure and a second SDB structure, and then forming a gate structure on the fin-shaped structure, the first SDB structure, and the second SDB structure.
1 . A semiconductor device, comprising:
a fin-shaped structure on a substrate;
a first single diffusion break (SDB) structure and a second SDB structure in the substrate, wherein each of the first SDB structure and the second SDB structure comprises a bottom portion and a top portion, the bottom portion and the top portion comprise different materials, and top surfaces of the top portion and the substrate are coplanar; and
a gate structure on the fin-shaped structure, the first SDB structure, and the second SDB structure.
2 . The semiconductor device of claim 1 , further comprising:
a third SDB structure and a fourth SDB structure adjacent to two sides of the first SDB structure and the second SDB structure, wherein each of the third SDB structure and the fourth SDB structure comprises the bottom portion and the top portion and the bottom portion and the top portion comprise different materials.
3 . The semiconductor device of claim 2 , further comprising a fifth SDB structure and a sixth SDB structure adjacent to two sides of the third SDB structure and the fourth SDB structure.
4 . The semiconductor device of claim 2 , wherein a depth of the first SDB structure is greater than a depth of the third SDB structure.
5 . The semiconductor device of claim 1 , further comprising:
a third SDB structure and a fourth SDB structure adjacent to two sides of the first SDB structure and the second SDB structure, wherein each of the third SDB structure and the fourth SDB structure comprises a single material.
6 . The semiconductor device of claim 5 , further comprising a fifth SDB structure and a sixth SDB structure adjacent to two sides of the third SDB structure and the fourth SDB structure.
7 . The semiconductor device of claim 5 , wherein a depth of the first SDB structure is greater than a depth of the third SDB structure.
8 . The semiconductor device of claim 1 , wherein the bottom portion comprises silicon oxide.
9 . The semiconductor device of claim 1 , wherein the top portion comprises silicon nitride.