Method for fabricating semiconductor device
A method for fabricating a semiconductor device includes the steps of forming a gate structure on a substrate, forming an epitaxial layer adjacent to the gate structure, and then forming a first cap layer on the epitaxial layer. Preferably, a top surface of the first cap layer includes a curve concave upward and a bottom surface of the first cap layer includes a planar surface higher than a top surface of the substrate.
1. A semiconductor device, comprising:
a gate structure on a substrate;
an epitaxial layer adjacent to the gate structure;
a first cap layer on the epitaxial layer, wherein a top surface of the first cap layer comprises a V-shape and two planar surfaces connected to two sides of the V-shape and a bottom surface of the first cap layer comprises a planar surface higher than a top surface of the substrate; and
a contact etch stop layer (CESL) adjacent to the gate structure and on the first cap layer.
2. The semiconductor device of claim 1 , further comprising:
a spacer adjacent to the gate structure; and
the epitaxial layer adjacent to the spacer.
3. The semiconductor device of claim 1 , wherein the epitaxial layer comprises a second cap layer, and the first cap layer is on the second cap layer.
4. The semiconductor device of claim 3 , wherein a top surface of the second cap layer is higher than a top surface of the substrate.
5. The semiconductor device of claim 3 , wherein a bottom surface of the second cap layer is even with a top surface of substrate.
6. The semiconductor device of claim 3 , wherein the first cap layer and the second cap layer comprise different materials.
7. The semiconductor device of claim 1 , wherein the epitaxial layer and the first cap layer comprise different materials.
8. The semiconductor device of claim 1 , wherein a top surface of the first cap layer is higher than half the height of the gate structure.