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 method for fabricating a semiconductor device, comprising:
forming a gate structure on a substrate;
forming an epitaxial layer adjacent to the gate structure; and
forming a first cap layer on the epitaxial layer, wherein the first cap layer is made of silicon, a top surface of the first cap layer comprises a curve concave upward, and a bottom surface of the first cap layer comprises a planar surface higher than a top surface of the substrate.
2. The method of claim 1 , further comprising:
forming a spacer adjacent to the gate structure; and
forming the epitaxial layer adjacent to the spacer.
3. The method 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 method of claim 3 , wherein a top surface of the second cap layer is higher than a top surface of the substrate.
5. The method of claim 3 , wherein a bottom surface of the second cap layer is even with a top surface of substrate.
6. The method of claim 3 , wherein the first cap layer and the second cap layer comprise different materials.
7. The method of claim 3 , wherein the epitaxial layer and the first cap layer comprise different materials.
8. The method of claim 1 , wherein a bottom surface of the first cap layer is higher than a top surface of the substrate.
9. The method of claim 1 , wherein a top surface of the first cap layer is higher than half the height of the gate structure.