Semiconductor device and method for fabricating the same
A method for fabricating semiconductor device includes the steps of: forming a gate structure on a substrate; forming a first spacer and a second spacer around the gate structure; forming a recess adjacent to two sides of the second spacer; performing a cleaning process to trim the second spacer for forming a void between the first spacer and the substrate; and forming an epitaxial layer in the recess.
1. A method for fabricating semiconductor device, comprising:
forming a gate structure on a substrate;
forming a first spacer and a second spacer around the gate structure;
forming a recess adjacent to two sides of the first spacer;
performing a cleaning process to trim the second spacer for forming a void between the second spacer and the substrate and reducing an overall width of the second spacer; and
forming an epitaxial layer in the recess.
2. The method of claim 1 , wherein at least a portion of the first spacer comprises an L-shape and at least a portion of the second spacer comprises an I-shape.
3. The method of claim 1 , wherein the first spacer comprises silicon oxide and the second spacer comprises silicon nitride.
4. The method of claim 1 , further comprising forming a third spacer around the gate structure before forming the first spacer.
5. The method of claim 4 , wherein at least a portion of the third spacer comprises an I-shape.
6. The method of claim 1 , further comprising a cap layer on the epitaxial layer while filling the void.
7. The method of claim 6 , wherein the cap layer comprises silicon.
8. The method of claim 6 , wherein the cap layer comprises a planar top surface and an inclined sidewall.
9. The method of claim 8 , wherein the cap layer further comprises a vertical sidewall connected to the inclined sidewall.