A method for fabricating semiconductor device is disclosed. The method includes the steps of: (a) providing a substrate; (b) forming a gate structure on the substrate; (c) performing a first deposition process to form a first epitaxial layer adjacent to the gate structure and performing a first etching process to remove part of the first epitaxial layer at the same time; and (d) performing a second etching process to remove part of the first epitaxial layer.