| abstract |
In a method of manufacturing a semiconductor device, a dummy gate structure is formed on a substrate. A first spacer layer is formed on the substrate to cover the dummy gate structure. A nitridation process is performed on the first spacer layer. An upper portion of the substrate adjacent to the dummy gate structure is removed to form a trench. An inner wall of the trench is cleaned. An epitaxial layer is formed to fill the trench. The dummy gate structure is replaced with a gate structure. |