A semiconductor device and method of manufacturing the semiconductor device are provided. The semiconductor device may include a semiconductor substrate, a gate insulation layer and a gate electrode, a first spacer, a second spacer, an epitaxial pattern, and/or source/drain regions. The gate insulation layer and the gate electrode may be formed on the semiconductor substrate. The first spacer may be formed on sidewalls of the gate electrode. The second spacer may be formed on sidewalls of the first spacer. The epitaxial pattern may be formed between the second spacer and the semiconductor substrate such that an outside profile of the epitaxial pattern is aligned with an outside profile of the second spacer. The source/drain regions may include primary source/drain regions that are aligned with the first spacer. The primary source/drain regions may be formed in the epitaxial pattern and the semiconductor substrate. The source/drain regions may also include secondary source/drain regions that are aligned with the second spacer and formed in the semiconductor substrate.