Semiconductor Devices and Methods of Fabricating the Same

A semiconductor device includes a substrate with an NMOSFET region and a PMOSFET region, a first active pattern on the NMOSFET region, a second active pattern on the PMOSFET region, a dummy pattern between the NMOSFET and PMOSFET regions, and device isolation patterns on the substrate that fill trenches between the first active pattern, the second active pattern, and the dummy pattern. Upper portions of the first and second active patterns have a fin-shaped structure protruding between the device isolation patterns. The upper portions of the first and second active patterns contain semiconductor materials, respectively, that are different from each other, and an upper portion of the dummy pattern contains an insulating material.