A semiconductor device, and a method of fabricating the same, include a substrate including two-dimensionally arranged active portions, device isolation patterns extending along sidewalls of the active portions, each of the device isolation patterns including first and second device isolation patterns, gate patterns extending across the active portions and the device isolation patterns, each of the gate patterns including a gate insulating layer, a gate line and a gate capping pattern, and ohmic patterns on the active portions, respectively. Top surfaces of the first device isolation pattern and the gate insulating layer may be lower than those of the second device isolation pattern and the gate capping pattern, respectively, and the ohmic patterns may include an extending portion on the first insulating layer.