Disclosed are semiconductor devices and methods of manufacturing the same. The semiconductor device includes active portions defined in a semiconductor substrate, a device isolation pattern in a trench formed between the active portions, a gate electrode in a gate recess region crossing the active portions and the device isolation pattern, a gate dielectric layer between the gate electrode and an inner surface of the gate recess region, and a first ohmic pattern and a second ohmic pattern on each of the active portions at both sides of the gate electrode, respectively. The first and second ohmic patterns include a metal-semiconductor compound, and a top surface of the device isolation pattern at both sides of the gate recess region is recessed to be lower than a level of a top surface of the semiconductor substrate.