A semiconductor device includes a gate structure disposed on a substrate. The gate structure has a first sidewall and a second sidewall facing the first sidewall. A first impurity region is disposed within an upper portion of the substrate. The first impurity region is spaced apart from the first sidewall. A third impurity region is within the upper portion of the substrate. The third impurity region is spaced apart from the second sidewall. A first trench is disposed within the substrate between the first sidewall and the first impurity region. The first trench is spaced apart from the first sidewall. A first barrier insulation pattern is disposed within the first trench.