A semiconductor device includes a first trench capacitor formed in a first trench, a second trench capacitor formed in a second trench, a first gate electrode disposed above a first active area, a second gate electrode disposed above a second active area, a first impurity doped region formed in an outer periphery of the second trench including a boundary adjacent to the second trench and doped with an impurity of a first conduction type, and a second impurity doped region formed in the first impurity doped region so as to include the first active area located below the first gate electrode, the second impurity doped region being doped with an impurity of a second conduction type opposite to the first conduction type impurity.