A semiconductor memory device includes a substrate having a first active area and a second active area in proximity to the first active area. A trench isolation region is between the first active area and the second active area. A source line region is disposed in the first active area and adjacent to the trench isolation region. An erase gate is disposed on the source line region. A floating gate is disposed on a first side of the erase gate. A first control gate is disposed on the floating gate. A first word line is disposed adjacent to the floating gate and the first control gate and insulated therefrom. A second control gate is disposed on a second side of the erase gate and directly on the trench isolation region. A second word line is disposed adjacent to the second control gate and insulated therefrom.