Semiconductor devices including a capacitor in which electrostatic capacity is improved by a simplified process and/or methods for fabricating the same are provided. The semiconductor device including an insulating structure defining a first trench on a substrate, a first conductive layer in the insulating structure, a first portion of an upper surface of the first conductive layer exposed by the first trench, a capacitor structure including a first electrode pattern on the first conductive layer, a dielectric pattern on the first electrode pattern, and a second electrode pattern on the dielectric pattern, the first electrode pattern extending along sidewalls and a bottom surface of the first trench and an upper surface of the insulating structure, and a first wiring pattern on the capacitor structure may be provided.