The present invention provides a semiconductor device and fabricating method thereof, by which capacitance is enhanced by increasing an effective area of a lower electrode of a capacitor. The present invention includes a first lower electrode on a semiconductor substrate to have a plate shape, a second lower electrode on the first electrode to have a type (or “wing”-type) cross-section, a dielectric layer covering surfaces of the first and second lower electrodes, and an upper electrode on the dielectric layer.