Patent ID: 8258555

Claim:
A semiconductor device having an extra capacitor structure, comprising: a semiconductor substrate, having an upper surface and a lower surface, wherein the semiconductor substrate has a first conductive type; a source metal layer, disposed on the upper surface of the semiconductor substrate; a gate metal layer, disposed on the upper surface of the semiconductor substrate; a drain metal layer, disposed on the lower surface of the semiconductor substrate; at least a transistor device, disposed in the semiconductor substrate between the source metal layer and the drain metal layer, and the transistor device comprising a source electrode, a gate electrode, and a drain electrode, wherein the source electrode is electrically connected to the source metal layer; the gate electrode is electrically connected to the gate metal layer; and the drain electrode is electrically connected to the drain metal layer; a heavily doped region, disposed in the semiconductor substrate between the gate metal layer and the drain metal layer, wherein the heavily doped region has a first conductive type; a capacitor dielectric layer, disposed on the semiconductor substrate and being in contact with the heavily doped region; a conductive layer, disposed between the capacitor dielectric layer and the gate metal layer and electrically connected to the source metal layer, wherein the heavily doped region, the capacitor dielectric layer, and the conductive layer constitute a capacitor structure; and an interlayer dielectric layer, disposed between the source metal layer and the semiconductor substrate and between the gate metal layer and the conductive layer.