US Patent 7759734 Semiconductor device

A semiconductor device including a plurality of doped regions, a metal layer and a polysilicon layer is provided. The doped regions are disposed in a substrate. The metal layer includes a plurality of metal line patterns. The polysilicon layer disposed between the substrate and the metal layer includes a gate pattern and at least one guard ring pattern. The at least one guard ring pattern connects to the gate pattern and surrounds at least one of the metal line patterns. One of the metal line patterns connects to the gate pattern. The others of the metal line patterns connect to one of the doped regions in the substrate.