Semiconductor device

A semiconductor device includes a substrate, a P-type heavily doped region, a N-type heavily doped region, a P-type lightly doped region, a gate dielectric layer and a gate layer. The P-type heavily doped region is in the substrate. The N-type heavily doped region is in the substrate and adjacent the P-type heavily doped region. The P-type lightly doped region is in the substrate and wrapped around the P-type heavily doped region and the N-type heavily doped region. The gate dielectric layer covers parts of the P-type lightly doped region. The gate layer is on the gate dielectric layer.