Patent attributes
A semiconductor device includes a substrate, a buried doped layer, a first doped well, a multiplication region and a first contact doped region. The substrate has a first doping type, wherein the substrate includes a surface. The buried doped layer is in the substrate and exposed from the surface of the substrate, wherein the buried doped layer has a second doping type opposite to the first doping type. The first doped well is over the buried doped layer, wherein the first doped well has the first doping type. The multiplication region is proximal to an interface between the buried doped layer and the first doped well. The first contact doped region is over the first doped well, wherein the first contact doped region has the first doping type and a doped concentration higher than a doped concentration of the first doped well.