US Patent 10008489 Electrostatic discharge protection semiconductor device

An electrostatic discharge protection semiconductor device includes a substrate, a gate set positioned on the substrate, a source region and a drain region formed in the substrate respectively at two sides of the gate set, at least a first doped region formed in the drain region, and at least a second doped region formed in the substrate. The source region and the drain region include a first conductivity type, the first doped region and the second doped region include a second conductivity type, and the first conductivity and the second conductivity type are complementary to each other. The first doped region and the second doped region are electrically connected to each other.