Electrostatic discharge protection device

An ESD protection device may include a substrate, a first conductivity region arranged at least partially within the substrate, a second conductivity region arranged at least partially within the first conductivity region, third and fourth conductivity regions arranged at least partially within the second conductivity region, and first and second terminal portions arranged at least partially within the third and fourth conductivity regions respectively. The third and fourth conductivity regions may be spaced apart from each other. The substrate and the second conductivity region may have a first conductivity type. The first conductivity region, third conductivity region, fourth conductivity region and first and second terminal portions may have a second conductivity type different from the first conductivity type. The first and second terminal portions may have higher doping concentrations than the third and fourth conductivity regions respectively.