Patent ID: 8129782

Claim:
A high-voltage transistor comprising: a substrate with a source, a drain, and a gate electrode above a channel region formed between the source and the drain; a well of a first conductivity type arranged in the substrate, the substrate having a second conductivity type; a well of the second conductivity type located adjacent to the well of the first conductivity type; a drain diffusion of the first conductivity type located above the well of the first conductivity type; a source diffusion of the first conductivity type located above the well of the second conductivity type; a further well of the first conductivity type located between the drain diffusion and the well of the first conductivity type, the further well of the first conductivity type having a lower doping concentration than the drain diffusion and a higher doping concentration than the well of the first conductivity type; and a further well of the second conductivity type located between the source diffusion and the well of the second conductivity type, the further well of the second conductivity type having a higher doping concentration than the well of the second conductivity type.