Design of cost-efficient ESD clamp circuits for the power rails of CMOS ASIC's with substrate-triggering technique

Four new device structures for power-rail ESD clamp circuits by using the substrate-triggering technique are investigated in submicron CMOS technology to improve ESD level of the protection device within a smaller silicon area. Experimental results in a 0.6-/spl mu/m CMOS process have verified that the ESD clamp circuit with the double-BJT structure can provide 200% higher ESD robustness in per unit layout area as comparing to the previous design with the NMOS device.