A Drain-Extended MOS Device With Spreading Filament Under ESD Stress

Based on 3-D TCAD simulations, a ten-times improvement in the ESD performance of drain-extended NMOS device is predicted by incorporating deep p-implant underneath the n⁺ drain region. The proposed modification does not degrade the intrinsic MOS characteristics, thus enabling a self-protection ESD concept. Moreover, a detailed physical insight toward the achieved improvement is given.