A novel high voltage LDMOS for HVIC with the multiple step shaped equipotential rings

A novel high voltage LDMOS with multiple step shaped equipotential rings (MSSER-LDMOS) to compensate the influence of a high voltage interconnection (HVI) is proposed, and its shielding model is explained and proved by 2D device simulation. The influences on the breakdown voltage (BV) of MSSER-LDMOS have been discussed in detailed, including the P-top dose, spacing between the adjacent equipotential rings and field oxide charge in the drift region. The simulation results indicate that the breakdown voltage of MSSER-LDMOS can reach 11.7 V/μm. It is increased by 156% in comparison to conventional LDMOS with HVI.