Abstract: A novel structure with multiple equipotential rings(MER-LDMOS) for shielding the influence of a high voltage interconnection(HVI) is proposed,and its shielding model is explained and proved with 2D device simulation.The influences of various factors on the breakdown voltage of MER-LDMOS are discussed in detail,including the p-top dose,the length of equipotential ring,the distance between the equipotential rings,and the thickness of the SiO2.A significant increase in the breakdown voltage is realized using the MER-LDMOS structure,and its breakdown voltage increases by more than 100% compared with that of conventional LDMOS.Furthermore,the proposed structure has the advantages of simple fabrication,large process tolerance,and small leakage current.It is a new method for shielding the influence a high voltage interconnection in a high voltage integrated circuit.

Key words: high voltage interconnection, equipotential rings, breakdown voltage, LDMOS