A lightly doped shallow junction extension for the high breakdown voltage by double diffusion process using the taper SiO/sub 2/ mask

A new Field Plate (FP) structure with taper oxide and shallow low doping region at the p-n junction edge, is proposed. The proposed structure relaxes the electric field crowding effect at the p-n junction of the FP structure by performing the high energy and low dose implantation through the taper SiO/sub 2/ implant mask. The fabricated p/sup +/-n diodes with the taper oxide and lightly doped junction extension structure, have a breakdown voltage of 500 V while the breakdown voltage of the conventional FP structure is 280 V. Also, numerical simulation shows that the termination area of the proposed structure is the 70% of that of the field limiting ring structure.