Analytical Model for Key Electrical Parameter of Superjunction VDMOS

Breakdown voltage (V _B ) and on-resistance (R _ON) are the key electricity parameters of Vertical Double-diffused Metal Oxide Semiconductor Field-effect Transistor (VDMOS). Compared with conventional VDMOS, the on-resistance of Superjunction (SJ) VDMOS can be reduced by one-fifth under the same breakdown voltage. In this paper, the potential equation of SJ-VDMOS is obtained based on device physics theory firstly. Then, we establish the analytical model of SJ-VDMOS for the relations between the key electrical parameter (breakdown voltage and on-resistance) and geometry accompanied by materials physics parameter. The results show that: (1) The breakdown voltage first increases then decreases with the increasing doping content of SJ-VDMOS; (2) The breakdown voltage increases with the increasing P depth of SJ-VDMOS at low doping content. However, it first increases then decreases with the increasing P depth of SJ-VDMOS at high doping content; (3) The breakdown voltage increases with the decreasing P lateral scale of SJ-VDMOS; (4) Due to the contradiction between breakdown voltage and on-resistance, there are the relations between the on-resistance and geometry and materials physics parameter. Our optimized results will provide important theoretical references to design and produce SJ-VDMOS.