A superjunction structure using high-kinsulator for power devices: theory and optimization

A superjunction (SJ) structure using a high-k (Hk) insulator is studied and optimized by using an analytic model. Results by using the proposed model match well with that of numerical calculations. Numerical calculation results show that, only needing an Hk insulator with a permittivity of I = 5S, the optimum specific on-resistance of the MOSFET applying the proposed structure is about 8%–20% lower than that of the conventional SJ-MOSFET with VB = 200–1000 V. An example with VB = 400 V shows that, the permissible error range of doping concentration of the p-region to maintain above 80% of VB is from −37% to +32% for the former and is only from −13% to +13% for the latter.