Experimental Demonstration of a 650-V Superjunction MOSFET With Dual Schottky Contacts for Fast Reverse Recovery

In this article, we demonstrate the experimental results of a 650-V superjunction MOSFET (SJ-MOSFET) featuring dual Schottky contacts at the source side to reduce the reverse recovery charge ( <tex-math notation="LaTeX">Qᵣᵣ)</tex-math> of its body diode. The n-type Schottky contact suppresses the operation of the p-n junction, and the p-type Schottky contact lowers the hole injection efficiency further. Both of them reduce <tex-math notation="LaTeX">Qᵣᵣ</tex-math> . According to the experimental results, <tex-math notation="LaTeX">Qᵣᵣ</tex-math> of the proposed SJ-MOSFET (1.4 <tex-math notation="LaTeX">μ</tex-math> C) is 20.5% of that of the conventional device (6.8 <tex-math notation="LaTeX">μ</tex-math> C) and 38.9% of that of the device with only n-type Schottky contact (3.6 <tex-math notation="LaTeX">μ</tex-math> C). The forward voltage drop of its body diode is 0.91 V, which is 0.07 V higher than that of the conventional device and 0.09 V higher than that of the device with only n-type Schottky contact. These characteristics make it be suitable for high-speed switching applications.