Jongoh Kim

A novel trench shielded MOSFET with buried field ring for tunable switching and improved ruggedness

In this paper, a novel trench shielded 600V MOSFET with buried field ring is proposed and demonstrated. The proposed structure achieves an active area die shrink of 35-55% compared to a conventional 600V planar MOSFET. Furthermore, it almost doubles the Unclamped Inductive Switching (UIS) rated current and improves 0.3% of the efficiency compared to the Superjunction device. It also shows better diode reverse recovery performance than Superjunction device.

A novel Trench Fast Recovery Diode with injection control

A novel Trench Fast Recovery Diode (FRD) structure with injection control is proposed in this paper. The proposed structure achieves improved carrier profile without the need for excess lifetime control. This substantially improves the device performance, especially at extreme temperatures (-40 °C to 175 °C). The device maintains low leakage at high temperatures, and its Qrr and Irm do not degrade as is the usual case in heavily electron radiated devices. A 1600 diode using this structure is proposed in this paper, with a low Vf and good reverse recovery properties. The experimental results show that the structure maintains its performance at high temperatures.