Yoshitaka Noda

600V-class Super Junction MOSFET with High Aspect Ratio P/N Columns Structure

A Super Junction (SJ) MOSFET with high aspect ratio p/n columns structure has been proposed to improve the trade-off relationship between breakdown voltage and specific on-resistance (Ron)- We have proposed a new trench filling epitaxial growth technique to fabricate this structure. In this work, we tried to apply this method to 600 V-class SJ-MOSFETs. We succeeded in fabricating p/n columns structure of which the aspect ratio is 25. It shows that its Ron is lower than that of IGBTs, and is the lowest in the reported 600 V-class Si devices.

200V Trench Filling Type Super Junction MOSFET with Orthogonal Gate Structure

A super junction (SJ) MOSFET which trench gates are orthogonal to p/n columns was fabricated to improve a tradeoff relationship between specific on-resistance (Ron) and gate-drain charge (Qgd). In this structure, a trench gate pitch and a p/n column pitch can be independently controlled. We experimentally demonstrated a dependence of Ron and Qgd on the orthogonal gate pitch. The experimental value of Ron*Qgd decreased with the increase of gate pitch, and this value of 0.16 OmeganC was achieved at the trench gate pitch of 10 mum and the p/n column pitch of 2.7 mum. This figure-of- merits (FOMs) value is about 36% lower than that of the previous reported for 200V SJ-MOSFETs. Moreover, the undamped inductive switching (UIS) endurance of this SJ- MOSFET was 24 mJ/mm2 and this result is 1.3 times stronger than that of conventional trench MOSFET.