Break-through of the Si limit under 300 V breakdown voltage with new concept power device: super 3D MOSFET

In this paper, we present a new conceptual power MOSFET named "super 3D MOSFET", breaking the R_on Si limit under 300 V breakdown voltage. It has a super wide current path in the depth direction of the substrate. The electrical characteristics of this device were verified by 3D device simulation. In the super 3D MOSFET with 30 μm current path width, the simulated results showed that the drift resistance was 6.6 mΩ-mm² for 70 V breakdown voltage. For this breakdown voltage, the R_on Si limit is 23 mΩ-mm². The total specific on-resistance containing the other elemental resistances was 19 mΩ-mm², and even this value was below the R_on Si limit. Moreover, we fabricated the super 3D MOSFET experimentally, and the I-V characteristics were verified.