Simulation, Fabrication and Characterization of 3300V/10A 4H-SiC Power DMOSFETs

Power devices of the 3.3 kV class are of much interest to various industries, particularly rail transportation and industrial medium voltage motor drives. In this paper, 4H-SiC power DMOSFETs with breakdown voltage higher than 3.6 kV has been successfully fabricated by using an. 30 μm-thick, 2.8×10 ¹⁵ cm ^-3 doped drift epilayer. The JFET regions were implanted with nitrogen ions to minimize the current spreading resistance. A 4H-SiC DMOSFET with an active area of 0.08 cm ² showed a specific on-resistance of 19.7 mΩ-cm ² at room temperature with a gate bias of 20 V. The device shows a leakage current of 23 μA, which corresponds to a leakage current density of 142μA/cm ^-2 at a drain bias of 3.3 kV. In this report, the influence of JFET region width to the DMOSFETs on-state current density was studied by a test MOSFET with an active area of 8.0×10 ^-4 cm ² .