Design consideration and fabrication of 1.2-kV 4H-SiC trenched-and-implanted vertical junction field-effect transistors

We present the design consideration and fabrication of 4H-SiC trenched-and-implanted vertical junction field-effect transistors (TI-VJFETs). Different design factors, including channel width, channel doping, and mesa height, are considered and evaluated by numerical simulations. Based on the simulation result, normally-on and normally-off devices are fabricated. The fabricated device has a 12 μm thick drift layer with 8× 10¹⁵ cm^-3 N-type doping and 2.6 μm channel length. The normally-on device shows a 1.2 kV blocking capability with a minimum on-state resistance of 2.33 mΩ · cm², while the normally-off device shows an on-state resistance of 3.85 mΩ ·cm². Both the on-state and the blocking performances of the device are close to the state-of-the-art values in this voltage range.