This paper presents the design and fabrication of an effective, robust and process-tolerant floating guard ring termination on high voltage 4H-SiC PiN diodes.Different design factors were studied by numerical simulations and evaluated by device fabrication and measurement.The device fabrication was based on a 12μm thick drift layer with an N-type doping concentration of 8 1015cm 3. PC regions in the termination structure and anode layer were formed by multiple aluminum implantations. The fabricated devices present a highest breakdown voltage of1.4 kV, which is higher than the simulated value. For the fabricated 15 diodes in one chip, all of them exceeded the breakdown voltage of 1 kV and six of them reached the desired breakdown value of 1.2 kV.
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 8×1015cm-3N-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 m?·cm2, while the normally-off device shows an on-state resistance of 3.85 m?·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.
