Design, Fabrication and Characterization of 6.5kV/100A 4H-SiC PiN power rectifier

Silicon carbide (SiC) materials have excellent physical properties and a wide range application prospects in the high-voltage devices field. A high-voltage 6.5kV/100A 4H-SiC PiN rectifier is designed, fabricated and characterized in this paper. The termination adopts a combination of mesa structure and multi-ring auxiliary modulation junction termination extension (MAM-JTE). The MAM-JTE expands the ion implantation dose window and increases the breakdown voltage. Compared with the traditional double-zone JTE (DZ-JTE), MAM-JTE does not require additional process steps and masks. The two-dimensional numerical simulation tool TCAD Silvaco is used to design and optimize the termination structure. The 6.5kV SiC PiN power rectifier adopts high-voltage metal ceramic package and the active area of chip is 4.6×4.6mm
²
. The device test results show that the breakdown voltage(BV) reaches 7.4kV, corresponding to 93% of an ideal parallel plane junction, the forward voltage drop(V
F
) is 3.78V (corresponding to 100A forward current), the differential specific on-resistance(R
ON, SP
) is 2.5mn.cm
²
(corresponding to 100A/cm
²
forward current density), and the Baliga's figure of merit (BFOM) is 21.9GW/cm
²
. In addition, the reverse recovery time is 166ns and softness factor is 1.23 at room temperature. The high termination efficiency shows that the termination structure combining the mesa and MAM-JTE is of great significance to the development of high-voltage SiC devices.