Experimental characterization of a 4H–SiC high voltage current limiting device

The aim of this paper is to show the first experimental results of a 600 V 4H–SiC current limiting device. This device limits the current which flows through it as the bias voltage between its two contacts increases. The static curves obtained from the first process run (T=300 K) show a current limitation capability with a saturation voltage ranging from 10 to 15 V. The device electrical characterization shows a RON≈150 mΩ cm2 and a current density of 150 A cm−2 under 50 V. The forward conduction is ensured by an N type implanted channel (doping species: nitrogen) on top of an P+ implanted layer (doping species: aluminum). The post-implantation annealing of 1700 °C/30 min leads to a good electrical activation (80%) of the Nchannel/P+ layer (analyzed by C(V) and SIMS methods) and a good channel mobility (100 cm2 V−1 s−1 for a 2×1017 cm−3 N compensated doping concentration). The prototypes of the second process run reach a saturation current density of 900 A cm−2 with a specific on-resistance of 13 mΩ cm2. The 4H–SiC current limiting devices of the second run belong to the best set of Accu-MOSFETs devices reported in the literature.