Low-loss, high-voltage 6H-SiC epitaxial p-i-n diode

The p-i-n diodes were fabricated using 31 μm thick n^-- and p-type 6H-SiC epilayers grown by horizontal cold-wall chemical vapor deposition (CVD) with nitrogen and aluminum doping, respectively. The diode exhibited a very high breakdown voltage of 4.2 kV with a low on-resistance of 4.6 mΩcm². This on-resistance is lower (by a factor of five) than that of a Si p-i-n diode with a similar breakdown voltage. The leakage current density was substantially lower even at high temperatures. The fabricated SiC p-i-n diode showed fast switching with a turn-off time of 0.18 μs at 300 K. The carrier lifetime was estimated to be 0.64 μs at 300 K, and more than 5.20 μs at 500 K. Various characteristics of SiC p-i-n diodes which have an advantage of lower power dissipation owing to conductivity modulation were investigated.