Electrical characteristics of 4.5 kV implanted anode 4H-SiC p-i-n junction rectifiers

Abstract

4500 V 4H-SiC p-i-n junction rectifiers with low on-state voltage drop (3.3-4.2 V), low reverse leakage current (3/spl times/10/sup -6/ A/cm/sup 2/), and fast switching (30-70 ns) have been fabricated and characterized. Forward current-voltage measurements indicate a minimum ideality factor of 1.2 which confirms a recombination process involving multiple energy levels. Reverse leakage current exhibits a square root dependence on voltage below the punchthrough voltage where leakage currents of less than 3/spl times/10/sup -6/ A/cm/sup 2/ are measured. Reverse recovery measurements are presented which indicate the presence of recombination at the junction perimeter where a surface recombination velocity of 2-8/spl times/10/sup 5/ cm/s is found. These measurements also indicate drift layer bulk carrier lifetimes ranging from 74 ns at room temperature to 580 ns at 250/spl deg/C.