Silicon carbide rectifying diode

The fabrication and operation of a p(+)-n-n(+) SiC rectifying diode are reported. Epitaxial n-type SiC films of thickness 3-5 microns and excess donor density (EDD) (5-20) x 10 to the 16th/cu cm are grown by a sandwich method on (0001) surfaces of monocrystalline SiC-6H wafers with EDD = about 10 to the 19th/cu cm; p-n junctions are formed by 95-keV implantation of Al at 5 x 10 to the 16th/sq cm and annealing; 300-400-micron-diameter mesa structures are plasma-chemical etched in an RF glow discharge; and p and n contacts of Al and Cr, respectively, are applied. The performance parameters are shown in graphs and characterized in detail. The diodes are found to have forward current in excess of 500 mA and avalanche breakdown voltage 200-350 V, with thermal breakdown at dc reverse currents of a few tens of mA and no microplasma emission characteristics at subbreakdown voltages.