DYNAMIC CHARGE STORAGE IN 6H SILICON-CARBIDE

pn-junction storage capacitors have been fabricated in 6H silicon carbide. The charge decay is dominated by surface generation at the mesa edges, and the storage time strongly depends on the method of surface passivation. Charge recovery is thermally activated. Devices passivated by dry oxidation and by wet oxidation exhibit activation energies of 0.66 and 1.48 eV, respectively. As a figure of merit, extrapolation of the dry-oxide data gives a room-temperature storage time of 10(6) S, while extrapolation of the wet-oxide data gives a room-temperature storage time of 10(14) S.