Investigation of Electrical and Luminescent Properties of Diffused and Epitaxial p-n Junctions in Aluminum-Doped Silicon Carbide

Abstract

An investigation was made of the current-voltage, luminescence intensity-voltage, capacitance-frequency, luminescence intensity-current, and relaxation characteristics of p-n junctions in silicon carbide. These junctions were prepared by the diffusion of aluminum from the gaseous phase or from solutions in rare-earth elements, as well as by the epitaxial growth of aluminum- or nitrogen-doped p- and n-type SiC films on SiC crystals of the opposite type of conduction (the crystals were also doped with nitrogen and aluminum). A comparison of these characteristics for high-resistivity and low-resistivity samples showed that the junctions in the low-resistivity samples were abrupt and the compensated regions in these samples were thin and had a relatively low resistivity. The fast response, high luminescence efficiency at current densities ≥20–50 A/cm2, and the low noise of the low-resistivity diffused and epitaxial p-n junctions in aluminum-doped silicon carbide should be very useful in their applications as sources of nanosecond light pulses.