InSb photodiodes, with high reverse breakdown voltage

Sensitive diffused indium antimonide mesa type photodiodes with very high reverse breakdown voltage have been developed for IR scanistor applications. Capacitance-voltage measurements at liquid nitrogen temperature indicate a C^-3dependence on applied reverse bias voltage, proving the pn junctions to be graded. Most devices exhibit values of reverse breakdown voltage in the range of 20 and 30 volts. These values are higher than previously reported in the literature for indium antimonide diodes. The breakdown mechanism can be explained as an avalanche effect and observed high breakdown voltages are due to the graded junction structure. Current voltage characteristics of typical devices at liquid nitrogen temperatures will be discussed.