The current leakage mechanism in InSb p+n diodes

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Abstract
The effect of different passivation processes, i.e., anodic oxidation and/or photochemical deposition of SiO2 on the current‐voltage characteristics of the InSb p+n diodes was studied. By applying different voltages on the gate electrode over the p+n junction periphery, various kinds of current‐voltage characteristics can be induced, including multiple negative differential resistance in forward bias. This strongly indicates that the major part of the current, especially the reverse leakage current, flows through the surface of the p+n junction. Tunneling due to field emission from the valence band of the p+ layer into a field‐induced inversion layer at the InSb/oxide interface in which the energy levels are quantized is responsible for the multiple negative differential resistance. Reverse leakage current as low as 20 μA/cm2 at −1.1 V for a p+n type diode with n‐type doping concentration of 2×1015cm−3 could be easily achieved by applying a gate voltage of −9 V. It is also found that diodes with similar performance can be fabricated by properly adjusting the photochemical vapor deposition passivation process.