Optimum Concentration of InSb Photodiode for Minimum Low Reverse Bias Leakage Current

摘要

We have investigated a relation between the impurity concentration and the leakage current for three types of InSb diodes. They were fabricated with different impurity concentrations on both sides of the junction such as p - n, p^+ - n; and p^+ - n+ in order to achieve the minimal level of noise. It is shown that the leakage current at a low reverse bias has a minimum for the p^+ - n diode structure (impurity concentration of order of 2х10^15 cm^-3 for the n-type and 1х10^18 cm^-3 for the p-type). Increasing the impurity beyond these values may cause the tunneling at a low reverse bias voltage close to zero, and decreasing the impurity causes increasing the diffusion current.