Influence of pixel mesa structure on the performance of InGaAs focal plane array detectors

In this paper, the research and analysis of mesa-type InGaAs FPA detectors with various pixel structures were reported. Three different pixel mesa structures in FPA were designed, including conventional mesa structure, double-mesa and surface pn junction mesa. The numerical simulation of above three pixel mesa structure devices and the conventional pixel planar structure device was carried out, and the optimal pixel structure was determined by comparing the electrical crosstalk and dark current. The results showed that the surface pn junction mesa structure can reduce the surface leakage current of the device by effectively suppressing the electric field of the device mesa etched surface, which was beneficial for reducing the difficulty of passivation protection process. InGaAs FPA detectors with surface pn junction mesa structure can simultaneously have relatively low electrical crosstalk and low dark current characteristics.