Process optimization of IR detectors based on In(Ga)Sb QDs in InAs matrix

Abstract: This diploma project has been focused on optimization of the D2B IR detector fabrication process using different mesa sidewall treatments and passivation methods. X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscope (AFM) measurements have been carried out on samples treated by different wet etching methods, to analyze their surface chemical composition and roughness. The surface roughness has been improved by critic etching, annealing and NaClO sequential treatment steps. Then these results have been utilized to improve the process of the D2B IR detectors. The dark current of the fabricated detectors passivated with various techniques have been characterized by I-V measurements at low (77 K) and room temperatures. The dark current mechanisms owing to surface shunt or bulk leakage are investigated by dark current temperature dependence analysis. By photoresist passivation devices with least leakage current are achieved.