Studies of Dark Current Reduction in InAsSb Mid-Wave Infrared HOT Detectors through Two Step Passivation Technique

Abstract

We report on the investigation of the surface leakage current for InAs1−xSbx (x = 0.09) high operation temperature photodiode grown on GaAs substrate in accelerated short-term stability test. The electrochemical passivation technique was proposed to modify the mesa sidewalls properties and obtain anodic sulphur coating covered by SU-8 negative photoresist. The electrical behavior of sulphur anodic film, SU-8 photoresist, and unpassivated devices was compared for devices in variable area diode array test. The surface resistivity for anodic sulphur film, SU-8 and unpassivated devices are equal to 1080, 226, 10200 kΩcm, respectively, at 150 K and 1340, 429, 2870 kΩcm, respectively, at 150 K after an exposure of 20 h to atmosphere at 373 K. The Auger recombination process was evaluated as the main mechanism of diffusion current in HOT devices.

Study of the Effectiveness of Anodic Films as Surface Passivation for InAsSb Mid-Wave Infrared HOT Detectors

“…What is more that results indicates that the surface leakage current is not a dominant dark current mechanism at HOT conditions. In that case the passivation layer in bulk barrier diode might play a main role as mechanical barrier to atmosphere, production technology, and might be crucial for long-term stability studies [11]. The XPS measurements confirmed the destructive nature of fluorine treatment.…”

Bulletin of the Polish Academy of Sciences: Technical Sciences

“…In addition, these substrates are more affordable and available as large size "epi-ready" wafers up to 6 inch in diameter. Transparent GaAs substrate allows for the backsided device illumination and fabrication of monolithic optical immersion [7].…”