Dark current reduction in InAs/InAsSb superlattice mid-wave infrared detectors through restoration etch

An investigation on the suppression of surface-related dark current in InAs/InAsSb superlattice mid-wave infrared detectors with pin architecture through the optimisation of device fabrication scheme is presented. In particular, the `restoration´ chemical etch for the removal of redeposited dry etch by-products that resulted in more than order of magnitude dark current level reduction is utilised. Further, electrochemical sulphur passivation was applied with no substantial effect on device performance. Thus, different passivation schemes shall be developed for the InAs/InAsSb-based detectors.