Fully passivated AR coated InP/InGaAs MSM photodetectors

Abstract
We report on a technique for antireflection (AR) coating and surface passivation of InP:Fe/InGaAs:Fe metal-semiconductor-metal (MSM) photodetectors using nonreactive radio frequency (RF) magnetron sputtered silicon nitride. Excessive leakage currents and photocurrent gain, major performance-limiting factors of unpassivated detectors, were strongly suppressed in this way. The influence of various chemical pretreatments including sulfide passivation applied to the InP:Fe surface prior to the low-temperature silicon nitride deposition in optimizing the passivating process is investigated.