Surface passivation of random alloy AlGaAsSb avalanche photodiode

Abstract AlGaAsSb attracts significant interest for near‐infrared avalanche photodiodes (APD). The authors report a two‐order reduction in the dark current and six‐time enhancement of gain random alloy (RA) APD that is surface passivated by conformal coating Al 2 O 3 via atomic layer deposition (ALD). currents APDs with 400‐µm diameter (dry etched) at 90% breakdown voltage (0.9 V br ) are (5.5 ± 0.5) × 10 −5 A, (2.1 0.4) (6.2 0.8) −7 A non‐passivated, Si N 4 passivated, devices, respectively. device 1 −8 which comparable to reported value 100‐µm mesa diodes SU‐8. Maximum values 6, 12, 35 were obtained Moreover, punch‐through capacitance 8 pF spectral response 450 850 nm was obtained. Thus, passivation can be best solution antimonide optoelectronic devices.