High performance InGaP Geiger-mode avalanche photodiodes

In the past decades significant improvement of the performance of III-V Geiger-mode APDs (GmAPD) has been achieved in Near Infrared (NIR) and Short Wavelength Infrared (SWIR) wavelengths. In order to meet the challenge to GmAPDs in visible wavelength for some special military and space applications, Acqubit developed a GaAs-based InGaP APD with a substrate removal structure. With a proprietary mesa passivation process, very low dark current, ~0.5 nA in a 50 um diameter device or 25 uA/cm2, was demonstrated just before breakdown at room temperature. Sufficient device thickness ensured an external quantum efficiency (QE) about 50% at 532 nm without a bottom reflector. The combination of mesa structure and substrate removal process greatly suppressed the array pixel crosstalk and afterpulsing while maintaining a high QE and photon detection efficiency (PDE). In this paper we will report the progress of the GmAPD detectors and arrays with low DCR and high PDE at 532 µm.