InGaAsP/InP Geiger-Mode Avalanche Photodiode Towards Sub-kHz Dark Count Rate at 20% Photon Detection Efficiency

Geiger-mode InGaAsP/InP single photon avalanche photodiode (SPAD) with a low dark count rate (DCR) of 870 Hz at a photon detection efficiency (PDE) of 20% at 1064 nm is achieved for a 40 micron diameter device at -30 degrees C. Extensively optimized and accurately controlled shallow/deep two-step pn junction and doping profiles are identified to play decisive roles for the performance improvement. While a state-of-the-art specific detectivity of 1.4x10(14) cm center dot Hz(1/2)/W is realized for the optimized SPAD, a temperature coefficient of the breakdown voltage (V-br) of 139 mV/K, a dark current of 200 pA at 90%V-br and a timing jitter of 280 ps at 20% PDE are also simultaneously attained. Thermal activation energies of approximate 0.5 eV are observed for both the dark current and the DCR at 253-293 K, indicates the dominant source of dark carriers is the mid-gap defect trapping states-related tunneling in the InGaAsP absorber.