A Low Noise Planar-Type Avalanche Photodiode using a Single-Diffusion Process in Geiger-Mode Operation

We report the performances of a planar-type Geiger-mode InGaAs/InP avalanche photodiode (APD) using a single-diffusion process based on a single wet recess-etching technique at a wavelength of 1.55 µm. The recess-etched window region is found to have a smoothly etched sidewall with a large slope width of 0.9 µm. The Geiger-mode characteristics have been measured at 240–280 K for a 20 µm diameter device. The fabricated Geiger-mode APD shows a low dark count probability (DCP) per gate pulse of 2.8×10 -3 , a high photon detection efficiency (PDE) of 17.4%, and a low noise equivalent power (NEP) of 1.74×10 -16 W/Hz 1/2 at 240 K. The results are the first demonstration of a planar-type single-diffused Geiger-mode APD using a single wet recess-etching.