GaInAs/InP PIN Photodiodes Fabricated by MOVPE and a New Zn Diffusion Technique

Abstract
GaInAs/InP photodiodes were fabricated by selective zinc diffusion using dimethylzinc as a zinc source to form the p+-region and selective p+-GaInAs growth to produce good ohmic contacts using low-pressure MOVPE. These photodiodes have an external quantum efficiency of 60–80% in the 0.95–1.55 µm-wave-length range, and a dark current of about 30 pA at -2 V and a -3 dB cutoff frequency of 1.4 GHz at 0 V were measured for 110 µm-diam diodes. These results show that this diffusion method is a useful process for fabricating photodiodes or other optical devices.