Monolithic integration of a waveguide InGaAs/InP pin photodiode with a locally ion implanted JFET for receiver OEIC applications

The device fabrication for a monolithic integration of a waveguide (WG), a photodiode (PD) and a junction field-effect transistor (JFET) in the InGaAs/InP material system is described. In an optimised WG/PD layer sequence, grown by metal organic vapour-phase epitaxy (MOVPE), JFETs have been realised using local Si and Be ion implantations. The JFETs (1.5 μm × 200 μm) have a maximum transconductance of 160 mS/ mm and a cutoff frequency of 12 GHz. The PDs are vertically coupled to the InGaAsP WG by evanescent field coupling. They show a low dark current of 3 nA and a 3 dB bandwidth of 5 GHz at −10 V bias. With the presented layer structure, a transimpedance receiver OEIC with monolithically integrated WG has been realised. The receiver sensitivity is −27.3 dBm at a BER of 10−9 for 400 Mbit/s data rate.