Low Dark Current and High Speed InGaAs Photodiode on CMOS-Compatible Silicon by Heteroepitaxy

Abstract

Top-illuminated proof-of-concept indium gallium arsenide (InGaAs) photodiode (PD) array and high speed InGaAs PDs were realized on (001) silicon (Si) substrate by direct heteroepitaxy using metal–organic chemical vapor deposition. The PDs containing InGaAs active layer lattice-matched to InP were grown on Si substrates employing InP-on-Si template with growth technique including GaAs on V-grooved Si, thermal cycle annealing and strained layer superlattice defect filters. Dry etched mesa structure with polyimide passivation was implemented. 8 × 8 InGaAs PD arrays with mesa diameters of 20, 30 and 40 µm were realized on (001) Si, and their performances were benchmarked with identical devices on a native InP substrate. A low dark current density of 0.45 mA/cm² and a responsivity of 0.72 A/W at 1550 nm were measured for 40-µm-diameter device on Si. Directly modulation has also been performed showing a 3-dB bandwidth up to 11.2 GHz and open eye diagram up to 25 Gbps. The imaging performance of InGaAs PD arrays on Si were also demonstrated for the first time by capturing the output beam profile of a single mode fiber at 1550 nm.