High performance germanium-on-silicon detectors for optical communications

S. Famą, L. Colace, G. Masini, G. Assanto, and H-C. Luan

Appl. Phys. Lett. 81, 586-588 (2002)


We demonstrate fast and efficient germanium-on-silicon p-i-n photodetectors for optical communications, with responsivities as high as 0.89 and 0.75 A/W at 1.3 and 1.55 µm, respectively, time response <200 ps and dark currents as low as 1.2µA. Ge was epitaxially grown on Si by Chemical Vapor Deposition, employing a low temperature buffer and cyclic thermal annealing to reduce the dislocation density. The overall performance is well suited for >2.5 Gb/s integrated receivers for the 2nd and 3rd fiber spectral windows.