Ge-on-Si approaches to the detection of near infrared light

L. Colace, G. Masini, and G. Assanto

IEEE J. Quantum Electron. 35, 1843-1852 (1999)


We review our recent results on Ge-based near infrared photodetectors grown on silicon. We fabricated metal-semiconductor-metal photodetectors based on epitaxial pure-Ge grown on silicon by Chemical Vapour Deposition. Material characterization and device performances are illustrated and discussed. Exploiting a novel approach based on evaporation of polycrystalline-Ge on silicon, we also realized efficient near infrared photodiodes with good speed and sensitivity. Finally, multiple element devices were designed, fabricated and tested, such as a voltage-tunable wavelength-selective photodetector based on a SiGe superlattice and a linear array of 16 photodetectors in poly-Ge on Si.