Si-based near infrared photodetectors operating at 10 Gbit/s

We report on fast p–i–n near infrared photodetectors in pure germanium on silicon. The diodes were fabricated by chemical vapor deposition at 600 °C followed by thermal annealing at 900 °C. We also verified that bypassing the thermal treatment did not have significant effects on the resulting crystal quality, allowing to considerably reducing the thermal budget hence simplify the integration with silicon. We demonstrate the operation of photodiodes with responsivities of 0.4 and 0.2 A/W at 1.3 and 1.55 μm, respectively, as well as open-eye diagrams at 10 Gbit/s.