Silicon-on-insulator waveguide photodetector with self-ion-implantation-engineered-enhanced infrared response

We describe the fabrication and characterization of silicon-on-insulator, p(+)-i-n(+) waveguide photodetectors with enhanced sensitivity to wavelengths around 1550 nm. Increased sensitivity to sub-band-gap light results from the deliberate introduction of mid-band-gap defects via 1.5 MeV silicon-ion implantation to a dose of 1 x 10(12) cm(-2). For a waveguide of length of 6 mm. an on-chip signal of 3.5 dBm generates a photocurrent of 5 mu A while the defect-induced excess optical absorption is 8 dB. Postimplantation annealing at a-temperature of 300 degrees C for 10 min increases the photocurrent to 19 mu A, corresponding to a responsivity of 9 mA/W, while reducing the excess loss to 2 dB. The devices described here are completely compatible with standard silicon processing and can be integrated easily with other photonic and electronic functionalities on the same silicon substrate. (c) 2006 American Vacuum Society.