High speed and high responsivity germanium photodetector integrated in a Silicon-On-Insulator microwaveguide

We report the experimental demonstration of a germanium metal-semiconductor-metal (MSM) photodetector integrated in a SOI rib waveguide. Femtosecond pulse and frequency experiments have been used to characterize those MSM Ge photodetectors. The measured bandwidth under 6V bias is about 25 GHz at 1.55 microm wavelength with a responsivity as high as 1 A/W. The used technological processes are compatible with complementary-metal-oxide-semiconductor (CMOS) technology.