Low dark current silicon-on-insulator waveguide metal-semiconductor-metal-photodetector based on internal photoemissions at 1550 nm

We report on the fabrication and characterization of a metal-semiconductor-metal photodetector operating at 1550 nm and integrated into a silicon-on-insulator waveguide. Detection uses internal photoemissions through a metal/Si interface. In particular, a small metal/Si contact layer directly deposited on the vertical output facet of the waveguide absorbs the incoming radiation confined into a rib waveguide. The device parameters for responsivity, dark current, and bandwidth take values 3.5 mA, 3.5 nA, and 1 GHz, respectively. The results obtained indicate device suitability in power monitoring and telecommunications applications.