Near infrared photodetectors based on <100> silicon substrates

We report the fabrication of e cient near-infrared photodetectors based on polycrystalline Ge &#174; lms on Sih100i. In view of integration with Si electronics, metal&#177; semiconductor&#177; metal photodiodes have been realized, for the &#174; rst time to the best of our knowledge, by low-temperature evaporation. The experiments performed on non-optimized devices indicate a substantial sensitivity at both 1.32 and 1.55 mm, with a responsivity as high as 16mAW&#161;1 at 1.32 mm with 0.2 V bias, and a time response of about 4 ns.