Metal-semiconductor-metal near-infrared light detector based on epitaxial Ge/Si

In this letter we report on a metal-semiconductor-metal photodetector based on thick relaxed Ge layers, epitaxially grown on silicon after insertion of a low-temperature-grown Ge buffer layer. The detector shows a good responsivity at normal incidence at both 1.3 and 1.55 mu m, with a maximum responsivity of 0.24 A/W at 1.3 mu m under a 1 V bias. A response time of about 2 ns has been measured. (C) 1998 American Institute of Physics.