Silicon resonant cavity enhanced photodetectors at 1.55 microns

Silicon optical receivers, operating at the optical communication wavelengths in the 1.3-1.55 mu m range, have attracted much research effort. Unfortunately, the performance of the devices proposed in literature are poor because this wavelength range is beyond the absorption edge of silicon. In order to extend the maximum detectable wavelength, the most common approach, in the realization of Si-based detectors, is the use of silicon-germanium layers on silicon, anyway, requiring processes non compatible with standard CMOS technology. In this paper, with the aim to extend the operation of silicon-based photo-detectors up to the 1.3-1.55 pm range, an alternative approach is investigated: we propose the design of a resonant cavity enhanced Schottky photodetector based on the internal photoemission effect. The device fabrication is completely compatible with standard silicon technology.