Fabrication and Characterization of a Back-Illuminated Resonant Cavity Enhanced Silicon Photo-Detector Working at 1.55 mu m

In this article, the realization and characterization of a new kind of resonant cavity enhanced photo-detector, fully compatible with silicon microelectronic technologies and working at 1.55 mu m, are reported. The detector is a resonant cavity enhanced structure incorporating a Schottky diode, and its working principle is based on the internal photo-emission effect. A comparison between a Schottky diode (Al/Si or Cu/Si) and the Schottky diode fed on a high-reflectivity Bragg mirror is carried out. Considering Al as Schottky metal, no difference in responsivity is obtained; considering Cu as Schottky metal, a three-fold responsivity improvement is experimentally demonstrated.