Advances in the field of poly-Ge on Si near infrared photodetectors

G. Masini, L. Colace, F. Galluzzi, and G. Assanto

Mat. Sci. Eng. B 69-70, 257-259 (1999)


We report on the fabrication and characterization of near infrared photodetectors integrated on silicon substrates where the active layer is a thermally evaporated polycrystalline germanium. We present our recent results in the effort to enhance the optoelectronic properties of the poly-Ge film in terms of uniformity for multiple device integration, speed and responsivity. In particular we demonstrate a 16 pixel linear array, a speed of photoresponse of about 650ps and an enhancement of responsivity by a factor of four. The fabrication process, including substrate cleaning and preparation, requires temperatures lower than 300C being fully compatible with silicon technology.