Near Infrared Waveguide Photodetectors Based On Polycrystalline Ge on SOI Substrates

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

Opt. Mater. 17, 243-246, (2001)


Polycristalline Germanium thermally evaporated on silicon has been demonstrated as a feasible way to the integration of fast near infrared photodetectors and functional devices on silicon substrates. However the use of such devices is currently limited to applications not critically depending on high responsivity. Several attempts are under investigation to overcome this problem: among them one of the most promising is the integration of the Poly-Ge photodetector with a waveguiding structure. This approach allows the distributed coupling of the incoming light to the thin sensitive layer of the poly-Ge/Si heterojunction thus increasing the effective absorption length. Moreover, waveguided photodetectors are well suited for fiber coupling of incident light.