Schottky Photodetector Integration On Locos-Defined Soi Waveguides

Ni/nSi and Pt/nSi Schottky barrier diodes have been integrated with SOI optical waveguides produced using the Local Oxidation of Silicon (LOCOS) technique. The smooth, nearly planar topography provided by LOCOS allows the Schottky metal to overlap the waveguide rib while still giving low leakage current densities (<10(-5) Acm(-2) for Ni and <10(-7) Acm(-2) for Pt at 1 V reverse bias). Correcting for input coupling loss, responsivities of 4.7 mA/W and 4 mu A/W were obtained for 500 mu m long Ni and Pt diodes respectively at 1310 nm. At 1550 nm the responsivity for Ni was 1.8 mA/W while Pt did not give a measureable response.