Effects of oxide formation around core circumference of silicon-on-oxidized-porous-silicon strip waveguides.
We have studied the effect of oxidation on the propagation loss and surface roughness of silicon-on-oxidized-porous-silicon strip waveguides fabricated using proton-beam irradiation and electrochemical etching. A thin thermal oxide is formed around the core of the waveguide, enabling the symmetric reduction of core size and roughness on all sides. Significant loss reduction from about 10 dB/cm to 1 dB/cm has been obtained in TE and TM polarizations after oxidation smoothening of both the bottom and the sidewalls by 20 nm. This corresponds well with simulations using the beam-propagation method that show significant contributions from both surfaces.
Centre for Ion Beam Applications, Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore. phytej@nus.edu.sg
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Bettiol