AUTHOR=Debnath Kapil , Khokhar Ali Z. , Boden Stuart A. , Arimoto Hideo , Oo Swe Zin , Chong Harold M. H. , Reed Graham T. , Saito Shinichi 

TITLE=Low-Loss Slot Waveguides with Silicon (111) Surfaces Realized Using Anisotropic Wet Etching

JOURNAL=Frontiers in Materials

VOLUME=3

YEAR=2016

URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2016.00051

DOI=10.3389/fmats.2016.00051

ISSN=2296-8016

ABSTRACT=<p>We demonstrate low-loss slot waveguides on silicon-on-insulator platform. Waveguides oriented along the (11-2) direction on the Si (110) plane were first fabricated by a standard e-beam lithography and dry etching process. A tetramethylammonium hydroxide-based anisotropic wet etching technique was then used to remove any residual side wall roughness. Using this fabrication technique, propagation loss as low as 3.7 dB/cm was realized in silicon slot waveguide for wavelengths near 1550 nm. We also realized low propagation loss of 1 dB/cm for silicon strip waveguides.</p>