Nanostructured silicon geometries for directly bonded hybrid III-V-silicon active devices

Abstract : We discuss geometries with nanostructured cladding for active InP/silicon structures made by hetero-epitaxial bonding, which means that InP is directly bonded to silicon from a silicon-on-insulator without any intermediate layer. Such a cladding features low-index confinement and adds thermal sinking channels to those practised on the InP side. The first approach is a one-dimensional effective medium viewpoint, easily showing why grooves parallel to the waveguide are better. Then, two dimensional nanostructures are examined and found to perform better, given etching constraints. A more sophisticated geometry balancing thermal and optical confinement merits is then introduced thanks to a flip-flop algorithm.