OPTICAL WAVEGUIDE TRENCHES IN COMPOSITE INTEGRATED CIRCUITS

摘要

High quality epitaxial layers of compound semiconductor materials (26) can be grown overlying large silicon wafers(22) by first growing an accommodating buffer layer (24) on a silicon wafer. The accommodating buffer layer is a layer of monocrystalline oxide spaced apart from the silicon wafer by an amorphous interface layer (28) of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline compound semiconductor layer. Any lattice mismatch between theaccommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer. Trenches (1038,1042,1046) in composite integrated circuits (1034) are provided that may be used for electrical isolation and strain relief. The trenches (1050,1052,1054) may also be implemented as optical waveguides to carry optical signals on- or off-chip.