Demonstration of heterogeneous III–V/Si integration with a compact optical vertical interconnect access

Heterogeneous III-V/Si integration with a compact optical vertical interconnect access is fabricated and the light coupling efficiency between the III-V/Si waveguide and the silicon nanophotonic waveguide is characterized. The III-V semiconductor material is directly bonded to the silicon-on-insulator (SOI) substrate and etched to form the III-V/Si waveguide for a higher light confinement in the active region. The compact optical vertical interconnect access is formed through tapering a III-V and an SOI layer in the same direction. The measured III-V/Si waveguide has a light coupling efficiency above ~90% to the silicon photonic layer with the tapering structure. This heterogeneous and light coupling structure can provide an efficient platform for photonic systems on chip, including passive and active devices.