Integrating InP membranes on silicon-on-insulator via tunnel epitaxy for silicon photonics

In this work, we present a tunnel epitaxy platform to integrate III–V membranes with the silicon (Si) waveguide layer on silicon-on-insulator substrates. Using metal-organic vapor-phase epitaxy, we demonstrate uniform, nearly dislocation-free InP membranes with the size of several hundred micrometers in length and a few micrometers in width. The InP membranes are positioned above Si waveguides with a thin SiN layer in between, closely resembling the vertical integration of III–V/Si bonded structures. Simulation studies reveal the versatility of the platform in fabricating hybrid modulators as well as membrane lasers with novel lateral junctions. Characterizations of the InP membranes by transmission electron microscopy and electron channeling contrast imaging show high crystalline quality. Room-temperature lasing from an InP Fabry–Pérot laser further confirms the excellent optical quality. This platform therefore offers a promising, fully epitaxial solution for next-generation Si photonics technologies.