InAs on Insulator by Hydrogen Implantation and Exfoliation
InAs on insulator structures were successfully fabricated using wafer bonding and hydrogen implantation and exfoliation processes. Material was exfoliated from either a bulk InAs substrate or from a metamorphic InAs layer grown by MBE via a graded buffer layer on InP. The InAs from the bulk substrate exfoliates as a uniform planar layer with a large surface roughness, ~150 nm, which is similar to the estimated straggle. Under certain conditions, the InAs from the graded buffer layer, however, exfoliates non-uniformly, only transferring long wires of InAs that lie along a specific  direction. The size and spacing of these wires resemble the cross-hatch induced by the graded buffer layer growth indicating the exfoliation is influenced by dislocation strain fields. High resolution x-ray diffraction indicates that strain-free InAs is transferred in both cases, however, mosaic tilt is induced into the transferred layer by the hydrogen implantation step.