Epitaxial growth and layer transfer of InP via electrochemically etching / annealing of porous buried InP layers: A pathway for III–V substrate re-use

High crystalline quality InP is epitaxially grown on porous InP layers and characterized. Etching the wafers in hydrochloric acid with different concentrations and current densities create a dual layer porous structure with a more dense top layer for epitaxial growth and a buried porous layer. Annealing the structure forms voids in the buried layer. Epitaxial layers with thickness of about 2 μm were grown on dense layers. The layers grown were analyzed by transmission electron microscopy and high resolution x-ray diffraction and determined to be high quality single crystal layers. The porous samples created were bonded to PDMS substrates and the top layer was easily peeled off due to fracture through the high porosity layer. Layer transfer was also performed by gluing the samples to glass slides and pulling them apart. The transferred layers were characterized by scanning electron microscopy. These results point to the usefulness of porous III-V layers as templates for epitaxial growth and device transfer for solar cell applications.