Release of epitaxial layers grown on InAs substrates

We present a process for selectively releasing large area epitaxial layers from InAs substrates. The technique employs the extreme selectivity between InAs and GaSb when etched by hydrochloric acid. The etch-stop layer isa strain-compensated superlattice containing GaSb. It is sandwiched between the desired epitaxial layer and the InAs substrate to effectively stop the etch process, leaving the desired epitaxial layer with high surface and crystal quality after the process. The etch-stop layer can be further etched away. The epitaxial thin film had been successfully grafted to a GaAs substrate by van der Waals bonding.