Wet chemical separation of low-temperature GaAs layers from their GaAs substrates

We reported a method of the wet chemical separation for low-temperature (LT) GaAs epitaxial layers grown by molecular beam epitaxy from their substrates. Samples with AlAs as well as AlGaAs etch-stop interlayers were used in this study, but better properties have been found for the samples with AlAs. Very interesting dependence of etching rate of the citric acid based etchant on the sample growth temperature is reported. For illustration of usefulness of this method, the temperature dependencies of the resistivity and Hall mobility measured on four separated LT-GaAs layers are presented.