The Influence of InxGa1–xAs and GaAs1–yPy Layers Surrounding the AlAs Release Layer in the Epitaxial Lift-Off Process

In this paper, the influence of intrinsic strain on the epitaxial lift-off (ELO) process induced by local lattice mismatch is determined as a function of the composition variation of two In x Ga 1– x As or two GaAs 1– y P y layers surrounding the AlAs etch layer. For this purpose, samples were grown by metal organic chemical vapor deposition, etched using a weight-induced ELO process, and analyzed by differential interference contrast microscopy and atomic force microscopy. It is shown that the etch rate decreases significantly for increasing In and P fractions in the surrounding layers. Morphology examinations after the ELO process revealed a relatively smooth interface roughness for the GaAs and GaAs 1– y P y samples plus the In x Ga 1– x As samples over a composition range from x = 0 to x = 0.075, indicating that the growth mechanism is controlled by a two-dimensional (2D) layer-by-layer mode. For In 0.10 Ga 0.90 As samples, however, a transition from a 2D layer-by-layer to a three-dimensional (3D) islanding growth mode was obtained.