Nanoindentation response of a thin InP membrane

Abstract

Small and thin InP membranes have been microfabricated and released on top of an InP substrate by photolithography, InGaAs preferential etching in InP/InGaAs/InP substructures and drying with CO2 at critical point. The mechanical response of the obtained 40 µm in diameter and 400 nm thin membranes could be tested at different loads by nanoindentation. While keeping their epitaxial orientation, delamination of the membrane occurred and then its cracking was detected as a pop-in on the loading curve under larger loads. Occurrence of delamination was detected using interferential microscopy. Transmission electron microscopy was used to get further insight into the deformation of the membranes.