The indentation response of GaAs[sbnd]AlAs heterostructures

Abstract

Low-load indentation has been used to investigate the deformation behaviour of a submicron layer of AlAs on a GaAs substrate. High-resolution scanning electron microscopy of cross-sections through the deformed regions under indentations into this structure reveals that the softer AlAs layer is not penetrated by the indenter and that unusual lateral cracking originates during the unloading phase. Data of intendation load against depth demonstrates the effect of the layer through the increase in composite hardness and elastic modulus with increasing load.