Determination of thicknesses and interface roughnesses of GaAs-based and InAs/AlSb-based heterostructures by X-ray reflectometry

Abstract

We present the X-ray reflectometry technique as a unique tool for the assessment of individual layer thicknesses inside complicated structure stacking of semi-conductors heterostructures. In particular, the use of an inverse fast Fourier transform applied to the reflectivity curve allows the fast determination of the layer thicknesses and the use of a simulation allows the determination of both interfacial roughnesses and individual layer thicknesses. We demonstrate the capability of this method by reporting X-ray reflectometry study on a novel AlGaAs-based waveguide with complicated structure stacking and on InAs/AlSb-based superlattices. Typical layer thicknesses from 0.5 to 500nm were successfully investigated.