Figure 2: Transverse scan from a QW structure highlighting the specular and diffuse scattering from the sample. Also, the specular omega-2theta scan of the structure. Figure 5: Summary of the interface roughness obtained by AFM and XRR for each sample. (Here the [11 -20] direction of the sample was perpendicular to the scattering plane.) Figure 6: RMS roughness obtained by XRR for different azimuthal angles Phi , with Phi = 0 deg corresponding to the [11- 20] direction of the sample perpendicular to the scattering plane. Figure 7: Comparison between the RMS roughness obtained by XRR (full line) and the standard deviation of the height gradient obtained from AFM scans (dotted line).