X-ray-diffraction measurement of interface structure in GaAs/Si(001)

Abstract

We have developed an x-ray-diffraction technique that provides depth sensitivity to the near-interface region of a thick, nonregistered film. By measuring the intensity profiles along the Si[00l] substrate crystal truncation rods, we compare the diffraction from the Si/GaAs interface with a model based on a grid of misfit dislocations. We find that the interface atoms have a root-mean-square displacement of 1.09\ifmmode\pm\else\textpm\fi{}0.10 \AA{} and that the interface has a roughness of 2.9\ifmmode\pm\else\textpm\fi{}1.0 \AA{}. The diffraction indicates an anomalously small strain perpendicular to the interface in the GaAs near the interface.