X-RAY STANDING-WAVE AND HIGH-RESOLUTION X-RAY-DIFFRACTION STUDY OF THE GAAS INAS/GAAS(100) HETEROINTERFACE/

The composition profile of a InAs monolayer buried in a GaAs matrix is studied by combining high-resolution x-ray diffraction and x-ray stan ding-wave experiments. This combination provides a comprehensive struc tural analysis in terms of strain status, layer thickness, and interfa cial atomic configuration of this extremely thin layer. We found the I nAs layer to be pseudomorphically matched to the GaAs host crystal. Mo reover, we measure a total amount of In (6.739 x 10(14) atoms/cm2) dis tributed, at the heterointerface, within 3 monolayers in the following percentages: 75% in the first monolayer and 20% and 5% in the second and third, respectively. The In atoms are not randomly distributed as they would be in GaxIn1-xAs alloy, but form InAs terraces. Finally, th ese results demonstrate the growth procedure employed to be very effic ient in minimizing the impact of In segregation.