DISTRIBUTION OF AS ATOMS IN INP INPAS (1-MONOLAYER) INP HETEROSTRUCTURES MEASURED BY X-RAY CRYSTAL TRUNCATION ROD SCATTERING/

The interfaces of InP/InPAs(1 monolayer)InP samples grown by organomet allic vapor-phase epitaxy were investigated by the x-ray crystal trunc ation rod scattering measurement. The distribution of As atoms around the InPAs heterolayer was clearly revealed in the atomic scale from th e measurement. It was shown that the distribution of As atoms into the layer under the InPAs layer was very small and that distribution of A s atoms in the InP cap layer was, on the other hand, noticeable and th e amount of As atoms was almost the same as that contained in the InPA s heterolayer. These results suggest that the extension of As atoms in the InP layer occurs due to the absorbed As atoms on the InPAs surfac e or As atoms remaining in the gas phase. Thus, to realize the abrupt InP/InPAs interface, the source-gas change sequence should be controll ed to be very abrupt. (C) 1997 American Institute of Physics.