INTERFACIAL STRAIN IN ALXGA1-XAS LAYERS ON GAAS

Detailed analysis of x-ray rocking curves was used to determine the depth profile of strain and composition in a 2500-A-thick layer of Al//xGa//1// minus //xAs grown by metalorganic chemical vapor deposition on LT AN BR 100 RT AN BR GaAs. The x value and layer thickness were in good agreement with the values expected from growth parameters. The presence of a transition region, 280 A thick, was detected by the rocking curve. In this region, the Al concentration varies smoothly from 0 to 0. 87. Measurement and control of the sharpness of such interfaces has important implications for heterojunction devices.