X-ray reflectivity determination of interface roughness correlated with transport properties of (AlGa)As/GaAs high electron mobility transistor devices

To explore the role of interface scattering in high electron mobility transistor (HEMT) structure were grown by molecular beam epitaxy (MBE) at temperatures ranging from 500 to 630 degrees C. Hall measurements indicate a trend toward higher mobilities in samples grown at higher temperatures. Subsequent x-ray reflectivity measurements were made, and the data were fitted by least-squares refinement of a calculated reflectivity curve determined from a model of the sample structure to obtain the composition profile along the growth direction. These results indicate smoother interfaces for the samples with higher mobilities. (C) 1996 American Institute of Physics.