Publications by April S. Brown.

Papers Published

  1. Griem, H. T. and Hsieh, K. H. and D'Haenens, I. J. and Delaney, M. J. and Henige, J. A. and Wicks, G. W. and Brown, A. S., CHARACTERIZATION OF STRAINED GaInAs/AlInAs QUANTUM WELL TEGFETS GROWN BY MOLECULAR BEAM EPITAXY., Journal of Crystal Growth, vol. 81 no. 1-4 (1986), pp. 383 - 390 [0022-0248(87)90421-0] .
    (last updated on 2007/04/14)

    Defect free strained layer epitaxy opens possibilities for further improvement on the quantum well two-dimensional electron gas FET (TEGFET) structures grown using the GaInAs/AlInAs on InP materials system. Increased freedom with composition allows for optimizing certain properties of the structure, such as, the conduction edge discontinuity which controls the maximum sheet concentration (n//s); and the electron effective mass which influences the speed of the structure. These enhancements can be made, respectively, by increasing the Al concentration in the AlInAs and/or by decreasing the Ga concentration in the GaInAs. The maximum amount of strain which can be incorporated into the unrelaxed material sets an upper limit on the compositional tolerances. The tolerances are large for the AlInAs and the active TEG GaInAs region. The compositions are obtained using the intensity oscillations observed in the reflection high energy electron diffraction (RHEED) specular beam during growth of GaAs, AlAs, and subsequently GaInAs and AlInAs on GaAs. X-ray rocking curves and photoluminescence (PL) are used to verify the calibrations for growths on InP.