GROWTH AND X-RAY CHARACTERIZATION OF STRAIN COMPENSATED GAAS ALAS DISTRIBUTED BRAGG REFLECTORS/

We have grown strain compensated GaAs/AlAs distributed Bragg reflector s by solid source molecular beam epitaxy using carbon doping densities up to about 2 X 10(20) cm(-3), The residual strain with respect to th e GaAs substrate can be as low as 1 X 10(-)4(.) This results in a larg e increase of their critical thickness with regard to the undoped case . We demonstrate that simulations of the x-ray diffraction patterns ar e essential in order to determine the chemical profile as well as the structural parameters of the GaAs:C and AlAs:C layers with high accura cy. The effective incorporation of carbon on lattice sites is in AlAs: C twice as large as in GaAs:C using the same incident carbon Bur. (C) 1996 American Institute of Physics.