TEM characterization of ion beam mixed Au/GaAs contacts

Au(40 nm)/GaAs(100) samples were treated by ion beam mixing i.e. by Xe ion implantation through the gold layer. The energy of the ions was in the range of 300-700 keV, while low (10(14) ions/cm(2)) and high (10(16) ions/cm(2)) doses have been applied, respectively. The structure of the implanted specimens has been studied using cross sectional transmission electron microscopy (TEM). Some of the specimens have been annealed at 400 degrees C resulting in the crystallization of the amorphous regions while GaAs grains appeared in the top covering layer as a consequence of gold diffusion into the GaAs substrate.