Rapid amorphization in InxGa1−xAs alloys at temperatures between 15 K and 300 K

Abstract The amorphization kinetics of In 0.53 Ga 0.47 As and In 0.20 Ga 0.80 As alloys has been investigated in comparison to its binary extremes as a function of the Ge ion fluence at room temperature and 15 K. The irradiated samples were analysed by means of Rutherford backscattering-channeling spectroscopy using an in situ technique in case of the 15 K experiments. Contrary to the Al x Ga 1− x As alloys, the system In x Ga 1− x As does not exhibit amorphization kinetics intermediate between those of its two binary extremes especially at room temperature. For In x Ga 1− x As a smaller ion fluence is necessary to render the material amorphous at room temperature than GaAs or InAs. This surprising behaviour is explained in terms of differences in the In–As and Ga–As bond-lengths leading to strain at the atomic scale. We suggest irradiation-induced defect clusters or amorphous nuclei in In x Ga 1− x As may serve to relieve residual strain and, consequently, retardation of dynamic annealing.