MORPHOLOGY OF THE IMPLANTATION-INDUCED DISORDER IN GAAS

Disorder is introduced into GaAs by implantation oi Si-30(+) ions, usi ng a very wide range of ion doses, and studied by Raman scattering (RS ) and Rutherford backscattering and ion channeling (RES). A comparativ e analysis of mechanisms influencing RS and RES signals has been made. This analysis revealed that, due to different sensitivity of each met hod to various defect structures, it is possible to distinguish severa l different types of implantation induced disorder. RS results indicat e that a second type of amorphous structure. having medium-range order , grows at the expense of the continuous-random-network structure, eve n at doses beyond the threshold for complete amorphization.