Dielectric functions, chemical and atomic compositions of the near surface layers of implanted GaAs by In ions.

The surfaces of (100) GaAs were irradiated with In ions. The implanted samples were isobaric annealed at 800°C and then of dielectric function, the surface atomic concentrations of atoms and also the chemical composition of the near surface layers in these implanted semiconductor samples were obtained. The following investigation methods were used: spectroscopic ellipsometry (SE), Rutherford backscattering spectrometry analyses (RBSA) and X-ray photoelectron spectroscopy (XPS) in the study of the above mentioned quantities, respectively. The change of the shape spectra of the dielectric functions at about 3.0eV phonon energy, diffusion of In ions as well as chemical composition changes were observed after ion implantation and the thermal treatment. Due to displacement of Ga ions from GaAs by the In ions the new chemical compound InAs was formed. The relative amounts GaO and AsO ratio increase in the native oxide layers with the fluences increase after the thermal treatment of the samples. Additionally, it was noticed that the quantities of InO increase with the increasing values of the irradiated ions before thermal treatment.