Characterization of the Segregation of Arsenic at the Interface SiO2/Si

The segregation of As atoms at the Si/SiO2 interface during annealing was investigated by grazing incidence X-ray fluorescence spectroscopy in combination with successive removal of silicon layers by etching with thicknesses on the order of a nanometer. With this method it is possible to clearly distinguish between the segregated atoms and the As atoms in the bulk over a large range of implantation doses from 3E12 cm-2 to 1E16 cm-2. The samples were annealed at 900 °C and 100 0 °C, respectively, for times sufficiently long to ensure that the segregation reflects an equilibrium effect. The results were confirmed by medium energy ion scattering, Z-contrast measurements and electron energy loss spectroscopy.