title: Radiation enhanced silicon self-diffusion and the silicon vacancy at high temperatures.
abstract: We report proton radiation enhanced self-diffusion (RESD) studies on Si-isotope heterostructures. Self-diffusion experiments under irradiation were performed at temperatures between 780 degrees C and 872 degrees C for various times and proton fluxes. Detailed modeling of RESD provides direct evidence that vacancies at high temperatures diffuse with a migration enthalpy of H(m)(V)=(1.8+/-0.5) eV significantly more slowly than expected from their diffusion at low temperatures, which is described by H(m)(V)<0.5 eV. We conclude that this diffusion behavior is a consequence of the microscopic configuration of the vacancy whose entropy and enthalpy of migration increase with increasing temperature.
authors.affiliation: Institut fuer Materialphysik, Universitaet Muenster, D-48149 Muenster, Germany. bract@uni-muenster.de
authors.forename: H
authors.initials: H
authors.lastname: Bracht
authors.forename: J Fage
authors.initials: JF
authors.lastname: Pedersen
authors.forename: N
authors.initials: N
authors.lastname: Zangenberg
authors.forename: A Nylandsted
authors.initials: AN
authors.lastname: Larsen
authors.forename: E E
authors.initials: EE
authors.lastname: Haller
authors.forename: G
authors.initials: G
authors.lastname: Lulli
authors.forename: M
authors.initials: M
authors.lastname: Posselt