Radiation enhanced silicon self-diffusion and the silicon vacancy at high temperatures.
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.
Bracht
H
H
Institut fuer Materialphysik, Universitaet Muenster, D-48149 Muenster, Germany. bract@uni-muenster.de
Pedersen
J Fage
JF
Zangenberg
N
N
Larsen
A Nylandsted
AN
Haller
E E
EE
Lulli
G
G
Posselt
M
M