A study was made of the relative thermal stability of perfect and faulted dislocation loops which formed during the annealing of pre-amorphized wafers. Samples were implanted with 150keV Ge+ or 50keV Si+ ions to a dose of 2 x 1015/cm2 and were annealed at 900C in N2, N2O or O2. Transmission electron microscopy was used to study the effect of the implantation parameters. Calculations of the formation energy of both types of dislocation loop showed that, for defects of a given size, faulted dislocation loops were more energetically stable than were perfect dislocation loops if their diameter was smaller than 80nm. Experimental results were analyzed in terms of the Ostwald ripening of 2 populations of interstitial defects. It was found that defect ripening was non-conservative if the surface was close to the end-of-range defect layer, or if the sample was oxidized during annealing. In both cases, a knowledge of the formation energy of the loop permitted a realistic estimate to be made of the interstitial flux to and from the surface during annealing. During conservative ripening, a direct correspondence existed between the formation energy of the 2 defect families and the numbers of atoms which were bound to them. In this case, the relative stability of faulted and perfect loops depended upon the initial supersaturation of Si interstitial atoms which was created during implantation.

Formation Energies and Relative Stability of Perfect and Faulted Dislocation Loops in Silicon F.Cristiano, J.Grisolia, B.Colombeau, M.Omri, B.De Mauduit, A.Claverie, L.F.Giles, N.E.B.Cowern: Journal of Applied Physics, 2000, 87[12], 8420-8