Nature of dislocation loops in As-implanted and postannealed Si wafers

Si wafers were implanted with As ions to a concentration of 1019 atoms/cm3 and subsequently annealed in the temperature range 600--1000 degreeC in an atmosphere of a low partial pressure of Ar. The surface density of the resulting interstitial dislocation loops was measured. The comparison with electrical measurement data suggests that the extra planes in the loops do not consist, at least in their majority, of As atoms