The annealing behavior of interstitial-type basal plane dislocation loops in Al ion implanted 4H-SiC was investigated. It was shown that the loops underwent a dynamical ripening process. For annealing below 1700C the total area of dislocation loops increases, indicating that point defects were still available for accumulation, but for annealing times longer than 100min at this temperature the value of the total loop area saturates. For longer annealing times, or higher temperatures, the dislocation loops were subjected to a conservative coarsening process, also known as Ostwald ripening. In this process the mean loop radius increased with increasing annealing time and temperature while the number of loops decreased. Meanwhile the summarized area of the loops stays constant. The observed ripening was suggested to occur by a mechanism, which involved coarsening by direct loop coalescence. Through this mechanism, loops on the same basal plane move towards each other until they coalesce into one, but loops on neighboring basal planes could only move until their loop edges meet (in a basal plane projection) where they remain. Climb along the c axis was not favorable as shown by experimental results and was suggested to be caused by the atomic configuration of the loop. Upon continuous annealing, this resulted in a situation where the loops were confined in clusters.

Ostwald Ripening of Interstitial-Type Dislocation Loops in 4H-Silicon Carbide. P.O.Å.Persson, L.Hultman, M.S.Janson, A.Hallén: Journal of Applied Physics, 2006, 100[5], 053521 (8pp)