Figure 4
Time evolution of Ge nanocrystallite size and coarsening under postoxidation annealing. (a) CTEM micrographs of coarsening of the Ge nanocrystallite clusters under further thermal annealing at 900°C for various times ranging from 10 to 100 min in an H2O ambient. (b) Ge nanocrystallite size as a function thermal annealing time. The Ostwald ripening process appears to stop around an annealing time of 70 min indicative of the depletion of these residual Si interstitials. (c) Schematic diagram for the very slight coarsening of the Ge nanocrystallite clusters mediated by the presence of small concentrations of residual Si interstitials remaining within the oxidized poly-Si0.85Ge0.15 pillars.