Mechanisms of void coarsening in helium implanted silicon

There: has been recent discussion of the mechanisms that give rise to the observed coarsening of void populations introduced into silicon by implanting helium and then annealing to remove the helium. Over the temperature range from approximately 700 to 1000 degreesC and beyond, further annealing leads to an increase of the average void size and decrease in void density. This paper sets out to calculate the coarsening expected from the two primary potential mechanisms, migration and coalescence (M&C) and Ostwald ripening (OR). The methodology of the calculations is carefully set out together with the surface diffusion and vacancy diffusion parameters on which the mechanisms depend. For moderate anneal temperatures, up to 1000 degreesC, it would seem unlikely that OR can play any part in void coarsening. On the other hand, M&C calculations show that this mechanism gives results consistent with the size range found in experimental results. (C) 2002 Elsevier Science B.V. All rights reserved.