The effects of radiation damage and impurities on void dynamics in silicon

Transmission electron microscopy (TEM) has been used to study the effects o f implanted oxygen or carbon on the dynamics of cavity growth in silicon. T he cavities are produced by implantation with helium ions followed by annea ling to convert small He-filled bubbles into large empty voids. We have als o investigated the effects of self-ion damage on cavity growth. Both impuri ties and self-ion damage can significantly inhibit void growth. In addition . hot stage TEM has been used to elucidate the processes responsible for ca vity growth in an attempt to understand the way in which both impurities an d radiation damage are able to modify these processes. Cavity growth is see n to be due to Ostwald ripening and coalescence in the early stages with so me sporadic, rapid motion of large bubbles leading to coalescence at higher temperatures. Our research indicates that void dynamics in silicon are qui te different from those in metallic systems. (C) 2001 Elsevier Science B.V. All rights reserved.