RADIATION-DAMAGE AND IMPLANTED HE ATOM INTERACTION DURING VOID FORMATION IN SILICON

He was implanted in silicon wafers to several doses (5x10(15)-4x10(16) cm(-2)) at different temperatures (from -196 up to 400 degrees C). Vo id formation and evolution was observed by cross-sectional and plan vi ew transmission electron microscopy analyses. We observed that void de nsity and morphology are strictly related to substrate temperature dur ing He implantation. Experiments show that for substrate temperature b etween 10 and 90 degrees C or higher than 150 degrees C, void formatio n is inhibited; when voids are observed, a few degrees of difference s ignificantly change their density. The results can be interpreted by c onsidering the interaction between He and the radiation damage produce d during He implantation that forms stable bubbles. (C) 1997 American Institute of Physics.