ETHEROGENEOUS PRECIPITATION IN OXYGEN-IMPLANTED SILICON

SiO2 precipitation in high-fluence oxygen-implanted silicon takes plac e in three regions: the region centred on the depth x(dam) of maximum damage production, the region centred on the most probable penetration depth x(max), and a region at greater depth x(double dagger). At flue nces Phi for which compositional changes and sputtering are of lower i mportance, x(max) and x(dam) do not depend on Phi (they depend only on the implantation energy E); in contrast, x(double dagger) varies sign ificantly with Phi The mechanism of SiO2 precipitation at x(dam) is he terogeneous precipitation; the mechanism active at x(max) is homogeneo us precipitation; the mechanism active at x(double dagger)(Phi), refer red to as etherogeneous precipitation, is a new mechanism characterisi tc of these mechanisms or for the prevalence of one or the other of th em after high temperature annealing is given for Phi in the interval 5 x 10(15)-2.5 x 10(17) cm(-2) and for E between 100 keV and 200 keV.