Injection of self-interstitials during sputter depth profiling of Si at room temperature

Samples consisting of multi B delta layers and a single Sb delta layer, grown using molecular beam epitaxy, have been sputter depth profiled using O-2(+) ions with incidence energy of 8.2 or 3.2 keV. The leading and the trailing edge of the B distributions show an anomalous broadening induced by the sputtering, which apparently increases with ion energy. Similar feature is not observed for the Sb distribution. Incorporation of substitutional C to concentrations similar to 10(19) cm(-3) suppresses the broadening feature almost completely. This anomalous broadening is interpreted as a consequence of injection of Si self-interstitials from the region damaged by the ion bombardment. These interstitials may migrate far beyond the mixing depth and interact with the B dopants, which yields a mixing of the B atoms before the distribution is within the "ordinary'' mixing depth. (C) 1998 American Institute of Physics. [S0003-6951(98)03147-7].