Thermal redistribution of Al implanted in Si: evidences for interactions with extended defects

摘要

Al was implanted at 180 keV to a dose of 4.5X10~14 cm~-2. Various anneals were performed in the temperature range (900-1100 deg C), for times varying from 15 min up to several hous. The SIMS measurements reveal anomalous redistribution of the aluminium profiles. The bulk side of the profiles diffuses normally at a rate in agreement of the Al intrinsic diffusivity, but two peaks of apparently immobile atoms are formed near the surface. Cross observations by Transmission Electronic Microscopy (TEM) prove that there is no Al precipitation, and reveal the existence of two extended defects bands, the position of which is perfectly correlated with Al peaks. This strongly suggests that these peaks are due to Al trapping on the extended defects. First simulations also support this assumption. direct c 1999 Elsevier Science B.V. All rights reserved.