Distribution of gettering centres at a buried amorphous layer in silicon

A buried amorphous layer in Si has been investigated by means of metal gettering before and after rc crystallization. Metal impurities, especially Cu atoms. are intentionally introduced and accumulated in damaged regions of Si, The measured Cu depth distributions have been compared to the corresponding strain profiles and the microstructure of the Si lattice, The buried amorphous layer has been found to act like a diffusion barrier for the Cu atoms. Cu gettering takes place at the crystalline side of the amorphous-to-crystalline (a/c) interface, In this region a Si lattice expansion is observed. After recrystallization of the amorphous layer Cu gettering occurs as well outside of the former amorphous layer, mainly at the interfaces. The behaviour of Cu atoms in Si seems to be: correlated to the supersaturation of self-interstitials. (C) 1999 Elsevier Science B.V. All rights reserved.