Investigation of CxSi defects in C implanted silicon by transmission electron microscopy

Buried CxSi layers were produced by high-energy implantation of carbon into CZ silicon. The depth distribution of carbon, the morphology of the buried layers, as well as the precipitation of C were investigated as functions of rapid thermal annealing between 700 and 1300 degrees C, using transmission electron microscopy, secondary ion mass spectroscopy, and positron annihilation measurements. Different kinds of microdefects occur: below approximate to 800 degrees C there are vacancy agglomerates as well as metastable C-Si agglomerates (Phi approximate to 2 nm), whereas at higher temperatures beta-SiC precipitates are observed. Results are discussed in terms of the interaction between C atoms and radiation-induced defects. (C) 1997 American Institute of Physics.