EPR study of erbium-impurity complexes in silicon

Electron paramagnetic resonance (EPR) measurements have been used to characterise Er complexes formed in FZ silicon by the implantation of erbium together with either oxygen or fluorine. The samples have a 2 mu m thick layer containing 10(19) Er/cm(3) alone or in addition 3 x 10(19) O/cm(3), 10(20) O/cm(3) or 10(20) F/cm(3). Various post-implantation anneals were carried out. Several different erbium centres, which have either C-1h monoclinic or trigonal symmetry, are observed and the way in which the type of centre depends on the implantation and annealing conditions is reported.