IDENTIFICATION OF THE IRON-BORON LINE SPECTRUM IN SILICON

A new line spectrum at about 860 meV has been observed in silicon co-d oped with iron and boron. The isochronal annealing behaviour, of this line spectrum and the FeB centre was studied by transmission spectrosc opy and electron paramagnetic resonance (EPR), respectively. The good agreement between the two measurements strongly suggests that the line spectrum originates from excitations at the trigonal FeB pair complex , well known from previous EPR studies. The positions of the FeB donor and acceptor levels were estimated to be at E(v) + 110 meV and E(c) - 275 meV respectively, in close agreement with previously reported val ues for the FeB pair. Furthermore, the energy difference between the g round and first excited states of this centre was determined to be 1.0 9 meV, which compares favourably with the 0.75 meV EPR value previousl y obtained