Recombination-enhanced Fe atom jump between the first and the second neighbor site of Fe-acceptor pair in Si

We studied the recombination-enhanced Fe atom jump between the first (1st) and second (2nd) neighbor sites of Fe-Al and Fe-B pairs in Si. We first annealed specimens at 80 degrees C to generate Fe-acceptor pairs after doping of Fe. Concentrations of the 1st and 2nd neighbor W-acceptor pairs were determined by electron-spin-resonance (ESR) measurement after annealing at around 150 K under optical excitation. The concentration of the Ist neighbor pair was decreased and that of the 2nd neighbor pair was increased by the above annealing. Activation energy for the above changes was about 0.11 eV in the case of the Fe-Al pair. This is much smaller than that (0.8 eV) of thermal annealing alone. In the case of the Fe-B pair, the ESR signal of the 2nd neighbor pair could be detected due to annealing at around 160 K under optical excitation. (C) 1996 American Institute of Physics.