Hybrid Laser Activation of Highly Concentrated Bi Donors in Wire-delta-Doped Silicon

Hybrid laser annealing, i.e., a serial combination of laser exposure and furnace annealing, is demonstrated to activate Bi donors that are wire-delta-doped in Si. The photoluminescence reveals that the dense Bi atoms are activated so efficiently that an impurity band develops upon rapid radiation heating of the focused area close to the melting point of Si. The unintentional defects that are created thereby can be totally eliminated by subsequent furnace annealing at 390 degrees C. As a result, we attained a record concentration of active Bi donors >10(18) cm(-3) in excess of the predicted solubility limit. (C) 2010 The Japan Society of Applied Physics