HYDROGEN PASSIVATION OF IRON-RELATED HOLE TRAPS IN SILICON

We have investigated the passivation of iron-related hole traps in p-t ype silicon by deep level transient spectroscopy (DLTS) and recombinat ion lifetime measurements. After hydrogen ion implantation (ranging in dose from 1.0 X 10(14) to 1.0 X 10(16) cm(-2)), all DLTS peaks relate d to iron impurities disappeared. This indicates that implanted hydrog en passivates the Fe-B pair as well as other iron-related hole traps t hat are not passivated by hydrogen plasma treatment. On the other hand , two kinds of hole traps were produced at E(upsilon) +0.23 eV and E(u psilon) +0.38 eV by the hydrogen ion implantation. The recombination l ifetime increases from 3 to 18 mu s (which is about 45% of the lifetim e in uncontaminated samples) with the implantation dose. The maximum v alue of the recombination lifetime was observed at a dose of 1.0 X 10( 15) cm(-2). We attribute the decrease in recombination lifetime in mor e heavily implanted samples (1.0 X 10(16) cm(-2)) to hole traps create d by the ion implantation. (C) 1996 American Institute of Physics.