Electrical signature for configurational bistability of self-interstitial clusters in ion-damaged silicon

Abstract

Self-interstitial clusters introduced by high-energy Ar ion implantation in silicon are studied by capacitance transient spectroscopic techniques. Trapping kinetics studies at low temperature over a wide range of trap-filling time reveal the presence of three trap levels, two of which are interrelated. A detailed analysis of the trap occupancy features using numerical simulation show that the two interrelated traps are two configurations of the same defect. From model simulation, it is also shown that exact occupancy features observed experimentally could be fitted by assuming the metastable defect to be a negative-U (Hubbard correlation energy) center.