Evidence of metastability with athermal ionization from defect clusters in ion-damaged silicon

We report on the observation of a metastability of defects in heavily damaged silicon. The ion-damaged buried layer is embedded in a Schottky diode and junction capacitance transient measurements are utilized to monitor charge relaxation following trap-filling pulse. The defect energy is observed to deepen progressively on carrier capture, and the emission rate of carrier from any relaxed state is nearly temperature independent. We propose that the phenomena can be understood in terms of large entropy changes acting as the driving force for the relaxation. Our results constitute experimental observation of metastability for small defect clusters in ion-damaged silicon