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

We report on the observation of a metastability of defects in heavily damag ed silicon. The ion-damaged buried layer is embedded in a Schottky diode an d junction capacitance transient measurements are utilized to monitor charg e 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 t he phenomena can be understood in terms of large entropy changes acting as the driving force for the relaxation. Our results constitute experimental o bservation bf metastability for small defect clusters in ion-damaged silico n.