Photothermal reflectance investigation of processed silicon. I. Room-temperature study of the induced damage and of the annealing kinetics of defects in ion-implanted wafers

Abstract

Silicon films damaged by ion implantation have been examined using the photothermal reflectance technique in the thermal wave regime (low-modulation frequencies, large laser beam spot sizes). Data are presented on the sensitivity of this method to the implant dose and to the effects of thermal annealing. It has been shown that the technique provides information about the state of the implanted layer, and is a sensitive probe for monitoring the annihilation of the induced damage as a function of the annealing temperature. A model for the kinetics of damage annihilation has been presented to estimate the activation energy of the local annealing recovery mechanism, found to be 0.15 eV. The presence of negative annealing has been detected at about 500°C, an advantage over the essentially insensitive Hall mobility method.