Cluster formation and growth in Si ion implanted c-Si

Formation condition and annealing kinetics of self-interstitial (I) clusters in ion implanted Si have been investigated. Deep level transient spectroscopy (DLTS) and photoluminescence (PL) measurements were performed on both p-type Czochralski Si samples implanted with Si ions at energies ranging from 40 keV to 1.2 MeV. They reveal that I-clusters form for implantation fluences above 1012 cm−2 and annealing temperatures higher than 550°C. Analysis of the annealing kinetics at temperatures in the range 550–700°C reveals that I-clusters dissociate with an energy depending on the implantation dose. The characteristic dissociation energy is ∼2.3 eV for 1×1012 cm−2 implants, and this value increased towards the typical {311} extended defects dissociation energy value (∼3.8 eV) by increasing the implantation fluence. Finally, the transition from I-clusters to {311} defects was followed using PL and DLTS in combination with transmission electron microscopy analysis. A PL line at 1375 nm has been associated to {311} extended defects and a threshold dose and annealing temperature for the extended defects formation identified.