Evolution of interstitial- and vacancy-type defects upon thermal annealing in ion implanted Si

We have quantitatively analyzed the structure and the annealing behavior of the point defects introduced by ion implantation in Si. We used deep-level transient spectroscopy to monitor and count interstitial-type (e.g., carbon-oxygen complexes) and vacancy-type (e.g., divacancies) defects introduced by MeV Si implants in crystalline Si and to monitor their annealing behavior for temperatures up to 400 degrees C. A small fraction (similar to 4%) of the initial interstitial-vacancy pairs generated by the ions escapes recombination: and forms equal concentrations of interstitial- and vacancy-type room-temperature stable defect pairs. At T less than or equal to 300 degrees C, vacancy-type defects dissociate, releasing free vacancies, which recombine with interstitial-type defects, producing their dissolution. This defect annihilation occurs preferentially in the bulk. At temperatures above 300 degrees C, all vacancy-type defects are annealed and the residual damage contains only similar to 3 interstitial-type defects per implanted ion. This imbalance between vacancies and interstitials is not observed in electron-irradiated samples, demonstrating that it is the direct consequence of the extra ion introduced by the implantation process.