EVOLUTION OF INTERSTITIAL-TYPE AND VACANCY-TYPE DEFECTS UPON THERMAL ANNEALING IN ION-IMPLANTED SI

We have quantitatively analyzed the structure and the annealing behavi or of the point defects introduced by ion implantation in Si. We used deep-level transient spectroscopy to monitor and count interstitial-ty pe (e.g., carbon-oxygen complexes) and vacancy-type (e.g., divacancies ) defects introduced by MeV Si implants in crystalline Si and to monit or their annealing behavior for temperatures up to 400 degrees C. A sm all fraction (similar to 4%) of the initial interstitial-vacancy pairs generated by the ions escapes recombination: and forms equal concentr ations of interstitial- and vacancy-type room-temperature stable defec t pairs. At T less than or equal to 300 degrees C, vacancy-type defect s dissociate, releasing free vacancies, which recombine with interstit ial-type defects, producing their dissolution. This defect annihilatio n occurs preferentially in the bulk. At temperatures above 300 degrees C, all vacancy-type defects are annealed and the residual damage cont ains only similar to 3 interstitial-type defects per implanted ion. Th is imbalance between vacancies and interstitials is not observed in el ectron-irradiated samples, demonstrating that it is the direct consequ ence of the extra ion introduced by the implantation process. (C) 1997 American Institute of Physics.