Analysis of vacancy and interstitial nucleation kinetics in Si wafers during rapid thermalannealing

Abstract

The successful application of the rapid thermal annealing (RTA) process for creation of amagic denude zone in individual Czochralski silicon wafers is based on vacancy controlledoxygen precipitation. The kinetics of the vacancy and self-interstitial processes inSi wafers are studied in this paper. Detailed insight into nucleation processes,out-diffusion and vacancy–interstitial recombination during the RTA leads to anew model of interaction between vacancies and oxygen. The calculation of thedistribution function of these defects follows from modified Becker–Döring equationstransformed for vacancies and interstitials and extended by diffusion and recombinationterms. The new model, which includes the vacancy influence on oxygen nucleationand which follows from this theoretical analysis, corresponds very well to theexperimental properties of formation of bulk micro-defects during RTA processes.