Calculating Silicon-Amorphization Doses under Medium-Energy Light-Ion Irradiation

Abstract

Based on the previously proposed diffusion-coagulation model of defect formation under the ion irradiation of silicon using the numerical solution of the corresponding kinetic equations, amorphization doses Φam for medium-energy ions with a mass of M1 ≤ 31 amu are calculated. It is assumed that amorphization at a specified depth occurs at a dose corresponding to a certain threshold total concentration Cam of vacancies and divacancies. In the calculation, the variable parameters are the ion energy, ion-current density, temperature, threshold atomic-displacement energy Ed, and Cam. The limits of applicability of the diffusion-coagulation model are determined. Comparison of the results of calculation within these limits with published experimental data shows, with regard to a variation in the experimental data and some freedom in choosing the parameters Ed and Cam, satisfactory agreement between the calculated and experimental Φam values.