Calculating silicon-amorphization doses under medium-energy light-ion irradiation

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 $\Phi_{\mathrm{am}}$ for medium-energy ions with a mass of $M_1\le$ 31 amu are calculated. It is assumed that amorphization at a specified depth occurs at a dose corresponding to a certain threshold total concentration $C_{\mathrm{am}}$ of vacancies and divacancies. In the calculation, the variable parameters are the ion energy, ion-current density, temperature, threshold atomic-displacement energy $E_d$, and $C_{\mathrm{am}}$. 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 $E_d$ and $C_{\mathrm{am}}$, satisfactory agreement between the calculated and experimental $\Phi_{\mathrm{am}}$ values.