Secondary ion emission from silicon and silicon oxide

The emission of Si⁺, Si²⁺, Si³⁺, Si₂⁺, SiO⁺ and B⁺ from boron doped silicon has been studied at oxygen partial pressures between 2 × 10^?10 and 2 × 10^?5 Torr. Sputtering was done with 2 to 15 keV argon ions at current densities between 3 and $\text{40}\text{μ}\text{A}\text{cm}{}^2$. The relative importance of the different ionization processes could be deduced from a detailed study of the yield variation at varying bombardment conditions. Comparison with secondary ion emission from silicon dioxide allows a rough determination of the composition of oxygen saturated silicon surfaces.