Diffusion and interaction of In and As implanted into SiO$_2$ films

By means of Rutherford backscattering spectrometry, electron microscopy, and energy-dispersive X-ray spectroscopy, the distribution and interaction of In and As atoms implanted into thermally grown SiO$_2$ films to concentrations of about 1.5 at % are studied in relation to the temperature of subsequent annealing in nitrogen vapors in the range of $T$ = 800–1100$^{\circ}$C. It is found that annealing at $T$ = 800–900$^{\circ}$C results in the segregation of As atoms at a depth corresponding to the As$^+$-ion range and in the formation of As nanoclusters that serve as sinks for In atoms. An increase in the annealing temperature to 1100$^{\circ}$C yields the segregation of In atoms at the surface of SiO$_2$ with the simultaneous enhanced diffusion of As atoms. The corresponding diffusion coefficient is $D_{\mathrm{As}}$ = 3.2 $\times$ 10$^{-14}$ cm$^2$ s$^{-1}$.