Diffusion and Interaction of In and As Implanted into SiO₂ 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 SiO₂ 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°C. It is found that annealing at T = 800–900°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°C yields the segregation of In atoms at the surface of SiO₂ with the simultaneous enhanced diffusion of As atoms. The corresponding diffusion coefficient is D_As = 3.2 × 10^–14 cm² s^–1.