Buried layer formation in silicon by laser radiation

The effect of CO2 laser radiation on the spatial distribution and state of oxygen or nitrogen atoms, implanted in silicon wafers, is investigated experimentally. Infrared spectroscopy of the implanted and irradiated samples showed the formation of a new phase inside the silicon. Auger spectrometry of the implanted oxygen atom distribution function showed a decrease in its width by 6%, and a shift of the distribution maximum toward the irradiated surface of the wafer by 0.25 of the initial half‐width. A stochastic model describing the process of buried layer formation from interacting impurities in the presence of a temperature gradient is proposed. A nonlinear diffusion equation is derived and the results obtained within this model are in qualitative agreement with our experiments. The possibility of forming buried layers in Si, i.e., SiO2 or Si3N4, as well as controlling their thickness and depth of location by means of CO2 laser irradiation is shown both experimentally and theoretically.