Diffusion and segregation of ion-implanted boron in silicon in dry oxygen ambients

The diffusion of ion-implanted boron in silicon has been studied in the temperature range 1050-1250\ifmmode^\circ\else\textdegree\fi{}C. The diffusion drive-ins were carried out in oxygen and in various oxygen-nitrogen mixtures. Computer calculations were made to solve the diffusion equation under oxidizing conditions and to yield values of sheet resistance, junction depth, etc., for given values of the diffusion coefficient and the coefficient of segregation of boron between silicon and silicon dioxide. By iteration, values of diffusion coefficient and segregation coefficient were found which yielded values closest to the experimental sheet resistance and junction depth. It was found that boron diffusion in (100) silicon was significantly enhanced if the oxygen content in the annealing ambient was more than 10%. During drive-in in oxygen as much as 2/3 of the initially implanted boron could be lost to the oxide. The temperature dependence of the segregation coefficient and of the diffusion coefficient could be described by $m=9.82\mathrm{exp}(\ensuremath{-}0.29 \frac{\mathrm{eV}}{\mathrm{kT}})$, $D=0.15\mathrm{exp}(\ensuremath{-}3.19\frac{\mathrm{eV}}{\mathrm{kT}})$ ${\mathrm{cm}}^{2}$/sec. These data have been discussed in light of the available data from previously reported investigations. A possible mechanism of diffusion in an oxidizing medium has been examined.