The kinetics of the supersaturation of self‐interstitials and the enhancement of impurity diffusivity in short‐time/low‐temperature oxidation of silicon is investigated analytically. It is found that, whereas in long‐time/high‐temperature oxidation the interstitial supersaturation and the diffusivity enhancement decrease with time ast−n(n&bartil;0.2–0.3), in short‐time low‐temperature oxidation they start from zero and increase with time, until some characteristic time determined by the linear‐parabolic oxide growth. This characteristic time increases rapidly with the decrease of temperature. This kinetic behavior has not been expected previously, mainly because there is no available data on stacking fault growth and on diffusion enhancement under the short‐time/low‐temperature condition which has become common in modern IC processings. The more general case of linear‐parabolic oxidation and the effect of bulk recombination have also been analyzed.