[en] The stacking faults (SFs) in the silicon overlayer, which is formed after the implantation of silicon wafers by high doses (2 x 10¹⁸ cm^-2) of oxygen ions, are studied. During the implantation, a three-dimensional network of SiO₂ precipitates is formed along the <100> directions. Stacking faults appear only after a high-temperature annealing when all the SiO₂ precipitates are dissolved. Due to the very low value of the anomalous absorption coefficients of silicon, α-fringe contrast profile calculations are needed for the characterization of SFs. The results show that these SFs are extrinsic in character, bounded by Frank partial dislocations. (author)