A new method of producing a buried oxide is proposed. It involves implanting a silicon wafer with helium rather than oxygen ions and then subjecting it to high- temperature oxidation. The voids formed by helium ion implantation and subsequent annealing enhance the diffusion of oxygen atoms into the silicon. The oxygen atoms cause thermal oxide to grow at the void/silicon interface and transform the voids into buried oxide precipitates. Auger electron spectroscopy revealed that the total number of oxygen atoms in the precipitates was 9.3 × 1016 cm−2 and that the peak value of oxygen atom concentration in the wafer was approximately 25%.