Abstract
Silicon wafers with and without a protective thermal oxide were implanted with oxygen at 150 keV with doses of 1.6–2.0×1018 cm2. Transmission electron microscopy and secondary‐ion mass spectroscopy were used to study the silicon layer above the implanted buried oxide. A regular array of spheroidal bubbles, postulated to be filled with oxygen gas, was observed only in the samples that were not protected by the oxide. The bubbles were aligned in individual columns whose orientation matched the direction of the implantation. The origin and kinetics of their formation are discussed. A model for column formation involving the overlap of ionization thermal spikes is proposed. It is also proposed that the observed phenomenon is a solid‐state analog of the bubble chamber effect.