Electron microscope study of stackingfault formation in boron implanted silicon

Upon annealing silicon, implanted with boron at fluences greater than 5 × 1015 B+/cm2, stacking faults in concentrations up to 2 × 108/cm2 were observed on all four {111} planes to a depth of 1800 Å below the specimen surface. The faults were enclosed by interstitial Frank sessile loops. Annihilation occurred on anealing between 980-1000°C. The region in which the loops nucleate is assumed to contain silicon rendered amorphous at this high fluence, and the faults are believed to be condensed sheets of silicon atoms whose sites become occupied by boron atoms upon annealing between 800-950°C. Annihilation at temperatures close to 1000°C may be caused by solute stress due to enhanced boron diffusion. Additional data on anneals in dry O2 at 1150°C are presented.