ELECTRON-MICROSCOPE STUDY OF STACKING-FAULT FORMATION IN BORON IMPLANTED SILICON

Upon annealing silicon, implanted with boron at fluences greater than 5 multiplied by 10**1**5 B** plus /cm**2, stacking faults in concentrations up to 2 multiplied by 10**8/cm**2 were observed on all four left brace 111 right brace planes to a depth of 1800 A below the specimen surface. The faults were enclosed by interstitial Frank sessile loops. Annihilation occurred on annealing between 980-1000 degree 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 degree C. Annihilation at temperatures close to 1000 degree C may be caused by solute stress due to enhanced boron diffusion.