Czochralski-type wafers, with a B concentration of 2.7 x 1017/cm3, were implanted with 50 or 150keV Si+ to doses ranging from 5 x 1012 to 5 x 1015/cm2; followed by annealing at 670, 720 or 820C in N. During annealing, B pile-up in the {311} defect region were observed for the first time. During higher-temperature annealing, B pile-ups formed and dissolved more quickly, but had a lower peak value. The pile-ups formed in regions where the self-interstitial concentration exceeded 3 x 1017/cm3; regardless of the implantation energy or dose. The pile-ups originated from B segregation to {311} defects. The process of B segregation was limited by B diffusion. The number of B atoms which segregated to {311} defects increased as the square root of the annealing time. After reaching a maximum, the number of segregated B atoms fell exponentially; with a characteristic decay time of 14h at 670C or 3h at 720C. Spreading resistance profiling revealed that the B atoms which segregated to {311} defects were electrically inactive.

Studies of Boron Segregation to {311} Defects in Silicon-Implanted Silicon. J.Xia, T.Saito, R.Kim, T.Aoki, Y.Kamakura, K.Taniguchi: Japanese Journal of Applied Physics - 1, 1999, 38[4B], 2319-23