Dislocation locking experiments were used to investigate N-doped float-zone Si. Experiments on N-doped float-zone Si with a N concentration of 2.2 x 1015/cm3 were carried out by annealing at 550 to 830C for up to 1500h, and experiments on N-doped float-zone Si with a N concentration of 3 x 1014/cm3 were carried out at 600C for up to 1200h. After an initial rise, the unlocking stress was found to saturate for all combinations of conditions investigated. The rate of the initial rise was found to be consistent with diffusion by a dimeric N species. The saturation value of the unlocking stress was found to be dependent on the N concentration. Experiments were also carried out on N-doped Czochralski Si with an O concentration of 5.74 x 1017/cm3 and a N concentration of 2.10 x 1015/cm3 at 600C from 0-5h. The dislocation locking due to O appeared to be unaffected by the presence of N for the conditions investigated.

Nitrogen Transport in Float-Zone and Czochralski Silicon Investigated by Dislocation Locking Experiments. J.D.Murphy, A.Giannattasio, S.Senkader, R.J.Falster, P.R.Wilshaw: Physica Status Solidi A, 2005, 202[5], 926-30