The effects of the substrate donor concentration upon the transient enhanced diffusion of B, which was implanted into wafers that had been pre-doped with As or P, was investigated by means of secondary ion mass spectroscopy and simulation. The 10 to 20keV B ions were implanted, and annealing was then carried out at 700 to 1000C. No detectable transient enhanced diffusion of B was observed in samples which had been uniformly pre-doped with B to a concentration of 1.2 x 1020/cm3. The transient enhanced diffusion of B was strongly reduced, even in samples which were pre-doped with As. At the highest As concentration of 1.3 x 1020/cm3, however, an exponential high-diffusivity tail was detected in the B profiles for all annealing temperatures. This anomalous effect was attributed to the interstitials which were produced by an As clustering reaction that occurred during low-temperature annealing.

Effects of Donor Concentration on Transient Enhanced Diffusion of Boron in Silicon. S.Solmi, M.Bersani: Journal of Applied Physics, 2000, 87[8], 3696-9