Samples of n-type material were implanted with B+ and As+ ions having energies such that their projected ranges (30nm) coincided. The As+ ions were implanted to doses of between 5 x 1014 and 2 x 1015/cm2, and B+ ions were then implanted to a dose of 1015/cm2. It was found that material which had been implanted with As+ doses that were greater than 2 x 1015/cm2, and with B+ ions to 1015/cm2, was n-type after annealing at 950C. A very shallow p-type layer was formed after annealing at 1000C. A reduction in diffusivity, and a decrease in the activation efficiency of the implanted B, increased with increasing As+ dose.

K.Yokota, T.Nakamura, F.Miyashita, K.Hirai, H.Takano, M.Kumagai, Y.Ando, K.Matsuda: Materials Science Forum, 1995, 196-201, 1637-42