Nickel: A very fast diffuser in silicon

Nickel is increasingly used in both IC and photovoltaic device fabrication, yet it has the potential to create highly recombination-active precipitates in silicon. For nearly three decades, the accepted nickel diffusivity in silicon has been D-Ni(T) = 2.3 x 10(-3) exp(-0.47 eV/k(B)T) cm(2)/s, a surprisingly low value given reports of rapid nickel diffusion in industrial applications. In this paper, we employ modern experimental methods to measure the higher nickel diffusivity D-Ni(T) = (1.6960 +/- 74) x 10(-4) exp (-0.15 +/- 0.04 eV/k(B)T) cm(2)/s. The measured activation energy is close to that predicted by first-principles theory using the nudged-elastic-band method. Our measured diffusivity of nickel is higher than previously published values at temperatures below 1150 degrees C, and orders of magnitude higher when extrapolated to room temperature. (C) 2013 AIP Publishing LLC.