Diffusion Rate of Li in Si at Low Temperatures

Abstract

The method of ion drift in the electric field of an $n-p$ junction has been used to measure the diffusion constant of Li in Si between 25°C and 125°C, taking particular care to avoid chemical and electrical interactions which might affect the results. When these data are combined with previous high-temperature data, there is obtained $D=(2.5\mathrm{}\pm 0.2)\times {10}^{-3\mathrm{}}\exp [-\frac{(0.655\mathrm{}\pm 0.01)e}{\mathrm{kT}}]$ ${\mathrm{cm}}^2$/sec, the data extending over eight decades in $D$. The results are compared with those from ion-pair relaxation experiments, and it is shown that the latter are consistant with the ion-drift results.