Growth kinetics and diffusion mechanism inPd2Si

We have studied the influence of substrate orientation and dopant on the growth kinetics of ${\mathrm{Pd}}_2$Si. Both $〈100〉$- and $〈111〉$-oriented Si wafers with P concentration in the range of 5×${10}^{13}$ to 4.8×${10}^{18}$ ${\mathrm{cm}}^{-3\mathrm{}}$ and with As concentration in the range of 2.8×${10}^{19}$ to 5×${10}^{20}$ ${\mathrm{cm}}^{-3\mathrm{}}$ have been used. Doping concentrations of the Si substrate below ${10}^{19}$ ${\mathrm{cm}}^{-3\mathrm{}}$ do not affect the growth kinetics but a significant influence is found for As doping levels exceeding ${10}^{19}$ ${\mathrm{cm}}^{-3\mathrm{}}$. For As concentrations of 5×${10}^{20}$ ${\mathrm{cm}}^{-3\mathrm{}}$ the activation energy is lowered by about 0.35 eV and the preexponential factor is lowered by 3 orders of magnitude. These changes are independent of the Si substrate orientation. The results have been combined with earlier results of marker motion to interpret the vacancy mechanism of diffusion in ${\mathrm{Pd}}_2$Si.