Decomposition of a solid solution of interstitial magnesium in silicon

The decomposition of a solid solution of interstitial magnesium Mg$_ i$ in silicon is studied. Float-Zone dislocation-free single-crystal $n$-Si with a resistivity of $\sim$8 $\times$ 10$^3$ $\Omega$ cm and oxygen and carbon contents of $\sim$5 $\times$ 10$^{14}$ cm$^{-3}$ and $\sim$1 $\times$ 10$^{15}$ cm$^{-3}$ is used in the experiments. The samples are doped using the diffusion sandwich method at $T$ =1100$^{\circ}$C followed by quenching. Decomposition of the supersaturated Mg$_i$ solid solution is studied by observing the kinetics of increasing the resistivity of doped samples resulting from their annealing in the range $T$ = 400–620$^{\circ}$C. It is found that the decomposition is characterized by an activation energy of $E_a\approx$ 1.6 eV, which is close to the previously determined diffusion activation energy of Mg$_ i$ in silicon. It is also shown that Si:Mg exhibits stable properties at temperatures not exceeding 400$^{\circ}$C, which is important for its possible practical application.