Kinetics of the electronically stimulated formation of a boron-oxygen complex in crystalline silicon

We present experimental data relating to the slow stage of the illumination-induced or electron-injection-induced generation, in crystalline $p$-type silicon, of the carrier-recombination center believed to be the defect complex ${\left({\mathrm{B}}_s{\mathrm{O}}_{2i}\right)}^{+}$ formed by diffusion of oxygen interstitial dimers $\mathrm{O}_{2i}{}^{++}$ to substitutional boron atoms $\mathrm{B}_s{}^{-}$ and, taking account of those data, we consider a detailed theoretical model for the kinetics of the diffusion reaction. The model proposes that the generation rate of the ${\left({\mathrm{B}}_s{\mathrm{O}}_{2i}\right)}^{+}$ defects is controlled by the capture of a majority-carrier hole by the dimer following the capture of a minority-carrier electron and by the Coulomb attraction of the $\mathrm{O}_{2i}{}^{++}$ to the $\mathrm{B}_s{}^{-}$ atom, and leads to predictions for the defect generation rate that are in excellent quantitative agreement with experiment.

Figure 1

Measured rate $R_{\mathrm{gen}}$ of the slow defect-formation process at $298\mathrm{K}$ as a function of the boron-doping concentration $\left[B_s\right]$. It is seen that the defect-generation rate is proportional to the square of the boron concentration over more than two orders of magnitude of $\left[B_s\right]$. The data of Rein et al. are from Ref. 15.

Figure 2

Measured rate $R_{\mathrm{gen}}$ of the slow defect-formation process at $298\mathrm{K}$ as a function of the interstitial oxygen concentration $\left[{\mathrm{O}}_i\right]$ in silicon having a boron-doping concentration of $2.2\times {10}^{16}{\mathrm{cm}}^{-3}$. The data show that the defect-generation rate is independent of the oxygen concentration.

Figure 3

The measured temperature dependence of the defect generation parameter $R_{\mathrm{gen}}$ of the slowly forming degradation defect for two silicon samples having boron-doping concentrations $\left[B_s\right]$ of $1.25\times {10}^{16}$ and $3.85\times {10}^{16}{\mathrm{cm}}^{-3}$, respectively. The symbol ${\kappa }_0$ indicates the values of the preexponential factors of the Arrhenius plots as deduced from the experimental data shown.