Maximum Active Concentration of Ion-Implanted Phosphorus During Solid-Phase Epitaxial Recrystallization

In this paper, we showed that the maximum active P concentration of approximately 2 times10²⁰ cm^-3 exists during solid-phase epitaxial recrystallization (SPER). This maximum active concentration is close to the reported values for other active impurity concentrations during SPER. We introduced the concept of an isolated impurity that has no neighbor impurities with a certain lattice range. Assuming that impurities interact with three or four neighbor impurities, we can explain the activation phenomenon during SPER. According to our model, the isolated P concentration N _iso has a maximum value of approximately 2 times10²⁰ cm^-3 at a total impurity concentration of approximately 10²¹ cm^-3, and it decreases with a further increase in total impurity concentration. Deactivation occurs after the completion of SPER with increasing annealing time, and the active impurity concentration decreases with time but is always higher than the maximum diffusion concentration N _{Diff max}. We also observed that N _{Diff max} is independent of the annealing time despite nonthermal activation in the high-concentration region. We evaluated the dependence of N _{Diff max} on annealing temperatures. We think that this N _{Diff max} can be regarded as the electrical solid solubility N _Esol that the active impurity concentration reaches in thermal equilibrium. We observed the transient enhanced diffusion (TED) after the completion of SPER, and that, the deactivation process continues during and after TED, and the corresponding diffusion coefficient is still much higher than that in thermal equilibrium even after TED has finished, which suggests that the deactivation process releases point defects.