First-principles calculations on impurity gettering by dopants in Si crystals

Metallic impurities in silicon wafers degrade the electrical performance of semiconductor devices. Therefore, techniques to remove these impurities, known as gettering, are becoming more important in semiconductor fabrication. In this paper, we systematically calculated the binding energies as a function of distance for all combinations of three dopants (B, P, and As) and twelve metal atoms (Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Hf, Ta, and W) using first-principles calculations based on the density functional theory. It was found that the dopant–metal impurity pairs are not necessarily most stable at the nearest-neighbor position to the dopant. Our results demonstrate a novel approach to assessing the gettering ability of dopants through distance-dependent interactions with metal impurities. The results of this study are useful for fabricating higher-performance semiconductor devices.