Uphill phosphorus diffusion in carbon co-implanted silicon
Résumé
An intriguing uphill diffusion phenomenon related to phosphorus has been observed in carbon co-implanted silicon. This phenomenon has been investigated using Transmission Electron Microscopy, Secondary Ion Mass Spectroscopy, and Atom Probe Tomography. Our results indicate that uphill diffusion occurs in crystalline silicon, once the recrystallization of the amorphous layer induced by ion implantation has ended. This phenomenon results in the formation of a steep, highly concentrated, and electrically active dopant peak. A one-dimensional model has been used to understand the underlying mechanism of peak formation. The heterogeneous concentration of self-interstitials across the implanted region has been shown to be responsible for the uphill diffusion phenomenon.