Phosphine Dissociation on the Si(001) Surface

Density functional calculations are performed to identify features observed in STM experiments after phosphine (${\mathrm{P}\mathrm{H}}_3$) dosing of the Si(001) surface. On the basis of a comprehensive survey of possible structures, energetics, and simulated STM images, three prominent STM features are assigned to structures containing surface bound ${\mathrm{P}\mathrm{H}}_2$, PH, and P, respectively. Collectively, the assigned features outline for the first time a detailed mechanism of ${\mathrm{P}\mathrm{H}}_3$ dissociation and P incorporation on Si(001).