Molecular dissociation of group-V hydrides on Si(001)

We present a comparative ab initio survey of possible dissociation products of NH₃, PH₃, and AsH₃ on the Si(001) surface. In agreement with previous studies, we find that the relative energetics of XH₃ and XH₂ species (X=N, P , As) are common across all three systems. In contrast, the energetics of the onward dissociation into XH and X species differs markedly between nitrogen on the one hand, and phosphorus and arsenic on the other.