Theoretical Investigation of the Ammonia Adsorption Process on Si(100)-2x1 Surface

The nature of the NH₃ adsorption process on Si(100)-2x1 surface has been studied by DV-X_α (discrete variational X_α method) and ASED-MO (atom superposition and electron delocalization molecular orbital theory) methods. The calculated results show that NH₃ is dissociatively adsorbed on the surface dangling bonds as NH₂(a) and H(a) un'th no activation barrier. But the further decomposion of NH₂(a) to NH(a) and N(a) has been found to have activation barriers of 0.87 and 1.65eV respectively. The bond geometries and electronic structures of these NH₃-derived adsorbed species are described in detail.