THEORETICAL INVESTIGATION OF THE AMMONIA ADSORPTION PROCESS ON SI(100)-2X1 SURFACE

The nature of the NH3 adsorption process on Si(100)-2 x 1 surface has been studied by D V-X-alpha (discrete variational X-alpha 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) with 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 1.65 e V respectively. The bond geometries and electronic structures of these NH3-derived adsorbed species are described in detail.