About the gas sensitivity of metal-silicon contacts with the superthin nickel and titanium films to the ammonia environment

In the present paper, the processes occurring on the external interface of the superthin metal film at the adsorption of the ammonia molecule and the influence of these processes on the functionally important property of metal-silicon Schottky barrier structures were investigated. The simulation analysis by quantum-chemistry NDDO method was used. The quantum-chemical modeling results were compared with the results of experimental investigations of Schottky barrier structures with superthin nickel and titanium metal layers. The results show that the adsorption process leads to the change of the dielectrical permittivity of the Schottky barrier structures. This can be explained by taking into account the charges redistribution on the electronic bonds of the intermediate layer, which were formed by edge atoms of the Schottky barrier structures. (C) 2000 Elsevier Science S.A. All rights reserved.