Systematic theoretical studies of the Schottky barrier control by passivating atomic intralayers

The effect of different atomic intralayers on the Schottky barrier height p hi(bn) of covalent and ionic semiconductors has been studied theoretically. The following cases have been analysed: H/Si(111), Sb/Si(111), S/Ge(100), H/GaAs(110), Sb/GaAs(110) and As/GaAs(110). Our results show that phi(bn) i s reduced by all the intralayers and that this reduction increases with the intralayer electronegativity and the semiconductor ionicity. These results are explained by the chemical interaction between the adsorbed metal orbit als and the new levels associated with the passivating layer. This interact ion shifts the semiconductor charge neutrality level to higher energies and , consequently, reduces the Schottky barrier height. (C) 1999 Elsevier Scie nce B.V. All rights reserved.