THE VAN-DER-WAALS CONTRIBUTION TO THE ADHESION ENERGY AT METAL-OXIDE INTERFACES

The van der Waals contribution to the adhesion energy between a metal and an insulating oxide is expressed in terms of a dielectric continuu m model. Values derived from the model are shown to give a good qualit ative account for experimental data. Furthermore, they are seen to rep roduce commonly reported trends in adhesion energy at metal-oxide inte rfaces since they tend to increase as the plasmon energy of the metal increases and/or as the bandgap of the insulator narrows. Such a model does not account for kinetic energy and electrostatic contributions; its relevancy to describe the adhesion energy in the metal-oxide case is discussed, and shown to be plausible provided the oxide energy gap is wide enough and the metal is sufficiently nonreactive.