Enhancement of the Adhesion of Beryllium Films with Interfacial Beo to Carbon Substrates

Abstract

AbstractWe have used 200 keV carbon ions to enhance the adhesion of 240-nm thick Be films to polished, vitreous carbon substrates. Adhesion of the as-deposited films was below that necessary to pass the scotch-tape test, but carbon ion fluences less than 1.6xl014 C/cm2 were sufficient to ensure the passage of the tape test without affecting the optical properties of the films. Adhesion failure of the as-deposited film was attributed to an inner oxide layer between the Be and the carbon. Because this oxide (-5 nm of BeO) was not measurably changed by the irradiation process, these results are consistent with adhesion enhancement occurring on the atomic scale at the interface between the inner oxide and the carbon substrate, and this conclusion was supported by Rutherford backscattering (RBS) data. Potential adhesion mechanisms are discussed with consideration of relative contributions from electronic and nuclear stopping.