ADHESION IMPROVEMENT OF DIAMOND AND OTHER FILMS AFTER MEV ION IRRADIATION

This paper reports the effects of MeV ion irradiation on the adhesion and quality of diamond films on WC-Co tool-bits and silver films on so da glass. Diamond films of about 3 mu m thickness were prepared, using the hot filament CVD technique, on WC-Co tool-bits. Silver films of 1 000 Angstrom thickness were prepared, using the Joule evaporation tech nique, on soda glass. 100 MeV I-127 beam was irradiated on the films a t various doses up to 1 x 10(14) ions/cm(2). Adhesion strength was mea sured using a pin-pull test. Scotch tape test was also performed on so me of the films; SEM images show no morphological modifications of the diamond films after irradiation. Laser Raman spectra show that the ir radiation causes almost complete elimination of non-diamond carbon pre sent in the films. Adhesion strength of the diamond films as determine d by Pin-pull test show improvement at least by 65 kgf/cm(2) after irr adiation. Improvement in the adhesion of silver films is found to be d ependent on the amount of electronic energy loss (S-e) at the film-sub strate interface. It is shown that for silver film on soda glass S-e > 0.7 keV/Angstrom, is needed if the adhesion is required to be achieve d at a dose of 1 x 10(13) ions/cm(2) using ion irradiation of 100 MeV I-127 beam. Main cause of the improvements in the adhesion and quality of the films is suggested to be the energy deposited to the electroni c system of the material by the projectile ion. (C) 1998 Elsevier Scie nce Ltd. All rights reserved.