ENHANCEMENT OF ADHESION IN ION-BEAM-MIXED CU/SIO2 SYSTEMS

A thin Cu layer (35 nm) deposited on SiO2 has been mixed with 80-keV Ar+ at room temperature, 550 K, and 650 K. Interfacial properties of the irradiated samples were investigated with Rutherford backscattering spectroscopy (RBS), grazing angle X-ray diffraction (GXRD), and X-ray photo-electron spectroscopy (XPS), and by using a scratch tester. Adhesion of the Cu film was improved by a factor of 3 and at a dose of 1.5 X 10(16) Ar+/cm2 by ion-beam mixing at room temperature, while high-temperature ion-beam mixing enhanced the adhesion by a factor of 5. Ballistic mixing plays a role in improving the adhesion for room-temperature ion-mixing, and creation of the Cu2O phase induced by ion-beam mixing contributes to the enhancement of the adhesion at high temperature.