Effect of annealing on preferred orientations in the Cu/SiO2 and Cu/SiO2/Si(1 0 0) interfaces

The morphology and preferred orientations of copper thin films over SiO2 and SiO2/Si(1 0 0) substrates have been experimentally investigated using scanning electron microscopy, X-ray diffraction and the modified sphere-plate techniques. The analysis was performed using diffraction intensity patterns and pole figures before and after annealing at 540 and 730 °C. The as-deposited films were found to be randomly oriented. The lower temperature annealing was insufficient to reveal the preferred orientations of the films because of limited recrystallization. However, for the copper thin film on the SiO2/Si(1 0 0) substrate, the (1 1 1) texture was found to be stronger for the as-deposited state and after annealing at 540 °C. At the higher temperature annealing, a strong (1 1 1) preferred orientation was detected for Cu on both substrates indicating the existence of a cusp in the interfacial energy curve corresponding to the close-packed plane in copper.