Rapid annealing of Au thin films by micron chevron-shaped laser beam scanning toward growth of single-grain crystal

A practicable solution to reduce the density of grain boundaries in metal thin films in order to improve their physical properties, and compatibility with nanoscale fabrications still remains a challenge for the thin film industry. We propose an alternative approach to the problem by using micron chevron-shaped laser beam (μCLB) annealing for rapid and selective growth of crystal grains in metal thin films. We investigate the laser annealing of various Au thin films and discuss the mechanisms of grain growth accounting for the microstructure of the Au films and interaction between the Au films and the substrate. The successful growth of single-grain crystal on a 50 nm Au film by μCLB annealing is also demonstrated and further optimization of the process is discussed. (author)