Effect of Pulsed Laser Irradiation on Microstructure and Evolution of Residual Stress for Gold Film

Gold film is extensively used in a variety of electronic, optical, and magnetic instruments or devices. Effect of pulsed laser irradiation on microstructure and evolution of residual stress for gold film is studied. Gold film deposited on a silica substrate is irradiated by pulsed laser with different energy densities. Microstructures of the gold film before and after laser irradiation are studied by using scanning electron microscope, scanning transmission electron microscope, and energy-dispersive X-ray spectrometry. Recrystallization occurs during laser irradiation. Most of the original defects in the as-deposited gold film are eliminated, and the films become smooth and more compact after laser irradiation. Curvature-based technique using Stoney formula is applied to evaluate the residual stress. Pulsed laser irradiation results in the increase in tensile residual stress and stability of the residual stress.