Nanoscale evaluation of surface roughness of metal films prepared by laser ablation

The surface roughness of laser-ablated metal films is evaluated by an atomic force microscope (AFM). The films are deposited on glass substrates using a pulsed Nd:YAG laser. The target is bulk metal such as Ni and Ti. The AFM is confirmed to be a useful tool for measurements of surface roughness on the nanometer scale. Measured values may differ from the real value, depending on the tip radius and the roughness. The reliability of the measured value is discussed in consideration of the locus of the rolling-circle of a tip radius, using simple models. The roughness obtained is 4.3-6.9 nm maximum peak-valley height, and this value is found to be affected by the laser energy density.