Evaluation of structural properties of AZO conductive films modification using low-temperature ultraviolet laser annealing

In this study, an ultraviolet (355 nm) laser processing system was developed to anneal aluminum-doped zinc oxide (AZO) thin films at room temperature in an air atmosphere; in this system, two key parameters, laser fluence and annealing speed, were varied. The structural properties of the films were thoroughly examined using field emission scanning electron microscopy, atomic force microscopy, and X-ray diffraction (XRD). The results showed that the laser fluence not only influenced the structural properties of the films, but also improved the crystallinity of the films after the laser annealing process, with minimal changes in the thickness of the films and the concentration of the elements in the films. The root mean square surface roughness (R-rms) of the films gradually increased as the laser fluence increased. Moreover, according to the XRD pattern of the films, the intensity of the main peak corresponding to the (002) direction increased as the laser fluence increased. The average crystallite size (20 nm) of the annealed films, determined using the Scherrer equation, was smaller than that of the as-deposited thin film (22 nm) due to the low temperature effect in the laser annealing process.