Combined study on conductive AFM and damascene process to visualize Nano-Scaled defects in Cr thin films on polymer substrate

The evolution of a direct observation technique for small-sized defects in a thin film is important in understanding of a water-vapor barrier layers. An investigation into the availability of direct observation techniques for detecting nano-scaled defects in a chromium thin film on a polymer substrate was performed. The best images of nano-scaled defects in Cr thin films were obtained using conductive atomic force microscopy (C-AFM) in conjunction with a damascene process. When a dielectric Al2O3 layer was filled into the defects, such as voids or grain boundaries, in the Cr coating via this damascene process, a distinctive conductivity image was obtained from C-AFM. The major role of the dielectric material of the Al2O3 layer, when filled into the nano-scaled defects in the Cr coating, was the generation of different values in conductivity during the C-AFM analysis. The results confirmed that the combination of C-AFM and the filling of the dielectric Al2O3 layer into the defects via the damascene process is a useful method for the direct observation of nano-scaled defects comprised of deep and narrow trenches in metallic thin films on a polymer substrate.