Morphological characterization and nanoindentation hardness scatter evaluation for Cu-W thin films based on wavelet transform

A strategy based on wavelet transform to describe surface morphology of thin films is presented in this paper. The evolution of surface morphology of Cu-W thin films with deposition time on silicon wafers was investigated by discrete wavelet transform (DWT) method. The results show that the surface morphology of the thin films is unstable until the sputtering time exceeds 10 min. The surface morphology variation of different thin films can be distinguished primarily by high frequency signals. A scattering of the nanoindentation hardness values, which results from the roughness of the thin films surface, can be characterized by the roughness defined by the surface texture based on wavelet transform.