Role of surface morphological parameters on wettability of obliquely deposited Cu thin films in a plasma focus device

Correlation between surface statistical parameters obtained by atomic force microscopy (AFM) analysis such as root-mean-square roughness, correlation length, fractal dimension, as well as surface chemistry and wetting behavior of obliquely deposited copper thin films is investigated. Six samples were positioned at different angular locations with respect to anode axis during deposition process in a plasma focus device. Grazing incidence x-ray diffraction (GIXRD) analysis of the samples shows formation of cubic copper crystalline structure and Fourier transform infrared spectroscopy (FTIR) studies depicts presence of copper oxide. The morphological characterization reveals that the wettability of films obeys the Wenzel regime and the surface fractal dimension plays a key role in determination of the contact angle of surfaces. There is a similar behavioral trend for fractal dimension and water contact angle in the investigated samples. Findings of this study reflect the role of irregularity at short length scales in surface wettability.

Automated summary

The correlation between surface statistical parameters and the wetting behavior of obliquely deposited copper thin films was investigated using atomic force microscopy (AFM) analysis. The study found that the surface fractal dimension played a key role in determining the contact angle of the surfaces, and there was a similar behavioral trend for fractal dimension and water contact angle in the investigated samples. This study highlights the importance of irregularity at short length scales in determining surface wettability.