Deposition and characterization of AlN thin films on ceramic electric insulators using pulsed DC magnetron sputtering

• Hydrophobic AlN thin film applied over porcelain electrical insulator surface.
• Thin film with self clean and dielectric properties.
• AlN thin film obtained with low time deposition without substrate heating.

Porcelain electric insulators are fundamental support devices to act as holders for transmission lines. The exposition to pollutants environments such as industrial areas, deserts and sea air, containing carbon, sand and salt are examples that can reduce the devices dielectric property. The present investigation aims to develop and characterize hydrophobic aluminum nitride thin films, deposited on porcelain insulators surfaces, using a pulsed direct current magnetron sputtering (PDMS). An aluminum target with 99.999% purity was used as precursor and nitrogen 99.999% purity was employed. The film characterization was performed using AFM, FEG and FTIR. The surface resistivity was evaluated by four-point probe method. Different deposition times lead to different wettability characteristics, verified by the sessile drop method using a goniometer. The experimental results show the formation of a low roughness aluminum nitride film with hydrophobic properties over the glazed surface of a commercial porcelain electrical insulator.