Electrical insulation and breakdown properties of SiO2 and Al2O3 thin multilayer films deposited on stainless steel by physical vapor deposition

• SiO2 and Al2O3 thin layers have been deposited on stainless steel substrates.
• Electrical insulation and breakdown properties have been characterized.
• Multilayered barriers showed improved insulation properties.
• The effect of a temperature annealing process has been quantified.

The electrical properties of dielectric thin layers deposited on conducting substrates still need to be thoroughly characterized for a wide variety of applications such as solar modules, flexible displays and sensor integration. In this work, thin dielectric films composed of layers and alternated multilayers of SiO2 and Al2O3 up to a total thickness of 3 μm have been deposited on flexible rough stainless steel substrates by means of reactive magnetron sputtering. Their electrical properties have been studied focusing on important parameters such as leakage current density and disruptive field strengths. Moreover, temperature annealing and bending effects have been quantified. It is concluded that the best electrical properties with this type of materials are achieved with multilayered structures.