AlxSiyOz coatings deposited by pulsed direct current reactive magnetron sputtering for dielectric applications

This research aims to study the structure, chemical composition, and dielectric strength of aluminum silicon oxide (Al x Si y O z ) coatings deposited on silicon and steel substrates by pulsed direct current reactive magnetron sputtering at a constant temperature of 150 °C. Four targets containing different concentrations of aluminum and silicon are sputtered in an argon-oxygen atmosphere to produce ternary oxide coatings of Al x Si y O z . Argon flow is maintained at 60 sccm during deposition, and the impact of different oxygen flows is studied ( = 3, 4, and 5 sccm). These experimental conditions produce Al x Si y O z coatings with the same columnar morphology and amorphous structure. On the other hand, the chemical composition, deposition rate, and dielectric strength of Al x Si y O z coatings are highly impacted by the target composition and oxygen flow rate used during deposition. The highest dielectric strength was obtained by sputtering an AlSi target (90 at.% of aluminum and 10 at.% of silicon) in a reactive atmosphere containing 60 sccm of argon and 5 sccm of oxygen.