Loss Properties of Anodized Thin-Film Capacitors Fabricated Using Hf-Doped Nb Alloy Films

Abstract

To improve the loss properties of Nb anodized thin-film capacitors, Nb-Hf alloy films and Nb-Hf anodized thin-film capacitors were prepared. As an example, various properties of a Nb-Hf (7 at. %) anodized thin-film capacitor with an oxide thickness of 160 nm were compared with those of pure-Nb. It was determined that the loss and leakage current properties of Nb anodized capacitors can be markedly improved by Hf doping while maintaining nearly the same capacitance density and relative permittivity. In addition, it was clarified that improvement in the loss properties of the Nb-Hf (7 at. %) anodized capacitor is due to the formation of a homogeneous complex oxide of Nb 2 O 5 and HfO 2 without lower oxides, as determined by depth analysis by Auger electron spectroscopy.

Dielectric Properties of Zr–Al Anodized Thin Film Capacitors Prepared Using Al-Doped Zr Alloy Films

“…1) These materials can be formed by various preparation methods, such as reactive sputtering, 2) pulsed laser deposition, 3) and anodic oxidation. 4,5) Among these preparation methods, anodic oxidation is the simplest method of obtaining nearly stoichiometric oxide films. As typical examples, the anodized films of Al and Ta have been extensively investigated and used as dielectric layers for thin-film capacitors.…”