Electrical Properties of a Thin Anodized Capacitor Made of Y-Doped Al Alloy Film

Sasaki³

et al. 2010

Jpn. J. Appl. Phys.

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We have examined the dielectric properties of Zr–Al anodized thin film capacitors prepared using Al-doped Zr alloy films to improve the thermal stability and capacitance density of pure-Zr anodized thin film capacitors. The Al content of the Zr–Al anodized film was varied from 0 to 24 at. %. It was revealed that the capacitance densities of the Zr–Al anodized capacitors increase with increasing Al content to 17 at. %, because the tetragonal ZrO2 phase grows and the monoclinic ZrO2 phase disappears, although pure-Zr anodized films consist of a mixture of monoclinic and tetragonal ZrO2 phases. In addition, it was confirmed that the thermal stability of the Zr–Al(17 at. %) anodized film is superior to that of the pure-Zr anodized film. We infer that this is due to the formation of the tetragonal ZrO2 phase by Al doping.

Section: Introductionmentioning

confidence: 99%

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

Kimizaki¹,

Sasaki³

et al. 2010

Jpn. J. Appl. Phys.

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“…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, it is well known that anodic oxidation is one of the simplest methods for obtaining nearly stoichiometric oxide films. As typical examples, anodized films of Ta and Al have been extensively investigated and practically used as dielectric layers for thin-film electrolytic capacitors.…”

Section: Introductionmentioning

confidence: 99%

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

Shibata¹,

Kimizaki²,

et al. 2009

Jpn. J. Appl. Phys.

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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.

“…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, anodized films of Al and Ta have been extensively investigated and used as dielectric layers for thin-film capacitors.…”

Section: Introductionmentioning

confidence: 99%

Preparation of Thin-Film Capacitor with High Reliability by Anodization of Zr–Al Alloy Film

Mikuni

Shibata²,

et al. 2007

jjap

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We have prepared Zr–Al thin-film capacitors by anodizing a sputter-deposited Zr–Al alloy film with 46 at. % Al, and examined their properties before and after heat treatment and their leakage current mechanism. In addition, anodized Zr–Al films were characterized by X-ray diffraction (XRD) analysis and Auger electron spectroscopy (AES). It is revealed that the reliability of an anodized pure-Zr capacitor is markedly improved by substituting the anodized Zr–Al film for anodized pure-Zr, because the crystallization of anodized Zr–Al amorphous films hardly occurs. In addition, it is clarified that the leakage current mechanism of the anodized Zr–Al capacitor is due to Schottky emission and that the thermal degradation observed after heat treatment above 350 °C is triggered by the diffusion of Zr atoms from the underlying unoxidized alloy layer into the anodized Zr–Al layer.