A study on the thin-film capacitor with high heatproof property and high reliability by using anodized film of Al3Hf intermetallic compound

✍ Scribed by Masahiko Ozeki; Misao Yamane; Katsutaka Sasaki; Yoshio Abe; Hideto Yanagisawa; Midori Kawamura

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 139 KB
• Volume: 82
• Category: Article
• ISSN: 8756-663X
• DOI: 10.1002/(sici)1520-6432(199904)82:4<17::aid-ecjb3>3.0.co;2-c

✦ Synopsis

In order to obtain thin-film capacitors with high heat resistance and high reliability, we have investigated the preparation conditions of stoichiometric Al 3 Hf intermetallic compound film and the capacitor properties and leakage current of Al 3 Hf anodized capacitors. The effect of reduction of oxide thickness on these capacitor properties and heat resistance were also studied. No appreciable change on tan G and TCC of the anodized film is found, even if anodization voltage is decreased to 10 V in order to reduce oxide thickness. Also, the leakage current remains at very low values of the order of 10 9 A at an applied voltage of 5 V. This indicates that sufficient thinning of the oxide layer is possible. In addition, no degradation of capacitor properties or leakage current is observed at heat-treatment temperatures up to 540 °C for the capacitors with a thick oxide layer anodized at 160 V, and up to 450 °C for those with a very thin oxide layer anodized at 10 V. Furthermore, almost no frequency dependence of capacitance is observed in the frequency range from 1 kHz to 1 MHz. It is concluded that Al 3 Hf anodized film is a very promising dielectric material to realize the thin-film capacitors with high heat resistance and high reliability.