Realization of High-Reliable Thin Film Capacitor by Anodizing A1- Transition Metal Intermetallic Compounds

一般来说，许多化学计量金属间化合物在高温下表现出高硬度和高热稳定性。由阀门金属组成的化学计量比和低阻金属间化合物可以通过阳极氧化来实现高耐热和低损耗的薄膜电容器。此外，由于Hf、Hf、Ta氧化物的介电常数较大，如果将Al、Hf、Ta组成的金属间化合物进行阳极氧化，有望实现高介电常数电容器。为此，我们采用共溅射法制备了Al_3Hf、Al_3Zr和Al_3Ta金属间化合物薄膜，并对其电容器性能、漏电流和耐热性能进行了测试。结果表明：(1)这些阳极氧化电容器的耐热性能优于目前广泛使用的Ta阳极氧化电容器。(2)Al_3Ta电容器的介电常数最高。(3)Al_3Hf电容器的耐热性能最好，Al_3Zr的初始电容器性能最好。(4)三种阳极氧化电容器的漏电流极性差异不明显，因此，铝过渡金属间化合物阳极氧化制备的薄膜电容器是实现高可靠性薄膜电容器的最有前途的方法之一。

Generally, many stoichiometric intermetallic compounds exhibit high hardeness and high thermal stability at high temperatures. It is then expected that thin film capacitors with high heat-proof properties and low loss properties can be realized by anodizing stoichiometric and low-resistive intermetallic compounds composed of valve metals which are able to anodize. In addition, if intermetallic compounds which are composed of Al and Hf, Zr and Ta are anodized, we expect that high permitivity capacitor can be realized because the dielectric constans of Hf, Zr and Ta oxides are relatively large. Therefore, we prepared the intermetallic compound films of Al_3Hf, Al_3Zr and Al_3Ta by co-sputtering method, and examined the capacitor properties, leakage current and the heat-proof properties of these anodized capacitors. Following results were obtained.(1) The heat-proof properties of these anodized capacitors were superior to that of Ta anodized capacitor which has been widely used to date. (2) The dielectric constant of Al_3Ta capacitor among these capacitors was the highest. (3)The best heat-proof property could be obtained by using Al_3Hf capacitor, while the initial capacitor properties of Al_3Zr was the best. (4) The difference of the polarity on the leakage current was not recognized in these three anodized capacitors.Therefore, it is concluded that the thin film capacitors prepared by anodizing Al-transition metal intermetallic compounds are one of the most promising mothods to realize high reliable thin film capacitors.