| 摘要 |
In a surface acoustic wave (SAW) filter including a substrate and an electrode formed on the substrate, the electrode includes a base layer, a first metal layer made of a metal consisting of Al or consisting mainly of Al, and having a given orientation relative to the substrate, a second layer for preventing the first metal layer from migration of Al atoms occurring in vertical to the substrate, and a third layer for adjusting a thickness of the layer. In this SAW filter having an arbitrary layer thickness, the layer hardly causes grain boundary diffusion, and grains of the layer can be made fine for effective resistance to stress. Thus, in this SAW filter, the migration of the Al atoms of the electrode that is associated with the SAW propagation-induced stress imposed on the electrode is inhibited. Accordingly, the filter exhibits excellent resistance against electric power. <IMAGE> |
