Surface acoustic wave filter and manufacturing method thereof

Comprising a piezoelectric substrate and a surface acoustic wave filter formed on a conductive film on the piezoelectric substrate, the conductive thin film comprising: a first layer formed on the piezoelectric substrate, comprising at least tantalum and aluminum; and forming on the first a second metallic layer on the layer of the second layer of aluminum or an alloy mainly composed of aluminum, between the first layer and the tantalum aluminum composition ratio of tantalum content of between 39% -75% (atomic percent). Thereby improving the alignment layer is mainly made of aluminum or aluminum alloy, to improve the strength of the conductive thin film.