Patent ID: 7357490

Claim:
An actuator device comprising: a vibration plate provided on one surface of a passage-forming substrate having pressure generating chambers formed therein; and a piezoelectric element which is provided on the vibration plate and is formed of a lower electrode, a piezoelectric layer and an upper electrode, wherein: the vibration plate has a first oxide film formed on the one surface of the passage-forming substrate, and a second oxide film formed on the first oxide film by use of a sputtering method; in only a part of an interface between the first and second oxide films, an altered layer is formed which has a first element that is a constituent element other than oxygen included in the first oxide film and a second element that is a constituent element other than oxygen included in the second oxide film, and which is a layer in which a proportion of the first element is lower than that in the first oxide film and a proportion of the second element is lower than that in the second oxide film; the first oxide film is a silicon oxide film and the first element is Si, and the second oxide film is a zirconium oxide film and the second element is Zr, and, in the altered layer, a ratio Si/Zr of a proportion of Si that is the first element to a proportion of Zr that is the second element is within a range of 1.5/1.0 to 2.0/1.0.; and a proportion of the altered layer in the entire interface between the first and second oxide films is not more than 10%.