US Patent 7102274 Piezoelectric device and its manufacturing method

A piezoelectric device includes a first electrode film, a second electrode film, and a piezoelectric thin film enclosed by the first electrode film and second electrode film, in which the piezoelectric thin film is an oxide piezoelectric thin film having an oxygen deficiency amount of more than 0% and not more than 10% of the stoichiometric composition. The piezoelectric device composed of the piezoelectric thin film having such oxygen deficiency has a greater piezoelectric performance as compared with the oxide piezoelectric thin film in an oxidized state of stoichiometric composition, and by manufacturing under such a condition, the film forming speed is increased, so that the mass producibility can be improved.