Piezoelectric element
A piezoelectric element 10 includes a lower electrode, constituted of a Pt/Ti laminated film, a PLT seed layer, formed on the lower electrode, a PZT piezoelectric film, formed on the PLT seed layer, and an upper electrode, formed on the PZT piezoelectric film. A curve Q 1 is a curve drawn such as to pass through a plurality of plotted points, each expressing a PLT ( 100 ) peak intensity with respect to a Pt ( 111 ) peak intensity according to a substrate setting temperature during forming of the Pt/Ti laminated film. A relationship of the PLT ( 100 ) peak intensity with respect to the Pt ( 111 ) peak intensity is within a range in the curve Q 1 until the PLT ( 100 ) peak intensity decreases by 5% from a peak point P, at which the PLT ( 100 ) peak intensity is the maximum, and a ( 100 ) orientation rate of PLT constituting the seed layer is not less than 85%.
1. A piezoelectric element comprising: an insulating film, formed on a substrate; a lead barrier film, formed on the insulating film; a lower electrode, formed on the lead barrier film; a seed layer, formed on the lower electrode and comprised of a sputtered film having lead lanthanum titanate (PLT) as a main component; and a piezoelectric film, formed on the seed layer and having lead zirconate titanate (PZT) or lead lanthanum zirconate titanate (PLZT) as a main component; and wherein the lower electrode is comprised of a laminated film of a Ti film at the substrate side and a Pt film laminated on the Ti film,
the piezoelectric element being such that a ( 111 ) orientation peak intensity of the Pt constituting the Pt film is 17×10000 counts to 35×10000 counts and a ( 100 ) orientation peak intensity of the PLT constituting the seed layer is not less than 70×1000 counts, and
a film thickness of the lead barrier film is thinner than a film thickness of the insulating film.
2. The piezoelectric element according to claim 1 , wherein a film thickness of the seed layer is 20 nm to 100 nm,
a film thickness of the Pt film is 50 nm to 200 mm, and
a film thickness of the Ti film is not more than 10 nm.
3. The piezoelectric element according to claim 1 , wherein the piezoelectric film is a piezoelectric film formed by a sol-gel method.
4. The piezoelectric element according to claim 1 , wherein the seed layer has, near the lower electrode side, a Pb-rich layer high in Pb concentration.
5. The piezoelectric element according to claim 1 , further comprising: an upper electrode formed on the piezoelectric film.
6. The piezoelectric element according to claim 1 , wherein the insulating film comprises SiO 2 .
7. The piezoelectric element according to claim 6 , wherein the lead barrier film comprises Al 2 O 3 .
8. The piezoelectric element according to claim 6 , wherein a film thickness of the insulating film is 300 nm to 2000 nm.
9. The piezoelectric element according to claim 7 , wherein a film thickness of the insulating film is 300 nm to 2000 nm and a film thickness of the lead barrier film is 50 nm to 100 nm.