| 摘要 |
PROBLEM TO BE SOLVED: To provide a piezoelectric thin film element with high durability and excellent reliability by satisfying a specific formula for the relation between the film thickness of a platinum lower part electrode and a silicon dioxide film thickeners. SOLUTION: In the piezoelectric thin film element 110, the relation between the film thickness X of a platinum lower part electrode 104 and the film thickness Y of a silicon dioxide film 201 is specified to satisfy the following inequities; 0.5<=X/Y<=4 and 3000Å<=X<=2μm. At this time, if X/Y exceeds 4, the platinum lower part electrode 104 becomes to be easily peeled by the tensile stress threrof, and if X/T does not exceed 0.5, floating may be caused in the platinum lower part electrode film and a PZT film, and the PZT film becomes to be easily peeled. On the other hand, if the film thickness X of the platinum lower part electrode 104 is lower than 3000Å, the adhesive properties if the electrode 104 becomes to be easily deteriorated, while of the film thickness X exceeds 2μm, the bond properties becomes to be easily deteriorated. The piezoelectric thin film element with high durability and excellent reliability can be provided by satisfying the specific formula. |
