| 摘要 |
PROBLEM TO BE SOLVED: To obtain a piezoelectric element showing good piezoelectric characteristic by setting a layer of a specific thickness and a lower dielectric constant than a piezoelectric layer along a lower electrode film. SOLUTION: In an oxygen ambience, a piezoelectric material is heated at 650 deg. for five minutes, and further at 850-950 deg.C for a short time (e.g. one minute) by RAT. At a lower temperature than this, a long-time heat treatment to complete crystallization is needed, which invites mixture of a lower electrode material, resulting in progress in segregation of the piezoelectric material. On the other hand, at a high temperature, even a short-time heat treatment owing to the high temperature causes mixture of the lower electrode material, thus promoting segregation of the piezoelectric material. A generated layer 401 of low dielectric constant has a minimum thickness at this temperature. A growth of the low-dielectric constant layer 401 is limited by the treatment to the thickness of at least 10 nm or smaller, preferably, 5 nm or smaller. |
