Patent ID: 8119192

Claim:
A method of manufacturing a piezoelectric element, comprising: a lower electrode forming step of forming a lower electrode on a surface of a substrate; a piezoelectric film deposition step of depositing a piezoelectric film made of a piezoelectric material by one of epitaxial growth and oriented growth onto a surface of the lower electrode reverse to a surface of the lower electrode that is adjacent to the substrate; an upper electrode forming step of forming an upper electrode onto a surface of the piezoelectric film reverse to a surface of the piezoelectric film that is adjacent to the lower electrode; a polarization direction reversal step of reversing a polarization direction of the piezoelectric film by maintaining, after the upper electrode forming step, a state for a prescribed duration where a temperature of the piezoelectric film is set to a first temperature while application of an electric field to the piezoelectric film in a direction from the upper electrode toward the lower electrode is performed, then keeping the application of the electric field while lowering the temperature of the piezoelectric film to a second temperature lower than the first temperature, and then stopping the application of the electric field; a wiring member bonding step of, after the polarization direction reversal step, bonding a wiring member to the upper electrode under a condition where the piezoelectric film is exposed to a third temperature not lower than 130° C. and not higher than 150° C., the wiring member having a wiring pattern to be connected to an external device; and a repolarization step of, immediately after the wiring member bonding step, carrying out repolarization processing by applying an electric field to the piezoelectric film in a direction from the upper electrode toward the lower electrode at normal temperature.