Piezoelectric actuator, method of producing piezoelectric actuator, and liquid discharge head

A piezoelectric actuator formed on a substrate by a method, the piezoelectric actuator including a first electrode and a second electrode that sandwich a piezoelectric film having a rectangular shape, the piezoelectric film being deformed by applying an electric voltage through the first electrode and the second electrode, the method comprising:

• a first electrode film forming process of forming a first electrode film on the substrate on which the piezoelectric actuator is to be formed, wherein the first electrode film is to be the first electrode;
• a monomolecular film forming process of forming a monomolecular film at a desired area on the first electrode film by causing molecules to be self-assembled;
• a pattering process of patterning the monomolecular film to remove a portion of the monomolecular film having the rectangular shape of the piezoelectric film and exposing a portion of the first electrode film having the rectangular shape;
• an application process of applying a precursor solution of a piezoelectric material to the portion of the first electrode film exposed in the rectangular shape, wherein the precursor solution of the piezoelectric material is to be the piezoelectric film;
• a piezoelectric film forming process of converting the applied precursor solution into the piezoelectric film;
• and
• a second electrode film forming process of forming a second electrode film on the formed piezoelectric film, wherein the second electrode film is to be a second electrode;
• wherein a material of the precursor solution, a material of the first electrode film, and a material of the monomolecular film are adjusted so that the first electrode film is lyophilic with respect to the precursor solution of the piezoelectric material and the monomolecular film is lyophobic with respect to the precursor solution of the piezoelectric material;
• and
• wherein the piezoelectric film forming process includes a drying and thermally decomposing process of drying and thermally decomposing the applied precursor solution;
• and a crystallizing process of crystallizing the thermally decomposed piezoelectric material.

A liquid discharge head having a piezoelectric actuator, the piezoelectric actuator being formed on a substrate by a method, the piezoelectric actuator including a first electrode and a second electrode that sandwich a piezoelectric film having a rectangular shape, the piezoelectric film being deformed by applying an electric voltage through the first electrode and the second electrode, the method comprising:

• a first electrode film forming process of forming a first electrode film on the substrate on which the piezoelectric actuator is to be formed, wherein the first electrode film is to be the first electrode;
• a monomolecular film forming process of forming a monomolecular film at a desired area on the first electrode film by causing molecules to be self-assembled;
• a patterning process of patterning the monomolecular film to remove a portion of the monomolecular film having the rectangular shape of the piezoelectric film and exposing a portion of the first electrode film having the rectangular shape;
• an application process of applying a precursor solution of a piezoelectric material to the portion of the first electrode film exposed in the rectangular shape, wherein the precursor solution of the piezoelectric material is to be the piezoelectric film;
• a piezoelectric film forming process of converting the applied precursor solution into the piezoelectric film;
• and
• a second electrode film forming process of forming a second electrode film on the formed piezoelectric film, wherein the second electrode film is to be a second electrode;
• wherein a material of the precursor solution, a material of the first electrode film, and a material of the monomolecular film are adjusted so that the first electrode film is lyophilic with respect to the precursor solution of the piezoelectric material and the monomolecular film is lyophobic with respect to the precursor solution of the piezoelectric material;
• and
• wherein the piezoelectric film forming process includes a drying and thermally decomposing process of drying and thermally decomposing the applied precursor solution;
• and a crystallizing process of crystallizing the thermally decomposed piezoelectric material.