Ferroelectric thin film, method of manufacturing same and method of manufacturing piezoelectric element

Patent metadata

Field	Value
Publication number	US-9705070-B2
Application number	US-201113884869-A
Country	US
Kind code	B2
Filing date	Oct 26, 2011
Priority date	Nov 10, 2010
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

In order to obtain a ferroelectric thin film that is formed to have a predetermined thickness on a substrate, that have satisfactory crystallization and that achieves a high piezoelectric property, a method of manufacturing such a ferroelectric thin film and a method of manufacturing a piezoelectric element having such a ferroelectric thin film, when a dielectric material of a perovskite structure is formed into a film on the substrate, a predetermined amount of additive is mixed with PZT, and the concentration of the additive mixed is varied in the thickness direction of the thin film.

First claim

The invention claimed is:

1. A ferroelectric thin film element comprising:
a base member; and
a ferroelectric thin film formed on the base member, the thin film being formed of a dielectric material of a perovskite structure,
wherein the dielectric material is a composite oxide in which an additive of a metallic material other than Pb, Zr and Ti is mixed with PZT, and a concentration of the additive is substantially zero in the vicinity of the base member and is varied in the thickness direction of the thin film, and
wherein the thin film includes a first layer in which the concentration of the additive is substantially zero and a second layer in which the concentration of the additive is a predetermined concentration and the first and second layers are alternately repeated in the thickness direction of the thin film.

2. The ferroelectric thin film element according to claim 1 ,
wherein the additive substitutes for an A site in the perovskite structure of an ABO.sub.3 configuration, and is at least one type of metallic ion selected from a group consisting of lanthanoides including La and Nd, Sr and Bi.

3. The ferroelectric thin film element according to claim 1 ,
wherein the additive substitutes for a B site in the perovskite structure of the ABO.sub.3 configuration, and is at least one type of metallic ion selected from a group consisting of Nb, Ta, W and Sb.

4. The ferroelectric thin film element according to claim 1 ,
wherein the additive is La, and the concentration of La in the first layer is substantially zero and the concentration of La in the second layer is 8%.

5. The ferroelectric thin film element according to claim 1 ,
wherein the entire thickness of the thin film is 3 to 5 μm.

Assignees

• Mawatari Kenji
• Konica Minolta Inc

Inventors

• Mawatari Kenji

Classifications

• G01J5/34 Primary

  using capacitors, e.g. pyroelectric capacitors · CPC title

• H03H9/02031

  consisting of ceramic · CPC title

• H01L41/0805

  Electricity · mapped topic

• C04B2235/3224

  Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide · CPC title

• C04B2235/3258

  Tungsten oxides, tungstates, or oxide-forming salts thereof · CPC title