Polycrystalline dielectric thin film and capacitor element

Patent metadata

Field	Value
Publication number	US-10707018-B2
Application number	US-201716069095-A
Country	US
Kind code	B2
Filing date	Feb 1, 2017
Priority date	Feb 1, 2016
Publication date	Jul 7, 2020
Grant date	Jul 7, 2020

Abstract

A polycrystalline dielectric thin film and a capacitor element have a large relative dielectric constant. The polycrystalline dielectric thin film has a perovskite oxynitride as a principal component. The perovskite oxynitride is represented by compositional formula A a1 B b1 O o N n (a1+b1+o+n=5), and the a-axis length of the crystal lattice of the perovskite oxynitride is larger than a theoretical value.

First claim

The invention claimed is:

1. A polycrystalline dielectric thin film, comprising a main component of a perovskite-type oxynitride,
wherein the perovskite-type oxynitride is represented by a composition formula of Sr a1 Ta b1 O o N n (a1+b1+o+n=5),
wherein an a-axis length of a crystal lattice of the perovskite-type oxynitride is larger than a theoretical value of a-axis length of the perovskite-type oxynitride, and

wherein the a-axis length is 5.695 Å or more.

2. The polycrystalline dielectric thin film according to claim 1 , wherein all of the a-axis length, a b-axis length, and a c-axis length of the crystal lattice are larger than their theoretical values of the a-axis length of the perovskite-type oxynitride, a b-axis length of the perovskite-type oxynitride, and a c-axis length of the perovskite-type oxynitride, respectively.

3. The polycrystalline dielectric thin film according to claim 1 , comprising an octahedron structure of TaO 4 N 2 , wherein an arrangement of N in the octahedron structure is cis-type.

4. The polycrystalline dielectric thin film according to claim 2 , comprising an octahedron structure of TaO 4 N 2 , wherein an arrangement of N in the octahedron structure is cis-type.

5. The polycrystalline dielectric thin film according to claim 1 , wherein a sum of an average valence of A-site ions and an average valence of B-site ions is seven.

6. The polycrystalline dielectric thin film according to claim 2 , wherein a sum of an average valence of A-site ions and an average valence of B-site ions is seven.

7. The polycrystalline dielectric thin film according to claim 1 , wherein the a-axis length is 5.705 Å or more.

8. The polycrystalline dielectric thin film according to claim 2 , wherein the a-axis length is 5.705 Å or more.

9. The polycrystalline dielectric thin film according to claim 1 , wherein the film has a thickness of 10 nm to 1 μm.

10. The polycrystalline dielectric thin film according to claim 2 , wherein the film has a thickness of 10 nm to 1 μm.

11. A capacitor element comprising the polycrystalline dielectric thin film according to claim 1 .

12. A capacitor element comprising the polycrystalline dielectric thin film according to claim 2 .

Assignees

• Tdk Corp

Inventors

• Yamazaki Kumiko
• Chihara Hiroshi
• Nagamine Yuki
• Yamazaki Junichi
• Umeda Yuji

Classifications

• H01G4/33 Primary

  Thin- or thick-film capacitors {(thin- or thick-film circuits; capacitors without a potential-jump or surface barrier specially adapted for integrated circuits, details thereof, multistep manufacturing processes therefor)} · CPC title

• H01B3/00

  Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties · CPC title

• C01B21/0821

  Oxynitrides of metals, boron or silicon · CPC title

• H01G4/08 Primary

  Inorganic dielectrics · CPC title

• C01P2006/40

  Electric properties · CPC title