Capacitor

Patent metadata

Field	Value
Publication number	US-10249434-B2
Application number	US-201815879882-A
Country	US
Kind code	B2
Filing date	Jan 25, 2018
Priority date	Aug 12, 2015
Publication date	Apr 2, 2019
Grant date	Apr 2, 2019

Abstract

A capacitor that includes a conductive porous substrate having a porous portion; a dielectric layer on the porous portion and containing an oxygen element and at least metal element; and an upper electrode on the dielectric layer. The porous portion has a path integral value of 1 μm/μm 2 to 16 μm/μm 2 , and a porosity of 20% to 90%, and a ratio Z expressed by (1) below is 0.79 or more,
Z = O d / M d O r / M r ( 1 )
where O d and M d respectively represent signal intensities of the oxygen element and the metal element when the dielectric layer is analyzed by energy dispersive X-ray spectroscopy (EDS), and where O r and M r respectively represent signal intensities of the oxygen element and the metal element when a reference material having stoichiometric composition of the oxygen element and the at least one metal element constituting the dielectric layer is analyzed by the EDS.

First claim

The invention claimed is:

1. A capacitor comprising:
a conductive porous substrate having a porous portion;
an upper electrode; and
a dielectric layer between the upper electrode and the porous portion and containing an oxygen element and at least one metal element; and
wherein the porous portion has a path integral value of 1 μm/μm 2 to 16 μm/μm 2 , and a porosity of 20% to 90%, and wherein a ratio Z expressed by (1) is 0.79 or more,

Z
=

O
d

/

M
d

O
r

/

M
r

(
1
)

where O d and M d respectively represent signal intensities of the oxygen element and the at least one metal element when the dielectric layer is analyzed by energy dispersive X-ray spectroscopy, and
where O r and M r respectively represent signal intensities of the oxygen element and the metal element when a reference material having stoichiometric composition of the oxygen element and the at least one metal element constituting the dielectric layer is analyzed by the energy dispersive X-ray spectroscopy.

2. The capacitor according to claim 1 , wherein, when the path integral value (μm/μm 2 ) and the porosity of the porous portion are indicated as x and y, respectively, and are plotted on a plane formed by an x-axis and a y-axis orthogonal to each other, (x, y) is within a region surrounded by points A (2.0, 49), B (12.2, 49), C (12.2, 63), D (15.0, 63), E (15.0, 88), F (4.6, 88), G (3.8, 85), and H (3.8, 63).

3. The capacitor according to claim 1 , wherein the porosity is 30% to 80%.

4. The capacitor according to claim 1 , wherein the path integral value is 2 μm/μm 2 to 15 μm/μm 2 .

5. The capacitor according to claim 1 , wherein the path integral value is 4 μm/μm 2 to 12 μm/μm 2 .

6. The capacitor according to claim 1 , wherein the at least one metal element is selected from Al, Hf, Si, Zr, Ta, Ti, Sr, Pb, La, Ba and Nb.

7. The capacitor according to claim 2 , wherein the at least one metal element is selected from Al, Hf, Si, Zr, Ta, Ti, Sr, Pb, La, Ba and Nb.

8. The capacitor according to claim 1 , wherein the at least one metal element is selected from Al, Hf, Si and Zr.

9. The capacitor according to claim 8 , wherein the reference material is at least one selected from Al 2 O 3 , HfO 2 , SiO 2 and ZrO 2 , or a mixture thereof.

10. The capacitor according to claim 2 , wherein the at least one metal element is selected from Al, Hf, Si and Zr.

11. The capacitor according to claim 10 , wherein the reference material is at least one selected from Al 2 O 3 , HfO 2 , SiO 2 and ZrO 2 , or a mixture thereof.

12. The capacitor according to claim 1 , wherein the ratio Z is 0.79 to 1.2.

13. The capacitor according to claim 1 , wherein the dielectric layer is an atomic layer deposited dielectric layer.

14. The capacitor according to claim 1 , wherein the upper electrode layer is an atomic layer deposited upper electrode layer.

Assignees

• Murata Manufacturing Co

Inventors

• Saeki Hiromasa
• Takada Mika

Classifications

• H01G9/04

  Electrodes {or formation of dielectric layers thereon} · CPC title

• H01G4/12

  Ceramic dielectrics {(H01G4/085 takes precedence)} · CPC title

• H01G4/00

  Fixed capacitors; Processes of their manufacture (electrolytic capacitors H01G9/00) · CPC title

• H01G4/008

  Selection of materials · CPC title

• H01G4/005

  Electrodes · CPC title