Capacitors using porous alumina structures

Patent metadata

Field	Value
Publication number	US-10147548-B2
Application number	US-201514733269-A
Country	US
Kind code	B2
Filing date	Jun 8, 2015
Priority date	Mar 12, 2013
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

Capacitors and methods of making the same are disclosed herein. In one embodiment, a capacitor comprises a structure having first and second oppositely facing surfaces and a plurality of pores each extending in a first direction from the first surface towards the second surface, and each having pore having insulating material extending along a wall of the pore; a first conductive portion comprising an electrically conductive material extending within at least some of the pores; and a second conductive portion comprising a region of the structure consisting essentially of aluminum surrounding individual pores of the plurality of pores, the second conductive portion electrically isolated from the first conductive portion by the insulating material extending along the walls of the pores.

First claim

The invention claimed is:

1. A capacitor, comprising:
an aluminum substrate having first and second oppositely facing surfaces and a plurality of pores each extending in a first direction from the first surface towards the second surface, and having insulating material extending along a wall of each pore, each of the plurality of pores being filled with at least one of a non-conductive material or voids,
the aluminum substrate having a first portion and a second portion, the second portion electrically isolated from the first portion by the insulating material extending along the walls of the pores; and
wherein the first portion, the second portion, and the insulating material separating the first portion from the second portion operate together as a capacitor.

2. The capacitor of claim 1 , wherein each pore has a diameter of less than 2 micrometers.

3. The capacitor of claim 1 , wherein the insulating material is alumina.

4. The capacitor as claimed in claim 1 , wherein at least some of the pores are disposed in an annular pattern, wherein the second conductive portion is separated from the first conductive portion by the annular pattern.

5. The capacitor of claim 1 , further comprising:
a first capacitor electrode electrically connected with the first conductive portion;
a second capacitor electrode electrically connected with the second conductive portion,
each of the first and second capacitor electrodes being accessible for connection with at least one component external to the capacitor.

6. The capacitor of claim 5 , wherein each of the first and second capacitor electrodes are accessible at one of the first or second surfaces for connection with the at least one component.

7. The capacitor of claim 1 , wherein the plurality of pores form at least a portion of a boundary between the first portion and the second portion.

8. A capacitor, comprising:
an aluminum substrate having first and second oppositely facing surfaces and a plurality of pores each extending in a first direction from the first surface towards the second surface, and having insulating material extending along a wall of each pore,
the aluminum substrate having a first portion and a second portion, the second portion electrically isolated from the first portion by the insulating material extending along the walls of the pores, wherein the first portion, the second portion, and the insulating material separating the first portion from the second portion operate together as a capacitor;
a dielectric region overlying the first surface;
a plurality of first conductive elements extending through dielectric region in the first direction towards the first surface, to electrically connect the first electrode to the first region; and
a plurality of second conductive elements, extending through the dielectric region in the first direction towards the first surface, to electrically connect the second electrode to the second region.

9. A method of fabricating a capacitor, comprising:
forming a plurality of pores in a structure consisting essentially of aluminum, each pore extending in a first direction from a first surface of the region towards a second surface opposite the first surface, and each pore having a dielectric material extending along a wall of the pore, the forming performed such that the insulating material of the pores adjacent to one another is merged together to provide a continuous dielectric region,
wherein first and second regions of the structure consisting essentially of aluminum are separated from one another by the continuous dielectric region and serve as a first conductive portion and a second conductive portion, respectively, of the capacitor.

10. The method of claim 9 , wherein each pore having a diameter of less than 2 micrometers.

11. A method of fabricating a capacitor, comprising:
forming a plurality of pores in a structure consisting essentially of aluminum, each pore extending in a first direction from a first surface of the structure towards a second surface opposite the first surface, and having a dielectric material extending along a wall of the pore; and
depositing an electrically conductive material within at least some of the pores to form a first electrically conductive portion,
wherein at least a region of the structure consisting essentially of aluminum serves as a second electrically conductive portion electrically insulated from the first electrically conductive portion by at least the dielectric material extending along the walls of the pores, and
wherein the second electrically conductive portion extends from the first surface towards the second surface between adjacent ones of the plurality of pores.

12. The method of claim 11 , wherein each pore having a diameter of less than 2 micrometers.

13. The method of claim 11 , further comprising:
depositing the dielectric material within the at least some pores prior to depositing the electrically conductive material to form the first conductive portion.

14. The method of claim 13 , wherein the depositing of the dielectric material includes depositing at least one material selected from the group consisting of ferroelectric dielectric materials, zeolites, and lead zirconium titanate (PZT).

15. The method of claim 14 , further comprising reducing a thickness of alumina within the at least some pores by at least 50% prior to the depositing of the dielectric material.

16. A capacitor formed in an aluminum substrate, the substrate having a thickness extending from a first surface to a second surface, the capacitor comprising:
a first electrically conductive aluminum substrate portion;
a second electrically conductive aluminum substrate portion; and
a plurality of pores, each pore extending in a first direction from the first surface towards the second surface, and having insulating material extending along a wall of each pore, each of the plurality of pores being filled with at least one of a non-conductive material or voids,
wherein the insulating material electrically isolates the first electrically conductive aluminum portion from the second electrically conductive aluminum portion, and
wherein the first electrically conductive aluminum substrate portion and the second electrically conductive aluminum substrate portion, separated by the insulating material, operate as a capacitor.

Assignees

• Invensas Corp

Inventors

• Katkar Rajesh
• Uzoh Cyprian Emeka

Classifications

• H01G4/385

  Single unit multiple capacitors, e.g. dual capacitor in one coil · CPC title

• 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

• H01G4/08

  Inorganic dielectrics · CPC title

• H01G4/10

  Metal-oxide dielectrics {(H01G4/085 takes precedence)} · CPC title

• H01G4/01

  Form of self-supporting electrodes · CPC title