High precision capacitors

• US 8,446,706 B1
• Filed: 10/10/2008
• Issued: 05/21/2013
• Est. Priority Date: 10/10/2007
• Status: Active Grant

• Current Assignee: Ensurge Micropower ASA
• Original Assignee: Kovio Incorporated (Ensurge Micropower ASA)
• Inventors: Kamath, Arvind, Smith, Patrick, Scher, Erik, Li, Jiang, Choi, Criswell
• Primary Examiner(s): THOMAS, ERIC W
• Application Number:
  US12/249,841
• Time in Patent Office: 1,684 Days
• Field of Search: 361/311, 361303-305, 340/572.3
• US Class Current: 361/311
• CPC Class Codes: H01G 13/00 Apparatus specially adapted for manufacturing capacitors; Processes specially adapted for manufacturing capacitors not provided for in groups H01G4/00 - H01G11/00
• CPC Class Codes: H01G 4/002 Details
• CPC Class Codes: H01G 4/005 Electrodes
• CPC Class Codes: H01G 4/008 Selection of materials
• CPC Class Codes: H01G 4/01 Form of self-supporting electrodes
• CPC Class Codes: H01G 4/10 Metal-oxide dielectrics H01G4/085 takes precedence
• CPC Class Codes: H01G 4/1209 characterised by the ceramic dielectric material H01G4/1272, H01G4/1281 take precedence
• CPC Class Codes: H01G 4/224 Housing; Encapsulation
• CPC Class Codes: H01G 4/30 Stacked capacitors H01G4/33 takes precedence
• CPC Class Codes: H01G 4/306 made by thin film techniques
• CPC Class Codes: H01G 4/33 Thin- or thick-film capacitors thin- or thick-film circuits H01L27/00; capacitors without a potential-jump or surface barrier specially adapted for integrated circuits, details thereof, multistep manufacturing processes therefor H01L28/40
• CPC Class Codes: H01G 4/40 Structural combinations of fixed capacitors with other electric elements, the structure mainly consisting of a capacitor, e.g. RC combinations
• CPC Class Codes: H01L 2223/6677 for antenna, e.g. antenna included within housing of semiconductor device
• CPC Class Codes: H01L 23/66 High-frequency adaptations
• CPC Class Codes: H01L 27/016 Thin-film circuits
• CPC Class Codes: H01L 28/60 Electrodes
• CPC Class Codes: H01Q 1/22 by structural association with other equipment or articles
• CPC Class Codes: H01Q 1/2283 mounted in or on the surface of a semiconductor substrate as a chip-type antenna or integrated with other components into an IC package
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: Y10T 29/43 Electric condenser making
• CPC Class Codes: Y10T 29/435 : Solid dielectric type
• CPC Class Codes: Y10T 29/49002 : Electrical device making
• CPC Class Codes: Y10T 29/49016 : Antenna or wave energy "plumbing" making

Abstract

High precision capacitors and methods for forming the same utilizing a precise and highly conformal deposition process for depositing an insulating layer on substrates of various roughness and composition. The method generally comprises the steps of depositing a first insulating layer on a metal substrate by atomic layer deposition (ALD); (b) forming a first capacitor electrode on the first insulating layer; and (c) forming a second insulating layer on the first insulating layer and on or adjacent to the first capacitor electrode. Embodiments provide an improved deposition process that produces a highly conformal insulating layer on a wide range of substrates, and thereby, an improved capacitor.

Claims

1. A capacitor structure, comprising:

a) an insulating substrate selected from the group consisting of a polyimide, a glass/polymer laminate, or a high temperature polymer;

b) a first metal capacitor electrode thereon;

c) a thin insulating layer on at least part of said first metal capacitor electrode, said thin insulating layer having a substantially uniform thickness of from 3 Å

to 200 Å and

a predetermined breakdown voltage;

d) a bulk insulating layer over said first capacitor electrode, said bulk insulating layer having a first opening therein;

e) a second capacitor electrode on said thin insulating layer in said first opening and on or over said thin insulating layer and said bulk insulating layer outside said first opening, wherein a portion of said second capacitor electrode outside said first opening forms a bulk capacitor having an area at least 1 order of magnitude greater than an area of the first opening;

f) a third insulating layer on said second capacitor electrode and said second insulating layer;

g) an antenna on said third insulating layer, said antenna electrically connected to each of said first metal capacitor electrode and said second capacitor electrode.

2. The capacitor of claim 1, wherein each of said first and second capacitor electrodes are independently selected from the group consisting of Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, or a combination thereof.

3. The capacitor of claim 1, wherein said thin insulating layer has a thickness of 20 Å

to 200 Å

.

4. The capacitor of claim 1, wherein each of said thin and bulk insulating layers independently comprise SiO₂, Si₃N₄, a silicon oxynitride, Al₂O₃, SiOC, SiOCH, TiO₂, or HfO₂.

5. The capacitor of claim 4, wherein at least one of said first and second capacitor electrodes has a dome-shaped cross-sectional profile.

6. The capacitor of claim 5, wherein said first metal capacitor electrode has the uppermost surface that is smooth and/or curved and the cross-sectional profile that varies smoothly in both horizontal and vertical dimensions.

7. The capacitor of claim 6, wherein both of said first and second metal capacitor electrodes have the uppermost surface that is smooth and/or curved and the cross-sectional profile that varies smoothly in both horizontal and vertical dimensions.

8. The capacitor of claim 6, wherein said uppermost surface has a second derivative that is not infinite at any point and that may be zero at no more than three points.

9. The capacitor of claim 1, further comprising an antenna electrically connected to said first and said second capacitor electrodes.

10. The capacitor of claim 1, further comprising a conductive layer on the third insulating layer, capacitively coupled to said capacitor electrode.

11. The capacitor of claim 1, wherein said capacitor electrode comprises a first capacitor electrode in said opening and a second capacitor electrode on said second insulating layer outside said opening.

12. The capacitor of claim 11, wherein the second capacitor electrode forms a bulk capacitor having a significantly greater area than said first upper capacitor electrode.

13. The capacitor of claim 12, wherein the area of the second capacitor electrode is at least 1 order of magnitude greater than the area of said first upper capacitor electrode.

14. The capacitor of claim 12, wherein the area of the second upper capacitor electrode is at least 2 orders of magnitude greater than the area of said first upper capacitor electrode.

15. The capacitor of claim 12, wherein the second capacitor electrode has most of the charge storage capability of the capacitor.

16. The capacitor of claim 1, wherein said predetermined breakdown voltage is determined by the thickness of the thin insulating layer.

17. The capacitor of claim 1, wherein said substrate further comprises a barrier layer or planarization layer thereon.

18. The capacitor of claim 17, wherein said barrier layer or planarization layer is formed on an entire area of said substrate.

19. The capacitor of claim 18, wherein said barrier layer or planarization layer is formed on a single major surface of said substrate.

20. The capacitor of claim 1, wherein said third insulating layer comprises SiO₂, Si₃N₄, a silicon oxynitride, Al₂O₃, SiOC, SiOCH, TiO₂, or HfO₂.

21. The capacitor of claim 1, wherein said thin insulating layer has a first thickness, and said bulk insulating layer has a second thickness significantly greater than said first thickness.

22. The capacitor of claim 1, wherein said third insulating layer has a third thickness similar to said second thickness.

23. The capacitor of claim 1, wherein said antenna comprises a printed conductor, said printed conductor ink having a spiral or concentric ring pattern.

46. The capacitor of claim 1, wherein said first metal capacitor electrode comprises a printed first metal capacitor electrode.

47. The capacitor of claim 46, wherein said printed first metal capacitor electrode is printed from an ink.

48. The capacitor of claim 47, wherein said ink comprises a metal precursor and a solvent.

24. A capacitor structure, comprising:

a) a metal substrate selected from the group consisting of foils and sheets of stainless steel, molybdenum, copper and aluminum;

b) a thin insulating layer on at least part of said metal substrate, said thin insulating layer having a substantially uniform thickness of from 3 Å

to 200 Å and

a predetermined breakdown voltage;

c) a bulk insulating layer on or in contact with said thin insulating layer, said bulk insulating layer having an opening therein and a thickness greater than that of the thin insulating layer;

d) a capacitor electrode on said thin insulating layer in said first opening and on or over (i) at least a part of said thin insulating layer and (ii) at least a part of said bulk insulating layer outside said first opening, wherein a portion of said capacitor electrode outside said first opening forms a bulk capacitor; and

e) a conductive layer on a third insulating layer, electrically coupled to said capacitor electrode and said metal substrate;

wherein said capacitor structure is configured to apply a voltage across said thin insulating layer, said voltage being less than said predetermined breakdown voltage when said capacitor structure is in an electric field configured to detect a surveillance or identification tag, and equal to or greater than said predetermined breakdown voltage when said capacitor structure is in said electric field configured to deactivate said surveillance or identification tag.

25. The capacitor of claim 24, wherein said capacitor electrode is capacitively coupled to said metal substrate.

26. The capacitor of claim 24, wherein said capacitor electrode comprises a first upper capacitor electrode in said opening and a second upper capacitor electrode on said second insulating layer outside said opening.

27. The capacitor of claim 26, wherein the second upper capacitor electrode has most of the charge storage capability of the capacitor.

28. The capacitor of claim 26, wherein the second upper capacitor electrode has an uppermost surface that is smooth and/or curved and a cross-sectional profile that varies smoothly in both horizontal and vertical dimensions.

29. The capacitor of claim 26, having a breakdown voltage determined by the thickness of the thin insulating layer.

30. The capacitor of claim 26, wherein said second upper capacitor electrode comprises a printed second upper capacitor electrode.

31. The capacitor of claim 30, wherein said printed second upper capacitor electrode is printed from an ink.

32. The capacitor of claim 31, wherein said ink comprises a metal precursor and a solvent.

33. The capacitor of claim 26, wherein the second upper capacitor electrode forms a bulk capacitor having a significantly greater area than said first upper capacitor electrode.

34. The capacitor of claim 33, wherein the area of the second upper capacitor electrode is at least 1 order of magnitude greater than the area of said first upper capacitor electrode.

35. The capacitor of claim 33, wherein the area of the second upper capacitor electrode is at least 2 orders of magnitude greater than the area of said first upper capacitor electrode.

36. The capacitor of claim 33, wherein said second capacitor electrode has an uppermost surface that is smooth and/or curved and a cross-sectional profile that varies smoothly in both horizontal and vertical dimensions.

37. The capacitor of claim 36, wherein said uppermost surface has a second derivative that is not infinite at any point and that may be zero at no more than three points.

38. The capacitor of claim 24, further comprising an antenna on said third insulating layer, electrically connected to said capacitor electrode and to said metal substrate.

39. The capacitor of claim 24, wherein said thin insulating layer has a thickness of from 20 Å

to 200 Å

.

40. The capacitor of claim 24, wherein said foil has a thickness from about 1 μ

m to about 300 μ

m.

41. The capacitor of claim 24, wherein each of said thin and bulk insulating layers independently comprises SiO₂, Si₃N₄, a silicon oxynitride, Al₂O₃, SiOC, SiOCH, or HfO₂.

42. The capacitor of claim 24, wherein said substrate further comprises a barrier layer or planarization layer thereon.

43. The capacitor of claim 42, wherein said barrier layer or planarization layer comprises an organic and/or inorganic dielectric material.

44. The capacitor of claim 26, wherein each of said first and second upper capacitor electrodes are independently selected from the group consisting of Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, or a combination thereof.

45. The capacitor of claim 24, wherein said first upper capacitor electrode has an uppermost surface that is smooth and/or curved and a cross-sectional profile that varies smoothly in both horizontal and vertical dimensions.