High reliability surveillance and/or identification tag/devices and methods of making and using the same
View Patent ↗The present invention relates to methods of making capacitors for use in surveillance/identification tags or devices, and methods of using such surveillance/identification devices. The capacitors manufactured according to the methods of the present invention and used in the surveillance/identification devices described herein comprise printed conductive and dielectric layers. The methods and devices of the present invention improve the manufacturing tolerances associated with conventional metal-plastic-metal capacitor, as well as the deactivation reliability of the capacitor used in a surveillance/identification tag or device.
1. A surveillance and/or identification device comprising:
a) a unitary conductive structure comprising a bottom capacitor electrode and an inductor;
b) a first dielectric layer on the bottom capacitor electrode and inductor;
c) a top capacitor electrode on the first dielectric layer, the top capacitor having a substantially dome-shaped profile;
d) a second dielectric layer on the top capacitor electrode and the conductive structure; and
e) an electrically conducting feature on the second dielectric layer, one portion of the electrically conducting feature contacting the top capacitor electrode and a second portion of the conducting feature contacting the conductive structure.
2. The device of claim 1 , wherein the unitary conductive structure comprises a metal film, metal foil, or metal sheet.
3. The device of claim 2 , wherein the metal substrate comprises aluminum, titanium, copper, silver, chromium, molybdenum, tungsten, nickel, gold, palladium, platinum, zinc, iron, stainless steel, or an alloy thereof.
4. The device of claim 1 , wherein the unitary conductive structure consists essentially of aluminum.
5. The device of claim 1 , wherein the capacitor electrodes comprise aluminum, titanium, copper, silver, chromium, molybdenum, tungsten, nickel, gold palladium, platinum, zinc, stainless steel, or an alloy thereof.
6. The device of claim 1 , wherein the bottom capacitor electrode comprises a multi-layer structure.
7. The device of claim 1 , wherein at least one of the capacitor electrodes comprises a semiconductor material.
8. The device of claim 7 , wherein at least one of the capacitor electrodes comprises a doped Group IVA element.
9. The device of claim 1 , wherein the inductor and/or antenna further comprises one or more interconnect pads.
10. The device of claim 1 , wherein the inductor comprises a coil having a plurality of loops or rings.
11. The device of claim 1 , wherein the first dielectric layer has a thickness of from 50 to 400 Å and a breakdown voltage of from about 10 to about 20 V.
12. The device of claim 1 , wherein the first dielectric layer comprises aluminum oxide.
13. The device of claim 1 , wherein the first dielectric layer comprises a corresponding oxide of the bottom capacitor electrode metal.
14. The device of claim 1 , wherein the second dielectric layer comprises an oxide and/or nitride of a Group IVA element.
15. The device of claim 14 , wherein the oxide of a Group IVA element further comprises boron and/or phosphorous.
16. The device of claim 1 , wherein the electrically conducting feature comprises one or more interconnect pads.
17. The device of claim 1 , wherein the electrically conducting feature comprises aluminum, titanium, copper, silver, chromium, molybdenum, tungsten, nickel, gold, palladium, platinum, zinc, iron, stainless steel, or an alloy thereof.
18. The device of claim 1 , wherein the electrically conducting feature consists essentially of silver, gold, copper, or aluminum.
19. The device of claim 1 , wherein the electrically conducting feature and the capacitor electrodes comprise a same material.
20. The device of claim 1 , further comprising a passivation layer.
21. The device of claim 1 , further comprising a support and/or backing layer on a surface of the inductor.
22. A surveillance and/or identification device comprising:
a) a bottom capacitor electrode on a substrate, the bottom capacitor electrode having a substantially dome-shaped profile;
b) a first dielectric layer on the bottom capacitor electrode;
c) a top capacitor electrode on the first dielectric layer, the top capacitor electrode having a substantially dome-shaped profile;
d) a second dielectric layer on the substrate, the second dielectric layer having first and second contact holes therein exposing the bottom capacitor electrode and the top capacitor electrode; and
e) an antenna and/or inductor having a first end coupled and/or connected to the bottom capacitor electrode and a second end coupled and/or connected to the top capacitor electrode.
23. The device of claim 22 , wherein the substrate comprises a plate, disc, and/or sheet of a glass, ceramic, dielectric, and/or plastic.
24. The device of claim 23 , wherein the substrate comprises glass or plastic and a planarization layer thereon.
25. The device of claim 22 , wherein the capacitor electrodes comprise aluminum, titanium, copper, silver, chromium, molybdenum, tungsten, nickel, gold, palladium, platinum, zinc, iron, stainless steel, or an alloy thereof.
26. The device of claim 22 , wherein at least one of the capacitor electrodes comprises a semiconductor material.
27. The device of claim 26 , wherein at least one of the capacitor electrodes comprises a doped Group IVA element.
28. The device of claim 22 , wherein the first dielectric layer has a thickness of from 50 to 400 Å and a breakdown voltage of from 10 to 20 V.
29. The device of claim 22 , wherein the first dielectric layer comprises aluminum oxide.
30. The device of claim 22 , wherein the first dielectric layer comprises a corresponding oxide of the bottom capacitor electrode metal.
31. The device of claim 22 , wherein the second dielectric layer comprises an oxide and/or nitride of a Group IVA element.
32. The device of claim 31 , wherein the oxide of the Group IVA element further comprises boron and/or phosphorous.
33. The device of claim 22 , wherein the inductor and/or antenna further comprises one or more interconnect pads.
34. The device of claim 33 , wherein the one or more interconnect pads further comprises a metal bump or anisotropic conductive paste.
35. The device of claim 33 , further comprising a conductive adhesive bonding the one or more interconnect pads to the capacitor electrodes.
36. The device of claim 22 , further comprising a backing and/or support layer attached to the inductor.
37. A method of detecting items with a surveillance and/or identification device, comprising:
a) causing or inducing a current sufficient for the device of claim 1 to radiate, reflect, or backscatter detectable electromagnetic radiation;
b) detecting the detectable electromagnetic radiation; and
c) optionally, selectively deactivating the device.
38. The method of claim 37 , wherein the detectable electromagnetic radiation has a frequency that is an integer multiple or an integer divisor of a fundamental frequency of an oscillating electromagnetic field or wave applied to the device.
39. The method of claim 37 , further comprising attaching, affixing or including the device on or in the item.
40. A method of detecting items with a surveillance and/or identification device, comprising:
a) causing or inducing a current sufficient for the device of claim 22 to radiate, reflect, or backscatter detectable electromagnetic radiation;
b) detecting the detectable electromagnetic radiation; and
c) optionally, selectively deactivating the device.
41. The method of claim 40 , wherein the detectable electromagnetic radiation has a frequency that is an integer multiple or an integer divisor of a fundamental frequency of an oscillating electromagnetic field or wave applied to the device.
42. The method of claim 40 , further comprising attaching, affixing or including the device on or in the item.