Low voltage microcavity plasma device and addressable arrays
View Patent ↗Microcavity plasma devices and arrays of microcavity plasma devices are provided that have a reduced excitation voltage. A trigger electrode disposed proximate to a microcavity reduce the excitation voltage required between first and second electrodes to ignite a plasma in the microcavity when gas(es) or vapor(s) (or combinations thereof) are contained within the microcavity. The invention also provides symmetrical microplasma devices and arrays of microcavity plasma devices for which current waveforms are the same for each half-cycle of the voltage driving waveform. Additionally, the invention also provides devices that have standoff portions and voids that can reduce cross talk. The devices are preferably also used with a trigger electrode.
1. A microcavity plasma device, the device comprising:
a substrate having a microcavity formed therein;
first and second electrodes disposed to excite a plasma in said microcavity upon application of application of a time-varying potential between the first and second electrodes;
dielectric isolating said first and second electrodes from a plasma formed in said microcavity; and
a trigger electrode disposed proximate said microcavity.
2. The device of claim 1 , further comprising a controller for applying a voltage waveform to said trigger electrode for reducing the required operating voltage applied to said first and second electrodes to excite a plasma in said microcavity.
3. The device of claim 1 , wherein said trigger electrode is disposed opposite said microcavity.
4. The device of claim 3 , wherein said trigger electrode comprises a transparent electrode.
5. The device of claim 4 , wherein said trigger electrode is disposed upon a transparent layer opposite said microcavity.
6. The device of claim 3 , wherein said trigger electrode is approximately 500 μm or less from said microcavity.
7. The device of claim 6 , wherein said microcavity comprises a tapered microcavity.
8. The device of claim 7 , wherein said microcavity comprises an inverted pyramidal microcavity.
9. The device of claim 1 , wherein said trigger electrode is disposed adjacent the microcavity.
10. The device of claim 9 , wherein said microcavity comprises a tapered microcavity.
11. The device of claim 10 , wherein said microcavity comprises an inverted pyramidal microcavity.
12. The device of claim 1 , wherein said microcavity comprises a tapered microcavity.
13. The device of claim 12 , wherein said microcavity comprises an inverted pyramidal microcavity.
14. The device of claim 1 , wherein said substrate comprises a conductive or semi-conductive substrate that acts as one of said first and second electrodes.
15. The device of claim 1 , wherein said substrate comprises one of a semiconductor and an insulator, and said first and second electrodes comprise metal electrodes.
16. The device of claim 15 , wherein one of said first and second electrodes is disposed in said microcavity.
17. An array of microcavity plasma devices, comprising a plurality of devices according to claim 15 , wherein said first and second electrodes comprise electrodes respectively interconnecting rows and columns of microcavities of said plurality of devices and said trigger electrode comprises a plurality of trigger electrode proximate rows or columns of the microcavities.
18. The array of claim 17 , further comprising a controller for applying voltage waveforms to said first and second and trigger electrodes.
19. The array of claim 18 , wherein a voltage waveform applied to said trigger electrodes comprise a series of pulses corresponding to voltage pulses applied to said first and second electrodes.
20. The array of claim 19 , wherein the series of pulses applied to said trigger electrodes has fewer cycles than that of voltage pulses applied to said first and second electrodes.
21. An array of microcavity plasma devices, comprising a plurality of devices according to claim 1 , wherein said first, second and trigger electrodes comprise electrodes respectively interconnecting pluralities of microcavities of said plurality of devices.
22. The array of claim 21 , wherein one of said first and second electrodes and said trigger electrodes are each patterned to border apertures of the pluralities of microcavities along two sides of the microcavities.
23. The array of claim 22 , wherein one of said first and second electrodes is disposed in said microcavity.
24. The device of claim 1 , further comprising phosphor disposed in said microcavity.
25. The device of claim 1 , further comprising phosphor disposed opposite said microcavity.
26. The device of claim 1 , wherein said dielectric comprises alternating layers of dielectric including a thick upper layer.
27. The device of claim 1 , wherein said dielectric comprises alternating layers of nitride and polymer including a thick polymer upper layer.
28. The device of claim 1 , wherein said microcavity comprises a double-sided, symmetrical microcavity.
29. An array of microcavity plasma devices, comprising a plurality of devices according to claim 1 , wherein said first and second electrodes comprise electrodes respectively interconnecting rows and columns of microcavities of said plurality of devices and said trigger electrode comprises a plurality of trigger electrode proximate rows or columns of the microcavities.
30. The array of claim 29 , further comprising a controller for applying voltage waveforms to said first and second and trigger electrodes.
31. The array of claim 30 , wherein a voltage waveform applied to said trigger electrodes comprise a series of pulses corresponding to voltage pulses applied to said first and second electrodes.
32. The array of claim 29 , wherein said microcavity comprises a tapered microcavity.
33. The array of claim 32 , wherein said microcavity comprises an inverted pyramidal microcavity.
34. A microcavity plasma device, the device comprising:
a substrate having a double-sided symmetrically microcavity formed therein;
first and second electrodes disposed to excite a plasma in said microcavity upon application of application of a time-varying potential between the first and second electrodes; and
dielectric isolating said first and second electrodes from a plasma formed in said microcavity.
35. The device of claim 34 , further comprising a trigger electrode disposed proximate said microcavity.
36. A microcavity plasma device, the device comprising:
a substrate having a tapered microcavity formed therein;
first and second electrodes disposed to excite a plasma in said microcavity upon application of application of a time-varying potential between the first and second electrodes, one of said first and second electrodes being formed in said tapered microcavity;
dielectric isolating said first and second electrodes from a plasma formed in said microcavity;
a layer to seal said microcavity;
standoff portions holding said layer to seal a distance away from an upper dielectric layer of said dielectric; and
a void disposed around said standoff portions.
37. The device of claim 36 , wherein said standoff portions comprise trigger electrodes.
38. The device of claim 36 , wherein said standoff portions comprise dielectric.