Micro LED display
A micro light emitting diode (LED) and a method of forming an array of micro LEDs for transfer to a receiving substrate are described. The micro LED structure may include a micro p-n diode and a metallization layer, with the metallization layer between the micro p-n diode and a bonding layer. A conformal dielectric barrier layer may span sidewalls of the micro p-n diode. The micro LED structure and micro LED array may be picked up and transferred to a receiving substrate.
1. A display substrate comprising:
a plurality of separate micro LED devices bonded to a corresponding plurality of separate driver contacts; and
a common contact line formed of a transparent material directly over and in electrical contact with a top surface of each of the plurality of separate micro LED devices, wherein each of the plurality of separate micro LED devices comprises:
a p-n diode including:
a bottom surface directly beneath the top surface;
a p-doped layer;
an n-doped layer; and
a quantum well layer between the n-doped layer and the p-doped layer;
wherein the p-n diode is less than 3 μm thick and less than 10 μm wide; and
a lower metallization layer including a top surface and a bottom surface, wherein the top surface of the lower metallization layer is underneath the bottom surface of the p-n diode, and the bottom surface of the lower metallization layer is directly over and bonded to a corresponding driver contact;
wherein a maximum thickness between the top surface of the p-n diode and the bottom surface of the lower metallization layer is less than 5 μm.
2. The display substrate of claim 1 , wherein the common contact line comprises indium tin oxide.
3. The display substrate of claim 1 , further comprising a plurality of separate bonding layers, wherein each lower metallization layer is bonded to a corresponding driver contact with a corresponding bonding layer.
4. The display substrate of claim 3 , wherein each bonding layer comprises indium.
5. The display substrate of claim 1 , wherein each p-n diode has a square configuration with tapered corners.
6. The display substrate of claim 1 , further comprising a plurality of dielectric barrier layers, wherein each dielectric barrier layer spans sidewalls of a corresponding p-n diode.
7. The display substrate of claim 6 , wherein each dielectric barrier layer covers the quantum well layer of a corresponding p-n diode.
8. The display substrate of claim 7 , wherein common contact line is on each dielectric barrier layer, such that each dielectric barrier layer electrically insulates a corresponding quantum well from the common contact line.
9. The display substrate of claim 8 , wherein the plurality of separate micro LED devices are arranged in a pixel group.
10. The display substrate of claim 9 , wherein the pixel group includes a red-emitting micro LED device, a green-emitting micro LED device, and a blue-emitting micro LED device.
11. The display substrate of claim 1 , wherein the p-doped layer is thinner than the n-doped layer.
12. The display substrate of claim 1 , wherein the p-n diode comprises an inorganic II-VI or III-V semiconductor.
13. The display substrate of claim 1 , wherein the top and bottom surface of each p-n diode are concentric.
14. The display substrate of claim 13 , wherein the top and bottom surface of each p-n diode are parallel.
15. The display substrate of claim 14 , wherein the top surface of each p-n diode is planar.
16. The display substrate of claim 15 , wherein the bottom surface of each p-n diode is wider than a corresponding lower metallization layer.
17. The display substrate of claim 13 , wherein the bottom surface of each p-n diode is wider than a corresponding lower metallization layer.
18. The display substrate of claim 1 , wherein the plurality of separate micro LED devices are arranged in a pixel group.
19. The display substrate of claim 1 , wherein the plurality of separate micro LED devices are arranged in a pixel group.
20. The display substrate of claim 19 , wherein the pixel group includes micro LED devices that are designed to emit different colors.