Stabilization structure including sacrificial release layer and staging bollards
A method and structure for stabilizing an array of micro devices is disclosed. The array of micro devices is within an array of staging cavities on a carrier substrate. Each micro device is laterally retained between a plurality of staging bollards of a corresponding staging cavity.
1. A stabilization structure comprising:
a carrier substrate;
a stabilization layer including an array of staging cavities on the carrier substrate;
a sacrificial release layer within the array of staging cavities;
an array of micro devices embedded in the sacrificial release layer;
wherein the stabilization layer spans directly underneath each micro device and includes an array of staging bollards protruding laterally between the array of micro devices, and each micro device is laterally retained between a plurality of the staging bollards that define a corresponding staging cavity in the stabilization layer;
wherein each micro device has a maximum width of 1 to 100 μm, each staging cavity has a maximum width between 0.5 μm and 10 μm larger than the maximum width of a corresponding micro device within the staging cavity, each of the staging bollards is 0.5 to 5 μm wide.
2. The stabilization structure of claim 1 , wherein an embedded portion of each micro device is completely laterally surrounded by the sacrificial release layer.
3. The stabilization structure of claim 2 , wherein the sacrificial release layer spans laterally around a plurality of staging bollards and over a bottom surface of each of the staging cavities.
4. The stabilization structure of claim 2 , wherein the sacrificial release layer comprises an oxide or nitride material.
5. The stabilization structure of claim 3 , further comprising a sacrificial cap layer over the array of micro devices and the plurality of staging bollards for each of the staging cavities.
6. The stabilization structure of claim 1 , wherein the stabilization layer is formed of a thermoset material.
7. The stabilization structure of claim 6 , wherein the thermoset material includes benzocyclobutene (BCB).
8. The stabilization structure of claim 1 , wherein each staging cavity has a maximum width of 1 to 100 μm.
9. The stabilization structure of claim 2 , further comprising a conductive contact on a bottom surface of each micro device.
10. The stabilization structure of claim 9 , wherein each micro device is a micro LED device.
11. The stabilization structure of claim 10 , further comprising a top conductive contact on a top surface of each micro LED device.
12. The stabilization structure of claim 9 , wherein each micro device is a micro chip.
13. The stabilization structure of claim 12 , further comprising a plurality of laterally separate bottom conductive contacts on the bottom surface of each micro chip.
14. The stabilization structure of claim 13 , wherein at least one of the laterally separate bottom conductive contacts on the bottom surface of each micro chip is electrically connected with a landing pad of the respective micro chip.
15. The stabilization structure of claim 9 , wherein each bottom conductive contact comprises a diffusion barrier and a bonding layer between the diffusion barrier and the sacrificial release layer.
16. The stabilization structure of claim 1 , wherein each staging cavity shares one of the staging bollards with an adjacent staging cavity.
17. The stabilization structure of claim 1 , wherein each staging cavity shares more than one of the staging bollards with an adjacent staging cavity.
18. The stabilization structure of claim 1 , wherein each staging cavity shares one of the staging bollards with a plurality of adjacent staging cavities.