Micro device with stabilization post
A method and structure for stabilizing an array of micro devices is disclosed. A stabilization layer includes an array of stabilization cavities and array of stabilization posts. Each stabilization cavity includes sidewalls surrounding a stabilization post. The array of micro devices is on the array of stabilization posts. Each micro device in the array of micro devices includes a bottom surface that is wider than a corresponding stabilization post directly underneath the bottom surface.
1. A method of forming an array of micro devices comprising:
patterning a device layer to form an array of micro device mesa structures over a handle substrate;
forming a patterned sacrificial layer including an array of openings over the corresponding array of micro device mesa structures;
forming a stabilization layer over the patterned sacrificial layer and within the array of openings; and
removing the handle substrate.
2. The method of claim 1 , wherein each micro device mesa structure includes a p-doped layer, an n-doped layer, and a quantum well layer between the p-doped layer and the n-doped layer.
3. The method of claim 2 , further comprising:
forming the array of openings in the patterned sacrificial layer directly over an array of conductive contacts of the corresponding array of micro device mesa structures.
4. The method of claim 2 , wherein the patterning the device layer to form the array of micro device mesa structures leaves unremoved portions of the device layer between the array of micro device mesa structures, and further comprising removing the unremoved portions of the device layer to form an array of laterally separate micro LED devices after removing the handle substrate.
5. The method of claim 4 , wherein removing the unremoved portions of the device layer comprises thinning the array of micro device mesa structures so that an exposed top surface of the array of micro LED devices is below an exposed top surface of the patterned sacrificial layer between the micro LED devices.
6. The method of claim 1 , further comprising bonding the stabilization layer to a carrier substrate prior to removing the handle substrate.
7. The method of claim 6 , wherein bonding the stabilization layer to the carrier substrate comprises curing the stabilization layer.
8. The method of claim 1 , further comprising removing the patterned sacrificial layer after removing the handle substrate.
9. The method of claim 1 , wherein the stabilization layer is formed of a thermoset material.
10. The method of claim 1 , wherein the array of openings are separated by a pitch of 1 μm to 10 μm.