Adhesive wafer bonding with controlled thickness variation
A method and structure for forming an array of micro devices is disclosed. An array of micro devices is formed over an array of stabilization posts included in a stabilization layer. The stabilization layer is bonded to a spacer side of a carrier substrate. The spacer side of the carrier substrate includes raised spacers extending from a spacer-side surface of the carrier substrate.
1. A structure comprising:
a stabilization layer including an array of stabilization posts;
an array of micro devices formed over the array of stabilization posts; and
a carrier substrate including raised spacers extending from a spacer-side surface of the carrier substrate, wherein the raised spacers extend into the stabilization layer to meet a subset of the stabilization posts in the array of stabilization posts.
2. The structure of claim 1 , wherein the micro devices are micro LED devices.
3. The structure of claim 1 , wherein 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.
4. The structure of claim 1 , further comprising a sacrificial layer between the stabilization layer and the array of micro devices, wherein the array of stabilization posts extend into a thickness of the sacrificial layer.
5. The structure of claim 4 , wherein the sacrificial layer spans along a side surface of each of the micro devices in the array of micro devices, the side surface running between a top surface and a bottom surface of each micro device in the array.
6. The structure of claim 1 , wherein the stabilization layer includes an array of stabilization cavities that include sidewalls surrounding the stabilization posts.
7. The structure of claim 1 , further comprising an array of bottom conductive contacts on bottom surfaces of the array of micro devices.
8. The structure of claim 1 , wherein the stabilization layer is formed of a thermoset material.
9. The structure of claim 1 , wherein a number of the raised spacers extending from the carrier substrate is less than a number of the micro devices formed over the array of stabilization posts.
10. The structure of claim 1 , wherein the array of stabilization posts are separated by a pitch of 1 μm to 10 μm.