Bonding methods for light emitting diodes
Disclosed herein are techniques for bonding LED components. According to certain embodiments, a first component including a semiconductor layer stack is hybrid bonded to a second component including a substrate that has a different thermal expansion coefficient than the semiconductor layer stack. The semiconductor layer stack includes an n-side semiconductor layer, an active light emitting layer, and a p-side semiconductor layer. The first component and the second component further include first contacts and second contacts, respectively. To hybrid bond the two components, the first contacts are aligned with the second contacts. Then dielectric bonding is performed to bond respective dielectric materials of both components. The dielectric bonding is followed by metal bonding of the contacts, using annealing. To compensate run-out between the first contacts and the second contacts, aspects of the present disclosure relate to changing a curvature of the first component and/or the second component during the annealing stage.
1. A method comprising:
aligning first contacts of a first component with second contacts of a second component, wherein the first component comprises a semiconductor layer stack including an n-side semiconductor layer, an active light emitting layer, and a p-side semiconductor layer, and wherein the second component comprises a substrate that has a different thermal expansion coefficient than the semiconductor layer stack;
performing hybrid bonding of the first component to the second component, the hybrid bonding comprising:
performing dielectric bonding of a first dielectric material of the first component with a second dielectric material of the second component, and
subsequently performing metal bonding of the first contacts with the second contacts through annealing; and
prior to performing the metal bonding, using chemical mechanical polishing to dish the first contacts, the second contacts, or both the first contacts and the second contacts, such that the first contacts are separated from the second contacts by gaps when the first contacts are aligned with the second contacts;
wherein a run-out between the first contacts and the second contacts is compensated through closing the gaps as a result of expansion of the first contacts and the second contacts during the annealing.
2. The method of claim 1 , wherein:
the first component further comprises a second substrate and a buffer layer,
the buffer layer is located between the n-side semiconductor layer and the second substrate,
the first dielectric material forms a dielectric layer that includes a first side nearer to the p-side semiconductor layer and a second side nearer to the n-side semiconductor layer, and
the first contacts are located on the first side of the dielectric layer.
3. The method of claim 1 , wherein the chemical mechanical polishing is performed prior to the dielectric bonding.
4. The method of claim 1 , wherein the first contacts are dished without dishing the second contacts.
5. The method of claim 1 , wherein the second contacts are dished without dishing the first contacts.
6. The method of claim 1 , wherein both the first contacts and the second contacts are dished.