Passivation for a semiconductor light emitting device
In embodiments of the invention, a passivation layer is disposed over a side of a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. A material configured to adhere to an underfill is disposed over an etched surface of the semiconductor structure.
1. A method comprising:
providing a semiconductor structure comprising an active region between an n-type region and a p-type region, the semiconductor structure being divided into a plurality of light-emitting devices (LEDs) separated by a gap between adjacent LEDs of the plurality of LEDs;
removing a portion of the p-type region and the active region in the gap to form a first exposed surface region of the n-type region and in a region adjacent the gap to form a second exposed surface region;
disposing a dielectric layer at least directly on the first exposed surface region;
disposing an underfill in areas between the semiconductor structure and a mount at least directly on a portion of the dielectric layer and the second exposed surface region; and
attaching the semiconductor structure to the mount.
2. The method of claim 1 , wherein the dielectric layer improves adhesion of the underfill to the first exposed surface region in the gap.
3. The method of claim 1 , wherein the dielectric layer comprises at least one of AlN, TiN, SiO 2 , SiN x O y , SiN x , and Si 3 N 4 .
4. The method of claim 1 , further comprising:
forming a p-contact on the p-type region; and
forming a guard layer on the p-contact.
5. The method of claim 1 , wherein the disposing the underfill material is performed one of before, during or after the attaching the semiconductor structure to the mount.
6. The method of claim 1 , wherein the attaching the semiconductor structure to the mount comprises at least one of ultrasonic bonding, thermosonic bonding or thermocompression bonding of a bond layer on the semiconductor structure to a bond layer on the mount.
7. The method of claim 1 , wherein the gap is between 1 and 10microns wide.
8. The method of claim 1 , wherein the disposing the underfill material comprises:
depositing a solid layer of a dielectric material on at least one of the semiconductor structure or the mount; and
patterning the solid layer.
9. The method of claim 1 , wherein the disposing the underfill material comprises injecting the underfill material between the semiconductor structure and the mount.
10. The method of claim 9 , wherein the underfill material is one of silicone or epoxy.
11. A method comprising:
providing a semiconductor structure comprising an active region between an n-type region and a p-type region, the semiconductor structure being divided into a plurality of light-emitting devices (LEDs) separated by a gap between adjacent LEDs of the plurality of LEDs and comprising an n-contact on an exposed portion of the n-type region;
removing a portion of the p-type region and the active region in the gap to form an exposed surface region of the n-type region;
disposing a passivation layer on the semiconductor structure, including over an outer side of the n-contact and on top of the exposed portion of the n-type region in the gap; and
attaching the semiconductor structure to a mount.
12. The method of claim 11 , further comprising:
forming a p-contact on the p-type region; and
forming a guard layer on the p-contact.
13. The method of claim 11 , further comprising forming a metal bonding layer coupled to the exposed portion of the n-type region.
14. The method of claim 13 , wherein the disposing the passivation layer on the semiconductor structure further comprises disposing the passivation layer on a bottom surface of the metal bonding layer.
15. The method of claim 14 , forming one or more openings in the passivation layer.
16. The method of claim 15 , wherein the disposing the passivation layer comprises patterning the passivation layer to form the one or more openings.
17. The method of claim 15 , wherein the attaching the semiconductor structure to the mount comprises at least one of ultrasonic bonding, thermosonic bonding or thermocompression bonding of the metal bonding layer in the one or more openings to a bond layer on the mount.
18. The method of claim 11 , wherein the passivation layer comprises at least one of AlN, TiN, SiO 2 , SiN x O y , SiN x , or Si 3 N 4 .
19. The method of claim 11 , wherein the disposing the passivation layer comprises at least one of sputtering, e-beam evaporation, CVD, or PECVD.
20. The method of claim 1 , wherein the disposing the passivation layer comprises:
at least one of spin-coating or dip-coating the semiconductor structure with precursor materials; and
curing the precursor materials to form a high density insulating dielectric.