Gap distributed Bragg reflectors
View Patent ↗A device includes one or more reflector components. Each reflector component comprises layer pairs of epitaxially grown reflective layers and layers of a non-epitaxial material, such as air. Vias extend through at least some of the layers of the reflector components. The device may include a light emitting layer.
1. A method of making a device, comprising:
epitaxially growing a layer stack including one or more reflective layers and one or more interstitial layers, each interstitial layer disposed between two reflective layers; and
forming vias that intersect at least some of the one or more reflective layers and the one or more interstitial layers;
exposing the interstitial layers to an etchant through the vias;
etching the interstitial layers;
detecting a color of the surface of the device, a reflectivity of the device, or both a color of the surface of the device and a reflectivity of the device; and
controlling the etching based on the detected color, the detected reflectivity, or both the detected color and the detected reflectivity.
2. The method of claim 1 , wherein the one or more reflective layers comprises two sets of one or more reflective layers and further comprising growing a light emitting layer between the sets of reflective layers.
3. The method of claim 1 , wherein growing the layer stack comprises growing only one reflective layer over or under a light emitting layer.
4. The method of claim 1 , wherein:
forming the vias comprises dry etching the vias; and
exposing the interstitial layers to the etchant comprises exposing the interstitial layers to a wet etchant through the vias.
5. The method of claim 1 , wherein forming the vias comprises forming the vias to surround a central region.
6. The method of claim 1 , wherein the reflective layers and the interstitial layers comprise group III-nitride materials.
7. The method of claim 6 , wherein the reflective layers and the interstitial layers comprise aluminum (Al) and the reflective layers have a lower Al content than the interstitial layers.
8. The method of claim 1 , comprising forming air gaps between the reflective layers.
9. The method of claim 1 , wherein etching the interstitial layers further comprises etching the interstitial layers for a predetermined period of time.