Light-emitting diode with textured substrate
View Patent ↗A light-emitting diode (LED) device is provided. The LED device has raised semiconductor regions formed on a substrate. LED structures are formed over the raised semiconductor regions such that bottom contact layers and active layers of the LED device are conformal layers. The top contact layer has a planar surface. In an embodiment, the top contact layers are continuous over a plurality of the raised semiconductor regions while the bottom contact layers and the active layers are discontinuous between adjacent raised semiconductor regions.
1. A method of forming a light-emitting diode (LED) device, the method comprising:
providing a substrate;
forming raised regions on the substrate;
forming a first contact layer over the raised regions, the first contact layer having a non-planar surface and being discontinuous between the raised regions;
forming an active layer over the first contact layer, the active layer having a non-planar surface; and
forming a second contact layer over the active layer, the second contact layer having a planar surface, the second contact layer being continuous over a plurality of the raised regions.
2. The method of claim 1 , wherein the forming raised regions comprises:
forming a mask layer over the substrate;
patterning the mask layer to expose portions of the substrate; and
forming the raised regions on the exposed portions of the substrate.
3. The method of claim 1 , wherein the active layer is discontinuous between the raised regions.
4. The method of claim 1 , wherein the forming the second contact layer comprises:
forming the second contact layer to a thickness greater than a desired thickness; and
planarizing the second contact layer to the desired thickness.
5. The method of claim 1 , wherein the substrate is a bulk silicon substrate.
6. The method of claim 1 , wherein the substrate is a bulk silicon substrate having a ( 100 ) surface orientation.
7. The method of claim 1 , wherein the raised regions comprise SiGe.
8. A method of forming a light-emitting diode (LED) device, the method comprising:
providing a substrate;
forming a dielectric layer over the substrate;
patterning the dielectric layer to form a patterned mask, the patterned mask defining openings in which the substrate is exposed;
forming raised regions on the substrate in the openings; and
forming an LED structure over the raised regions, the LED structure having a top contact layer with a planar surface and a bottom contact layer having a non-planar surface.
9. The method of claim 8 , wherein the substrate is a bulk silicon substrate having a ( 100 ) surface orientation.
10. The method of claim 8 , wherein the raised regions comprise SiGe.
11. The method of claim 8 , wherein the bottom contact layer is not a continuous layer over multiple raised regions.
12. The method of claim 8 , wherein an active layer interposed between the top contact layer and the bottom contact layer has a non-planar surface.
13. The method of claim 8 , wherein the top contact layer extends over a plurality of the raised regions.
14. A method of forming a light-emitting diode (LED) device, the method comprising:
providing a substrate;
forming raised regions on the substrate, wherein the forming raised regions comprises:
forming a mask layer over the substrate;
patterning the mask layer to expose portions of the substrate; and
forming the raised regions on the exposed portions of the substrate;
forming a first contact layer over the raised regions;
forming an active layer over the first contact layer, the active layer having a non-planar surface; and
forming a second contact layer over the active layer, the second contact layer having a planar surface.
15. The method of claim 14 , wherein the first contact layer is discontinuous between the raised regions.
16. The method of claim 14 , wherein the active layer is discontinuous between the raised regions.
17. The method of claim 14 , wherein the forming the second contact layer comprises:
forming the second contact layer to a thickness greater than a desired thickness; and
planarizing the second contact layer to the desired thickness.
18. The method of claim 14 , wherein the substrate is a bulk silicon substrate having a ( 100 ) surface orientation.
19. The method of claim 14 , wherein the raised regions comprise SiGe.