Light Emitting Diode (LED) Devices With Nucleation Layer
Described are light emitting diode (LED) devices having patterned substrates and methods for effectively growing epitaxial III-nitride layers on them. A nucleation layer, comprising a III-nitride material, is grown on a substrate before any patterning takes place. The nucleation layer results in growth of smooth coalesced III-nitride layers over the patterns.
1 . A light emitting diode device comprising:
a patterned substrate comprising a substrate body, a plurality of integral features protruding from the substrate body, and a base surface defined by a plurality of voids between the plurality of integral features, the plurality of integral features having a top surface and sidewalls and a height, a pitch, and a width;
a nucleation layer on a top surface of the plurality of integral features and not in the plurality of voids, the nucleation layer comprising a first III-nitride material; and
a III-nitride layer on the nucleation layer, the III-nitride layer comprising a second III-nitride material.
2 . The light emitting diode device of claim 1 , wherein the first III-nitride material and the second III-nitride material independently comprise one or more of aluminum, gallium, and indium.
3 . The light emitting diode device of claim 2 , wherein the first III-nitride material comprises aluminum nitride (AlN).
4 . The light emitting diode device of claim 2 , wherein the first III-nitride material and the second III-nitride material are the same.
5 . The light emitting diode device of claim 1 , wherein the second III-nitride material comprises gallium nitride (GaN).
6 . The light emitting diode device of claim 1 , wherein the nucleation layer has a thickness in a range of from 5 nm to 50 nm.
7 . A method of manufacturing a light emitting diode (LED) device, the method comprising:
depositing a nucleation layer on a substrate, the nucleation layer comprising a first III-nitride material;
patterning the substrate to form a plurality of nucleation layer-coated substrate posts separated by the plurality of voids; and
epitaxially growing the III-nitride layer on the plurality of nucleation layer-coated substrate posts, the III-nitride layer comprising a second III-nitride material.
8 . The method of claim 7 , wherein the first III-nitride material and the second III-nitride material independently comprise one or more of aluminum, gallium, and indium.
9 . The method of claim 8 , wherein the first III-nitride material comprises aluminum nitride (AlN).
10 . The method of claim 8 , wherein the first III-nitride material and the second III-nitride material are the same.
11 . The method of claim 7 , wherein the second III-nitride material comprises gallium nitride (GaN).
12 . The method of claim 7 , wherein the nucleation layer has a thickness in a range of from 5 nm to 50 nm.