Distributed bragg reflector using AIGaN/GaN
First Claim
1. A supported distributed Bragg reflector, comprising:
- a substrate;
a nucleation layer deposited on said substrate, said nucleation layer being of sufficient thickness to promote contiguous growth of subsequent deposited layers;
an interlayer deposited on said nucleation layer, said interlayer controlling mismatch-induced stress and suppressing formation of cracks and said interlayer comprising a material selected from AlN, AlyGa1-yN, and AlyB1-yN, where 0<
y<
1; and
multiple pairs of (AlwGaxB1-w-xN/Alw′
Gax′
B1-w′
-x′
N layers, where 0≦
w≦
1,0≦
x≦
1,0≦
w′
≦
1,0≦
x′
≦
1, deposited on said interlayer, thereby forming a supported distributed Bragg reflector.
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Accused Products
Abstract
A supported distributed Bragg reflector or superlattice structure formed from a substrate, a nucleation layer deposited on the substrate, and an interlayer deposited on the nucleation layer, followed by deposition of (Al,Ga,B)N layers or multiple pairs of (Al,Ga,B)N/(Al,Ga,B)N layers, where the interlayer is a material selected from AlN, AlxGa1-xN, and AlBN with a thickness of approximately 20 to 1000 angstroms. The interlayer functions to reduce or eliminate the initial tensile growth stress, thereby reducing cracking in the structure. Multiple interlayers utilized in an AlGaN/GaN DBR structure can eliminate cracking and produce a structure with a reflectivity value greater than 0.99.
40 Citations
13 Claims
-
1. A supported distributed Bragg reflector, comprising:
-
a substrate;
a nucleation layer deposited on said substrate, said nucleation layer being of sufficient thickness to promote contiguous growth of subsequent deposited layers;
an interlayer deposited on said nucleation layer, said interlayer controlling mismatch-induced stress and suppressing formation of cracks and said interlayer comprising a material selected from AlN, AlyGa1-yN, and AlyB1-yN, where 0<
y<
1; and
multiple pairs of (AlwGaxB1-w-xN/Alw′
Gax′
B1-w′
-x′
N layers, where 0≦
w≦
1,0≦
x≦
1,0≦
w′
≦
1,0≦
x′
≦
1, deposited on said interlayer, thereby forming a supported distributed Bragg reflector.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
11.The supported distributed Bragg reflector of claim 10 wherein the distributed Bragg reflector has a reflectivity value greater than 0.99. -
11. The supported distributed Bragg reflector of claim 1 wherein said interlayer results in an Initial compressive growth stress.
-
-
12. A supported distributed Bragg reflector, comprising:
-
a substrate;
a GaN nucleation layer deposited on said substrate, said GaN nucleation layer having a thickness greater than approximately 0.5 microns;
a first interlayer deposited on said nucleation layer, said first interlayer controlling mismatch-induced stress and suppressing formation of cracks and comprising a material selected from, AlN, AlxGa1-xN, and AlxB1-xN, where 0<
x<
1;
at least five pairs of AlyGa1-yN/GaN layers, where 0<
y<
1, deposited on said interlayer;
a second Interlayer deposited on said AlyGa1-yN/GaN layers, said second interlayer controlling mismatch-induced stress and suppressing formation of cracks and composing a material selected from AlN, AlxGa1-xN, and AlxB1-xN, where 0<
x<
1; and
multiple pairs of (AlwGaxB1-w-xN/Alw′
Gax′
B1-w′
-x′
N) layers, where 0≦
w≦
1,0≦
x≦
1,0≦
w′
≦
1,0≦
x′
≦
1, deposited on said interlayer, thereby forming a supported distributed Bragg reflector.
-
-
13. A supported semiconductor lattice structure, comprising:
-
a substrate, said substrate comprising a material selected from sapphire, silicon, silicon carbide, lithium gallate, lithium aluminate, and lithium nitrate;
a nucleation layer deposited on said substrate, said nucleation layer being of sufficient thickness to promote continuous growth of subsequent deposited layers;
an interlayer deposited on said nucleation layer, said interlayer controlling mismatch-induced stress and suppress formation of cracks and comprising a material selected from an AlwGaxB1-w-xN material, where 0≦
w≦
1,0≦
x≦
1, said interlayer having a thickness greater than approximately 20 Angstroms and less than approximately 1000 Angstroms; and
a layer of Alw′
Gax′
B1-w′
-x′
N, where 0≦
w′
≦
1,0≦
x≦
x′
≦
1, material deposited on said interlayer.
-
Specification