III-nitride light-emitting devices with reflective engineered growth templates and methods of manufacture

• US 8,253,157 B2
• Filed: 03/29/2011
• Issued: 08/28/2012
• Est. Priority Date: 08/06/2006
• Status: Active Grant

• Current Assignee: Lightwave Photonics, Inc.
• Original Assignee: Lightwave Photonics, Inc.
• Inventors: Jorgenson, Robbie J.
• Primary Examiner(s): Nguyen, Dao H
• Assistant Examiner(s): Nguyen, Tram H
• Application Number:
  US13/075,104
• Publication Number:
  US 20120001213A1
• Time in Patent Office: 518 Days
• Field of Search: 257/13, 257/94, 257/79, 257/86, 257/98, 257/592, 257/929, 257/81, 257/82, 257/91, 257/99, 257/100, 257/116, 257/117, 257432-437, 257/749, 257E33056-E33059, 257/E25.032, 257/E21.086, 257E21097-E211, 257E21108-E21113, 257E21117-E21118, 257/E21.542, 257E21697-E21699, 257/E31.371, 257/E21.387, 257E21403-E21407, 257/E21.441, 257/E21.445, 257E21448-E21452, 257/11, 257/12, 257/51, 257/85, 257/90, 257/96, 257/97, 257/183, 438/29, 438/46, 438/22, 438/39, 438/40, 438/41, 438/44, 438/47, 438/222, 438/226, 438/241, 438/269, 438/363, 438/384, 438/388, 438/413, 438/416, 438/429, 438/442, 438/478, 438/481, 438/486, 438/489, 438492-509, 438/607, 438/903, 438/969, 438/77, 438/84, 438 93- 95, 438/102, 438/401, 438/188, 438/189, 438/285, 438603-604, 438/606, 438930-933
• US Class Current: 257/98
• CPC Class Codes: H01L 33/105 with a resonant cavity structure
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/465 with a resonant cavity structure
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

A light emitter includes a first mirror that is an epitaxially grown metal mirror, a second mirror, and an active region that is epitaxially grown such that the active region is positioned at or close to, at least, one antinode between the first mirror and the second mirror.

Claims

1. A light emitter comprising:

a crystalline III-nitride layer;

a first mirror having a first major face that is epitaxially coupled to a first major face of the crystalline III-nitride layer and includes a metal;

a second mirror;

an active region epitaxially coupled to a second major face of the first mirror that is opposite the first major face of the first mirror such that the first mirror, the active region, and the second mirror form a resonant-cavity light-emitting diode (RC-LED),

wherein the crystalline III-nitride layer and the first mirror have lattice constants that are substantially equal to one another.

2. The light emitter of claim 1, wherein the second mirror is epitaxially coupled to the active region and includes a metal.

3. The light emitter of claim 1, further comprising a substrate that is in contact with a second surface of the crystalline III-nitride layer that is opposite the first surface of the crystalline III-nitride layer and that includes at least one of the following:

Sapphire, Silicon, Silicon Carbide, Zinc Oxide, Spinel (MgAl₂O₄), AlN, GaP, MgO, LiGaO₂, LiAlO₂, NdGaO₃, ScAlMgO₄, and Ca₈La₂(PO₄)₆O₂.

4. The light emitter of claim 1, wherein the first mirror includes zirconium nitride.

5. The light emitter of claim 1, wherein the first mirror includes hafnium nitride.

6. The light emitter of claim 1, wherein the first mirror includes titanium nitride.

7. The light emitter of claim 1, wherein the first mirror includes yttrium nitride.

8. The light emitter of claim 1, wherein the first mirror, the active region, and the second minor form a micro-cavity light-emitting diode (MCLED).

9. The light emitter of claim 1, wherein a bottom surface of the crystalline III-nitride layer is roughened.

10. The light emitter of claim 1, wherein the second minor has a roughened top surface located opposite of the active region.

11. The light emitter of claim 1, wherein the second minor includes a photonics crystal.

12. The light emitter of claim 1, wherein the second minor includes a distributed Bragg reflector (DBR).

13. The light emitter of claim 1 further comprising, a distributed Bragg reflector (DBR) located between, and coupled to, the first mirror and the active region.

14. A light emitting device comprising:

a substrate;

a first III-nitride layer in contact with the substrate, wherein the first III-nitride layer has a first conductivity type and a first bandgap energy;

a planar specular epitaxial first metal-mirror layer in contact with the first III-nitride layer;

a second III-nitride layer in contact with the planar specular epitaxial first metal mirror layer, wherein the second III-nitride layer has a second conductivity type and a second bandgap energy;

a light-emitting layer in contact with the second III-nitride layer;

a third III-nitride layer in contact with the light-emitting layer, wherein the third III-nitride layer has a third conductivity type and a third bandgap energy;

a fourth III-nitride layer in contact with the third III-nitride layer, wherein the fourth III-nitride layer has a fourth conductivity type and a fourth bandgap energy; and

a second metal-mirror layer in contact with the fourth III-nitride layer,

wherein the first III-nitride layer and the first metal mirror layer have lattice constants that are substantially equal to one another.

15. The light emitting device of claim 14,

wherein the first conductivity type and the second conductivity type are equal types and the third conductivity type and the fourth conductivity type are equal types, and

wherein the first bandgap energy, the second band gap energy, and the fourth bandgap energy are substantially equal to one another, and are less than the third bandgap energy.

16. The light emitting device of claim 14, wherein the light-emitting layer includes at least one quantum well.

17. The light emitting device of claim 14, wherein the first metal minor layer has a thickness that is approximately 20 nm such that the first metal mirror layer is partially reflective and partially transmissive.

18. The light emitting device of claim 14, further comprising a photonic crystal structure embedded in the fourth III-nitride layer.

19. A light emitting device comprising:

a substrate;

a first III-nitride layer in contact with the substrate, wherein the first III-nitride layer has a first conductivity type and a first bandgap energy;

a planar specular epitaxial metal mirror layer in contact with the first III-nitride layer;

a second III-nitride layer in contact with the planar specular epitaxial metal mirror layer, wherein the second III-nitride layer has a second conductivity type and a second bandgap energy;

a light-emitting layer in contact with the second III-nitride layer;

a third III-nitride layer in contact with at least a portion of the light-emitting layer, wherein the third III-nitride layer has a third conductivity type and a third bandgap energy;

a fourth III-nitride layer in contact with the third III-nitride layer, wherein the fourth III-nitride layer has a fourth conductivity type and a fourth bandgap energy; and

a transparent contact layer in contact with the fourth III-nitride layer,

wherein the first III-nitride layer and the metal mirror layer have lattice constants that are substantially equal to one another.

20. The light emitting device of claim 19, wherein the metal minor layer has a thickness that is at least approximately 150 nm such that the metal minor is highly reflective.