Semi-polar III-nitride optoelectronic devices on M-plane substrates with miscuts less than +/− 15 degrees in the C-direction

Patent metadata

Field	Value
Publication number	US-9917422-B2
Application number	US-201514721729-A
Country	US
Kind code	B2
Filing date	May 26, 2015
Priority date	Feb 12, 2007
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

An optoelectronic device grown on a miscut of GaN, wherein the miscut comprises a semi-polar GaN crystal plane (of the GaN) miscut x degrees from an m-plane of the GaN and in a c-direction of the GaN, where −15<x<−1 and 1<x<15 degrees.

First claim

What is claimed is:

1. A device, comprising:
one or more semi-polar III-Nitride layers epitaxially grown on a semi-polar crystal plane of GaN, the semi-polar crystal plane oriented x degrees from an m-plane of the GaN and in a c-direction of the GaN, where −15<x<−1 and 1<x<15 degrees; and wherein:
the III-Nitride layers comprise a layer having a thickness greater than or equal to a critical thickness for such layer deposited on a {11-22} crystal plane of GaN; and
one or more of the semi-polar III-Nitride layers have a surface roughness of 0.75 nanometers or less.

2. The device of claim 1 , wherein the semi-polar crystal plane is a {30-31}, {30-3-1}, {40-41}, or {40-4-1} plane.

3. The device of claim 1 , wherein the semi-polar crystal plane is a top surface of Gallium Nitride (GaN).

4. The device of claim 1 , wherein the semi-polar crystal plane is a top surface of a Gallium Nitride substrate.

5. The device of claim 1 , wherein the layer is an InGaN layer.

6. The device of claim 1 , wherein the device is a laser diode and the one or more semi-polar III-nitride layers comprise an indium containing waveguide that provides a modal confinement for the laser diode of at least 4.9%, the laser diode having a lasing peak at a wavelength of at least 444.7 nm.

7. The device of claim 1 , wherein one or more of the semi-polar III-Nitride layers include a light emitting active layer including one or more indium containing quantum wells, one or more of the quantum wells having an Indium composition of at least 16% and a thickness greater than 4 nanometers.

8. The device of claim 1 , wherein the one or more semi-polar III-Nitride layers comprise an Indium composition of at least 7%.

9. The device of claim 1 , wherein the device is grown on a miscut or vicinal surface of a GaN substrate, the miscut or vicinal surface including the semi-polar crystal plane, and the semi-polar III-Nitride layers further comprising:
one or more n-type (Al,In,Ga)N layers;
one or more p-type (Al,In,Ga)N layers; and
an InGaN active layer comprising one or more InGaN quantum well layers between the n-type (Al,In,Ga)N layers and the one or more p-type (Al,In,Ga)N layers, wherein the n-type (Al,In,Ga)N layers, the p-type (Al,In,Ga)N layers, and the InGaN quantum well layers have a semi-polar orientation of the semi-polar crystal plane and the InGaN quantum well layers have a peak light emission or a peak light absorption at a wavelength of at least 477 nm.

10. The device of claim 1 , wherein the device is a laser diode and the semi-polar III-Nitride layers comprise:
an n-type GaN layer on or above the semipolar crystal plane;
an n-type InGaN waveguiding layer on or above the n-type GaN layer, the n-type InGaN waveguiding layer having a thickness of at least 50 nm and an Indium composition of 7% or more;
an InGaN active layer on or above the n-type InGaN waveguiding layer, including one or more InGaN quantum well layers with an Indium composition of at least 7% and a thickness of more than 4 nm;
a p-type InGaN waveguiding layer on or above the InGaN active layer; and
a p-type GaN layer on or above the p-type InGaN waveguiding layer, the p-type InGaN waveguiding layer having a thickness of at least 50 nm and an Indium composition of 7% or more, wherein the semi-polar III-Nitride layers have a semipolar orientation of the semipolar crystal plane.

11. The device of claim 1 , wherein the semi-polar crystal plane comprises an atomically specific plane, so that a smooth epitaxial growth of the III-Nitride layers is achieved.

12. The device of claim 1 , wherein the device grown on the semi-polar crystal plane includes a laser diode, light emitting diode, superluminescent diode, semiconductor amplifier, photonic crystal laser, VCSEL laser, solar cell, or photodetector.

13. The device of claim 1 , wherein the device is a laser diode grown on the semi-polar crystal plane, the laser diode comprising a waveguide oriented in a c-projection direction of the laser diode, for higher gain.

14. The device of claim 1 , wherein the device is a laser diode having a threshold current density of no more than 12.2 kiloamps per centimeter square and comprises a coherently strained structure as measured by Bragg peaks for each of the III-nitride layers lining up vertically on a Q x axis of an X-ray Reciprocal Space Map.

15. A method of fabricating a device, comprising:
depositing one or more semi-polar III-Nitride layers epitaxially on a semi-polar crystal plane, the semi-polar crystal plane oriented x degrees from an m-plane of the GaN and in a c-direction of the GaN, where −15<x<−1 and 1<x<15 degrees, and wherein:
the III-Nitride layers comprise a layer having a thickness greater than or equal to a critical thickness for such layer deposited on a {11-22} crystal plane of GaN; and
the depositing is under conditions wherein one or more of the semi-polar III-Nitride layers have a surface roughness of 0.75 nanometers or less.

16. The method of claim 15 , wherein the semi-polar crystal plane is a {30-31}, {30-3-1}, {40-41}, or {40-4-1} plane.

17. The method of claim 15 , wherein the semi-polar crystal plane is a top surface of Gallium Nitride (GaN) and the conditions include an N 2 ambient.

18. The method of claim 15 , wherein the layer is an InGaN layer.

19. The method of claim 15 , wherein the device is a laser diode and the one or more semipolar III-nitride layers comprise an indium containing waveguide that provides a modal confinement for the laser diode of at least 4.9%, the laser diode having a lasing peak at a wavelength of at least 444.7 nm.

20. The method of claim 15 , wherein the depositing of the semi-polar III-Nitride layers further includes depositing a light emitting active layer including one or more Indium containing quantum wells, one or more of the quantum wells having an Indium composition of at least 16% and a thickness greater than 4 nanometers.

Assignees

• Univ California

Inventors

• Hsu Po Shan
• Kelchner Kathryn M
• Farrell Robert M
• Haeger Daniel A
• Ohta Hiroaki
• Tyagi Anurag
• Nakamura Shuji
• Denbaars Steven P
• Speck James S

Classifications

• H10P14/3466

  Crystal orientation · CPC title

• H10P14/3416

  Nitrides · CPC title

• H10P14/2926

  Crystal orientations · CPC title

• H10P14/2908

  Nitrides · CPC title

• H01S5/320275

  semi-polar orientation · CPC title