Fabrication of nonpolar indium gallium nitride thin films, heterostructures and devices by metalorganic chemical vapor deposition

• US 8,502,246 B2
• Filed: 02/12/2009
• Issued: 08/06/2013
• Est. Priority Date: 05/10/2004
• Status: Active Grant

• Current Assignee: Japan Science & Technology Trading Co. Limited, Regents of the University of California (University of California)
• Original Assignee: Japan Science & Technology Trading Co. Limited, Regents of the University of California (University of California)
• Inventors: Chakraborty, Arpan, Haskell, Benjamin A., Keller, Stacia, Speck, James S., DenBaars, Steven P., Nakamura, Shuji, Mishra, Umesh K.
• Primary Examiner(s): FOURSON III, GEORGE R
• Application Number:
  US12/370,479
• Publication Number:
  US 20090146162A1
• Time in Patent Office: 1,636 Days
• Field of Search: 257/94, 257/96, 257/97, 257/103, 257/E33.027, 257/E33.003, 257/E33.025, 257/E33.028, 257/E33.043, 437/47, 437/81
• US Class Current: 257/97
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: C30B 25/02 Epitaxial-layer growth
• CPC Class Codes: C30B 29/403 AIII-nitrides
• CPC Class Codes: H01L 21/0237 Materials
• CPC Class Codes: H01L 21/02389 Nitrides
• CPC Class Codes: H01L 21/02433 Crystal orientation
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/02502 consisting of two layers
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02609 Crystal orientation
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01S 2304/04 MOCVD or MOVPE
• CPC Class Codes: H01S 2304/12 Pendeo epitaxial lateral overgrowth [ELOG], e.g. for growing GaN based blue laser diodes
• CPC Class Codes: H01S 5/0213 Sapphire, quartz or diamond based substrates
• CPC Class Codes: H01S 5/32025 non-polar orientation
• CPC Class Codes: H01S 5/34333 with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser

Abstract

A method for the fabrication of nonpolar indium gallium nitride (InGaN) films as well as nonpolar InGaN-containing device structures using metalorganic chemical vapor deposition (MOVCD). The method is used to fabricate nonpolar InGaN/GaN violet and near-ultraviolet light emitting diodes and laser diodes.

Claims

1. A p-n junction device structure, comprising at least:

a nonpolar oriented III-nitride substrate, wherein nonpolar III-nitride layers grown epitaxially on the nonpolar III-nitride substrate have a threading dislocation density below 10⁹ cm<sup>−

2</sup> and a stacking fault density below 1×

10⁴ cm<sup>−

1</sup>;

the nonpolar III-nitride layers, comprising at least one or more nonpolar oriented Indium-containing III-nitride layers, are deposited on or above a top surface of the nonpolar oriented III-nitride substrate; and

wherein a material quality of the nonpolar III-nitride layers enables the p-n junction device structure to function in response to direct current density above 43 amps per centimeter square.

2. The device structure of claim 1, wherein the nonpolar oriented Indium-containing III-nitride layers are a growth along a nonpolar III-nitride crystallographic direction.

3. The device structure of claim 1, further comprising a light-emitting diode (LED) structure or laser diode (LD) structure including the p-n junction, wherein the non-polar oriented Indium-containing III-nitride layers are one or more light-emitting active layers for the LED or LD structure, and the p-n junction emits optical power or electroluminescence in response to direct current.

4. The device structure of claim 3, wherein the active layers emit light having a wavelength in a range 360 nm-600 nm.

5. The device structure of claim 1, wherein the material quality enables an external quantum efficiency (EQE) of at least 0.4%.

6. The device structure of claim 1, wherein the material quality is characterized by an amount of one or more of the following:

carbon contamination, threading dislocation, stacking fault dislocation, and Indium incorporation.

7. The device structure of claim 1, wherein:

the nonpolar oriented Indium-containing III-nitride layers are one or more nonpolar active layers, and

a material quality of the nonpolar Indium-containing III-nitride layers enables a measurement of an amount of nonpolarity of the nonpolar oriented Indium-containing III-nitride layers.

8. The device structure of claim 7, wherein:

(1) the device structure is a light-emitting device structure for emitting electroluminescence as a function of the drive current;

(2) the nonpolar oriented Indium-containing III-nitride layers are the active layers emitting the electroluminescence; and

(3) the amount of nonpolarity is measured by a blue-shift of an emission peak of the electroluminescence, with increasing drive current over a drive current range, wherein the blue-shift is reduced as compared to a blue-shift of an emission peak emitted by a c-plane light-emitting device structure.

9. The device structure of claim 1, wherein the device structure is a laser diode or light emitting diode structure having an absence of blue-shift of an emission peak when the direct current density is increased from at least 11 amps per centimeter square.

10. The device structure of claim 7, wherein the amount of nonpolarity is measured by an effective hole mass, in the nonpolar oriented Indium-containing III-nitride layers, which is reduced as compared to an effective hole mass in a c-plane Indium-containing III-nitride layer.

11. The device structure of claim 1, further comprising:

a cap layer on or above the Indium-containing III-nitride layers; and

one or more III-nitride device layers on or above the cap layer, wherein the cap layer prevents Indium desorbing from the Indium-containing III-nitride layers when the III-nitride device layers are formed.

12. The device structure of claim 1, wherein the device structure is a light emitting diode (LED) or Laser Diode (LD) structure:

capable of emitting 1.5 milliwatts of output power, and

having a linewidth of less than 25 nanometers at the direct current density of at least 111 Amps per centimeter square.

13. The device structure of claim 1, wherein the nonpolar oriented III-nitride substrate is a gallium nitride (GaN) substrate.

14. The device structure of claim 13, wherein the GaN substrate is an a-plane GaN substrate and the top surface is an a-plane of the GaN substrate.

15. The device structure of claim 13, wherein the GaN substrate is an m-plane GaN substrate and the top surface is an m-plane of the GaN substrate.

19. The device structure of claim 1, wherein the device structure is a light emitting diode or laser diode structure having an External Quantum Efficiency (EQE) reduction of at most 20% at a direct current density of 111 Amps per centimeter square, as compared to a maximum EQE.

20. The device structure of claim 1, wherein the threading dislocation density is below 5×

10⁶cm<sup>−

2</sup> and the stacking fault density is below 3×

10³cm<sup>−

1</sup>.

16. A method of fabricating a p-n junction device structure, comprising at least:

growing nonpolar III-nitride layers epitaxially on or above a top surface of a nonpolar oriented III-nitride substrate, wherein;

the nonpolar III-nitride layers comprise at least one or more nonpolar oriented Indium-containing III-nitride layers,

a material quality of the nonpolar III-nitride layers enables the p-n junction device structure to function in response to direct current density above 43 amps per centimeter square, and

the epitaxially grown nonpolar layers having a threading dislocation density below 10⁹ cm<sup>−

2</sup> and a stacking fault density below 1×

10⁴ cm<sup>−

1</sup>.

17. The method of claim 16, wherein the device structure is a light emitting diode or laser diode structure:

grown on the substrate that is Gallium Nitride, and

having an External Quantum Efficiency (EQE) reduction of at most 20% at a direct current density of 111 Amps per centimeter square, as compared to a maximum EQE.

18. The method of claim 16, wherein the substrate is Gallium Nitride, the threading dislocation density is below 5×

10⁶ cm<sup>−

2</sup>, and the stacking fault density is below 3×

10³ cm<sup>−

1</sup>.

21. The method of claim 16, wherein the p-n junction is grown by metal organic vapor phase deposition (MOCVD).

22. The method of claim 16, wherein the nonpolar oriented III-nitride substrate is grown by hydride vapor phase epitaxy.