UV LIGHT EMITTING DEVICES AND SYSTEMS AND METHODS FOR PRODUCTION

• US 20160079471A1
• Filed: 11/23/2015
• Published: 03/17/2016
• Est. Priority Date: 10/05/2012
• Status: Abandoned Application

• Current Assignee: Rayvio Corporation
• Original Assignee: Rayvio Corporation
• Inventors: Walker, Robert, Collins, Doug, Liao, Yitao
• Application Number:
  US14/949,755
• Publication Number:
  US 20160079471A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C23C 14/0036 Reactive sputtering
• CPC Class Codes: C23C 14/0617 AIII BV compounds, where A is Al, Ga, In or Tl and B is N, P, As, Sb or Bi
• CPC Class Codes: C23C 14/568 Transferring the substrates through a series of coating stations C23C14/562 takes precedence
• CPC Class Codes: C23C 16/303 Nitrides
• CPC Class Codes: C23C 16/481 by radiant heating of the substrate
• CPC Class Codes: C23C 16/54 Apparatus specially adapted for continuous coating
• CPC Class Codes: H01L 33/0025 comprising only AIIIBV compounds
• CPC Class Codes: H01L 33/007 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: H01L 33/32 containing nitrogen

Abstract

A method of fabricating an ultraviolet (UV) light emitting device includes receiving a UV transmissive substrate, forming a first UV transmissive layer comprising aluminum nitride upon the UV transmissive substrate using a first deposition technique at a temperature less than about 800 degrees Celsius or greater than about 1200 degrees Celsius, forming a second UV transmissive layer comprising aluminum nitride upon the first UV transmissive layer comprising aluminum nitride using a second deposition technique that is different from the first deposition technique, at a temperature within a range of about 800 degrees Celsius to about 1200 degrees Celsius, forming an n-type layer comprising aluminum gallium nitride layer upon the second UV transmissive layer, forming one or more quantum well structures comprising aluminum gallium nitride upon the n-type layer, and forming a p-type nitride layer upon the one or more quantum well structures.

Claims

1. A method of fabricating an ultraviolet (UV) light emitting device comprising:

receiving a UV transmissive substrate;

forming a UV transmissive layer upon the UV transmissive substrate, comprising;

forming a first UV transmissive layer comprising aluminum nitride upon the UV transmissive substrate using a first deposition technique at a temperature less than about 800 degrees Celsius or greater than about 1200 degrees Celsius; and

forming a second UV transmissive layer comprising aluminum nitride upon the first UV transmissive layer comprising aluminum nitride using a second deposition technique that is different from the first deposition technique, at a temperature within a range of about 800 degrees Celsius to about 1200 degrees Celsius; and

forming a UV light emitting layer structure on the UV transmissive layer, comprising;

forming an n-type layer comprising aluminum gallium nitride layer upon the UV transmissive layer using a technique selected from a group consisting of;

physical vapor deposition (PVD), sputtering, RF sputtering, Pulsed Laser Deposition (PLD), Magnetron sputtering and hydride vapor phase epitaxy (HVPE);

forming one or more quantum well structures comprising aluminum gallium nitride upon the n-type layer; and

forming a p-type nitride layer upon the one or more quantum well structures.

2. The method of claim 1 wherein the forming the n-type layer comprises physical vapor deposition including a silicon precursor selected from a group consisting of:

silane, diluted silane, silicon-containing compound.

3. The method of claim 1 wherein the n-type layer may include indium or boron.

4. The method of claim 1 wherein the forming the p-type nitride layer upon the one or more quantum well structures comprises using a technique selected form a group consisting of:

physical vapor deposition (PVD), sputtering, RF sputtering, Pulsed Laser Deposition (PLD), Magnetron sputtering and hydride vapor phase epitaxy (HVPE).

5. The method of claim 1 wherein the forming the p-type layer comprises physical vapor deposition including a magnesium precursor selected from a group consisting of:

Bis(cyclopentadienyl) magnesium, a magnesium-containing compound.

6. The method of claim 7 wherein the n-type layer may include indium or boron.

7. The method of claim 1 wherein the UV light emitting layer is fabricated in a form selected from a group consisting of:

nano-wires, nano-disks, nano-columns, and a nano-structure.

8. The method of claim 1

wherein the forming the first UV transmissive layer comprising the aluminum nitride comprises forming the aluminum nitride at a first growth rate;

wherein forming the second UV transmissive layer comprising aluminum nitride comprises forming the aluminum nitride at a second growth rate; and

wherein the first growth rate exceeds the second growth rate.

9. The method of claim 1

wherein the aluminum nitride of the first UV transmissive layer is characterized by a first crystalline quality;

wherein the aluminum nitride of the second UV transmissive layer is characterized by a second crystalline quality; and

wherein the second crystalline quality exceeds the first crystalline quality.

10. The method of claim 1

wherein the forming the first UV transmissive layer comprising the aluminum nitride comprises a first growth time;

wherein forming the second UV transmissive layer comprising aluminum nitride comprises a second growth time and

wherein the second growth time exceeds the first growth time.

11. An ultraviolet (UV) light emitting device comprising:

a UV transmissive substrate;

a UV transmissive layer disposed upon the UV transmissive substrate, the UV transmissive layer comprising;

a first UV transmissive layer comprising aluminum nitride disposed upon the UV transmissive substrate at a temperature less than about 800 degrees Celsius or greater than about 1200 degrees Celsius, wherein the aluminum nitride is characterized by a first crystalline quality;

a second UV transmissive layer comprising aluminum nitride disposed upon the first UV transmissive aluminum nitride material at a temperature within a range of about 800 degrees Celsius to about 1200 degrees Celsius, wherein the aluminum nitride is characterized by a second crystalline quality; and

wherein the second crystalline quality exceeds the first crystalline quality; and

a UV light emitting structure disposed upon the UV transmissive layer, the UV light emitting layer structure comprising;

an n-type layer comprising aluminum gallium nitride disposed upon the UV transmissive layer;

one or more quantum well structures disposed upon the n-type layer; and

a p-type layer comprising nitride material disposed upon the one or more quantum well structures.

12. The UV device of claim 11 wherein the n-type layer also comprises indium or boron.

13. The UV device of claim 11 wherein the p-type layer comprises magnesium.

14. The UV device of claim 11 wherein the p-type layer comprises indium or boron.

15. The UV device of claim 11 wherein the UV light emitting structure is fabricated in a form selected from a group consisting of:

nano-wires, nano-disks, nano-columns, and a nano-structure.

16. The UV device of claim 11 wherein the UV transmissive substrate is selected from a group consisting of:

sapphire and quartz.

17. The UV device claim 11

wherein the first UV transmissive layer comprises a first thickness;

wherein the second UV transmissive layer comprises a second thickness; and

wherein the first thickness exceeds the second thickness.

18. The UV device of claim 11

wherein the aluminum nitride of the first UV transmissive layer is characterized by a first defect density;

wherein the aluminum nitride of the second UV transmissive layer is characterized by a second defect density; and

wherein the first defect density exceeds the second defect density.

19. The UV device of claim 18 wherein the first defect density is less than about 10E10 cm−

3.

20. The UV device of claim 18 wherein the first defect density is characterized by a contamination density of the aluminum nitride of the first UV transmissive layer, wherein the contamination density is than about 10E18 cm−

3.