OPTOELECTRONIC DEVICE WITH IMPROVED LIGHT EXTRACTION EFFICIENCY

• US 20170047477A1
• Filed: 04/20/2015
• Published: 02/16/2017
• Est. Priority Date: 04/22/2014
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation), Aledia
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation), Aledia
• Inventors: Hyot, Brangre, Dupont, Florian
• Granted Patent: US 9,793,431 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• CPC Class Codes: H01L 33/005 Processes
• CPC Class Codes: H01L 33/0066 with a substrate not being a III-V compound
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/18 within the light emitting region
• CPC Class Codes: H01L 33/24 of the light emitting region, e.g. non-planar junction
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector

Abstract

The optoelectronic device (1) comprises a substrate (2), a light-emitting member (3) comprising an elongate element (4) extending in a direction forming an angle with the substrate (2). An intermediate element (5) is interposed between the substrate (2) and a longitudinal end of the elongate element (4) closest to the substrate (2). Furthermore, the substrate (2) is transparent to said light and the intermediate element (5), transparent to said light, comprises at least one nitride of a transition metal, and has a thickness less than or equal to 9 nm.

Claims

1. An optoelectronic device comprising:

a substrate,

a light-emitting member comprising an elongate element extending in a direction forming an angle with the substrate, and

an intermediate element interposed between the substrate and a longitudinal end of the elongate element closest to the substrate,

wherein;

the substrate is transparent to said light, and

the intermediate element, transparent to said light, comprises at least one nitride of a transition metal, and has a thickness less than or equal to 9 nm.

2. The device as claimed in claim 1, wherein at least one of (i) the substrate is electrically insulating and (ii) the intermediate element is configured so as to contribute to the injection of charge carriers into the elongate element (4) with a view to emitting said light.

3. The device as claimed in claim 1, wherein the transition metal is chosen from the group consisting of titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum, and combinations thereof.

4. The device as claimed in claim 1, wherein the substrate is of oxide glass.

5. The device as claimed in claim 1, comprising a zone for restoration of said light and a mirror arranged so as to orient at least a part of said light from the light-emitting member toward said restoration zone.

6. The device as claimed in claim 1, comprising a plurality of light-emitting members each comprising an elongate element, and wherein (i) the intermediate element forms a common layer associated with each of the elongate elements, or (ii) each of the elongate elements is associated with a corresponding intermediate element, taking the form of a block, which is specific thereto.

7. A method for fabricating an optoelectronic device as claimed in claim 1, comprising:

providing the substrate transparent to said light,

forming the intermediate element so that the intermediate element is transparent to said light and so that the intermediate element has a growth surface for the elongate element, and

forming the light-emitting member comprising growing the elongate element from the growth surface.

8. The method as claimed in claim 7, wherein, the intermediate element is formed by a nitride of a transition metal, and the formation of the intermediate element comprises depositing the intermediate element from a gaseous mixture comprising nitrogen and the transition metal.

9. The method as claimed in claim 7, wherein the formation of the intermediate element comprises:

depositing a layer of the transition metal,

nitriding at least a part of the layer of transition metal.

10. The method as claimed in claim 9, wherein the nitriding comprises:

a first nitriding performed at least partly at a first temperature by enforcing an injection of a nitriding gas according to a first flow rate, and

a second nitriding performed at least partly at a second temperature less than or equal to the first temperature by enforcing an injection of the nitriding gas according to a second flow rate distinct or not from the first flow rate.

11. The method as claimed in claim 10, wherein the nitriding gas injected is ammonia, and wherein:

the first temperature lies between 1000°

C. and 1050°

C.,

the first flow rate lies between 500*V/8 sccm and 2500*V/8 sccm,

the second temperature lies between 950°

C. and 1050°

C.,

the second flow rate lies between 500*V/8 sccm and 2500*V/8 sccm,

where V is a total capacity in liters of a corresponding nitriding chamber.

12. The method as claimed in claim 9, wherein the nitriding comprises:

a first nitriding performed at least partly at a first temperature by enforcing an injection of a nitriding gas according to a first flow rate, and

a second nitriding performed at least partly at a second temperature greater than or equal to the first temperature by enforcing an injection of the nitriding gas according to a second flow rate distinct or not from the first flow rate.

13. The method as claimed in claim 12, wherein the nitriding gas injected is ammonia, and wherein:

the first temperature lies between 400°

C. and 1400°

C.,

the first flow rate lies between 10*V/18 sccm and 4000*V/18 sccm,

the second temperature lies between 400°

C. and 1400°

C.,

the second flow rate lies between 10*V/18 sccm and 4000*V/18 sccm,

where V is a total capacity in liters of a corresponding nitriding chamber.

14. The method as claimed in claim 9, wherein the nitriding is performed in a nitriding chamber placed at a pressure of between 50 mbar and 800 mbar.

15. The method as claimed in claim 9, wherein the growth of the elongate element is performed after the second nitriding, or is initiated during the second nitriding.

16. The method as claimed in claim 7, wherein the growth of the elongate element comprises injecting Ga so as to form the elongate element from gallium nitride, the elongate element extending from the corresponding growth surface.

17. The device as claimed in claim 2, wherein the substrate is of oxide glass.

18. The device as claimed in claim 17, wherein the substrate is of SiO₂-based silicate glass.

19. The device as claimed in claim 4, wherein the substrate is of SiO₂-based silicate glass.

20. The device as claimed in claim 2, wherein the transition metal is chosen from the group consisting of titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum, and combinations thereof.