Nitride semiconductor light emitting element

• US 7,986,722 B2
• Filed: 10/21/2009
• Issued: 07/26/2011
• Est. Priority Date: 10/22/2008
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Omae, Kunimichi, Higuchi, Yu
• Primary Examiner(s): Stultz; Jessica T
• Assistant Examiner(s): Nguyen; Phillip
• Application Number:
  US12/603,301
• Publication Number:
  US 20100098127A1
• Time in Patent Office: 643 Days
• Field of Search: 372/50.124, 372/43.01, 372/46.01, 372/87
• US Class Current: 372/50.124
• CPC Class Codes: H01S 5/0217 Removal of the substrate
• CPC Class Codes: H01S 5/04252 characterised by the material
• CPC Class Codes: H01S 5/04253 having specific optical properties, e.g. transparent electrodes
• CPC Class Codes: H01S 5/04254 characterised by the shape
• CPC Class Codes: H01S 5/18308 having a special structure for lateral current or light confinement
• CPC Class Codes: H01S 5/18341 Intra-cavity contacts
• CPC Class Codes: H01S 5/18369 based on dielectric materials
• CPC Class Codes: H01S 5/18397 Plurality of active layers vertically stacked in a cavity for multi-wavelength emission
• CPC Class Codes: H01S 5/3095 Tunnel junction

Abstract

A method of manufacturing a nitride semiconductor light emitting element includes: forming a stacked layer body of a nitride semiconductor having a second conductive-type layer, a light emitting layer, and a first conductive-type layer stacked on a growth substrate in this order; forming a first Bragg reflector made of a dielectric multilayer film above the first conductive-type layer; forming a first electrode over the first Bragg reflector with the first electrode being electrically connected to the first conductive-type layer; bonding the stacked layer body to a supporting substrate via the first Bragg reflector and the first electrode; removing the growth substrate from the stacked layer body to expose the second conductive-type layer; and forming over the exposed second conductive-type layer a second electrode and a second Bragg reflector made of a dielectric multilayer film so that the second Bragg reflector faces the first Bragg reflector across the stacked layer body.

Claims

1. A nitride semiconductor light emitting element comprising:

a supporting substrate;

a first Bragg reflector made of a dielectric multilayer film;

a stacked layer body of nitride semiconductor disposed on an opposite side of the first Bragg reflector from the supporting substrate, the stacked layer body having a first conductive-type layer, a light emitting layer, and a second conductive-type layer stacked in this order;

a second Bragg reflector made of a dielectric multilayer film and facing the first Bragg reflector across the stacked layer body; and

a first electrode electrically connected to the first conductive-type layer with the first electrode being disposed between the supporting substrate and the first Bragg reflector such that the first electrode at least partially overlaps the first Bragg reflector when viewed in a stacking direction of the stacked layer body.

2. The nitride semiconductor light emitting element according to claim 1, wherein

the first electrode is electrically connected to the first conductive-type layer via a first transparent electrode disposed between the first Bragg reflector and the first conductive-type layer, the first transparent electrode protruding outwardly from the first Bragg reflector in a direction perpendicular to a stacking direction of the stacked layer body.

3. The nitride semiconductor light emitting element according to claim 1, wherein

the first electrode and the first conductive-type layer are electrically connected via a connecting electrode disposed on a side surface of the first Bragg reflector or penetrating through the first Bragg reflector.

4. The nitride semiconductor light emitting element according to claim 3, wherein

the connecting electrode has a width smaller than a width of the supporting substrate.

5. The nitride semiconductor light emitting element according to claim 1, wherein

the stacked layer body has a side surface covered with an insulating film and a metal film in this order.

6. The nitride semiconductor light emitting element according to claim 1, wherein

a part of the stacked layer body on a side of the first conductive-type layer has a width smaller than a width of a part of the stacked layer body on a side of the second conductive-type layer.

7. The nitride semiconductor light emitting element according to claim 1, wherein

the second Bragg reflector covers a region facing the first Bragg reflector across the stacked layer body.

8. The nitride semiconductor light emitting element according to claim 2, further comprising

an insulating layer having an aperture and disposed contiguous to the first conductive-type layer, and

a second electrode having an aperture and disposed over the second conductive-type layer,

the first transparent electrode covering the aperture of the insulating layer,

the second Bragg reflector being disposed at least at the aperture of the second electrode, and

the second Bragg reflector having an area larger than an area of the first Bragg reflector disposed at the aperture of the insulating layer.

9. The nitride semiconductor light emitting element according to claim 8, wherein

the insulating layer is disposed above the connecting electrode.

10. The nitride semiconductor light emitting element according to claim 1, wherein

the second Bragg reflector is a light emitting side of the nitride semiconductor light emitting element.

11. The nitride semiconductor light emitting element according to claim 2, wherein

the first transparent electrode includes at least one element selected from the group consisting of zinc, indium, tin, and magnesium.

12. The nitride semiconductor light emitting element according to claim 11, wherein

the first transparent electrode is made of conductive oxide selected from the group consisting of ZnO, In₂O₃, SnO₂, ATO, ITO, and MgO.

13. The nitride semiconductor light emitting element according to claim 1, wherein

the first Bragg reflector includes a multilayer structure selected from the group consisting of a combination of SiO₂ layer and Nb₂O₅ layer, a combination of SiO₂ layer and ZrO₂ layer, and a combination of SiO₂ layer and AlN layer.

14. The nitride semiconductor light emitting element according to claim 1, wherein

the first Bragg reflector has one of a circular shape, an oval shape and a rectangle shape when viewed in the stacking direction of the stacked layer body.

15. The nitride semiconductor light emitting element according to claim 1, wherein

the first electrode is made of material selected from the group consisting of (Ti/Si)—

Pt—

Pd, Ti—

Pt—

Au—

(Au/Sn), Ti—

Pt—

Au—

(Au/Si), Ti—

Pt—

Au—

(Au/Ge), Ti—

Pt—

Au—

In, Au—

Sn, In, Au—

Si, Au—

Ge, and Al—

Rh—

Au—

(Au/Sn).

16. The nitride semiconductor light emitting element according to claim 8, wherein the second electrode is made of material selected from the group consisting of Ni—

Au system, Ni—

Au—

Pt system, Pd—

Pt system, Ni—

Pt system, Ti—

Pt—

Au system, and Ti—

Al—

Au system.

17. The nitride semiconductor light emitting element according to claim 1, wherein the first Bragg reflector and the second Bragg reflector are made of the same material.

18. The nitride semiconductor light emitting element according to claim 1, wherein

the second Bragg reflector has a larger surface area than the first Bragg reflector when viewed in the stacking direction of the stacked layer body.

19. The nitride semiconductor light emitting element according to claim 1, wherein

the nitride semiconductor light emitting element is a vertical cavity surface emitting laser.

20. The nitride semiconductor light emitting element according to claim 1, wherein

the supporting substrate is selected from the group consisting of a semiconductor substrate, a single metal substrate, and a metal substrate made of a complex of two or more metals.