METHOD OF MANUFACTURING LIGHT EMITTING DEVICE

• US 20170162752A1
• Filed: 12/07/2016
• Published: 06/08/2017
• Est. Priority Date: 12/08/2015
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: WAKAKI, Takayoshi, TADA, Takaaki
• Granted Patent: US 9,893,239 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 2224/49111 the connectors connecting two common bonding areas, e.g. Litz or braid wires
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 2924/19107 off-chip wires
• CPC Class Codes: H01L 2933/0025 relating to coatings
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 33/005 Processes
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

A method of manufacturing a light emitting device includes providing a light emitting element; and forming a protective film on a surface of the light emitting element, wherein the step of forming the protective film includes: (i) providing first quantity of oxygen at the surface of the light emitting element, (ii) combining a first quantity of a first metal with the first quantity of oxygen, (iii) combining a second quantity of oxygen with the first quantity of metal, (iv) combining a first quantity of a second metal, different from the first metal, with the second quantity of oxygen and first quantity of the first metal, and (v) combining a third quantity of oxygen with the first quantity of the second metal.

Claims

1. A method of manufacturing a light emitting device, comprising:

providing a light emitting element that includes;

a semiconductor structure in which an n-type semiconductor layer, an active layer, and a p-type semiconductor layer, each containing a nitride semiconductor, are layered in this order,

a p-electrode disposed on a portion of a surface of the p-type semiconductor layer on a side opposite to a surface provided with the active layer, and

an n-electrode disposed on a surface of the n-type semiconductor layer on a side opposite to a surface provided with the active layer in a region other than a region facing the p-electrode,

wherein the light emitting element has a peak wavelength of 410 nm or less; and

forming a protective film on a surface of the light emitting element, wherein the step of forming the protective film includes;

(i) providing a first quantity of oxygen at the surface of the light emitting element, using a first quantity of oxygen raw material gas,

(ii) combining a first quantity of a first metal with the first quantity of oxygen provided at the surface of the light emitting element, using a first quantity of a first metal raw material gas,

(iii) combining a second quantity of oxygen with the first quantity of the first metal combined with the first quantity of oxygen, using a second quantity of oxygen raw material gas,

(iv) combining a first quantity of a second metal, different from the first metal, with the second quantity of oxygen combined with the first quantity of the first metal, using a second metal raw material gas, and

(v) combining a third quantity of oxygen with the first quantity of the second metal, using a third quantity of oxygen raw material gas,

wherein the protective film is formed so as to continuously cover a surface of the n-electrode and a surface of the n-type semiconductor layer.

2. The method of manufacturing a light emitting device according to claim 1, wherein the oxygen raw material gas is an ozone gas.

3. The method of manufacturing a light emitting device according to claim 1, wherein the first metal and the second metal are each selected from the group consisting of Al, Nb, Ti and Si.

4. The method of manufacturing a light emitting device according to claim 1, wherein the first metal raw material gas is a trimethylaluminum gas.

5. The method of manufacturing a light emitting device according to claim to 4, wherein the second metal raw material gas is a bis(diethylamino)silane gas.

6. The method of manufacturing a light emitting device according to claim 5, wherein, in the step of forming the protective film, the protective film is formed using a film formation temperature in a range of 200°

C. to 250°

C.

7. The method of manufacturing a light emitting device according to claim 1, further comprising,

after sub-step (v), (vi) combining a second quantity of the first metal with the third quantity of oxygen combined with the first quantity of the second metal, using a second quantity of the first metal raw material gas, and

after step (v), repeating sub-steps (vi), (iii), (iv), and (v) in this order at least one additional time.

8. The method of manufacturing a light emitting device according to claim 1, further comprising:

between sub-steps (ii) and (iii),

(vii) combining a fourth quantity of oxygen to the first quantity of the first metal combined with the first quantity of oxygen, using a fourth quantity of oxygen raw material gas, and

(viii) combining a second quantity of the first metal with the fourth quantity of oxygen combined with the first quantity of the first metal, using a second quantity of the first metal raw material gas, and

repeating sub-steps (vii) and (viii) at least one additional time; and

between sub-steps (iv) and (v),

(ix) combining a fifth quantity of oxygen to the first quantity of the second metal combined with the second quantity of oxygen, using a fifth quantity of oxygen raw material gas, and

(x) combining a second quantity of the second metal with the fifth quantity of oxygen combined with the first quantity of the second metal, and

repeating sub-steps (ix) and (x) at least one additional time.

9. The method of manufacturing a light emitting device according to claim 1, wherein, in the step of providing the light emitting element, the light emitting element includes a p-side protective film on the surface of the p-type semiconductor layer on the side opposite to the surface provided with the active layer in a region facing the p-electrode.

10. The method of manufacturing a light emitting device according to claim 9, further comprising:

after the step of providing the light emitting element and before the step of forming the protective layer;

mounting the light emitting element to a base that includes a p-side electrode layer and an n-side electrode layer such that the p-side electrode layer and the p-electrode are connected, and

connecting the n-electrode and the n-side electrode layer via a wire,

wherein, in the step of forming the protective film, the protective film is formed to continuously cover a surface of the n-electrode and a surface of the n-type semiconductor layer.

11. The method of manufacturing a light emitting device according to claim 10, wherein:

in the step of providing the light emitting element, the base includes a recess, and

the method further comprises, after the step of forming the protective film, fixing a cover so as to close an opening of the recess of the base.

12. The method of manufacturing a light emitting device according to claim 11, wherein, in the step of fixing the cover, the cover is fixed to the base such that a gas is present between the light emitting element and the base.

13. The method of manufacturing a light emitting device according to claim 9, wherein, in the step of providing the light emitting element, SiO₂ is used for the p-side protective film.

15. The light emitting device according to claim 11, wherein:

the light emitting device further comprises a base including a p-side electrode layer and an n-side electrode layer,

the p-electrode is connected to the p-side electrode layer,

the n-electrode is connected to the n-side electrode layer via a wire, and

the protective layer continuously covers a surface of the wire, a surface of the n-electrode, and a surface of the n-type semiconductor layer.

16. The light emitting device according to claim 15, wherein:

the light emitting device further comprises a cover,

the base includes a recess, and

the cover is fixed to the base so as to close an opening of the recess of the base.

17. The light emitting device according to claim 16, wherein:

a light-transmissive resin is not arranged between the light emitting element and the cover.

18. The light emitting device according to claim 17, wherein:

the recess of the base includes a first bottom surface at a central portion of the recess and a second bottom surface surrounding the first bottom surface, a height of the second bottom surface being different from a height of the first bottom surface, and

the p-side electrode layer is disposed on the first bottom surface of the recess, and the n-side electrode layer is disposed on the second bottom surface of the recess.

14. A light emitting device comprising:

a light emitting element including;

a semiconductor structure including an n-type semiconductor layer, an active layer, and a p-type semiconductor layer, in this order, each containing a nitride semiconductor,

a p-electrode disposed on a portion of a surface of the p-type semiconductor layer on a side opposite to a surface provided with the active layer, and

an n-electrode disposed on a surface of the n-type semiconductor layer on a side opposite to a surface provided with the active layer in a region other than a region facing the p-electrode,

wherein the light emitting element has a peak wavelength of 410 nm or less; and

a protective film continuously covering a surface of the n-electrode and a surface of the n-type semiconductor layer,

wherein the protective film includes a first metal oxide film and a second metal oxide film that are alternately layered, the first metal oxide film containing a first metal, and the second metal oxide film containing a second metal,

wherein the first metal oxide film includes one or more individual first metal oxide film layers, and

the second metal oxide film includes one or more individual second metal oxide film layers.