Semiconductor light emitting device capable of suppressing silver migration of reflection film made of silver

• US 20050211989A1
• Filed: 10/19/2004
• Published: 09/29/2005
• Est. Priority Date: 03/29/2004
• Status: Active Grant

• Current Assignee: Stanley Electric Company Limited
• Original Assignee: Stanley Electric Company Limited
• Inventors: Horio, Naochika, Tamura, Hitoshi, Tsuchiya, Masahiko
• Granted Patent: US 7,141,825 B2
• Time in Patent Office: Days
• US Class Current: 257/79
• CPC Class Codes: H01L 2224/02166 Collar structures
• CPC Class Codes: H01L 2224/0603 Bonding areas having different sizes, e.g. different heights or widths
• CPC Class Codes: H01L 2224/16145 the bodies being stacked
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/40 Materials therefor
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector

Abstract

A luminous lamination structure includes a first layer made of n-type nitride semiconductor and a second layer made of p-type nitride semiconductor and disposed over the first layer wherein a luminous region is defined between the first and second layers. The second layer is removed to expose the first layer in a first area which is a partial surface of the first layer. A p-side electrode is disposed on a surface of the second layer and electrically connected to the second layer. An insulating film covers the p-side electrode. An n-side electrode electrically connected to the first layer is disposed in the first area. A reflection film disposed on the insulating film extends to the n-side electrode and electrically connected to the n-side electrode. The reflection film is made of silver containing alloy or silver.

Claims

1. A semiconductor light emitting device comprising:

a luminous lamination structure including a first layer made of n-type nitride semiconductor and a second layer made of p-type nitride semiconductor and disposed over the first layer wherein a luminous region is defined between the first and second layers and the second layer is removed to expose the first layer in a first area which is a partial surface of the first layer;

a p-side electrode disposed on a surface of the second layer and electrically connected to the second layer;

an insulating film covering the p-side electrode;

an n-side electrode electrically connected to the first layer in the first area; and

a reflection film disposed on the insulating film, extending to the n-side electrode, electrically connected to the n-side electrode, and made of silver containing alloy or silver.

2. A semiconductor light emitting device according to claim 1, wherein the p-side electrode transmits light having a luminescence wavelength of the luminous region.

3. A semiconductor light emitting device according to claim 1, wherein the p-side electrode is made of a metal selected from a group consisting of Pt, Rh and Pd, and has a thickness of 1 nm to 15 nm.

9. A semiconductor light emitting device according to claim 1, further comprising an intermediate layer disposed between the p-side electrode and the insulating film, the intermediate layer being made of at least a metal selected from a group consisting of Ti, Ni, W and Mo.

10. A semiconductor light emitting device according to claim 1, wherein the p-side electrode transmits light having a luminescence wavelength of the luminous region.

11. A semiconductor light emitting device according to claim 1, wherein the insulating film is made of at least a material selected from a group consisting of silicon oxide, titanium oxide, tantalum oxide, alumina, zirconium oxide, hafnium oxide, and insulating polymeric material.

12. A semiconductor light emitting device according to claim 1, further comprising an insulating protective film covering the reflection film.

13. A semiconductor light emitting device according to claim 12, wherein the protective film is made of at least a material selected from a group consisting of silicon oxide, titanium oxide, tantalum oxide, alumina, zirconium oxide, hafnium oxide, and insulating polymeric material.

14. A semiconductor light emitting device according to claim 12, further comprising an intermediate layer disposed between the reflection film and the protective film, the intermediate layer being made of at least a metal selected from a group consisting of Ti, Ni, Al, W and Mo.

15. A semiconductor light emitting device according to claim 1, further comprising:

a p-side pad for flip chip bonding disposed on a partial surface area of the p-side electrode; and

an n-side pad for flip chip bonding disposed on a partial surface area of the n-side electrode.

16. A semiconductor light emitting device according to claim 1, further comprising:

a p-side pad for flip chip bonding disposed on a partial surface area of the p-side electrode; and

an n-side pad for flip chip bonding disposed on a surface of the reflection film superposing the second layer.

17. A semiconductor light emitting device according to claim 1, wherein the reflection film has a plane shape which scatters light irradiated from the luminous region and propagating toward the reflection film, and the semiconductor light emitting device further comprises a fluorescent material member which produces fluorescence when light scattered by the reflection film becomes incident.

4. A semiconductor light emitting device comprising:

a luminous lamination structure including a first layer made of n-type nitride semiconductor and a second layer made of p-type nitride semiconductor and disposed over the first layer wherein a luminous region is defined between the first and second layers and the second layer is removed to expose the first layer in a first area which is a partial surface of the first layer;

a p-side electrode disposed on a surface of the second layer, electrically connected to the second layer, and transmitting light irradiated from the luminous region;

an insulating film covering the p-side electrode;

an n-side electrode electrically connected to the first layer in the first area; and

a reflection film disposed on the insulating film, extending to the n-side electrode, electrically connected to the n-side electrode, and reflecting light irradiated from the luminous region.

5. A semiconductor light emitting device comprising:

a luminous lamination structure including a first layer made of n-type nitride semiconductor and a second layer made of p-type nitride semiconductor and disposed over the first layer wherein a luminous region is defined between the first and second layers and the second layer is removed to expose the first layer in a first area which is a partial surface of the first layer;

a p-side electrode disposed on a surface of the second layer and electrically connected to the second layer;

an insulating film covering the p-side electrode;

an n-side electrode electrically connected to the first layer in the first area; and

a reflection film disposed on the insulating film, made of silver containing alloy or silver, and made in an electrically floating state, being connected neither to the p-side electrode nor to the n-side electrode.

6. A semiconductor light emitting device according to claim 5, wherein the p-side electrode transmits light having a luminescence wavelength of the luminous region.

7. A semiconductor light emitting device according to claim 5, wherein the p-side electrode is made of a metal selected from a group consisting of Pt, Rh and Pd, and has a thickness of 1 nm to 15 nm.

8. A semiconductor light emitting device comprising:

a luminous lamination structure including a first layer made of n-type nitride semiconductor and a second layer made of p-type nitride semiconductor and disposed over the first layer wherein a luminous region is defined between the first and second layers and the second layer is removed to expose the first layer in a first area which is a partial surface of the first layer;

a p-side electrode disposed on a surface of the second layer, electrically connected to the second layer, and transmitting light irradiated from the luminous region;

an insulating film covering the p-side electrode;

an n-side electrode electrically connected to the first layer in the first area; and

a reflection film disposed on the insulating film, made in an electrically floating state, being connected neither to the p-side electrode nor to the n-side electrode, and reflecting light irradiated from the luminous region.