SEMICONDUCTOR LIGHT EMITTING DEVICE AND METHOD FOR MANUFACTURING THE SAME

• US 20140231844A1
• Filed: 03/21/2013
• Published: 08/21/2014
• Est. Priority Date: 02/18/2013
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: AKIMOTO, Yosuke, KOJIMA, Akihiro, SHIMADA, Miyoko, TOMIZAWA, Hideyuki, SUGIZAKI, Yoshiaki, FURUYAMA, Hideto
• Granted Patent: US 8,933,476 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/0008 having p-n or hi-lo junctions
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

According to one embodiment, a semiconductor light emitting device includes a semiconductor layer, a p-side electrode, an n-side electrode, a fluorescent material layer and a scattering layer. The semiconductor layer has a first surface and a second surface on an opposite side to the first surface and includes a light emitting layer. The p-side electrode and the n-side electrode are provided on the semiconductor layer on a side of the second surface. The fluorescent material layer is provided on a side of the first surface and includes a plurality of fluorescent materials and a first bonding material. The first bonding material integrates the fluorescent materials. The scattering layer is provided on the fluorescent material layer and includes scattering materials and a second bonding material. The scattering materials are configured to scatter radiated light of the light emitting layer. The second bonding material integrates the scattering materials.

Claims

1. A semiconductor light emitting device comprising:

a semiconductor layer having a first surface and a second surface on an opposite side to the first surface and including a light emitting layer;

a p-side electrode provided on the semiconductor layer on a side of the second surface;

an n-side electrode provided on the semiconductor layer on the side of the second surface;

a fluorescent material layer provided on a side of the first surface, the fluorescent material layer including a plurality of fluorescent materials and a first bonding material, the fluorescent materials being configured to be excited by radiated light of the light emitting layer and to radiate light of a different wavelength from the radiated light of the light emitting layer, the first bonding material integrating the fluorescent materials and being configured to transmit the radiated light of the light emitting layer and the radiated light of the fluorescent material; and

a scattering layer provided on the fluorescent material layer, the scattering layer including a plurality of scattering materials and a second bonding material, the scattering materials being configured to scatter the radiated light of the light emitting layer, the second bonding material integrating the scattering materials and being configured to transmit the radiated light of the light emitting layer and the radiated light of the fluorescent material.

2. The device according to claim 1, wherein

a size of the scattering materials is smaller than a size of the fluorescent materials and

the scattering layer is thinner than the fluorescent material layer.

3. The device according to claim 1, wherein the scattering layer has a recess.

4. The device according to claim 1, wherein a size of the scattering materials is 1/10 or less of a wavelength of the radiated light of the light emitting layer.

5. The device according to claim 1, wherein a wavelength of the radiated light of the light emitting layer is 430 to 470 nm.

6. The device according to claim 1, wherein

the semiconductor layer does not include a substrate on the side of the first surface and

the fluorescent material layer is provided on the side of the first surface without interposing a substrate between the semiconductor layer and the fluorescent material layer.

7. The device according to claim 1, further comprising:

a p-side interconnection unit provided on the side of the second surface, having an externally connectable end, and connected to the p-side electrode;

an n-side interconnection unit provided on the side of the second surface, having an externally connectable end, and connected to the n-side electrode; and

an insulating film provided in contact with a side surface of the p-side interconnection unit and a side surface of the n-side interconnection unit between the p-side interconnection unit and the n-side interconnection unit and constituting a support body along with the p-side interconnection unit and the n-side interconnection unit.

8. The device according to claim 7, wherein

the p-side interconnection unit includes a p-side interconnection layer connected to the p-side electrode and a p-side metal pillar connected to the p-side interconnection layer, the p-side metal pillar having a larger thickness than the p-side interconnection layer and

the n-side interconnection unit includes an n-side interconnection layer connected to the n-side electrode and an n-side metal pillar connected to the n-side interconnection layer, the n-side metal pillar having a larger thickness than the n-side interconnection layer.

9. The device according to claim 8, wherein the insulating film includes a resin provided between the p-side metal pillar and the n-side metal pillar.

10. The device according to claim 1, wherein a side surface of the scattering layer and a side surface of the fluorescent material layer are even with each other.

11. The device according to claim 7, wherein a side surface of the scattering layer, a side surface of the fluorescent material layer, and a side surface of the insulating film are even with one another.

12. A method for manufacturing a semiconductor light emitting device comprising:

forming a wafer with a plurality of light emitting elements formed, each of the plurality of light emitting elements including a semiconductor layer having a first surface and a second surface on an opposite side to the first surface and including a light emitting layer, a p-side electrode provided on the semiconductor layer on the side of the second surface, and an n-side electrode provided on the semiconductor layer on the side of the second surface;

forming a fluorescent material layer on a side of the first surface, the fluorescent material layer including a plurality of fluorescent materials and a first bonding material, the fluorescent materials being configured to be excited by radiated light of the light emitting layer and to radiate light of a different wavelength from the radiated light of the light emitting layer, the first bonding material integrating the fluorescent materials and being configured to transmit the radiated light of the light emitting layer and the radiated light of the fluorescent material;

forming a scattering layer on the fluorescent material layer, the scattering layer including a plurality of scattering materials and a second bonding material, the scattering materials being configured to scatter the radiated light of the light emitting layer, the second boding material integrating the scattering materials and being configured to transmit the radiated light of the light emitting layer and the radiated light of the fluorescent material; and

adjusting an in-wafer-plane distribution of a volume of the scattering layer.

13. The method according to claim 12, further comprising causing the light emitting layer to emit light and measuring an optical characteristic of light emitted from a side of the scattering layer after forming the scattering layer and

the in-wafer-plane distribution of the volume of the scattering layer being adjusted in accordance with the optical characteristic.

14. The method according to claim 13, wherein the optical characteristic is an in-wafer-plane distribution of a peak wavelength of the light emitting layer or an in-wafer-plane distribution of an emission spectrum of the light emitting layer.

15. The method according to claim 13, wherein the optical characteristic is an in-wafer-plane distribution of a chromaticity of the light emitted from the side of the scattering layer.

16. The method according to claim 12, wherein the adjusting the in-wafer-plane distribution of the volume of the scattering layer includes cutting the scattering layer to adjust a film thickness of the scattering layer.

17. The method according to claim 12, wherein the adjusting the in-wafer-plane distribution of the volume of the scattering layer includes forming a recess in the scattering layer.

18. The method according to claim 12, wherein

the light emitting element is formed on a substrate and

the fluorescent material layer is formed on the first surface after the substrate is removed.

19. The method according to claim 18, further comprising forming a support body more flexible than the semiconductor layer on the side of the second surface of the semiconductor layer and

the substrate being removed in a state where the light emitting element is supported by the support body.

20. The method according to claim 19, wherein the forming the support body includes:

forming a p-side interconnection unit connected to the p-side electrode on the side of the second surface;

forming an n-side interconnection unit connected to the n-side electrode on the side of the second surface; and

forming an insulating film in contact with a side surface of the p-side interconnection unit and a side surface of the n-side interconnection unit between the p-side interconnection unit and the n-side interconnection unit.