Semiconductor light-emitting device

• US 20090206354A1
• Filed: 08/26/2008
• Published: 08/20/2009
• Est. Priority Date: 02/20/2008
• Status: Active Grant

• Current Assignee: Sumitomo Chemical Company Limited
• Original Assignee: Hitachi Cable Limited (Proterial Ltd.)
• Inventors: Iizuka, Kazuyuki, Arai, Masahiro, Kitano, Nobuaki
• Granted Patent: US 8,071,992 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/387 with a plurality of electrode regions in direct contact with the semiconductor body and being electrically interconnected by another electrode layer
• CPC Class Codes: H01L 33/405 Reflective materials

Abstract

A semiconductor light-emitting device includes a support structure, and a light-emitting structure. The support structure includes a support substrate, and a support substrate side bonding layer disposed on one surface of the support substrate. The light-emitting structure includes a light-emitting structure side bonding layer bonded to the support substrate side bonding layer, a reflection region disposed on the support substrate side bonding layer opposite the support substrate, and a semiconductor multilayer structure including a light-emitting layer disposed on the reflection region opposite the light-emitting structure side bonding layer for emitting a light with a predetermined wavelength, and a light-extraction surface disposed on the light-emitting layer opposite the reflection region for reflecting diffusely the light. The reflection region includes a transparent layer of a material with a lower refractive index than that of the semiconductor multilayer structure, and a reflection layer of a metallic material. The transparent layer has such a thickness that interference caused by multiple reflection of light inputted to the transparent layer can be suppressed.

Claims

1. A semiconductor light-emitting device, comprising:

a support structure; and

a light-emitting structure,

wherein the support structure comprises;

a support substrate; and

a support substrate side bonding layer disposed on one surface of the support substrate, and

the light-emitting structure comprises;

a light-emitting structure side bonding layer bonded to the support substrate side bonding layer;

a reflection region disposed on the light-emitting structure side bonding layer opposite the support substrate; and

a semiconductor multilayer structure including a light-emitting layer disposed on the reflection region opposite the light-emitting structure side bonding layer for emitting a light with a predetermined wavelength, and a light-extraction surface disposed on the light-emitting layer opposite the reflection region for reflecting diffusely the light, wherein the reflection region includes a transparent layer comprising a material with a lower refractive index than that of the semiconductor multilayer structure, and a reflection layer comprising a metallic material, and

the transparent layer comprises such a thickness that interference caused by multiple reflection of light inputted to the transparent layer can be suppressed.

2. The semiconductor light-emitting device according to claim 1, wherein:

the transparent layer comprises a thickness of not less than about half of a value obtained by dividing a central wavelength of light emitted from the light-emitting layer by a refractive index of the transparent layer.

3. The semiconductor light-emitting device according to claim 2, wherein:

the transparent layer comprises a refractive index of about 1.3 to about 3.0, and a thickness of not less than about ¾

of the value obtained by dividing the central wavelength by the refractive index.

4. The semiconductor light-emitting device according to claim 2, wherein:

the transparent layer comprises a refractive index of about 1.2 to about 3.0, and a thickness of not less than about 5/4 of the value obtained by dividing the central wavelength by the refractive index.

5. The semiconductor light-emitting device according to claim 1, wherein:

the light-emitting structure further comprises an interface electrode between the reflection layer and the semiconductor multilayer structure, the interface electrode connecting electrically a surface of the semiconductor multilayer structure opposite the light-extraction surface to the reflection layer;

the semiconductor multilayer structure further comprises a surface electrode on a part of a surface thereof where the light-extraction surface is formed; and

the support substrate comprises a back electrode on a surface thereof opposite the support substrate side bonding layer.

6. The semiconductor light-emitting device according to claim 1, wherein:

the semiconductor multilayer structure further includes a semiconductor layer of a first conductive type and a semiconductor layer of a second conductive type different from the first conductive type, the light-emitting layer being disposed between the semiconductor layer of the first conductive type and the semiconductor layer of the second conductive type; and

the semiconductor multilayer structure further includes a first electrode on a part of a surface of the semiconductor layer of the first conductive type on a side of the light-extraction surface and a second electrode on a part of a surface of the semiconductor layer of the second conductive type.

7. The semiconductor light-emitting device according to claim 5, wherein:

the interface electrode is formed in an area not more than 30% of a surface of the semiconductor multilayer structure on the side of the reflection layer.

8. The semiconductor light-emitting device according to claim 1, wherein:

the light-extraction surface includes an unsmooth surface that comprises an arithmetic average roughness not less than about ¼

of a value obtained by dividing a wavelength of the light by a refractive index of a semiconductor layer composing the light-extraction surface, and at least an angle being not zero and defined by a normal line of an average surface of the light-extraction surface and a normal line of a surface of the light-extraction surface.

9. The semiconductor light-emitting device according to claim 1, wherein:

the light-extraction surface comprises a plurality of three-dimensional structures that include a convex or concave substantially hemispherical shape.

10. The semiconductor light-emitting device according to claim 1, wherein:

the reflection layer comprises gold (Au), silver (Ag), copper (Cu) or aluminum (Al), or an alloy including at least one selected from the group of gold, silver, copper and aluminum.