Semiconductor light emitting device, semiconductor light emitting apparatus, and method of manufacturing a semiconductor light emitting device

• US 20060202216A1
• Filed: 02/23/2006
• Published: 09/14/2006
• Est. Priority Date: 03/08/2005
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Itonaga, Shuji
• Application Number:
  US11/359,371
• Publication Number:
  US 20060202216A1
• Time in Patent Office: Days
• US Class Current: 257/94
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• 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 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers

Abstract

A semiconductor light emitting device comprises: a semiconductor multilayer structure; and an aluminum nitride layer. The semiconductor multilayer structure includes a light emitting layer that emits a light. The aluminum nitride layer is provided on a surface of the semiconductor multilayer structure. The aluminum nitride layer has asperities with an average pitch of not more than half an in-medium wavelength of the light in aluminum nitride. Alternatively, the semiconductor light emitting device may have asperities composed of a plurality of protrusions including the aluminum nitride layer and a plurality of depressions intruding into the semiconductor multilayer structure.

Claims

1. A semiconductor light emitting device comprising:

a semiconductor multilayer structure including a light emitting layer that emits a light; and

an aluminum nitride layer provided on a surface of the semiconductor multilayer structure, the aluminum nitride layer having asperities with an average pitch of not more than half an in-medium wavelength of the light in aluminum nitride.

2. A semiconductor light emitting device according to claim 1, wherein the semiconductor multilayer structure includes at least one of InGaAIP-based, GaAIAs-based, and GaN-based materials.

3. A semiconductor light emitting device according to claim 1, wherein the semiconductor multilayer structure further includes a contact layer on the surface thereof, and an electrode forming an ohmic contact with the contact layer is further provided on the surface of the semiconductor multilayer structure outside a region where the aluminum nitride layer is provided.

4. A semiconductor light emitting device according to claim 1, wherein the asperities have an average height difference of 500 nanometers or more.

5. A semiconductor light emitting device according to claim 1, wherein the aluminum nitride layer has an average grain diameter of 50 nanometers or more.

6. A semiconductor light emitting device according to claim 1, wherein the aluminum nitride layer is a columnar polycrystal oriented so that their crystalline axes perpendicular to said surface are c-axis.

7. A semiconductor light emitting device comprising:

a semiconductor multilayer structure including a light emitting layer that emits light; and

an aluminum nitride layer provided on a surface of the semiconductor multilayer structure,

the semiconductor light emitting device having asperities composed of a plurality of protrusions including the aluminum nitride layer and a plurality of depressions intruding into the semiconductor multilayer structure.

8. A semiconductor light emitting device according to claim 7, wherein the semiconductor multilayer structure includes at least one of InGaAIP-based, GaAIAs-based, and GaN-based materials.

9. A semiconductor light emitting device according to claim 7, wherein the semiconductor multilayer structure further includes a contact layer on the surface thereof, and an electrode forming an ohmic contact with the contact layer is further provided on the surface of the semiconductor multilayer structure outside a region where the aluminum nitride layer is provided.

10. A semiconductor light emitting device according to claim 7, wherein an average pitch of the asperities is not more than half an in-medium wavelength of the light in a semiconductor part at the surface of the semiconductor multilayer structure.

11. A semiconductor light emitting device according to claim 7, wherein the asperities have an average height difference of 500 nanometers or more.

12. A semiconductor light emitting device according to claim 7, wherein the aluminum nitride layer is a columnar polycrystal oriented so that their crystalline axes perpendicular to said surface are c-axis.

13. A semiconductor light emitting apparatus comprising:

a packaging member;

a semiconductor light emitting device mounted on the packaging member; and

a sealing resin sealing the semiconductor light emitting device,

the semiconductor light emitting device having;

a semiconductor multilayer structure including a light emitting layer that emits a light; and

an aluminum nitride layer provided on a surface of the semiconductor multilayer structure, the aluminum nitride layer having asperities with an average pitch of not more than half an in-medium wavelength of the light in aluminum nitride,

or

the semiconductor light emitting device having;

a semiconductor multilayer structure including a light emitting layer that emits light; and

an aluminum nitride layer provided on a surface of the semiconductor multilayer structure,

the semiconductor light emitting device having asperities composed of a plurality of protrusions including the aluminum nitride layer and a plurality of depressions intruding into the semiconductor multilayer structure.

14. A semiconductor light emitting apparatus according to claim 13 wherein the semiconductor light emitting device having formed by:

forming a polycrystalline aluminum nitride layer on a surface of a semiconductor multilayer structure including a light emitting layer; and

etching the aluminum nitride layer to form asperities that generally correspond to distribution of crystal grains constituting the polycrystal.

15. A method of manufacturing a semiconductor light emitting device comprising:

forming a polycrystalline aluminum nitride layer on a surface of a semiconductor multilayer structure including a light emitting layer; and

etching the aluminum nitride layer to form asperities that generally correspond to distribution of crystal grains constituting the polycrystal.

16. A method of manufacturing a semiconductor light emitting device according to claim 15, wherein the asperities are formed inside the aluminum nitride layer.

17. A method of manufacturing a semiconductor light emitting device according to claim 15, wherein the asperities are formed in the aluminum nitride layer and in the semiconductor multilayer structure.

18. A method of manufacturing a semiconductor light emitting device according to claim 15, wherein the aluminum nitride layer is etched off and thereby the asperities are formed in the semiconductor multilayer structure.

19. A method of manufacturing a semiconductor light emitting device according to claim 15, wherein the polycrystalline aluminum nitride layer is formed oriented so that their crystalline axes perpendicular to said surface are c-axis.

20. A method of manufacturing a semiconductor light emitting device according to claim 15, wherein the asperities are formed by reactive ion etching with a gas containing chlorine.