SEMICONDUCTOR LIGHT-EMITTING DEVICE AND METHOD FOR MANUFACTURING SAME

• US 20100051987A1
• Filed: 03/09/2009
• Published: 03/04/2010
• Est. Priority Date: 08/28/2008
• Status: Active Grant

• Current Assignee: Alpad Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Ohba, Yasuo, Kaneko, Kei, Kushibe, Mitsuhiro, Katsuno, Hiroshi
• Granted Patent: US 9,070,837 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/05001 Internal layers
• CPC Class Codes: H01L 2224/05022 the internal layer being at least partially embedded in the surface
• CPC Class Codes: H01L 2224/05124 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05139 Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/05155 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/05166 Titanium [Ti] as principal constituent
• CPC Class Codes: H01L 2224/05169 Platinum [Pt] as principal constituent
• CPC Class Codes: H01L 2224/05171 Chromium [Cr] as principal constituent
• CPC Class Codes: H01L 2224/05181 Tantalum [Ta] as principal constituent
• CPC Class Codes: H01L 2224/05184 Tungsten [W] as principal constituent
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05644 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/05664 Palladium [Pd] as principal constituent
• CPC Class Codes: H01L 2224/05669 Platinum [Pt] as principal constituent
• CPC Class Codes: H01L 2224/0603 Bonding areas having different sizes, e.g. different heights or widths
• CPC Class Codes: H01L 2224/06051 Bonding areas having different shapes
• CPC Class Codes: H01L 2224/06102 the bonding areas being at different heights
• CPC Class Codes: H01L 2224/13 of an individual bump connector
• CPC Class Codes: H01L 2224/1703 Bump connectors having different sizes, e.g. different diameters, heights or widths
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 24/05 : of an individual bonding area
• CPC Class Codes: H01L 24/06 : of a plurality of bonding areas
• 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 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/013 : Alloys
• CPC Class Codes: H01L 33/0025 : comprising only AIIIBV compounds
• CPC Class Codes: H01L 33/06 : within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/24 : of the light emitting region, e.g. non-planar junction
• CPC Class Codes: H01L 33/38 : with a particular shape
• CPC Class Codes: H01L 33/44 : characterised by the coatings, e.g. passivation layer or anti-reflective coating

Abstract

A semiconductor light-emitting device includes: a laminated structure, a first electrode, a second electrode and a dielectric laminated film. The laminated structure includes, a first semiconductor layer, a second semiconductor layer, and a light-emitting layer provided between the first semiconductor layer and the second semiconductor layer, in which the second semiconductor layer and the light-emitting layer are selectively removed and a part of the first semiconductor layer is exposed to a first main surface on the side of the second semiconductor layer. The first electrode is provided on the first main surface of the laminated structure and connected to the first semiconductor layer and has a first region including a first metal film provided on the first semiconductor layer of the first main surface, and a second region including a second metal film provided on the first semiconductor layer and having a higher reflectance for light emitted from the light-emitting layer than the first metal film and having a higher contact resistance with respect to the first semiconductor layer than the first metal film. The second electrode is provided on the first main surface of the laminated structure and connected to the second semiconductor layer. The dielectric laminated film is provided on the first and second semiconductor layer being not covered with the first and second electrode and has a plurality of dielectric films having different refractive indices being laminated.

Claims

1. A semiconductor light-emitting device comprising:

a laminated structure including, a first semiconductor layer, a second semiconductor layer, and a light-emitting layer provided between the first semiconductor layer and the second semiconductor layer, the second semiconductor layer and the light-emitting layer being selectively removed and a part of the first semiconductor layer being exposed to a first main surface on a side of the second semiconductor layer;

a first electrode provided on the first main surface of the laminated structure and connected to the first semiconductor layer and having a first region including a first metal film provided on the part of the first semiconductor layer and a second region including a second metal film provided on the part of the first semiconductor layer, the second region having a higher reflectance for light emitted from the light-emitting layer than the first metal film and the second region having a higher contact resistance with respect to the first semiconductor layer than the first metal film;

a second electrode provided on the first main surface of the laminated structure and connected to the second semiconductor layer; and

a dielectric laminated film provided on a surface of the first semiconductor layer and the second semiconductor layer, the surface being not covered with any one of the first electrode and the second electrode on the first main surface, the dielectric laminated film having a plurality of dielectric films having different refractive indices being laminated.

2. The semiconductor light-emitting device according to claim 1, wherein the first metal film has ohmic contact characteristics with respect to the first semiconductor layer.

3. The device according to claim 1, wherein the first region is a part of the first electrode, the part being opposed to the second electrode.

4. The device according to claim 1, wherein the second electrode includes:

a third metal film;

a fourth metal film provided between the third metal film and the second semiconductor layer and having a higher reflectance for the light than the third metal film.

5. The device according to claim 4, wherein the fourth metal film includes a material used for the second metal film.

6. The device according to claim 4, wherein the second electrode further has a fifth metal film provided between the third metal film and the fourth metal film, the fifth metal film suppressing diffusion of a material contained in the third metal film to the fourth metal film.

7. The device according to claim 1, further comprising a transparent electrode provided in at least part of at least one between the first semiconductor layer and the first electrode and between the second semiconductor layer and the second electrode.

8. The device according to claim 1, wherein a side surface of the portion where the second semiconductor layer and the light-emitting layer are selectively removed is sloped with respect to layer surfaces of the first and second semiconductor layers.

9. The device according to claim 1, wherein the dielectric laminated film is made by alternately laminating a first dielectric layer having a first refractive index n₁ and a second dielectric layer having a second refractive index n₂, the second refractive index n₂ being different from the first refractive index n₁, and when a emission wavelength of the light-emitting layer is λ

, a thickness of each of the first dielectric layers is substantially λ

/(4 n₁) and a thickness of each of the second dielectric layers is substantially λ

/(4 n₂).

10. The device according to claim 9, wherein the dielectric laminated film includes at least one of oxide, nitride, and oxynitride of at least one selected from the group consisting of silicon (Si), aluminum (Al), zirconium (Zr), titanium (Ti), niobium (Nb), tantalum (Ta), magnesium (Mg), hafnium (Hf), cerium (Ce), and zinc (Zn).

11. The device according to claim 9, wherein the laminating number of combination of the first dielectric film and the second dielectric film is 3 or more.

12. The device according to claim 1, further comprising a dielectric film provided between the dielectric laminated film and the laminated structure.

13. The device according to claim 12, wherein the dielectric film has a projecting portion being not covered with the dielectric laminated film, and one of the first and second electrodes is provided on the projecting portion or a conductive film being connected to one of the first and second electrodes is provided on the projecting portion.

14. The device according to claim 1, wherein the laminated structure further includes a substrate made of sapphire provided on a side of a second main surface facing the first main surface.

15. The device according to claim 14, wherein the laminated structure further includes an aluminum nitride layer of single crystal provided between the substrate and the first semiconductor layer.

16. The device according to claim 15, wherein on a side of the substrate in the aluminum nitride layer, a portion having a relatively high concentration of carbon is provided.

17. A method for manufacturing a semiconductor light-emitting device, comprising:

laminating a first semiconductor layer, a light-emitting layer, and a second semiconductor layer, on a substrate;

removing a part of the second semiconductor layer and the light-emitting layer being configured to expose the first semiconductor layer;

forming a first metal film on a first region of the exposed first semiconductor layer;

forming a second metal film having a higher reflectance for light emitted from the light-emitting layer than the first metal film and having a higher contact resistance with respect to the first semiconductor layer than the first metal film, on a second region adjacent to the first region of the exposed first semiconductor layer and on the second semiconductor layer; and

forming a dielectric laminated film by alternately laminating dielectric films having different refractive indices on the first metal film and the second metal film being not covered with the first electrode and the second electrode.

18. A method for manufacturing a semiconductor light-emitting device, comprising:

laminating a first semiconductor layer, a light-emitting layer, and a second semiconductor layer, on a substrate;

removing a part of the second semiconductor layer and the light-emitting layer being configured to expose the first semiconductor layer;

selectively forming a dielectric laminated film by alternately laminating dielectric films having different refractive indices on the first semiconductor layer and the second semiconductor layer; and

forming a first metal film on a first region of the first semiconductor layer being not covered with the dielectric laminated film, and forming a second metal film having a higher reflectance for light emitted from the light-emitting layer than the first metal film and having a higher contact resistance with respect to the first semiconductor layer than the first metal film, on a second region of the first semiconductor layer being adjacent to the first region and being not covered with the dielectric laminated film.

19. The method according to claim 18, wherein between exposing the first semiconductor layer and selectively forming the dielectric laminated film, the method further includes forming a dielectric film having higher step coverage characteristics than the dielectric laminated film, on the first semiconductor layer and the second semiconductor layer.

20. The method according to claim 19, wherein the dielectric film is formed by a chemical vapor deposition method.