SEMICONDUCTOR LIGHT EMITTING DEVICE, SEMICONDUCTOR LIGHT EMITTING APPARATUS, AND METHOD FOR MANUFACTURING SEMICONDUCTOR LIGHT EMITTING DEVICE

• US 20110284908A1
• Filed: 08/02/2011
• Published: 11/24/2011
• Est. Priority Date: 02/20/2009
• Status: Active Grant

• Current Assignee: Alpad Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: OKA, Toshiyuki, NUNOUE, Shinya, MURAMOTO, Eiji
• Granted Patent: US 8,994,054 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• 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 2924/00014 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 2924/12032 Schottky diode
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• 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

Abstract

According to one embodiment, a semiconductor light emitting device includes a stacked structural body, a first electrode, a second electrode, a third electrode, and a fourth electrode. The stacked structural body 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. The first electrode is electrically connected to the first semiconductor layer. The second electrode forms an ohmic contact with the second semiconductor layer. The second electrode is translucent to light emitted from the light emitting layer. The third electrode penetrates through the second electrode and is electrically connected to the second electrode to form Shottky contact with the second semiconductor layer. The third electrode is disposed between the fourth electrode and the second semiconductor layer. A shape of the fourth electrode as viewed along a stacking direction of the first semiconductor layer, the light emitting layer, and the second semiconductor layer is same as a shape of the third electrode as viewed along the stacking direction.

Claims

1. A semiconductor light emitting device, comprising:

a stacked structural body 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;

a first electrode electrically connected to the first semiconductor layer;

a second electrode forming an ohmic contact with the second semiconductor layer, the second electrode being translucent to light emitted from the light emitting layer;

a third electrode penetrating through the second electrode and electrically connected to the second electrode to form Shottky contact with the second semiconductor layer; and

a fourth electrode, the third electrode being disposed between the fourth electrode and the second semiconductor layer, a shape of the fourth electrode as viewed along a stacking direction of the first semiconductor layer, the light emitting layer, and the second semiconductor layer being same as a shape of the third electrode as viewed along the stacking direction.

2. The device according to claim 1, wherein a reflectance of the third electrode to the emitted light is greater than a reflectance of the fourth electrode to the emitted light.

3. The device according to claim 2, wherein a transmittance of the second electrode to the emitted light is greater than a transmittance of the third electrode to the emitted light.

4. The device according to claim 3, wherein,

the first semiconductor layer is made of an n-type semiconductor;

the second semiconductor layer is made of a p-type semiconductor and opposes a part of the first semiconductor layer;

the stacked structural body has a first major surface on a side of the second semiconductor layer; and

the first electrode, the second electrode, the third electrode, and the fourth electrode are provided on a side of the first major surface of the stacked structural body.

5. The device according to claim 3, wherein:

the first semiconductor layer is made of a p-type semiconductor;

the second semiconductor layer is made of an n-type semiconductor;

the stacked structural body has a second major surface on a side of the first semiconductor layer and a third major surface on a side of the second semiconductor layer;

the first electrode is provided on a side of the second major surface of the stacked structural body; and

the second electrode, the third electrode, and the fourth electrode are provided on a side of the third major surface of the stacked structural body.

6. The device according to claim 5, wherein the third electrode covers a part of the second electrode.

7. The device according to claim 6, wherein the fourth electrode is a pad electrode.

8. The device according to claim 7, wherein the first semiconductor layer and the second semiconductor layer include In_xAl_yGa_1-x-yN (0≦

x≦

1, 0≦

y≦

1, x+y≦

1).

9. The device according to claim 8, wherein a conductivity of the third electrode is lower than a conductivity of the second electrode.

10. The device according to claim 9, wherein the second electrode includes at least one oxide selected from the group consisting of In, Zn, Sn, Ni, Mg, Cu, Au, Pd, Rh, and Ga.

11. The device according to claim 10, wherein the third electrode includes at least one selected from the group consisting of Al, Ag, and Rh.

12. The device according to claim 10, wherein the reflectance of the third electrode to the emitted light is 80% or more.

13. The device according to claim 11, wherein the fourth electrode includes an Ni layer provided on the third electrode and an Au layer provided on the Ni layer.

14. The device according to claim 11, wherein the fourth electrode includes a stacked body including a Ti layer provided on the third electrode, a Pt layer provided on the Ti layer, and an Au layer provided on the Pt layer.

15. The device according to claim 13, wherein the emitted light is emitted from a side on which the second electrode of the stacked structure unit is provided.

16. A semiconductor light emitting apparatus, comprising:

a semiconductor light emitting device, including;

a stacked structural body 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;

a first electrode electrically connected to the first semiconductor layer;

a second electrode forming an ohmic contact with the second semiconductor layer, the second electrode being translucent to light emitted from the light emitting layer;

a third electrode penetrating through the second electrode and electrically connected to the second electrode to form Shottky contact with the second semiconductor layer; and

a fourth electrode, the third electrode being disposed between the fourth electrode and the second semiconductor layer, a shape of the fourth electrode as viewed along a stacking direction of the first semiconductor layer, the light emitting layer, and the second semiconductor layer being same as a shape of the third electrode as viewed along the stacking direction; and

a wavelength conversion layer configured to absorb light emitted from the semiconductor light emitting device and emit light having a different wavelength from a wavelength of the light emitted from the semiconductor light emitting device.

17. A method for manufacturing a semiconductor light emitting device, the device including:

a stacked structural body including a first semiconductor layer, a second semiconductor layer, and a light emitting layer disposed between the first semiconductor layer and the second semiconductor layer;

a first electrode electrically connected to the first semiconductor layer;

a second electrode forming an ohmic contact with the second semiconductor layer, the second electrode being translucent to light emitted from the light emitting layer;

a third electrode penetrating through the second electrode and electrically connected to the second electrode to form Shottky contact with the second semiconductor layer; and

a fourth electrode formed on a side of the third electrode opposite to the second semiconductor layer, the method comprising;

stacking the first semiconductor layer, the light emitting layer, and the second semiconductor layer;

forming the first electrode on the first semiconductor layer;

forming the second electrode on a part of the second semiconductor layer;

stacking, a film to be the third electrode and a film to be the fourth electrode on the second semiconductor layer exposed from the second electrode; and

collectively processing the film to be the third electrode and the film to be the fourth electrode using a common mask.

18. The method according to claim 17, wherein the forming the second electrode includes performing a heat treatment forming a film to be the second electrode on the second semiconductor layer, the heat treatment being performed at a temperature not lower than 300°

C. and not higher than 800°

C.

19. The method according to claim 18, wherein the stacking of the film to be the third electrode and the film to be the fourth electrode is performed after the forming of the second electrode.

20. The method according to claim 19, wherein forming the third electrode and the fourth electrode is performed at a temperature lower than a temperature applied in the forming of the second electrode.