Light emitting element and method for manufacturing same

• US 8,816,378 B2
• Filed: 06/27/2013
• Issued: 08/26/2014
• Est. Priority Date: 12/27/2010
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Nunotani, Shinji, Akaike, Yasuhiko, Kondo, Katsufumi, Matsunaga, Tokuhiko, Inoue, Kayo
• Primary Examiner(s): Such, Matthew W
• Assistant Examiner(s): SPALLA, DAVID C
• Application Number:
  US13/929,465
• Publication Number:
  US 20130292729A1
• Time in Patent Office: 425 Days
• US Class Current: 257/98
• CPC Class Codes: H01L 33/14 with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/42 Transparent materials

Abstract

According to one embodiment, a light emitting element, includes: a semiconductor stacked body including a light emitting layer; a first upper electrode being connected directly to the semiconductor stacked body; at least one second upper electrode extending from the first upper electrode, the at least one second upper electrode being connected to the semiconductor stacked body via a first contact layer; a lower electrode; a transparent conductive layer; an intermediate film containing oxygen provided between the semiconductor stacked body and the transparent conductive layer; a light reflecting layer; and a current-blocking layer, at least one slit being provided selectively in the current-blocking layer as viewed from a direction perpendicular to a major surface of the light emitting layer.

Claims

1. A light emitting element, comprising:

a semiconductor stacked body including a light emitting layer;

a first upper electrode provided on the semiconductor stacked body, the first upper electrode being connected directly to the semiconductor stacked body;

at least one second upper electrode extending from the first upper electrode on the semiconductor stacked body, the at least one second upper electrode being connected to the semiconductor stacked body via a first contact layer;

a lower electrode provided under the semiconductor stacked body;

a transparent conductive layer provided between the semiconductor stacked body and the lower electrode, the transparent conductive layer transmitting light emitted from the light emitting layer;

an intermediate film containing oxygen provided between the semiconductor stacked body and the transparent conductive layer;

a light reflecting layer provided between the transparent conductive layer and the lower electrode; and

a current-blocking layer between the semiconductor stacked body and the transparent conductive layer or between the semiconductor stacked body and a pair of the first upper electrode and the second upper electrode,

wherein at least one slit is provided selectively in the current-blocking layer as viewed from a direction perpendicular to a major surface of the light emitting layer.

2. The element according to claim 1, wherein, as viewed from the direction perpendicular to the major surface of the light emitting layer, the second upper electrode includes a first electrode unit extending from the first upper electrode toward a peripheral portion of a plane of the semiconductor stacked body, and a second electrode unit connected to the first electrode unit to extend substantially parallel to an outer circumference of the plane.

3. The element according to claim 1, wherein the slit is provided selectively at a periphery of the second electrode unit.

4. The element according to claim 1, wherein a support substrate is further provided between the lower electrode and the light reflecting layer.

5. The element according to claim 1, wherein a refractive index of the current-blocking layer is lower than a refractive index of the semiconductor stacked body at a wavelength of the light emitted from the light emitting layer.

6. The element according to claim 1, wherein the slit is not provided directly under at least one selected from the first upper electrode and the second upper electrode.

7. The element according to claim 1, wherein a distance between the second electrode unit and the slit is not less than 10 μ

m as viewed from the direction perpendicular to the major surface of the light emitting layer.

8. The element according to claim 1, wherein the surface area of a square defined by the length of one side of the square being a width of the slit as viewed from the direction perpendicular to the major surface of the light emitting layer is not more than 1000 μ

m².

9. The element according to claim 1, wherein a thickness of the current-blocking layer is not more than 100 nm.

10. The element according to claim 1, wherein a refractive index of the transparent conductive layer is lower than a refractive index of the semiconductor stacked body at a wavelength of the light emitted from the light emitting layer.

11. The element according to claim 1, wherein a total surface area A (cm²) of the transparent conductive layer contacting the semiconductor stacked body via the slit is not less than 5% of a surface area of the semiconductor stacked body and not more than 15% of the surface area of the semiconductor stacked body when viewed from the direction perpendicular to the major surface of the light emitting layer.

12. The element according to claim 1, wherein a thickness of the transparent conductive layer is not less than 30 nm and not more than 100 nm.

13. The element according to claim 4, wherein the light reflecting layer includes a first light reflecting layer and a second light reflecting layer unit, the first light reflecting layer unit is bonded to the second light reflecting layer unit, the first light reflecting layer unit being provided on the semiconductor stacked body side, the second light reflecting layer unit being provided on the support substrate side.

14. The element according to claim 13, further comprising a barrier layer provided between the first light reflecting layer unit and the second light reflecting layer unit,

the barrier layer including at least one element selected from the group consisting of nickel (Ni), platinum (Pt), and titanium (Ti).

15. The element according to claim 14, further comprising a bonding layer including gold (Au) between the barrier layer and the second light reflecting layer unit.

16. The element according to claim 4, wherein the support substrate is a conductive substrate.

17. The element according to claim 1, wherein a space is made in the light reflecting layer under the slit.

18. The element according to claim 4, wherein a surface area of the semiconductor stacked body is less than a surface area of the support substrate as viewed from the direction perpendicular to the major surface of the light emitting layer.