Method for manufacturing substrate for semiconductor light emitting element and semiconductor light emitting element using the same

• US 9,054,271 B2
• Filed: 01/10/2014
• Issued: 06/09/2015
• Est. Priority Date: 12/21/2006
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Minato, Shunsuke, Narita, Junya, Wakai, Yohei, Narukawa, Yukio, Yamada, Motokazu
• Primary Examiner(s): Lee, Hsien Ming
• Application Number:
  US14/152,765
• Publication Number:
  US 20140124805A1
• Time in Patent Office: 515 Days
• Field of Search: 257/59, 257/72, 257/81, 257/88, 257/91, 438/22, 438/24, 438/27, 438/29
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/48095 Kinked
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• 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 2924/01012 Magnesium [Mg]
• CPC Class Codes: H01L 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/0102 Calcium [Ca]
• CPC Class Codes: H01L 2924/01046 Palladium [Pd]
• CPC Class Codes: H01L 2924/01057 Lanthanum [La]
• CPC Class Codes: H01L 2924/01063 Europium [Eu]
• CPC Class Codes: H01L 2924/01077 Iridium [Ir]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/24 of the light emitting region, e.g. non-planar junction
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

A light emitting element having a recess-protrusion structure on a substrate is provided. A semiconductor light emitting element 100 has a light emitting structure of a semiconductor 20 on a first main surface of a substrate 10. The first main surface of the substrate 10 has substrate protrusion portion 11, the bottom surface 14 of each protrusion is wider than the top surface 13 thereof in a cross-section, or the top surface 13 is included in the bottom surface 14 in a top view of the substrate. The bottom surface 14 has an approximately polygonal shape, and the top surface 13 has an approximately circular or polygonal shape with more sides than that of the bottom surface 14.

Claims

1. A semiconductor light emitting element, comprising:

a substrate comprising at least one protrusion having a top surface and a bottom portion on a main surface of the substrate, and

in cross-sections of the substrate, the bottom portion of the protrusion having a width greater than a width of the top surface of the protrusion, or

in a top view of the substrate, an outline of the top surface being at an inner side of an outline of the bottom portion of the protrusion, and

the top surface and the bottom portion of the protrusion are each formed, respectively, by constituent sides connecting apexes to form an approximately triangular shape, with an outer shape of the approximately triangular shape curving outwardly, and

the outer shape of one of the constituent sides of the top surface has a curvature radius that is smaller than a curvature radius of the outer shape of one of the constituent sides of the bottom portion; and

a semiconductor structure including a light emitting layer.

2. The semiconductor light emitting element according to claim 1, wherein the substrate is a sapphire substrate and comprises a plurality of the protrusions, wherein the plurality of the protrusions are arranged in a triangular matrix, and are respectively oriented at an angle of approximately 30°

to an A-axis direction of the substrate.

3. The semiconductor light emitting element according to claim 1, wherein a luminous intensity in a direction of the optical axis perpendicular on the semiconductor light emitting element surface is greater than a luminous intensity at an angle of 60°

or less and 120°

or greater to a direction of the optical axis.

4. The semiconductor light emitting element according to claim 1, wherein a luminous intensity is highest in a direction of the optical axis perpendicular on the semiconductor light emitting element surface.

5. The semiconductor light emitting element according to claim 1, wherein the semiconductor structure includes a GaN layer and the constituent side of the bottom portion intersects a M-Plane of the GaN layer in a plan view.

6. The semiconductor light emitting element according to claim 1, wherein an angle of inclination of side surfaces of the protrusion is in a range of 30°

to 60°

in a relation to a bottom surface of the protrusion.

7. The semiconductor light emitting element according to claim 1, wherein the at least one protrusion has a height in a range of 0.5 μ

m to 1.5 μ

m.

8. The semiconductor light emitting element according to claim 1, wherein the at least one protrusion has a width in a range of 0.2 μ

m to 3 μ

m.

9. The semiconductor light emitting element according to claim 1, wherein the substrate is a sapphire substrate, a SiC substrate, or a GaN substrate.

10. The semiconductor light emitting element according to claim 1, wherein the semiconductor is represented by general formula In_xAl_yGa_1-x-yN (0≦

x≦

1, 0≦

y≦

1, 0≦

x+y≦

1).

11. The semiconductor light emitting element according to claim 1, wherein in said top view of the substrate, the outline of the top surface is at an inner side of the outline of the bottom portion of the protrusion.

12. A semiconductor light emitting element, comprising:

a substrate comprising at least one protrusion having a top surface and a bottom portion on a main surface of the substrate, and

in cross-sections of the substrate, the bottom portion of the protrusion having a width greater than a width of the top surface of the protrusion, or

in a top view of the substrate, an outline of the top surface being at an inner side of an outline of the bottom portion of the protrusion, and

the top surface and the bottom portion of the protrusion are each formed, respectively, by constituent sides connecting apexes to form an approximately triangular shape, with an outer shape of the approximately triangular shape curving outwardly; and

on a line L

that is perpendicular to a straight constituent side of the bottom portion of the protrusion and

that passes through an apex facing the straight constituent side, wherein the straight constituent side is a straight segment that connects two apexes of the bottom portion,

a distance x between a straight constituent side and its corresponding curved constituent side of the top surface of the protrusion is greater than a distance y between the straight constituent side and its corresponding curved side of the bottom portion of the protrusion; and

a semiconductor structure including a light emitting layer.

13. The semiconductor light emitting element according to claim 12, wherein the substrate is a sapphire substrate and comprises a plurality of the protrusions, wherein the plurality of the protrusions are arranged in a triangular matrix, and are respectively oriented at an angle of approximately 30°

to an A-axis direction of the substrate.

14. The semiconductor light emitting element according to claim 12, wherein a luminous intensity in a direction of the optical axis perpendicular on the semiconductor light emitting element surface is greater than a luminous intensity at an angle of 60°

or less and 120°

or greater to a direction of the optical axis.

15. The semiconductor light emitting element according to claim 12, wherein a luminous intensity is highest in a direction of the optical axis perpendicular on the semiconductor light emitting element surface.

16. The semiconductor light emitting element according to claim 12, wherein the semiconductor structure includes a GaN layer and the constituent side of the bottom portion intersects a M-Plane of the GaN layer in a plan view.

17. The semiconductor light emitting element according to claim 12, wherein an angle of inclination of side surfaces of the protrusion is in a range of 30°

to 60°

in a relation to a bottom surface of the protrusion.

18. The semiconductor light emitting element according to claim 12, wherein the at least one protrusion has a height in a range of 0.5 μ

m to 1.5 μ

m.

19. The semiconductor light emitting element according to claim 12, wherein the at least one protrusion has a width in a range of 0.2 μ

m to 3 μ

m.

20. The semiconductor light emitting element according to claim 12, wherein the substrate is a sapphire substrate, a SiC substrate, or a GaN substrate.

21. The semiconductor light emitting element according to claim 12, wherein the semiconductor is represented by general formula In_xAl_yGa_1-x-yN (0≦

x≦

1, 0≦

y≦

1, 0≦

x+y≦

1).

22. The semiconductor light emitting element according to claim 12, wherein in said top view of the substrate, the outline of the top surface is at an inner side of the outline of the bottom portion of the protrusion.