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

• US 8,686,457 B2
• Filed: 02/05/2013
• Issued: 04/01/2014
• 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): Wilson, Allan R
• Application Number:
  US13/759,892
• Publication Number:
  US 20130146892A1
• Time in Patent Office: 420 Days
• Field of Search: 257/98, 257/623, 257/E33.005, 257/E33.006, 257/E33.068, 438/39, 438/40
• US Class Current: 257/98
• 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 a plurality of protrusions; and

a light emitting structure of a semiconductor provided on said substrate,

wherein for each protrusion of said plurality of protrusions, a bottom portion of the protrusion is formed by constituent sides such that the bottom portion has a shape which is approximately triangular, and

the plurality of protrusions are arranged in a plurality of aligning directions, wherein;

a first aligning direction of said aligning directions

intersects first constituent sides of said constituent sides of the bottom portions, and

passes through vertexes where respective constituent sides of the bottom portions, different from said first constituent sides, meet, and

a second aligning direction of said aligning directions

intersects second constituent sides of the bottom portions which are different from the first constituent sides, and

passes through vertexes vertex where constituent sides of the bottom portions, different from said second constituent sides, meet, and

a third aligning direction of said aligning directions

intersects third constituent sides of the bottom portions which are different from the first constituent sides and from the second constituent sides, and

passes through vertexes where constituent sides of the bottom portions, different from said third constituent sides, meet, and

bottom portions of said plurality of protrusions, which are closest to each other, have the same aligning directions and thereby have the same orientation.

2. The semiconductor light emitting element according to claim 1,

wherein protrusions are arranged in a plurality of rows along the first aligning direction, and

a width of a region between two adjacent rows of protrusions is set such that, along the first aligning direction, at least a part of one adjacent row overlaps with at least a part of the other adjacent row.

3. The semiconductor light emitting element according to claim 1,

wherein a constituent side of a bottom portion is inclined with respect to the first aligning direction such that:

at an intersection between the constituent side and the first aligning direction, the constituent side is directed perpendicularly with respect to the first aligning direction.

4. The semiconductor light emitting element according to claim 2,

wherein the row width of one of the two adjacent rows of protrusions is smaller than a width measured across the two adjacent rows.

5. The semiconductor light emitting element according to claim 1,

wherein a recess region is located between some of the protrusions and is surrounded by said protrusions, and

a part of a constituent side of a bottom portion of one of said protrusions is adjacent to the recess region, said part of the constituent side being less than the entire constituent side.

6. The semiconductor light emitting element according to claim 1,

wherein a recess region is located between some of the protrusions and is surrounded by said protrusions, and

the recess region is surrounded by half of a constituent side from each of said protrusions.

7. The semiconductor light emitting element according to claim 1,

wherein said plurality of protrusions are arranged in a periodic arrangement in a triangular, quadrangular, or hexagonal lattice.

8. The semiconductor light emitting element according to claim 1,

wherein a height of the protrusions in said plurality of protrusions is in a range from 0.2 μ

m to 2 μ

m.

9. The semiconductor light emitting element according to claim 1,

wherein a distance between adjacent protrusions is in a range from 0.5 μ

m to 5 μ

m.

10. The semiconductor light emitting element according to claim 1,

wherein a protrusion width of said protrusions is in a range from 0.2 μ

m to 5 μ

m.

11. The semiconductor light emitting element according to claim 1,

wherein the substrate is a light transmitting substrate.

12. The semiconductor light emitting element according to claim 1,

wherein the substrate is a sapphire substrate.

13. The semiconductor light emitting element according to claim 1,

wherein the substrate is a GaN semiconductor crystal.

14. The semiconductor light emitting element according to claim 1, wherein one or more of the constituent sides, which form a bottom portion of a protrusion, are curved.

15. The semiconductor light emitting element according to claim 2,

wherein the width of the region between the two adjacent rows is narrower than the row width of each of the two adjacent rows.

16. A semiconductor light emitting element, comprising:

a substrate, and

a light emitting structure of a semiconductor provided on the substrate,

wherein the substrate has a plurality of protrusions, and a bottom surface of each of the protrusions is approximately triangular in shape between three endpoints, and a constituent side of the protrusion is formed between each two endpoints of said three endpoints, and

any line that

passes through four endpoints that are the endpoints of two corresponding constituent sides of a first and second protrusions, said first and second protrusions being protrusions for which said two corresponding constituent sides are closest to each other along said line,

also passes

through a space between the first and second protrusions, and

through a third protrusion that is partially disposed between the first and second protrusions.

17. The semiconductor light emitting element according to claim 16, wherein said plurality of protrusions are aligned along three different aligning directions such that:

for a first direction of said three aligning directions;

any line that is parallel to said first aligning direction and that passes through a space between protrusions, also intersects at least two adjacent protrusions, said at least two adjacent protrusions thereby mutually overlapping along said line which is parallel to said first aligning direction, and

for a second direction of said three aligning directions;

any line that is parallel to said second aligning direction and that passes through a space between protrusions, also intersects at least two adjacent protrusions of said plurality of protrusions, such that said adjacent protrusions mutually overlap along said line which is parallel to said second aligning direction, and

for the third direction of said three aligning directions;

any line that is parallel to said third aligning direction and that passes through a space between protrusions, also intersects at least two adjacent protrusions of said plurality of protrusions, such that said adjacent protrusions mutually overlap along said line which is parallel to said third aligning direction.

18. A semiconductor light emitting element, comprising:

a substrate, and

a light emitting structure of a semiconductor provided on the substrate,

wherein the substrate has an arrangement of a plurality of protrusions, and for each protrusion of said plurality of protrusions, a bottom surface of the protrusion is formed by constituent sides such that the bottom surface is approximately triangular in shape, and

said plurality of protrusions are aligned along three different aligning directions, and

said plurality of protrusions are packed such that, for a first aligning direction of said three aligning directions, all light

that originates outside the protrusions and travels in said first aligning direction between protrusions that are located inside said arrangement of protrusions,

is also reflected by at least one constituent side of a protrusion of said plurality of protrusions.

19. The semiconductor light emitting element according to claim 18, wherein said plurality of protrusions are packed such that:

with respect to a second direction of said three aligning directions, light travelling in said second aligning direction and between protrusions, is reflected by a constituent side of a protrusion of said plurality of protrusions, and

with respect to the third direction of said three aligning directions, light travelling in said third aligning direction and between protrusions, is reflected by a constituent side of a protrusion of said plurality of protrusions.

20. A semiconductor light emitting element, comprising:

a substrate comprising a plurality of protrusions; and

a light emitting structure of a semiconductor provided on said substrate,

wherein for each protrusion of said plurality of protrusions, a bottom portion of the protrusion is formed by constituent sides comprising a first constituent side, a second constituent side, and a third constituent side, such that the bottom portion has a shape which is approximately triangular, and

the plurality of protrusions are arranged in a plurality of aligning directions, wherein a first straight line passes along a first aligning direction of said aligning directions, intersecting the first constituent side of one of the protrusions and passing through a vertex where the second constituent side and the third constituent side of said one protrusion meet, and

a second straight line, which is parallel to a line that passes through both endpoints of the second constituent side, passes through the vertex, and

a third straight line, which is parallel to a line that passes through both endpoints of the third constituent side, passes through the vertex, and

a second protrusion, adjacent to said one protrusion, is disposed along the first aligning direction in a region where;

both the second straight line and the third straight line pass through, and the second straight line and the third straight line intersect the second protrusion.

21. A semiconductor light emitting element, comprising:

a substrate, and

a light emitting structure of a semiconductor provided on the substrate,

wherein the substrate has a plurality of protrusions, and a bottom surface of each of the protrusions is approximately triangular in shape, and

said plurality of protrusions are aligned along multiple aligning directions, and said plurality of protrusions are packed such that, for a first aligning direction of said aligning directions;

all lines that

are parallel to said first aligning direction and that pass through a space located between at least three protrusions,

also intersect at least two adjacent protrusions, said at least two adjacent protrusions thereby mutually overlapping along said respective line.