TW201709556A - Light emitting element and light emitting device - Google Patents

Abstract

A light emitting element with a hexagonal planar shape, has: an n-side semiconductor layer; a p-side semiconductor layer provided on the n-side semiconductor layer; a plurality of holes that are provided to an area excluding three corners at mutually diagonal positions of the p-side semiconductor layer in plan view, and expose the n-side semiconductor layer; a first p-electrode provided in contact with the p-side semiconductor layer; second p-electrodes provided to three corners on the first p-electrode; and an n-electrode that is provided on the first p-electrode and is electrically connected to the n-side semiconductor layer through the plurality of holes.

Description

Light-emitting element and light-emitting device using the same

The present invention relates to a light-emitting element and a light-emitting device using the same.

In the past, various studies have been conducted on light-emitting elements having excellent light extraction efficiency and obtaining uniform light emission (for example, refer to Patent Documents 1 to 3 and the like).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2010-251481

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2006-203058

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2008-524831

It is an object of the present invention to provide a light-emitting element which can minimize light emission from a corner portion of a light-emitting element and its peripheral portion and which can further improve light extraction from the upper surface, and a light-emitting device using the same.

Light-emitting element according to an embodiment of the present invention

(1) A light-emitting element characterized in that it has a hexagonal shape in plan view, and includes: an n-side semiconductor layer; a p-side semiconductor layer provided on the n-side semiconductor layer; a plurality of holes equal to a region of the p-side semiconductor layer disposed at a position other than a diagonal position of the p-side semiconductor layer in a plan view, such that the n-side The semiconductor layer is exposed; the first p-electrode is disposed in contact with the p-side semiconductor layer; the second p-electrode is disposed on each of the three corners of the first p-electrode; and the n-electrode is disposed on the first p- The electrode is electrically connected to the n-side semiconductor layer through the plurality of holes.

(2) A light-emitting element characterized in that it has a hexagonal shape in plan view, and includes: an n-side semiconductor layer; a p-side semiconductor layer provided on the n-side semiconductor layer; and a plurality of holes equal to a plan view Providing the n-side semiconductor layer in a region other than the two corner portions of the p-side semiconductor layer opposite to each other and located at the farthest position; wherein the first p-electrode is disposed in contact with the p-side semiconductor layer; The second p-electrode is provided on the three corners of the first p-electrode, and the n-electrode is provided on the first p-electrode, and is electrically connected to the n-side semiconductor layer through the plurality of holes.

The light-emitting device of the embodiment of the present invention is

(3) comprising: the light-emitting element; a substrate provided with the light-emitting element; and a hemispherical light-transmitting member covering the light-emitting element.

According to the embodiment of the present invention, it is possible to realize a light-emitting element that can minimize light emission from the corner portion of the light-emitting element and its peripheral portion, and can further improve light extraction from the upper surface, and a light-emitting device using the same.

2n‧‧‧n side semiconductor layer

3p‧‧‧p side semiconductor layer

4a‧‧‧Insulation film

4p‧‧‧1p electrode

5‧‧‧2p electrode

5p‧‧‧2p electrode

6‧‧‧ hole

7n‧‧‧n electrode

7ni‧‧‧n inner circumference of the electrode

7no‧‧‧n electrode outside the week

8‧‧‧Sapphire substrate

9‧‧‧Insulation film

9a‧‧‧ Opening

10‧‧‧Lighting elements

15‧‧‧2p electrode

20‧‧‧Lighting elements

25‧‧‧2p electrode

25p‧‧‧2p electrode

27n‧‧‧n electrode

30‧‧‧Lighting elements

35‧‧‧2p electrode

40‧‧‧Lighting elements

45‧‧‧2p electrode

45p‧‧‧2p electrode

47n‧‧‧n electrode

47ni‧‧‧n inner circumference of the electrode

47no‧‧‧n electrode outside the week

50‧‧‧Lighting elements

55‧‧‧2p electrode

60‧‧‧Lighting device

61‧‧‧Lighting device

65‧‧‧Light source unit

66‧‧‧Light source unit

70‧‧‧Lighting elements

80‧‧‧ base

81‧‧‧ circuit board

90‧‧‧Transparent components

91‧‧‧Transparent components

92‧‧‧Fluorescent layer

93‧‧‧ lens

94‧‧‧Fresnel lens

A‧‧‧Lighting elements

Ac‧‧‧active layer

B‧‧‧Lighting elements

BP‧‧‧Bumps

C‧‧‧Lighting elements

D‧‧‧Lighting elements

E‧‧‧Lighting elements

R1‧‧‧ corner

R2‧‧‧ corner

R3‧‧‧ corner

R4‧‧‧ corner

R5‧‧‧ corner

R6‧‧‧ corner

Fig. 1A is a schematic plan view schematically showing a configuration of a light-emitting element according to an embodiment of the present invention.

Fig. 1B is a plan view showing an enlarged main portion of the light-emitting element of Fig. 1A.

1C is a cross-sectional view taken along line AA' of FIG. 1A.

Figure 1D is a cross-sectional view taken along line BB' of Figure 1A.

Fig. 1E is a schematic plan view schematically showing a partial configuration of a light-emitting device according to an embodiment of the present invention including the light-emitting element of Fig. 1A.

Fig. 1F is a cross-sectional view taken along line AA' of Fig. 1E.

Fig. 2 is a schematic plan view schematically showing the configuration of a light-emitting element according to another embodiment of the present invention.

Fig. 3 is a schematic plan view schematically showing the configuration of a light-emitting element according to still another embodiment of the present invention.

Fig. 4A is a schematic plan view schematically showing a configuration of a light-emitting element according to still another embodiment of the present invention.

Fig. 4B is a plan view showing an enlarged main portion of the light-emitting element of Fig. 4A.

4C is a cross-sectional view taken along line AA' of FIG. 4A.

Fig. 5 is a view showing a simulation result of a current density distribution of a light-emitting element according to an embodiment of the present invention.

6A and 6B are diagrams showing simulation results of current density distributions of light-emitting elements for reference.

7A to 7F are schematic plan views for explaining the position of the second p-electrode in the light-emitting device of the embodiment of the present invention.

Fig. 8A is a plan view schematically showing a configuration of a light-emitting device using a light-emitting element according to an embodiment of the present invention.

Fig. 8B is a cross-sectional view taken along line AA' of Fig. 8A.

9A is a view schematically showing a light-emitting element using an embodiment of the present invention; A top view of the composition of his illuminating device.

Figure 9B is a cross-sectional view taken along line AA' of Figure 9A.

Fig. 10A is a plan view schematically showing a configuration of a light source unit of the light-emitting device of Fig. 9A according to an embodiment of the present invention.

Fig. 10B is a cross-sectional view taken along line AA' of Fig. 10A.

Fig. 11A is a plan view schematically showing a configuration of another light source unit of the light-emitting device of Fig. 9A according to an embodiment of the present invention.

Figure 11B is a cross-sectional view taken along line A-A of Figure 11A.

In the following description, terms indicating a particular direction or position (eg, "upper", "lower", "right", "left", and other terms including those terms) are used as needed. The use of such terms is to facilitate the understanding of the invention with reference to the drawings, and is not intended to limit the technical scope of the invention. The same reference numerals are used in the plural drawings to indicate the same parts or components. In order to facilitate the understanding of the invention, a plurality of embodiments are described. However, the embodiments are not independent of each other, and the portions that can be shared are described in other embodiments.

Embodiment 1: Light-emitting element

As shown in FIG. 1A, the light-emitting element 10 of the present embodiment has a hexagonal planar shape. As shown in FIGS. 1A and 1B, the light-emitting element 10 includes an n-side semiconductor layer 2n, a p-side semiconductor layer 3p disposed on the n-side semiconductor layer 2n, and a plurality of holes 6, which are disposed in the p-side semiconductor layer 3p. a specific position; the first p-electrode 4p is disposed in contact with the p-side semiconductor layer 3p; and the second p-electrode 5p is disposed on the first p-electrode 4p and is not provided with the corner portions R1, R3 of the plurality of holes 6 and R5; and an n-electrode 7n electrically connected to the n-side semiconductor layer 2n via a plurality of holes 6. The plurality of holes 6 are disposed in a region other than the corners of the p-side semiconductor layer at a diagonal position, such as R1, R3, and R5 in FIG. 1A (in other words, the corner portion R2 in FIG. 1A). , R4, R6, the area adjacent to each side, and the area closer to the inside than the other).

In the light-emitting element 10, the second p-electrode 5p connected to the outside is disposed in a region of the p-side semiconductor layer 3p which is located at three corners of the diagonal position. On the other hand, a plurality of holes 6 are provided in a region other than the three corner portions R1, R3, and R5 in which the second p-electrode is disposed, and the n-electrode 7n and the n-side semiconductor layer 2n are electrically connected via the plurality of holes 6. . Thereby, the current supplied to the corner portions R1, R3, and R5 where the second p-electrode 5p is disposed in the current supplied to the semiconductor layer is suppressed, and the region other than the equiangular portion, that is, the plural can be disposed. The area of the hole 6 adjacent to the side of the p-side semiconductor layer and the area supplied further to the inner side than the corner portions R1, R3, and R5 increase. As a result, the light emission of the corner portions R1, R3, and R5 of the light-emitting element 10 and the peripheral region thereof can be minimized, and the upper surface of the light-emitting element 10 other than the above-described region can be further improved (especially, by the corner portion R1) Light extraction from the inner region surrounded by R3 and R5.

The planar shape of the light-emitting element 10 is preferably a regular hexagon, but the angle of the six corners is also allowed to vary by about 120 degrees ± 5 degrees. Each side constituting the hexagon is usually a straight line, but may be slightly bent or bent depending on the processing precision of the semiconductor layer or the like. Therefore, in consideration of such a case, the planar shape of the light-emitting element also includes a regular hexagon and a shape similar to a regular hexagon.

In such a light-emitting element having a hexagonal planar shape, for example, one side has a length of about 300 to 2000 μm. In other words, the diagonal line connecting the corner portions located at the farthest position is a length of about 600 to 4000 μm. Further, in other words, the planar area of the light-emitting element is about 0.2 to 10 mm ² .

(semiconductor layer)

The semiconductor layer includes at least an n-side semiconductor layer 2n and a p-side semiconductor layer 3p. Further, it is preferred to include an active layer between the two. In order to form the planar shape of the light-emitting element into a hexagonal shape, the n-side semiconductor layer 2n and/or the p-side semiconductor layer 3p preferably have a hexagonal shape in the outer periphery. However, the n-side semiconductor layer 2n and/or the p-side semiconductor layer 3p may have a portion in which one or all of the film thickness direction is removed in one or both of the outer circumferences. Furthermore, the light-emitting region (in the present embodiment, the active layer corresponds to the light-emitting region) is used as a reference. The semiconductor connected to the side of the n-electrode is the n-side semiconductor layer 2n, and the semiconductor to which the side of the p-electrode is connected is the p-side semiconductor layer 3p.

As the n-side semiconductor layer, the active layer, and the p-side semiconductor layer, for example, a nitride semiconductor represented by In _X Al _Y Ga _1-XY N (0≦X, 0≦Y, X+Y<1) can be used. The film thickness and layer structure of each layer constituting the semiconductor layer can be utilized as known in the art.

The semiconductor layer is formed on a substrate for semiconductor growth. In the case where a nitride semiconductor is used for the semiconductor layer, a substrate made of sapphire (Al ₂ O ₃ ) can be used.

(hole)

The plurality of holes 6 are provided in a region other than the three corner portions of the p-side semiconductor layer which are located at diagonal positions in plan view, and the n-side semiconductor layer is exposed.

Here, the corner portions located at diagonal positions with each other mean that they are not adjacent to each other and are located at opposite positions. Further, in the case where the three corner portions located at the diagonal positions are in the form of a hexagonal p-side semiconductor layer, they refer to every other three corner portions.

The holes 6 may be formed in any region of the p-side semiconductor layer as long as they are provided in regions other than the three corner portions located at diagonal positions. In other words, as long as it is not formed in every other three corners, it may not be formed in four corners including every other three corners, or may not be formed in every other three corners. The five corners inside may not be formed at all corners. In any of these cases, it is preferable to provide a hole in a region of the p-side semiconductor layer other than the corner portion, in particular, an inner region surrounded by at least three corner portions, and it is possible to increase the self-luminous element. Surface extraction light.

For example, in the light-emitting element A shown in FIG. 7A, the holes 6 are formed at every other three corner portions, that is, three corner portions indicated by R2, R4, and R6, and are not formed at diagonal positions with each other. Three corners indicated by R1, R3 and R5. In the light-emitting element B shown in FIG. 7B, the holes 6 are not formed at three corner portions indicated by R1, R3, and R5 at diagonal positions, and are not formed at the corners indicated by R2, but are formed. At the two corners indicated by R4 and R6. In the light-emitting element C shown in FIG. 7C, the holes 6 are not formed at the diagonal positions from each other by R1, R3, and R4. And the corners indicated by R6 are formed at two corners indicated by R2 and R5. In the light-emitting element D shown in FIG. 7D, the holes 6 are formed at one corner portion indicated by R6, but are not formed at three corner portions indicated by R1, R3, and R5 which are located at diagonal positions with each other, and are not It is formed at two corners indicated by R2 and R4. However, here, the corner portion in which the hole 6 is formed may be any one of R1 to R6. Further, in the light-emitting element E shown in Fig. 7E, the holes 6 are not formed at any of the corner portions including the three corner portions indicated by R1, R3 and R5 which are located at diagonal positions.

In the present specification, the term "corner" means that two lines constituting the outer edge of the light-emitting element and/or the n-side semiconductor layer and/or the p-side semiconductor layer in plan view intersect at 120 degrees ± 5 degrees. The above two lines are fan-shaped regions formed on both sides (refer to 7ni in Fig. 1B). However, as long as the area including the sector is included, it may be a region including a portion slightly extended inward (see 27n in Fig. 2 and 47ni in Fig. 4B). The two lines are preferably formed to have a length of about 1/3 or less of the side forming the hexagon, and more preferably a length of about 1/4 or less.

As described above, the hole 6 is a hole in which the n-side semiconductor layer is exposed. The plurality of n-side semiconductor layers exposed by the holes can be used to be electrically connected to the n-side semiconductor layer integrally by the n-electrode described below.

The number, size, shape, and position of the holes can be appropriately set depending on the size, shape, connection state, and the like of the intended light-emitting element.

More preferably, the holes are all arranged in the same size and in the same shape. Thereby, the uniformity of the current supply amount can be achieved. As a result, as the entire light-emitting element, it is possible to uniformize the light-emission intensity and suppress unevenness in luminance.

The shape of the hole is a circle or an ellipse, a triangle, a rectangle, a hexagon, or the like in a plan view, and is preferably a circle or an ellipse. The size of the holes can be appropriately adjusted depending on the size of the semiconductor layer, the output of the desired light-emitting element, the brightness, and the like. The pores are preferably, for example, a diameter (one side) of a length of several tens to several hundreds of micrometers. From another point of view, the diameter is preferably about 1/20 to 1/5 of the length of one side of the semiconductor layer. From another point of view, for example, it can be appropriately adjusted according to the total plane area occupied by the holes. Specifically, the total planar area is about 1/100 to 1/20 with respect to the plane area of the light-emitting element. In other words, about 2000 μm ² to 0.5 mm ^{2 is} listed. The number of holes is, for example, about 2 to 100, preferably about 4 to 80.

Preferably, for example, as shown in FIG. 1A, the holes are arranged in a plurality of planes along the sides of the p-side semiconductor layer in plan view. In this case, it is more preferable to arrange adjacent holes at equal intervals. However, it is also possible to make the spacing between the holes different. Here, the term "equal spacing" means that not only the holes are arranged at the same interval, but also the intervals therebetween are allowed to vary within a range of about ±5%. The shortest distance between the holes (hereinafter, the distance between the centers of the holes) is, for example, about 2 to 8 times the size (for example, the diameter) of the holes, and preferably about 4 to 6 times. Specifically, when the p-side semiconductor layer has a hole having a diameter of about 50 μm, the shortest distance is about 100 to 400 μm, preferably about 200 to 300 μm.

By the arrangement of the holes as described above, it is possible to control the current injected into the n-side semiconductor layer, and to improve the luminous efficiency.

(1st p electrode, 2p p electrode, and n electrode)

The light-emitting element includes at least the first p-electrode 4, the second p-electrode 5, and the n-electrode 7.

The electrodes may be formed of a metal such as Ag, Au, Pt, Pd, Rh, Ni, W, Mo, Cr, Ti, Al, Cu, or the like, or may be selected from, for example, selected from, for example, Zn, In, Sn. A single layer film or a laminated film such as a light-transmitting conductive film of at least one element selected from the group consisting of Ga and Mg. Examples of the light-transmitting conductive film include ITO, ZnO, IZO, GZO, In ₂ O _{3 ,} and SnO ₂ .

The 1st p electrode 4 is provided on the p-side semiconductor layer in contact with the p-side semiconductor layer. The first p-electrode is an ohmic electrode layer, but can also function as, for example, a light-reflecting electrode layer. Therefore, the contact area between the first p-electrode and the p-side semiconductor layer is preferably larger, for example, more preferably 50% or more, 60% or more, or 70% or more of the planar area of the semiconductor layer, and further preferably formed in the inclusion. The above-mentioned corners are substantially the entire surface.

As the light-reflecting electrode layer, a layer (including an Ag layer) including Ag or an Ag alloy may be used. to make. The layer formed using Ag or an Ag alloy is preferably in contact with or disposed at a position closest to the semiconductor layer. As the Ag alloy, any of materials well known in the art can be used. The thickness of the light-reflecting electrode layer is not particularly limited, and the thickness which can effectively reflect the light emitted from the semiconductor layer is, for example, about 20 nm to 1 μm. In order to prevent the migration of Ag, it is preferable to provide a further conductive layer or insulating layer covering the upper surface (preferably the upper surface and the side surface).

Such a further conductive layer may be formed of a single layer film or a laminate film comprising the above-described metal as an electrode material or alloys thereof. For example, a single layer film containing at least a metal such as Al, Cu, or Ni, and a laminated film of Ni/Ti/Ru or Ni/Ti/Pt are exemplified. Further, in order to effectively prevent the migration of Ag, the thickness of the conductive layer is about several hundred nm to several μm.

Further, in the insulating layer, for example, an insulating layer such as SiN or SiO ₂ may be formed to partially open the surface of the light reflecting electrode layer and cover the side surface of the light reflecting electrode layer, thereby preventing migration of Ag. Furthermore, the insulating layer may be either a single layer film or a laminated film.

As the ohmic electrode layer, a single layer film or a laminated film composed of the above-mentioned light-transmitting conductive film is exemplified.

The second p-electrode is disposed on the first p-electrode and at a corner portion in a plan view. However, the second p-electrode is not disposed in the region where the hole is disposed. The second p-electrode is disposed at three corner portions where the holes are not disposed as described above and are located at diagonal positions. However, the second p-electrode may be disposed at a corner portion where no hole is disposed as long as it is disposed at three corner portions which are located at diagonal positions.

In other words, the second p-electrode is preferably disposed at three or more corners of the six corners of the light-emitting element. When the second p-electrode is disposed at three corners, it is preferably arranged at three corner portions which are not adjacent to each other, in other words, at three corner portions which are not adjacent to each other, as shown in FIG. 7A. When the second p-electrode is disposed at four corners, as shown in FIG. 7B, it is preferably disposed not only at three corner portions located at diagonal positions but also at any one of the corner portions. When the second p-electrode is disposed at five or six corners, as shown in FIG. 7D and FIG. 7E, It is preferable that the arbitrary corner portions are disposed such that the two corner portions of the second p-electrode are not disposed adjacent to each other (see FIGS. 7B and 7C). In particular, the second p-electrode is preferably disposed at three corners or six corners which are excellent in uniformity of the current density distribution and are not adjacent to each other, and in particular, when disposed at six corners, the self-environment can be further improved. It is preferred that the light is extracted from the inner region surrounded by the corners.

The second p-electrode is preferably a fan shape having a corner portion, that is, two lines intersecting at 120 degrees ± 5 degrees in a plan view, and a shape formed by the two lines as two sides, a shape similar to a sector, or a shape including the shape (hereinafter, Sometimes it is described as "fan shape, etc."). The two lines are set to have a length of 40% or less of the side forming the hexagon, preferably about 35% or less, about 30% or less, about 25% or less, about 20% or less, and about 15% or less. In other words, a shape such as a sector having one side of about 30 to 300 μm or one side of about 100 to 300 μm is cited.

The n electrode is disposed on the 1st p electrode. The n-electrode is not disposed on the second p-electrode, but is disposed apart from the second p-electrode in plan view. Further, the n-electrode is electrically connected to the n-side semiconductor layer through the plurality of holes. The n-electrode may be divided into a plurality of electrodes. However, in order to uniformly supply a current in the connection region at the time of mounting, it is preferable to connect one n-electrode to the n-side semiconductor layer through a plurality of holes.

Specifically, the second p-electrode and/or the n-electrode are Ti/Rh/Au, Ti/Pt/Au, W/Pt/Au, Rh/Pt/Au, Ni/Pt/Au, Al from the semiconductor layer side. -Cu alloy/Ti/Pt/Au, Al-Si-Cu alloy/Ti/Pt/Au, Ti/Rh, Ti/Rh/Ti/Pt/Au, Ag/Ni/Ti/Pt, Ti/ASC/Ti /Rt/Au (here, ASC means Al/Si/Cu alloy) or the like. Moreover, the above-mentioned light-transmitting conductive film may be disposed on the side of the semiconductor layer of the laminated structure.

Preferably, the n-electrode is partially interposed between the exposed surface of the n-side semiconductor layer provided on the bottom surface of the hole provided in the p-side semiconductor layer, and extends to the side surface of the hole (the side surface of the active layer and the p-side semiconductor layer), and the p side An insulating film in a region on the semiconductor layer is disposed from the inside of the hole to the p-side semiconductor layer. The insulating film herein is preferably a material film which is well known in the art and which is used in the form of a single layer film or a laminated film in a thickness which ensures electrical insulation.

The n-electrode may be slightly smaller than the n-side semiconductor layer in plan view, or may be equivalent to the n-side semiconductor layer, or may be slightly larger than the n-side semiconductor layer. Further, it is preferable that the n-electrode has an opening corresponding to a sector or the like so as to be spaced apart from the second p-electrode in plan view.

Further, a dielectric multilayer film, for example, a DBR (Distributed Bragg Reflector) film may be included between the n-electrode and the second p-electrode, the n-side semiconductor layer, and the p-side semiconductor layer.

Embodiment 2: Light-emitting element

In the second embodiment, the position of the plurality of holes 6 and the position of the second p-electrode in the light-emitting element are partially different, and the configuration is substantially the same as that of the light-emitting element of the first embodiment.

(hole)

In the light-emitting element, as shown in FIG. 7F, a plurality of holes are provided in a view of the p-side semiconductor layer at two corners located at the farthest position, such as R1 and R4 in FIG. 7F, in a plan view. The side semiconductor layer is exposed.

Here, the two corner portions located at the farthest position refer to the corner portions disposed at both ends of the longest diagonal line.

The hole 6 can be formed in any region of the p-side semiconductor layer as long as it is provided in a region other than the two corner portions located at the farthest position. In other words, as long as it is not formed at the two corner portions located at the farthest position, it may not be formed at a corner portion adjacent to either of the two corner portions, or may not be formed at the two corner portions including the farthest position. The five corners inside may not be formed at all corners. In any of these cases, it is preferable that a hole is provided in a region of the p-side semiconductor layer other than the corner portion, in particular, an inner region sandwiched by at least two corner portions, and the self-luminous element can be added. Light extracted from the surface (especially the inner region sandwiched by the two corners).

For example, in the light-emitting element F shown in FIG. 7F, the hole 6 is not formed at the two corners indicated by R2 and R5 at the farthest position, and is formed at 4 as indicated by R1, R3, R4 and R6. One Corner. Further, in the light-emitting element B shown in FIG. 7B, the hole 6 is not formed at the two corner portions indicated by R2 and R5 at the farthest position, and is not formed at the corner portion indicated by R1 and R3. It is formed at two corners indicated by R4 and R6. Further, in the light-emitting element C shown in FIG. 7C, the hole 6 is not formed at the two corner portions indicated by R3 and R6 at the farthest position, and is not formed at the corner portion indicated by R1 and R4. It is formed at two corners indicated by R2 and R5. Further, in the light-emitting element D shown in FIG. 7D, the hole 6 is formed at one corner shown by R6, but is not formed at the four corners indicated by R2 and R5 or R1 and R4 at the farthest position. And it is not formed at the corner shown by R3. However, here, the corner portion in which the hole 6 is formed may be any one of R1 to R6. Further, in the light-emitting element E shown in Fig. 7E, the hole 6 is not formed at any corner portion including R2 and R5, R1 and R4, or six corner portions indicated by R6 and R6 at the farthest position.

(2p electrode)

The second p electrode is disposed at a corner of the first p electrode. However, the second p-electrode is not disposed in the region where the hole is disposed. The second p-electrode is disposed at two corner portions which are not disposed with the holes and are located at the farthest position as described above. However, the second p-electrode may be disposed at a corner portion where the hole is not disposed as long as it is disposed at two corner portions located at the farthest position.

In other words, the second p-electrode is preferably disposed at two or more corners of the six corners of the light-emitting element. When the second p-electrode is disposed at two corners, it is preferably arranged at two corners located at the farthest position as shown in FIG. 7F. When the second p-electrode is disposed at four corners, as shown in FIGS. 7B and 7C, it is preferably disposed not only at the two corner portions located at the farthest position but also at any corners of the two corner portions. Any two corners of the corners adjacent to each other. In other words, it is preferable that the second side electrode is disposed so that the two corner portions of the second p-electrode are not disposed adjacent to each other. When the 2pth electrode is disposed at five or six corners, it can be disposed at any corner as shown in FIGS. 7D and 7E. Among them, the 2pth electrode is more preferably disposed at six corners.

The light-emitting element of the second embodiment having the above configuration can minimize the light emission of the corner portion of the region in which the second p-electrode is disposed and the peripheral region thereof, and can further improve Light extraction from the upper surface of the high self-luminous element.

Embodiment 3: Light-emitting device

As shown in FIGS. 8A and 8B, the light-emitting device according to the embodiment of the present invention includes the light-emitting element 70, a base 80 on which the light-emitting element 70 is provided, and a hemispherical light-transmitting member 90 that covers the light-emitting element.

Further, in the light-emitting device, it is also possible to arrange light-reflecting, transmissive, and light-shielding on the side surface, the upper surface, or the lower surface of the light-emitting element or the like (and further, the side surface, the upper surface, or the lower surface of the substrate). Functional components such as properties and wavelength conversion properties. For example, a phosphor layer may be formed by plating or spraying equal to the side surface and the upper surface of the light-emitting element. Further, an optical member (for example, a lens) that covers the light transmissive member 90 may be disposed.

(matrix)

The base system comprises, for example, a metal, a ceramic, a resin, a dielectric, a pulp, a glass, a paper or a composite material thereof (for example, a composite resin), or a composite material of the material and a conductive material (for example, metal, carbon, etc.). The surface of the substrate has a plurality of wiring patterns arbitrarily inside and/or on the back surface.

The wiring pattern may be formed of a material, a thickness, a shape, or the like which is generally used in the art as long as it can supply a current to the light-emitting element. Further, the wiring pattern may have another pattern that is disposed independently of the pair of positive and negative patterns as long as it includes a pair of positive and negative patterns connected to the electrodes (the second p-electrode and the n-electrode) of the light-emitting element.

Further, the mounting of the light-emitting element on the substrate is preferably performed by a bonding member such as a bump or solder. The joining member can use any material well known in the art.

(transparent member)

When the light transmissive member is coated with the light emitting element, it also functions as a lens. Therefore, it is preferably a hemispherical shape. However, the shape of the hemisphere may not be a ball in a strict sense, or a half in a strict sense, and may be a part of a cut body such as a spheroid, a long ball, an egg shape, or a spindle shape.

The light transmissive member may be formed of glass or the like, but is preferably formed of a resin. Examples of the resin include a thermosetting resin, a thermoplastic resin, these modified resins, and a mixed resin containing one or more of these resins.

(functional component)

Examples of the functional member include members capable of attaching various functions such as a lens and a phosphor layer. The functional member may be disposed in one or a plurality of light-emitting elements, or may be disposed in one of a plurality of light-emitting elements.

Examples of the lens include a meniscus lens, a Fresnel lens, and the like. These lenses may use lenses made using well known manufacturing methods using materials well known in the art. The lens may also contain a light diffusing material or the like. Examples of the light-diffusing material include fibrous fillers such as glass fibers and ash, inorganic fillers such as aluminum nitride and carbon, crystals or sintered bodies of cerium oxide, titanium oxide, zirconium oxide, magnesium oxide, glass, and phosphors. A sintered body of a combination of a light body and an inorganic material.

A protective film, a reflective film, an anti-reflection film, or the like may be formed on the light incident surface and/or the light exit surface of the lens. As the antireflection film, a four-layer structure including cerium oxide and zirconium dioxide can be applied.

Fluors can be used as is well known in the art. For example, it can also be activated by 铈. aluminum. YAG (Yttrium Aluminum Garnet) is a fluorescent body that is activated by yttrium. aluminum. Garnet (LAG, Lumetium Aluminum Garnet) is a phosphor, a nitrogen-containing aluminum aluminosilicate (CaO-Al ₂ O ₃ -SiO ₂ )-based phosphor activated by cerium and/or chromium, and a ceric acid activated by cerium Salt ((Sr,Ba) ₂ SiO ₄ ) is a phosphor, a β-Sialon phosphor, a CASN (CaAlSiN ₃ :Eu) system or a SCASN ((Sr,Ca)AlSiN ₃ :Eu)-based phosphor A compound-based phosphor, a KSF-based phosphor (K ₂ SiF ₆ : Mn), a sulfide-based phosphor, a so-called nanocrystal, and a luminescent substance called a quantum dot. Examples of the luminescent material include semiconductor materials, for example, II-VI, III-V, IV-VI semiconductors, specifically, CdSe, core-shell type CdS _x Se _1-x /ZnS, GaP, etc. Highly dispersed particles. One type or two or more types of phosphors can be used in combination.

With the miniaturization of the light-emitting device in recent years and the miniaturization of the light-transmitting member that covers the light-emitting element, the surface of the light-transmitting member is close to the light-emitting element, and as a result, the lens effect of the light-transmitting member cannot be obtained and the light is directly emitted. The light passing through the side of the device is increased, and it is feared that the light extracted from above the self-illuminating device cannot be obtained with the desired efficiency. On the other hand, when the light-emitting element having a hexagonal planar shape is covered by the light-transmitting member as in the present embodiment, it is possible to further ensure light emission as compared with the light-emitting element having the same planar area and a quadrangular planar shape. The distance between the component and the surface of the light transmissive member. Thereby, the lens effect of a translucent member can be utilized effectively. Further, the light-emitting element of the present embodiment has a structure for suppressing light emission at the corner portion, in other words, a structure for increasing the current supplied to the region other than the corner portion instead of suppressing the current supply to the semiconductor layer of the diagonal portion. Thereby, it is possible to reduce light that is directly passed toward the side of the light-emitting device from the corner portion of the light-emitting element that is easily accessible to the surface of the light-transmitting member, thereby more effectively utilizing the lens effect of the light-transmitting member to efficiently illuminate toward the light-emitting member. Light is extracted above the device.

Hereinafter, embodiments of a light-emitting element and a light-emitting device using the same will be described in detail based on the drawings.

Example 1: Light-emitting element

As shown in FIGS. 1A to 1D, the planar shape of the light-emitting element 10 of the present embodiment is hexagonal. Such a light-emitting element 10 includes an n-side semiconductor layer 2n and a p-side semiconductor layer 3p, a first p-electrode 4p, a second p-electrode 5p, and an n-electrode 7n. The length of one side of the light-emitting element 10 is about 1.2 mm.

The semiconductor layer is formed by sequentially laminating an n-side semiconductor layer 2n, an active layer Ac, and a p-side semiconductor layer 3p on a hexagonal sapphire substrate 8. The semiconductor layer has a region where the p-side semiconductor layer 3p and the active layer Ac are partially removed and the n-side semiconductor layer 2n is exposed on the outermost periphery thereof.

The p-side semiconductor layer 3p has a plurality of holes 6. In the hole 6, the active layer Ac existing under it is also removed to expose the n-side semiconductor layer 2n. However, the p-side semiconductor layer 3p here is not provided with holes at the three corner portions of the hexagon which are not adjacent to each other, and the periphery thereof is disposed. The corner portion and its periphery have a plurality of holes 6.

The hole 6 is substantially circular and has a diameter of about 27 μm and is formed, for example, by 58 pieces. The holes 6 are arranged substantially in parallel with respect to the sides of the hexagon in plan view, and the distance between the centers is about 300 μm. The total area of the holes 6 is about 0.92% of the planar area of the semiconductor layer, which is about 33,000 μm ² .

The first p-electrode 4p is disposed on substantially the entire surface except the plurality of holes 6 in contact with the p-side semiconductor layer 3p. Here, the substantially entire surface refers to a region other than the outer edge of the upper surface of the p-side semiconductor layer 3p and the inner edge of the vicinity of the hole 6. For example, the first p-electrode 4p is preferably provided on the surface of 90% or more of the upper surface of the p-side semiconductor layer 3p. The 1st p electrode 4p includes: an Ag-containing layer formed on substantially the entire surface of the p-side semiconductor layer 3p; a layer covering the upper surface of the Ag-containing layer; and an insulating layer 4a which is further coated with the upper surface of the Ag-containing layer Part and side and contain SiN. The layer covering the Ag layer is formed of a laminated film of a Ni layer, a Ti layer, and a Pt layer from the semiconductor layer side. According to such a laminated structure, the light emitted from the active layer Ac can be reflected toward the sapphire substrate 8 side, and the light extraction efficiency can be improved. Further, by coating the layer containing the Ag layer and the insulating layer 4a, migration of Ag can be effectively prevented.

The second p-electrode 5p is disposed on the first p-electrode 4p and includes a region where the three corners of the hole 6 are not disposed and the periphery thereof. The second p-electrode 5p has a sector shape having two sides substantially parallel to one of two sides of the p-side semiconductor layer 3p constituting the corner portion including the corner portion and the periphery thereof. Both sides of the sector are about 1/5 of the length of one side of the p-side semiconductor layer 3p, which is about 300 μm.

An n-electrode 7n electrically connected to the n-side semiconductor layer 2n through a plurality of holes 6 is disposed on the first p-electrode 4p. In FIG. 1B, the outer circumference of the n-electrode 7n is represented as 7no, and the inner circumference is represented as 7ni. The first p electrode 4p is disposed above the first p electrode 5p other than the second p electrode 5p and the insulating film 9 including SiO ₂ . The insulating film 9 is disposed on the side surface of the hole 6 and a partial region (the upper surface of the n-side semiconductor layer 2n) of the exposed n-side semiconductor layer 2n. The insulating film 9 is provided on a portion of the first p-electrode 3p disposed on the p-side semiconductor layer 3p, that is, the portion where the first p-electrode 4p and the second p-electrode 5p are connected, and has an opening 9a exposing the upper surface of the first p-electrode 4p. . Moreover, the insulating film 9 is also covered with the n-side semiconductor layer 2n in which the p-side semiconductor layer 3p and the active layer Ac are partially removed and exposed on the outermost periphery of the light-emitting element 10.

Each of the second p-electrode 5p and the n-electrode 7n is formed of a laminated film of Ti/Al-Si-Cu alloy/Ti/Pt/Au from the semiconductor layer side.

When the light-emitting device is manufactured using the light-emitting device 10, as shown in FIGS. 1E and 1F, the bump electrode BP connected to the second p-electrode 5p is formed one by one with respect to each of the second p-electrodes 5p, and is connected to the electrode 7n. The bump electrode BP is uniformly formed over the entire surface. The bump electrode BP connected to the n-electrode 7n is preferably formed at a position that does not overlap the hole 6 in plan view, so that the insulating film 9 is not broken by the excessive load when the light-emitting element 10 is mounted.

Example 2: Light-emitting element

As shown in FIG. 2, the light-emitting element 20 of the second embodiment has a shape in which the second p-electrode 25p is not fan-shaped and has two shapes extending slightly from the inner side toward the inner side, and has the light-emitting element 10 of the first embodiment. Substantially the same composition.

Example 3: Light-emitting element

As shown in FIG. 3, the light-emitting element 30 of the third embodiment has a sector-shaped second p-electrode 5p disposed in a region including all the corner portions and its periphery. Along with this, the holes 6 are not disposed in the corners including the six corner portions of the p-side semiconductor layer 3p and the periphery thereof, and the number of the holes is 55. Therefore, the total area of the holes 6 is about 0.87% of the planar area of the semiconductor layer, which is about 3100 μm ² .

Other than the above configuration, it has substantially the same configuration as that of the light-emitting element 10 of the first embodiment.

Example 4: Light-emitting element

As shown in FIG. 4, the light-emitting element 40 of the fourth embodiment has a region in which the p-side semiconductor layer 3p and the active layer Ac are partially removed to expose the n-side semiconductor layer 2n, but has no insulation at the corner portion. The area covered by the film 9. Further, a second sector-shaped second p-electrode 45p having a laterally concave shape is disposed in a region including all the corner portions and its periphery. Moreover, in the configuration At a corner portion of the 2p electrode 45p, a portion of the n-electrode 7n is in contact with and electrically connected to the n-side semiconductor layer 2n in a region not covered by the insulating film 9.

Other than the above configuration, it has substantially the same configuration as that of the light-emitting element 30 of the third embodiment.

<Evaluation of light-emitting elements>

The distribution of the current density in the light-emitting elements 10, 20, and 30 of Examples 1 to 3 was analyzed by using the simulation software of the finite element method. The results are shown in Figures 5A to 5C, respectively. In Figs. 5A to 5C, the case where the darkness is richer, the current density is higher.

Further, for reference, the current density distribution is also analyzed for the light-emitting element 40, which has the second p-electrode 55 disposed along a pair of diagonal lines as shown in FIG. 6A, and has The light-emitting elements 10 are substantially identical in configuration. The results are shown in Fig. 6B.

5A to 5C, the light-emitting elements 10, 20, and 30 can make the current density in the region where the second p-electrode 5 is disposed lower than the current density in the region adjacent to the side of the semiconductor layer and the inner region.

In particular, in the light-emitting element 20, as the area of the second p-electrode 25 is increased relative to the light-emitting element 10, the current density at the corner portion where the second p-electrode 25 is disposed can be reduced, and the inner region can be In particular, the central region of the semiconductor layer increases the current density.

Further, in the light-emitting element 30, as the number of the second p-electrodes 35 is increased to six, the current density can be lowered at the corner portion where the second p-electrode 35 is disposed, and the current can be more uniformly increased over the entire inner side. density.

These phenomena indicate that the current density distribution can be more significantly increased in the inner region of the semiconductor layer than the current density distribution of the corner portion and the outer peripheral portion of the semiconductor layer in the light-emitting element 50.

Further, with respect to the light-emitting elements 10, 20, and 30, the forward voltage Vf of a current of a current of 350 mA was analyzed by simulation using a finite element method. The result and the hole The total number of areas (the area of the n-side contact region) and the area of the first p-electrode (the area of the p-side contact region) of the region where the n-electrode is connected to the n-side semiconductor layer via the hole are shown in Table 1. Further, the areas of the n-side contact region and the p-side contact region each have an area of the light-emitting element 10 of 100%, and are represented by their relative values.

As shown in Table 1, it was confirmed that the Vf values of the light-emitting elements 20 and 30 were reduced by 0.011 V (about 3.1%) and 0.012 V (about 3.5%) with respect to the light-emitting elements 10, respectively. It is considered that the light-emitting element 20 has the same area as the p-side contact region as compared with the light-emitting element 10, but the area of the second p-electrode is large, and the current concentration in the vicinity of the second p-electrode is moderated, and as a result, the Vf value is lowered. Further, in the light-emitting element 30, the number of the second p-electrodes is increased from three to six, and the current is supplied to the semiconductor layer more uniformly than the light-emitting element 10 and the light-emitting element 20. Therefore, the Vf value is lowered.

Embodiment 5: Light emitting device

As shown in FIGS. 8A and 8B, the light-emitting device 60 of the fifth embodiment includes a light-emitting element 70 having a hexagonal planar shape as in the light-emitting element 10 of the first embodiment, and a pair of positive and negative wiring patterns on the surface (not shown). The base 80 of the base.

The light-emitting element 70 is mounted face down on the base 80, and the n-electrode and the p-electrode of the light-emitting element 70 are connected to the wiring pattern of the base 80 via the joint member. Further, the light-emitting element 70 is covered with a translucent member 90 including a hemispherical shape such as polyoxyn resin. The light transmissive member 90 also covers a portion of the upper surface of the base 80 together with the light emitting element 70.

Such a light-emitting device can more effectively utilize the lens effect of the light transmissive member 90 The light is extracted well above the illuminating device.

Example 6: Light emitting device

As shown in FIGS. 9A and 9B, the light-emitting device 61 of the sixth embodiment includes a light-emitting element 70 having a hexagonal planar shape as in the light-emitting element 10 of the first embodiment, and a pair of positive and negative wiring patterns on the surface (not shown). The base 80 of the base. The light-emitting element 70 is mounted face down on the base 80, and its side surface and the upper surface as the light extraction surface are covered by a phosphor layer 92 containing YAG or the like. Further, the surface of the light-emitting element 70 covered with the phosphor layer 92 is covered with a substantially quadrangular shape by a light-transmissive member 91 containing a polysiloxane resin or the like.

Such a light-emitting device can efficiently extract light of any color by the wavelength conversion effect of the phosphor layer 92.

Embodiment 7: Light source unit

As shown in FIGS. 10A and 10B, the light source unit 65 of the seventh embodiment includes a circuit board 81, a plurality of light-emitting devices 61 of the sixth embodiment mounted on the circuit board 81 so as to be spaced apart from each other, and a lens 93 covering each of the light-emitting devices 61. . Here, as shown in FIG. 10A, the lens 93 has a substantially circular shape capable of effectively utilizing light from the light-emitting device 61. Further, it may be above the light-emitting device 61 and the lens 93 is located on the upper surface opposite to the lower surface of the light-emitting device 61, and has a concave portion capable of diffusing the light emitted from the light-emitting device 61 as shown in FIG. 10B. .

In such a light source unit, the light-emitting device can be used as a backlight source and a light source for illumination by being vertically and/or laterally, randomly or regularly arranged.

Embodiment 8: Light source unit

As shown in FIGS. 11A and 11B, the light source unit 66 of the eighth embodiment includes a circuit board 81, a light-emitting device 61 of the sixth embodiment mounted on the circuit board 81, and a Fresnel lens covering the light-emitting device 61. 94. Here, the Fresnel lens 94 has a shape that can reduce the visibility from the outside of the light-emitting element disposed in the light-emitting device 61 or the phosphor layer disposed thereon.

Such a light source unit can be used as a flash of a camera or the like.

[Industrial availability]

The light-emitting element according to the embodiment and the embodiment of the present invention can be used for various lighting fixtures, flashlights for cameras, backlight sources for liquid crystal displays, various indicator light sources, vehicle light sources, sensor light sources, signal machines, vehicle parts, and kanban illuminators. Various light sources such as words.

2n‧‧‧n side semiconductor layer

3p‧‧‧p side semiconductor layer

4p‧‧‧1p electrode

5p‧‧‧2p electrode

6‧‧‧ hole

7n‧‧‧n electrode

9a‧‧‧ Opening

10‧‧‧Lighting elements

R1‧‧‧ corner

R2‧‧‧ corner

R3‧‧‧ corner

R4‧‧‧ corner

R5‧‧‧ corner

R6‧‧‧ corner

Claims (14)

A light-emitting element characterized in that it has a hexagonal shape in plan view, and includes: an n-side semiconductor layer; a p-side semiconductor layer disposed on the n-side semiconductor layer; and a plurality of holes which are equal to The p-side semiconductor layer is exposed in a region other than the three corner portions of the diagonal position to expose the n-side semiconductor layer; the first p-electrode is provided in contact with the p-side semiconductor layer; and the second p-electrode is provided. The three corner portions respectively provided on the first p-electrode and the n-electrode are provided on the first p-electrode, and are electrically connected to the n-side semiconductor layer through the plurality of holes. A light-emitting element characterized in that it has a hexagonal shape in plan view, and includes: an n-side semiconductor layer; a p-side semiconductor layer disposed on the n-side semiconductor layer; and a plurality of holes which are equal to The n-side semiconductor layer is exposed in a region other than the two corner portions located at the farthest position of the p-side semiconductor layer; the first p-electrode is provided in contact with the p-side semiconductor layer; and the second p-electrode is respectively provided The three corner portions provided on the first p-electrode and the n-electrode are provided on the first p-electrode, and are electrically connected to the n-side semiconductor layer through the plurality of holes. The light-emitting element of claim 1 or 2, wherein the plurality of holes are not provided in a region other than the three corner portions which are located at diagonal positions with respect to each other, or two corner portions which are apart from each other and are located at the farthest position 6 corners of the area outside. The light-emitting element of claim 3, wherein the second p-electrode is respectively disposed on the first The above six corners on the p electrode. The light-emitting element according to claim 1 or 2, wherein the second p-electrode has a sector shape having two sides parallel to one of two sides constituting the corner portions respectively provided. The light-emitting element of claim 1 or 2, wherein the plurality of holes are disposed along a side of the p-side semiconductor layer. The light-emitting element of claim 1 or 2, wherein the n-electrode is provided on the first p-electrode from a portion of the insulating layer that is electrically connected to the n-side semiconductor layer. The light-emitting element of claim 7, wherein the insulating layer is a dielectric multilayer film. The light-emitting element of claim 1 or 2, wherein the first p-electrode comprises a silver-containing layer that is in contact with the p-side semiconductor layer. The light-emitting element of claim 1 or 2, wherein the first p-electrode is a light-transmitting conductive film. The light-emitting element according to claim 1 or 2, wherein the n-electrode is electrically connected to the n-side semiconductor layer via the light-transmitting conductive film that is in contact with the n-side semiconductor layer in the plurality of holes. A light-emitting device comprising: the light-emitting element according to any one of claims 1 to 11, a substrate provided with the light-emitting element; and a hemispherical light-transmitting member covering the light-emitting element. The light-emitting device of claim 12, further comprising a phosphor layer between the light-emitting element and the light-transmitting member. The light-emitting device of claim 12 or 13, which further comprises an optical member covering the light transmissive member.