JP2010027824A - Light-emitting element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting element of flip-chip type, flowing current entirely and uniformly to a spreading electrode and improving light-emitting efficiency of the light-emitting element. <P>SOLUTION: The light-emitting element includes: a spreading electrode 11 including an extended part 11a supplying current to a light-emitting layer and extending in a predetermined direction; plural intermediate electrodes 12 formed on the spreading electrode 11, arranged in a longitudinal direction of the extended part 11a and centered in a width direction of the extended part 11a, and disposed such that a distance of half a pitch thereof in the longitudinal direction is equal to or shorter than a distance to an outer edge of the extended part 11a; an insulating layer formed on the spreading electrode 11; and a junction electrode formed on the insulating layer and supplying current to the spreading electrode 11 through the intermediate electrodes 12 formed on the insulating layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light emitting device in which a diffusion electrode is covered with an insulating layer and an intermediate electrode is provided on the diffusion electrode.

2. Description of the Related Art Conventionally, in a flip-chip type light emitting device, a p-side diffusion electrode, an intermediate electrode provided on the diffusion electrode, and a diffusion electrode in a region other than immediately above the intermediate electrode are formed. There has been proposed one including a reflective layer having a three-layer structure, and a bonding electrode that is formed on an insulating film of the reflective layer and supplies a current to a diffusion electrode through an intermediate electrode (see Patent Document 1). And what provided multiple intermediate electrodes is also proposed (refer patent document 2).
JP 2007-300063 A JP 2001-203386 A

  However, when there are a plurality of intermediate electrodes as in the light-emitting element described in the cited document 2, it is difficult to flow a current uniformly to the diffusion electrode, and the light-emitting efficiency of the light-emitting element is deteriorated. is there.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to provide a flip chip type light emitting device capable of flowing a current uniformly to the diffusion electrode and improving the light emitting efficiency of the light emitting device. It is to provide an element.

  In order to achieve the above object, in the present invention, a current is supplied to the light emitting layer, a diffusion electrode having an extending portion extending in a predetermined direction, and provided on the diffusion electrode, at the center in the width direction of the extending portion. A plurality of intermediate electrodes that are arranged in the longitudinal direction of the extending portion and that have half the length in the longitudinal direction of the extending portion are the same as or shorter than the dimension to the outer edge of the extending portion; and an insulating layer formed on the diffusion electrode; There is provided a flip-chip type light emitting device including a bonding electrode formed on the insulating layer and supplying a current to the diffusion electrode through the intermediate electrode.

  In the flip-chip light emitting device, the diffusion electrode preferably has a comb-like shape in plan view in which a plurality of the extending portions are arranged in the width direction of the extending portions.

  In the flip chip type light emitting device, the intermediate electrode preferably has a circular shape in a plan view having a diameter of 20 μm or more and less than 80 μm.

  According to the present invention, a current can be uniformly flowed to the diffusion electrode as a whole, and the light emission efficiency of the light emitting element can be improved.

  1 to 6 show an embodiment of the present invention, and FIG. 1 is a plan view of a light emitting element.

  As shown in FIG. 1, the light emitting element 1 is a flip chip type light emitting diode (LED) that emits light having a wavelength in a blue region. The light emitting element 1 emits light having a peak wavelength of 450 nm when the forward voltage is 3.2 V and the forward current is 350 mA. The light emitting element 1 is formed in a quadrangular shape when viewed from above. As for the planar dimension of the light emitting element 1, the vertical dimension and the horizontal dimension are approximately 1000 μm.

  The light-emitting element 1 includes a p-side electrode 10 as a first electrode, an n-side electrode 20 as a second electrode, a p-side bump 30 as a first bump formed on the p-side electrode 10, and an n-side electrode. And n-side bumps 40 as second bumps formed on the substrate 20. The light emitting element 1 is a flip chip type in which the p-side electrode 10 and the n-side electrode 20 are formed on the same surface, and has a substantially square shape in plan view.

  The p-side electrode 10 has a larger area than the n-side electrode 20 in plan view. In the present embodiment, the diffusion electrode 11 of the p-side electrode 10 has an extending portion 11a extending in a predetermined direction, and is formed in a comb shape in plan view. A plurality of long p-side bumps 30 that are parallel to each other are formed on the portion of the diffusion electrode 11 corresponding to the comb teeth via the bonding electrode 13 (not shown in FIG. 1). The outer joining electrode 13 and the p-side bump 30 in the width direction are formed shorter than the other joining electrode 13 and the p-side bump 30.

  The ohmic electrode 21 of the n-side electrode 20 is formed on the mesa portion of the p-side electrode 10. An n-side bump 40 is formed on the ohmic electrode 21 via a bonding electrode 22 (not shown in FIG. 1). In the present embodiment, the junction electrode 22 and the n-side bump 40 of the n-side electrode 20 are formed at two corners of the light emitting element 1, and the tips of the p-side junction electrode 13 and the p-side bump 30 formed short are formed. And in plan view.

FIG. 2 is a cross-sectional view taken along the line AA of FIG.
As shown in FIG. 2, the light-emitting element 1 includes a sapphire substrate 50 having a (0001) plane, a buffer layer 60 provided on the sapphire substrate 50, and an n-side contact layer 61 provided on the buffer layer 60. , An n-side cladding layer 62 provided on the n-side contact layer 61, a light-emitting layer 63 as a light-emitting portion provided on the n-side cladding layer 62, and a p-side cladding layer 64 provided on the light-emitting layer 63. And a p-side contact layer 65 provided on the p-side cladding layer 64.

  The buffer layer 60, the n-side contact layer 61, the n-side cladding layer 62, the light emitting layer 63, the p-side cladding layer 64, and the p-side contact layer 65 are layers made of a group III nitride compound semiconductor, respectively. is there. The layers from the buffer layer 60 to the p-side contact layer 65 are, for example, metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), and halide vapor phase epitaxy. (Halide Vapor Phase Epitaxy: HVPE) etc.

In the present embodiment, the buffer layer 60 is made of AlN. The n-side contact layer 61 and the n-side cladding layer 62 are each formed from n-GaN doped with a predetermined amount of Si as an n-type dopant. The light emitting layer 63 has a multiple quantum well structure formed of In _x Ga _1-x N / GaN. Furthermore, the p-side cladding layer 64 and the p-side contact layer 65 are each formed from p-GaN doped with a predetermined amount of Mg as a p-type dopant. The buffer layer 60 may be formed of GaN, and the quantum well structure of the light emitting layer 63 may be a single quantum well structure instead of a multiple quantum well structure.

  The p-side electrode 10 of the light-emitting element 1 includes the above-described diffusion electrode 11 provided on the p-side contact layer 65 and the intermediate electrode 12 provided in a partial region on the diffusion electrode 11. Yes. The diffusion electrode 11 is covered with an insulating portion 70 except for the intermediate electrode 12, and a reflecting portion 80 is disposed inside the insulating portion 70. The insulating part 70 has an opening 71 in which the intermediate electrode 12 is provided. Further, the p-side electrode 10 has a bonding electrode 13 that covers the upper surface of the insulating portion 70 and contacts the intermediate electrode 12.

In the present embodiment, the diffusion electrode 11 of the p-side electrode 10 is a transparent electrode and is made of ITO (Indium Tin Oxide). The insulating unit 70 is made of silicon dioxide (SiO ₂ ). Moreover, the reflection part 80 is formed from aluminum (Al). The insulating portion 70 is formed from a metal oxide such as titanium oxide (TiO ₂ ), alumina (Al ₂ O ₃ ), tantalum pentoxide (Ta ₂ O ₅ ), or a resin material having electrical insulation properties such as polyimide. You can also Moreover, the reflection part 80 can also be formed from Ag, and can also be formed from the alloy which contains Al or Ag as a main component. The reflecting unit 80 may be a distributed Bragg reflector (DBR) formed from a plurality of layers of two materials having different refractive indexes.

The intermediate electrode 12 has a circular shape in a plan view and has a relatively small area of, for example, less than 80 μm ² . The intermediate electrode 12 includes a Ni layer formed at a contact portion with the diffusion electrode 11, an Al layer formed at a contact portion with the bonding electrode 13, an Au layer formed between the Ni layer and the Al layer, Have

  The junction electrode 13 includes a contact metal in contact with the insulating portion 70 and the intermediate electrode 12, a first barrier metal as a diffusion prevention portion formed on the contact metal, and a diffusion prevention formed on the first barrier metal. A second barrier metal as a portion, a third barrier metal as a diffusion preventing portion formed on the second barrier metal, and a solder electrode formed on the third barrier metal. In this embodiment, the contact metal is made of Ti, the first barrier metal and the third barrier metal are made of Ni, the second barrier metal is made of Ti, and the solder electrode is made of Au that melts at a predetermined temperature. It is composed of an alloy material with Sn.

  A p-side bump 30 having a predetermined height is formed on the bonding electrode 13. In the present embodiment, the p-side bump 30 is made of Au—Sn solder whose surface layer is Au.

  The n-side electrode 20 includes the aforementioned ohmic electrode 21 provided on the n-side contact layer 61 and the junction electrode 22 provided on the ohmic electrode 21. The ohmic electrode 21 is formed to include at least one metal selected from the group consisting of Ti, Al, Pd, Pt, V, Ir, and Rh metals. The insulating part 70 covers the n-side contact layer 61 except for the region where the ohmic electrode 21 is formed. The insulating portion 70 has an opening 72 that exposes the ohmic electrode 21.

  The p-side bump 30 and the n-side bump 40 are each made of Au—Sn solder, and are formed on the bonding electrodes 13 and 22 by plating, screen printing, sputter deposition, or the like. The joining electrode 22 of the n-side electrode 20 is smaller than the joining electrode 13 of the p-side electrode 10 in plan view, and the n-side bump 40 of the smaller n-side joining electrode 22 is formed higher than the p-side bump 30. Has been. The n-side bumps 40 are formed higher than the p-side bumps 30 in consideration of manufacturing errors, and the p-side bumps 30 do not become higher due to manufacturing errors.

FIG. 3 is a partial top view of the p-side electrode.
As shown in FIG. 3, each intermediate electrode 12 is disposed at the center in the width direction of each extending portion 11 a, and a dimension “a” (hereinafter referred to as a unit dimension “a”) that is half of the longitudinal pitch of each extension portion is It is equal to the dimension b to the outer edge of the extension part 11a. As used herein, “longitudinal pitch” refers to the dimension between the centers of the intermediate electrodes 12, and “dimension to the outer edge” refers to the dimension from the intermediate electrode 12 to the outer edge. In addition, the unit dimension a of each intermediate electrode 12 may be shorter than the dimension b to the outer edge of the extending part 11a. In the present embodiment, the unit dimension a of each intermediate electrode 12 is relatively narrow at 65 μm. The total area of the extending portions 11a of the diffusion electrode 11 is 578000 μm ² , and one intermediate electrode 12 is provided per 14450 μm ² . Here, the area of each intermediate electrode 12 is 615 μm ² , but the amount of light emitted from the light emitting element 1 increases as the area decreases.

  4 to 6 show an example of a manufacturing process of the light emitting device according to the first embodiment. FIG. 4A is a longitudinal sectional view before etching for exposing the surface of the n-side contact layer is performed. FIG. 4B is a longitudinal sectional view after etching for exposing the surface of the n-side contact layer. FIG. 4C is a longitudinal sectional view showing a state where a mask is formed on the diffusion electrode. Further, FIG. 4D is a longitudinal sectional view after etching the diffusion electrode.

  First, a sapphire substrate 50 is prepared, and on this sapphire substrate 50, a buffer layer 60, an n-side contact layer 61, an n-side cladding layer 62, a light emitting layer 63, a p-side cladding layer 64, and a p-side. The contact layer 65 is epitaxially grown in this order to form an epitaxial growth substrate.

  Subsequently, a mask 100 made of a photoresist is formed on the p-side contact layer 65 by using a photolithography technique (FIG. 4A). Next, after etching the part other than the part where the mask 100 is formed from the p-side contact layer 65 to a part of the n-side contact layer 61, the mask 100 is removed. Thereby, a mesa portion composed of a plurality of compound semiconductor layers from the n-side cladding layer 62 to the p-side contact layer 65 is formed (FIG. 4B).

  Thereafter, the diffusion electrode 11 is entirely formed on the n-side contact layer 61 and the p-side contact layer 65. In this embodiment, the diffusion electrode 11 is ITO and is formed using a vacuum deposition method. The diffusion electrode 11 can also be formed by a sputtering method, a CVD method, a sol-gel method, or the like. Then, a mask 102 made of a photoresist is formed in a region where the diffusion electrode 11 is left (FIG. 4C). Subsequently, a region of the diffusion electrode 11 that is not covered with the mask 102 is etched. Thereby, the diffusion electrode 11 is formed in a predetermined region of the p-side contact layer 65 (FIG. 4D).

  FIG. 5A is a longitudinal sectional view after the n-side ohmic electrode is formed. FIG. 5B is a longitudinal sectional view after forming the intermediate electrode. Furthermore, FIG.5 (c) is a longitudinal cross-sectional view after forming a reflection part.

  Next, the ohmic electrode 21 is formed in a predetermined region of the n-side contact layer 61 using a vacuum deposition method and a photolithography technique (FIG. 5A). In addition, the material before the heat treatment of the ohmic electrode 21 may be provided on the n-side contact layer 61 and the ohmic electrode 21 may be heat treated.

  Subsequently, the intermediate electrode 12 is formed at a predetermined position of the diffusion electrode 11 by using a vacuum deposition method and a photolithography technique (FIG. 5B). The upper surface height of the ohmic electrode 21 and the intermediate electrode 12 is higher in the ohmic electrode 21. In the present embodiment, the difference in the upper surface height between the ohmic electrode 21 and the intermediate electrode 12 at this stage is the difference in the upper surface height between the p-side bump 30 and the n-side bump 40. Next, the insulating part 70 that covers the n-side contact layer 61, the n-side ohmic electrode 21, the mesa portion, the diffusion electrode 11, and the intermediate electrode 12 is formed by vacuum deposition. Then, the reflecting portion 80 is formed in a predetermined region on the insulating portion 70 except for the upper part of the intermediate electrode 12 and the ohmic electrode 21 by using a vapor deposition method and a photolithography technique (FIG. 5C).

  FIG. 6A is a longitudinal sectional view after an insulating portion is formed on the reflecting portion. FIG. 6B is a longitudinal sectional view after an opening is formed in a part of the insulating portion. Furthermore, FIG.6 (c) is a longitudinal cross-sectional view after forming a joining electrode.

  Thereafter, the insulating portion 70 is entirely formed on the upper side of the element by using a vacuum deposition method (FIG. 6A). Subsequently, the insulating portion 70 on the ohmic electrode 21 and the insulating portion 70 on the intermediate electrode 12 are removed using a photolithography technique and an etching technique. As a result, an opening 71 is formed on the intermediate electrode 12 and an opening 72 is formed on the ohmic electrode 21 (FIG. 6B).

  Next, the p-side bonding electrode 13 and the n-side bonding electrode 22 are formed inside the opening 71 and the opening 72, respectively, using a vacuum deposition method and a photolithography technique (FIG. 6C). In the present embodiment, the p-side bonding electrode 13 and the n-side bonding electrode 22 are produced in the same process, and the vertical dimension of each other is the same. The n-side contact layer 61, the intermediate electrode 12, and the bonding electrodes 13 and 22 can also be formed by sputtering. Moreover, the insulating part 70 can also be formed by chemical vapor deposition (Chemical Vapor Deposition: CVD).

  Then, Au—Sn solder is grown on each of the bonding electrodes 13 and 22 by plating to produce the p-side bump 30 and the n-side bump 40. At this time, the height of the upper surface of the n-side bump 40 is made higher than the height of the upper surface of the p-side bump 30 to complete the light emitting element 1 (FIG. 1). In the present embodiment, the p-side bump 30 and the n-side bump 40 are manufactured in the same process, and the vertical dimension of each other is the same.

  The light emitting element 1 formed through the above processes is mounted by flip chip bonding at a predetermined position of a submount made of ceramic or the like in which a wiring pattern of a conductive material is formed in advance. At this time, since the upper surface height of the n-side bump 40 is higher than that of the p-side bump 30, the n-side bump 40 is accurately connected to the wiring pattern on the submount side. Further, although the p-side bump 30 is lower than the n-side bump 40, the p-side bump 30 has a larger volume than the n-side bump 40, and therefore does not hinder the connection with the wiring pattern on the submount side. And the light emitting element 1 is packaged by sealing the light emitting element 1 mounted in the board | substrate integrally with sealing materials, such as an epoxy resin and glass.

  According to the light emitting element 1 configured as described above, each intermediate electrode 12 is disposed in the center of the diffusion electrode 11 in the width direction, and the unit dimension a of each intermediate electrode 12 is the dimension b to the outer edge of each intermediate electrode 12. Therefore, when a current is supplied to the diffusion electrode 11 through the bonding electrode 13, the current can be uniformly supplied to the entire diffusion electrode 11, and the light emission amount of the light emitting element 1 is increased. Further, since the interval between the intermediate electrodes 12 is relatively narrow, the forward voltage at a predetermined current value can be reduced.

  Further, as in the present embodiment, the intermediate electrode 12 is circular in plan view, the area of each intermediate electrode 12 is relatively small, and the interval between the intermediate electrodes 12 is reduced, so that the outer edge length of each intermediate electrode 12 can be reduced. The total extension can be increased to reduce the current density flowing through the diffusion electrode 11, and the deterioration of the electrode can be effectively suppressed.

7 and 8 show experimental examples of the present invention, and are graphs created based on data obtained by producing a plurality of sample bodies. The sample body had the same layer configuration as that of the above embodiment, and a plurality of types of sample bodies were produced by changing the area of the intermediate electrode and changing the interval between the intermediate electrodes. Specifically, four types of light-emitting elements are manufactured. The first light-emitting element has a total area of the diffusion electrode of 578000 μm ² , the diameter of the intermediate electrode is 20 μm, the unit dimension of the intermediate electrode is 27 μm, the intermediate electrode to the diffusion electrode The dimension up to the end in the width direction is 67 μm. Further, the second light emitting element has a total area of the diffusion electrode of 578000 μm ² , the diameter of the intermediate electrode is 40 μm, the unit dimension of the intermediate electrode is 37 μm, and the dimension from the intermediate electrode to the end in the width direction of the diffusion electrode is 67 μm. ing. The third light-emitting element has a total area of the diffusion electrode of 578000 μm ² , the diameter of the intermediate electrode is 60 μm, the unit dimension of the intermediate electrode is 55 μm, and the dimension from the intermediate electrode to the end in the width direction of the diffusion electrode is 67 μm. ing. The fourth light emitting element has a total area of the diffusion electrode of 578000 μm ² , the diameter of the intermediate electrode is 80 μm, the unit dimension of the intermediate electrode is 110 μm, and the dimension from the intermediate electrode to the end in the width direction of the diffusion electrode is 67 μm. ing.

  FIG. 7 is a graph plotting data obtained from the sample body with the horizontal axis as the total area of the intermediate electrode and the vertical axis as the radiant flux of all the light emitted from the light emitting element. When measuring the radiant flux, an integrating sphere was used to detect the radiant flux in all directions. Further, the radiant flux was measured by flowing a current of 350 mA through the first to fourth light emitting elements. As shown in FIG. 7, as the area of the intermediate electrode increased, the total radiant flux decreased. Thus, it can be seen that the area of the intermediate electrode may be reduced in order to increase the amount of light extracted from the light emitting element. The first light emitting element has a light amount comparable to that of the conventional product, and the second to fourth light emitting elements have an increased light amount than the conventional product. Therefore, it was confirmed that the amount of light increases by setting the diameter of the intermediate electrode to 20 μm or more and less than 80 μm.

  FIG. 8 is a graph in which the horizontal axis is a value obtained by dividing the total area of the diffusion electrode by the total area of the intermediate electrode, the vertical axis is the forward voltage necessary for light emission, and the data obtained in the sample body is plotted. . As shown in FIG. 8, when the area of the diffusion electrode per unit area of the intermediate electrode is large, the forward voltage increases. Therefore, it can be seen that in order not to increase the forward voltage, the area per intermediate electrode should be increased or the number of intermediate electrodes should be increased.

FIG. 9 shows an experimental example of the present invention and is a graph created based on data obtained by producing a plurality of sample bodies. The sample body had the same layer configuration as that of the above embodiment, and a plurality of types of sample bodies were produced by changing the area of the intermediate electrode and changing the interval between the intermediate electrodes. Specifically, three types of light-emitting elements are manufactured. The fifth light-emitting element has a total diffusion electrode area of 578000 μm ² , an intermediate electrode area of 28 μm, an intermediate electrode unit size of 110 μm, and an intermediate electrode to a diffusion electrode. The dimension up to the end in the width direction is 67 μm. The sixth light-emitting element has a total area of the diffusion electrode of 578000 μm ² , the diameter of the intermediate electrode is 28 μm, the unit dimension of the intermediate electrode is 55 μm, and the dimension from the intermediate electrode to the end in the width direction of the diffusion electrode is 67 μm. ing. The seventh light-emitting element has a total area of the diffusion electrode of 578000 μm ² , the diameter of the intermediate electrode is 72 μm, the unit dimension of the intermediate electrode is 110 μm, and the dimension from the intermediate electrode to the end in the width direction of the diffusion electrode is 67 μm. ing.

  FIG. 9 is a graph plotting data obtained from the sample body with the horizontal axis as the forward voltage and the vertical axis as the radiant flux of all the light emitted from the light emitting element. As shown in FIG. 9, the light amount is relatively small in the seventh light emitting element, but the light amount is relatively large in the fifth and sixth light emitting elements. Further, the forward voltage was relatively large in the fifth light emitting element, but the forward voltage was relatively small in the sixth light emitting element. Therefore, it can be seen that the sixth light-emitting element is preferable among the fifth to seventh light-emitting elements in order to make the light amount relatively large and the forward voltage relatively small.

In the embodiment, since the area of the p-side electrode is large, the first electrode is the p-side electrode and the second electrode is the n-side electrode. However, when the area of the n-side electrode is large, The first electrode may be an n-side electrode and the second electrode may be a p-side electrode. In this case, the height of the upper end of the p-side bump of the p-side electrode is higher than that of the n-side bump.
Moreover, in the said embodiment, although the light emitting element provided with the group III nitride semiconductor layer was shown, you may provide the other semiconductor layer.

  Moreover, in the said embodiment, although the p side electrode 10 showed what has the five extension parts 11a, for example, as shown in FIG. 10, the extension part 11a may be three, and an extension part The number of 11a is arbitrary. Further, the shape, structure, etc. of the n-side electrode 20 can be arbitrarily changed. In the light emitting device 1 of FIG. 10, the unit dimension a of the intermediate electrode 12 is 55 μm, and the dimension b from the intermediate electrode 12 to the outer edge of the extending portion 11a is 127 μm.

  As mentioned above, although embodiment of this invention was described, embodiment described above does not limit the invention which concerns on a claim. In addition, it should be noted that not all combinations of the features described in the embodiments are essential to the means for solving the problems of the invention.

FIG. 1 is a plan view of a light emitting device showing an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. FIG. 3 is a partial top view of the p-side electrode. 4A and 4B show an example of a manufacturing process of a light-emitting element. FIG. 4A is a longitudinal sectional view before etching for exposing the surface of the n-side contact layer, and FIG. 4B is a surface of the n-side contact layer. FIG. 4C is a longitudinal sectional view after etching for exposing the diffusion electrode, FIG. 4C is a longitudinal sectional view of a state where a mask is formed on the diffusion electrode, and FIG. 4D is a longitudinal sectional view after etching the diffusion electrode. . 5A and 5B show an example of a manufacturing process of a light-emitting element, in which FIG. 5A is a longitudinal sectional view after forming an n-side ohmic electrode, FIG. 5B is a longitudinal sectional view after forming an intermediate electrode, and FIG. FIG. 3 is a longitudinal sectional view after forming a reflection portion. 6A and 6B show an example of a manufacturing process of a light emitting device, where FIG. 6A is a longitudinal sectional view after forming an insulating portion on the reflecting portion, and FIG. 6B is a view after forming an opening in a part of the insulating portion. A longitudinal sectional view, (c) is a longitudinal sectional view after forming the bonding electrode. FIG. 7 is a graph plotting data obtained from the sample body with the horizontal axis as the total area of the intermediate electrode and the vertical axis as the radiant flux of all the light emitted from the light emitting element. FIG. 8 is a graph in which the horizontal axis is a value obtained by dividing the total area of the diffusion electrode by the total area of the intermediate electrode, the vertical axis is the forward voltage necessary for light emission of the element, and the data obtained in the sample body is plotted. It is. FIG. 9 is a graph plotting data obtained from the sample body with the horizontal axis as the forward voltage and the vertical axis as the radiant flux of all the light emitted from the light emitting element. FIG. 10 is a plan view of a light emitting device showing a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light emitting element 10 P side electrode 11 Diffusion electrode 11a Extension part 12 Intermediate electrode 13 Bonding electrode 20 N side electrode 21 Ohmic electrode 22 Bonding electrode 25 Recess 30 P side bump 40 N side bump 50 Sapphire substrate 60 Buffer layer 61 N side contact Layer 62 n-side cladding layer 63 light-emitting layer 64 p-side cladding layer 65 p-side contact layer 70 insulating part 71 opening 72 opening 80 reflecting part 100 mask 102 mask

Claims (3)

A diffusion electrode for supplying current to the light emitting layer and having an extending portion extending in a predetermined direction;
Provided on the diffusion electrode, arranged in the longitudinal direction of the extending portion at the center in the width direction of the extending portion, and the dimension of half of each longitudinal pitch is the same as or shorter than the dimension to the outer edge of the extending portion A plurality of intermediate electrodes;
An insulating layer formed on the diffusion electrode;
A flip-chip light-emitting element, comprising: a bonding electrode formed on the insulating layer and supplying a current to the diffusion electrode through the intermediate electrode.   2. The flip-chip type light emitting device according to claim 1, wherein the diffusion electrode has a comb-like shape in a plan view in which a plurality of the extending portions are arranged in a width direction of the extending portions.   The flip-chip light-emitting element according to claim 2, wherein the intermediate electrode has a circular shape in a plan view having a diameter of 20 μm or more and less than 80 μm.

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