KR20180096546A - Semiconductor light emitting device - Google Patents

Abstract

The present invention relates to a semiconductor light emitting element. The semiconductor light emitting element comprises: a plurality of semiconductor layers having a first semiconductor layer having a first conductivity, a second semiconductor layer having a second conductivity different from the first conductivity, and an active layer disposed between the first semiconductor layer and the second semiconductor layer, and generating light through recombination of electrons and holes; a non-conductive reflective film formed on the plurality of semiconductor layers to reflect the light generated in the active layer toward the first semiconductor layer; an insulating layer formed on the non-conductive reflective film; a first electrode part electrically connected to the first semiconductor layer and supplying one of electrons and holes; and a second electrode part electrically connected to the second semiconductor layer and supplying the remaining one of electrons and holes. At least one of the first electrode part and the second electrode part includes: a connection electrode formed on the non-conductive reflective film; a first electrical connection electrically connecting the connection electrode and the plurality of semiconductor layers through the non-conductive reflective film; a pad electrode formed on the insulating layer; a second electrical connection electrically connecting the pad electrode and the connection electrode through the insulating layer; a branch electrode formed between the plurality of semiconductor layers and the non-conductive reflective film; and an additional electrical connection electrically connecting the branch electrode and the connection electrode. The additional electrical connection is disposed in one of the first electrode part and the second electrode part. According to the present invention, the current supply is smooth such that the uniformity of the current diffusion is improved.

Description

Technical Field [0001] The present invention relates to a semiconductor light emitting device,

The present disclosure relates generally to a semiconductor light emitting device, and more particularly, to a semiconductor light emitting device that reduces light absorption loss due to metal and improves heat dissipation efficiency.

Here, the semiconductor light emitting element means a semiconductor light emitting element that generates light through recombination of electrons and holes, for example, a group III nitride semiconductor light emitting element. The Group III nitride semiconductor is made of a compound of Al (x) Ga (y) In (1-x-y) N (0? X? 1, 0? Y? 1, 0? X + y? A GaAs-based semiconductor light-emitting element used for red light emission, and the like.

Herein, the background art relating to the present disclosure is provided, and these are not necessarily meant to be known arts.

1 is a view showing an example of a conventional Group III nitride semiconductor light emitting device. The III-nitride semiconductor light emitting device includes a substrate 10 (e.g., sapphire substrate), a buffer layer 20 grown on the substrate 10, an n-type III-nitride semiconductor layer 30 grown on the buffer layer 20, The active layer 40 is formed on the p-type III nitride semiconductor layer 30 and the p-type III-nitride semiconductor layer 50 is grown on the p-type III-nitride semiconductor layer 50. 60, a p-side bonding pad 70 formed on the current diffusion electrode 60, an n-type III nitride semiconductor layer 30 exposed by mesa etching the p-type III nitride semiconductor layer 50 and the active layer 40 An n-side bonding pad 80 formed on the substrate 90, and a protective film 90.

The buffer layer 20 is intended to overcome the difference between the lattice constant and the thermal expansion coefficient between the substrate 10 and the n-type III nitride semiconductor layer 30. In U.S. Patent No. 5,122,845, US Pat. No. 5,290,393 discloses a technique of growing an AlN buffer layer having a thickness of 100 ANGSTROM to 500 ANGSTROM at a temperature of 200 to 900 DEG C, 1-x) N (0 < x < 1) buffer layer is disclosed in US Patent Application Publication No. 2006/154454, and a SiC buffer layer (seed layer) is grown at a temperature of 600 캜 to 990 캜 And growing an In (x) Ga (1-x) N (0 &lt; x? 1) layer thereon. A GaN layer which is not doped is grown before the growth of the n-type III-nitride semiconductor layer 30, which may be regarded as a part of the buffer layer 20 or a part of the n-type III-nitride semiconductor layer 30 .

The current diffusion electrode 60 is provided to supply current to the entire p-type III nitride semiconductor layer 50 well. The current diffusion electrode 60 is formed over substantially the entire surface of the p-type III nitride semiconductor layer 50. For example, the current diffusion electrode 60 may be formed of a transparent conductive film using ITO, ZnO, or Ni and Au, And may be formed of a reflective conductive film.

The p-side bonding pad 70 and the n-side bonding pad 80 are metal electrodes for supplying a current and for wire bonding to the outside, for example, nickel, gold, silver, chromium, titanium, platinum, , Iridium, aluminum, tin, indium, tantalum, copper, cobalt, iron, ruthenium, zirconium, tungsten, molybdenum or any combination thereof.

The protective film 90 is formed of a material such as silicon dioxide and may be omitted.

2 is a diagram showing an example of LEDs A and B connected in series disclosed in U.S. Patent No. 6,547,249. Due to various advantages, a plurality of LEDs A and B are connected in series as shown in Fig. For example, when a plurality of LEDs (A, B) are connected in series, the number of external circuits and wire connections is reduced, and the light absorption loss due to the wires is reduced. Further, since the operating voltage of the LEDs A and B connected in series increases, the power supply circuit can be further simplified. In the case where a plurality of LEDs (A, B) are connected in series on a single substrate, the mounting density can be improved because the area occupied by the individual semiconductor light emitting devices is smaller than that of connecting the individual semiconductor light emitting devices in series, It is possible to reduce the size of the lighting apparatus and the like.

On the other hand, in order to connect the plurality of LEDs A and B in series, the interconnector 34 is deposited to connect the p-side electrode 32 and the n-side electrode 32 of the neighboring LEDs A and B. However, in the isolation process for electrically isolating the plurality of LEDs A and B, a plurality of semiconductor layers must be etched so that the sapphire substrate 20 is exposed. Since the etching depth is long and takes a long time, It is difficult to form the inter connecter 34. When the insulator 30 is used to form a gentle inclination of the inter connecter 34 as shown in Fig. 2, the spacing between the LEDs A and B increases, which leads to a problem in improving the degree of integration.

3 is a diagram showing another example of a series-connected LED disclosed in U.S. Patent No. 6,547,249. Another method of isolating the plurality of LEDs A and B is to perform ion implantation without etching the lower semiconductor layer 22 (e.g., the n-type nitride semiconductor layer) between the plurality of LEDs A and B ion implantation to isolate the plurality of LEDs A and B, the step of the inter connecter 34 is reduced. However, it is difficult to implant ions deep into the lower semiconductor layer 22, which is a problem because the process time is long.

Fig. 4 is a diagram showing an example of an LED array disclosed in U.S. Patent No. 7,417,259, in which an LED array two-dimensionally arrayed on an insulating substrate is formed for high-voltage drive and low-current drive. A sapphire monolithic substrate is used as the insulating substrate, and two LED arrays are connected in parallel in the reverse direction on the substrate. Therefore, an AC power source can be directly used as a driving power source.

5 is a view showing an example of a semiconductor light emitting device disclosed in Korean Patent Laid-Open No. 10-2011-0031099.

FIG. 5A is a plan view of the light emitting device 201, FIG. 5B is a sectional view taken along the line A-A in FIG. 5A, and FIG. 5C is a sectional view taken along the line B-B in FIG. The light emitting element 201 is provided with a transparent conductive layer 230 provided on the p-side contact layer 228 and a plurality of p-electrodes 240 provided on a part of the region on the transparent conductive layer 230. [ The light emitting element 201 is also provided with a plurality of n electrodes (not shown) provided on the n-side contact layer 222 exposed by the plurality of vias formed from the p-side contact layer 228 to the surface of at least the n-side contact layer 222 A lower insulating layer 250 provided on the inner surface of the via and the transparent conductive layer 230 and a reflective layer 260 provided inside the lower insulating layer 250 are provided. The reflective layer 260 is provided at a portion except the upper portion of the p-electrode 240 and the n-electrode 242. The lower insulating layer 250 contacting the transparent conductive layer 230 includes a via 250a extending in the vertical direction on each p electrode 240 and a via 250b extending in the vertical direction on each n electrode 242. [ ). A p wiring 270 and an n wiring 272 are provided on the lower insulating layer 250 in the light emitting element 201. [ The p wiring 270 includes a second planar conductive portion 2700 extending in the planar direction on the lower insulating layer 250 and a plurality of second planar conductive portions 2730 electrically connected to the respective p- And has a vertical conductive portion 2702. The n wiring 272 includes a first planar conductive portion 2720 extending in the planar direction on the lower insulating layer 250 and a via hole 250b formed in the lower insulating layer 250 and a via formed in the semiconductor laminated structure And a plurality of first vertical conductive portions 2722 electrically connected to the respective n-electrodes 242 through the first vertical conductive portions 2722. The light emitting element 201 is also provided with an upper insulating layer 280 provided on the lower insulating layer 250 contacting the p wiring 270, the n wiring 272 and the transparent conductive layer 230, Side junction electrode 290 electrically connected to the p-wiring 270 through the p-side opening 280a provided in the layer 280 and the n-side opening 280b provided in the upper insulating layer 280, An n-side junction electrode 292 electrically connected to the wiring 272 is provided.

This will be described later in the Specification for Implementation of the Invention.

SUMMARY OF THE INVENTION Herein, a general summary of the present disclosure is provided, which should not be construed as limiting the scope of the present disclosure. of its features).

According to one aspect of the present disclosure, in a semiconductor light emitting device, a first semiconductor layer having a first conductivity, a second semiconductor layer having a second conductivity different from the first conductivity, A plurality of semiconductor layers interposed between the first semiconductor layer and the second semiconductor layer and having an active layer that generates light through recombination of electrons and holes; A non-conductive reflective film formed on the plurality of semiconductor layers to reflect light generated in the active layer toward the first semiconductor layer; An insulating layer formed on the non-conductive reflective film; A first electrode part electrically connected to the first semiconductor layer and supplying one of electrons and holes; And a second electrode part electrically connected to the second semiconductor layer and supplying the remaining one of electrons and holes, and at least one of the first electrode part and the second electrode part comprises: a connection electrode formed on the non-conductive reflective film; A first electrical connection for electrically connecting the connection electrode and the plurality of semiconductor layers through the non-conductive reflective film; A pad electrode formed on the insulating layer; A second electrical connection for electrically connecting the pad electrode and the connection electrode through the insulating layer; A branched electrode formed between the plurality of semiconductor layers and the non-conductive reflective film; And a further electrical connection for electrically connecting the branch electrode and the connection electrode, wherein the further electrical connection is located in one of the first electrode portion and the second electrode portion.

This will be described later in the Specification for Implementation of the Invention.

FIG. 1 is a view showing an example of a conventional Group III nitride semiconductor light emitting device,
2 is a diagram illustrating an example of a cascaded LED disclosed in U.S. Patent No. 6,547,249,
3 is a diagram illustrating another example of a cascaded LED disclosed in U.S. Patent No. 6,547,249,
4 is a diagram showing an example of an LED array disclosed in U.S. Patent No. 7,417,259,
5 is a view showing an example of a semiconductor light emitting device disclosed in Korean Patent Laid-Open No. 10-2011-0031099,
6 and 7 are views for explaining an example of a semiconductor light emitting device according to the present disclosure,
8 is a view for explaining another example of the semiconductor light emitting device according to the present disclosure,
9 is a view for explaining another example of the semiconductor light emitting device according to the present disclosure,
10 is a view for explaining another example of the semiconductor light emitting device according to the present disclosure,
11 is a view for explaining another example of the semiconductor light emitting device according to the present disclosure,
12 is a view for explaining another example of the semiconductor light emitting device according to the present disclosure;

The present disclosure will now be described in detail with reference to the accompanying drawings.

FIG. 6 is a view for explaining an example of a semiconductor light emitting device according to the present disclosure, and FIG. 7 is a view for explaining an example of a cross section cut along the line A-A 'in FIG.

The semiconductor light emitting device includes a substrate 10, a plurality of semiconductor layers 30, 40 and 50, a nonconductive reflective film 91, an insulating layer 95, a first electrode portion 78, and a second electrode portion 88 . Hereinafter, a group III nitride semiconductor light emitting device will be described as an example.

The substrate 10 is mainly made of sapphire, SiC, Si, GaN or the like, and the substrate 10 can be finally removed.

The plurality of semiconductor layers 30, 40 and 50 includes a first semiconductor layer 30, an active layer 40 and a second semiconductor layer 50 which are sequentially stacked.

The positions of the first semiconductor layer 30 and the second semiconductor layer 50 may be changed, and they are mainly composed of GaN in the III-nitride semiconductor light emitting device.

The plurality of semiconductor layers 30, 40, and 50 may include a buffer layer 20 formed on the substrate 10, a first semiconductor layer 30 having a first conductivity (e.g., Si-doped GaN) A second semiconductor layer 50 (e.g., Mg-doped GaN) having conductivity, and an active layer interposed between the first semiconductor layer 30 and the second semiconductor layer 50 and generating light through recombination of electrons and holes 40, e.g., InGaN / (In) GaN multiple quantum well structure). Each of the plurality of semiconductor layers 30, 40, and 50 may have a multi-layer structure, and the buffer layer 20 may be omitted.

The active layer 40 is formed between the first semiconductor layer 30 and the second semiconductor layer 50 and generates light.

The semiconductor light emitting element is provided with a current diffusion electrode 60 between the second semiconductor layer 50 and the nonconductive reflective film 91 between the plurality of semiconductor layers 30, 40, 50 and the nonconductive reflective film 91 . The current diffusion electrode 60 may be omitted.

The current diffusion electrode 60 may be formed of a current diffusion electrode (ITO or the like), an ohmic metal layer (Cr, Ti or the like), a reflective metal layer (Al, Ag or the like), or a combination thereof. In order to reduce light absorption by the metal layer, the current diffusion electrode 60 is preferably made of a light-transmitting conductive material (e.g., ITO).

The non-conductive reflective film 91 is formed on the plurality of semiconductor layers 30, 40, and 50 to reflect light generated in the active layer 40 toward the first semiconductor layer 30, and may be formed of a dielectric.

In this example, the non-conductive reflective film 91 is a flip chip having electrical insulation and electrically communicating with a plurality of semiconductor layers by an electrical connection through the non-conductive reflective film 91. [

For example, the non-conductive reflective film 91 may be formed of an insulating material to reduce light absorption by the metal reflective film, and may preferably be a multi-layered structure including DBR (Distributed Bragg Reflector) or ODR (Omni-Directional Reflector) have.

The insulating layer 95 is formed on the nonconductive reflective film 91. [ The insulating layer 95 may be made of SiO ₂ . The insulating layer 95 is not limited thereto, and SiN, TiO2, Al2O3, Su-8, or the like may be used.

The refractive index of the insulating layer 95 covering the non-conductive reflective film 91 is similar to the refractive index of the non-conductive reflective film 91, and is not reflected but transmitted well. Therefore, a part of the light which is not reflected by the non-conductive reflective film 91 passes through the insulating layer 95, which results in a problem that the light efficiency is lowered. The light exiting the insulating layer 95 is reflected by the connecting electrodes 72 and 82 so as to cover the nonconductive reflecting film 91 as a whole.

Therefore, a part of light not reflected by the non-conductive reflective film 91 is also reflected by the connection electrodes 72 and 82, so that the extraction efficiency of light is enhanced by coming out of the semiconductor light emitting element.

The first electrode portion 78 and the second electrode portion 88 are connected to the ohmic electrodes 71 and 81, the branch electrodes 78 and 88, the connection electrodes 72 and 82, the electrical connections 73, 78, 83 and 88 And pad electrodes 70 and 80, respectively.

The first electrode portion 78 is provided to be in electrical communication with the first semiconductor layer 30 and supplies one of electrons and holes.

The second electrode portion 88 is provided to be in electrical communication with the second semiconductor layer 50 and supplies the remaining one of electrons and holes.

The first connecting electrode 72 and the second connecting electrode 82 are formed on the non-conductive reflective film 91.

The first connection electrode 72 is electrically connected to the first semiconductor layer 30 through a first electrical connection 71.

The second connection electrode 82 is electrically connected to the second semiconductor layer 50 through the second electrical connection 81.

It is preferable that the first connecting electrode 72 and the second connecting electrode 82 are formed largely over the non-conductive reflective film 91. The first connecting electrode 72 and the second connecting electrode 82 absorb the impact of the pin on the non-conductive reflective film 91 to prevent the non-conductive reflective film 91 from cracking or breaking.

Since the first connection electrode 72 and the second connection electrode 82 are formed of metal and the first connection electrode 72 and the second connection electrode 82 can also absorb light, I think it is a way to increase brightness.

However, since most of the light is reflected toward the first semiconductor layer 30 in the non-conductive reflective film 91, only a small amount of light enters the first connection electrode 72 and the second connection electrode 82, It is found that the first connecting electrode 72 and the second connecting electrode 82 do not have a large influence on the luminance. Therefore, by forming the first connection electrode 72 and the second connection electrode 82 wide on the non-conductive reflective film 91, the stability and reliability of the semiconductor light emitting device can be enhanced.

The first connection electrode 72 and the second connection electrode 82 may be formed of metal. For example, Cr, Ti, Ni, Au, Ag, TiW, Pt, Al or the like.

The first electrical connection 73 and the second electrical connection 83 pass through the non-conductive reflective film 91 and electrically connect the first connection electrode 72 and the second connection electrode 82 to the plurality of semiconductor layers do. The first electrical connection 73 electrically connects the first connection electrode 72 and the first semiconductor layer 30 and the second electrical connection 83 electrically connects the second connection electrode 82 and the second The semiconductor layer 50 is electrically connected.

The first ohmic electrode 71 is formed for reducing the contact resistance between the first electrical connection 73 and the first semiconductor layer 30 and for stable electrical connection.

The second ohmic electrode 81 is formed for reducing the contact resistance between the second electrical connection 83 and the second semiconductor layer 50 and for stable electrical connection.

The first ohmic electrode 71 and the second ohmic electrode 81 may be formed of an ohmic metal such as Cr or Ti and may be formed of a reflective metal such as Al or Ag or a combination thereof . The operating voltage of the semiconductor light emitting device is lowered due to the first ohmic electrode 71 and the second ohmic electrode 81.

The third and fourth electrical connections 74 and 84 extend through the insulating layer 95 and extend through the first and second pad electrodes 70 and 80 and the first and second connection electrodes 72 and 72, 2 connecting electrodes 82 are electrically connected to each other. In this example, the third electrical connection 74 electrically communicates the first pad electrode 70 and the first connection electrode 72, and the fourth electrical connection 84 electrically connects the second pad electrode 80 and the second Thereby electrically connecting the connection electrode 82.

The branch electrode includes a first branch electrode 75 and a second branch electrode 85 which are electrically connected to the first connection electrode 72 and the second connection electrode 82 through the nonconductive reflective film 91 do.

Referring to FIG. 7, a second branched electrode 85 is formed to extend from the second ohmic electrode 81 on the second semiconductor layer 50 toward the first electrode portion 78. That is, the second branched electrode 85 extends from below the second pad electrode 80 to below the first pad electrode 70.

The second branched electrode 85 is electrically connected to the first connecting electrode 72 by an additional first electrical connection 77 passing through the non-conductive reflective film 91. The non-conductive reflective film 91 is formed so as to cover the second branch electrode 85.

The additional first electrical connections 77 are spaced apart from the first electrical connections 73 and are not overlapped with each other.

The additional first electrical connection 77 may be located on the same line as the third electrical connection 74, but may be located on another line.

As shown in Fig. 7 in the present disclosure, one additional first electrical connection 77 is shown, but is not limited thereto and may be formed in a plurality of one or more.

The size of the opening of the additional first electrical connection 77 may be equal to, smaller than, or greater than the size of the opening of the first electrical connection 73 and the third electrical connection 74.

The additional first electrical connection 77 is in contact with the first island-like Ohmic electrode 76 and is electrically connected to the second branched electrode 85, thereby reducing the contact resistance and improving the stability of the electrical connection. The first island-like Ohmic electrode 76 does not extend differently from the second branched electrode 85, but may be formed in a circular shape, a polygonal shape, or the like.

The second branched electrode 85 may be formed of a plurality of metal layers and may include a contact layer having good electrical contact with the current diffusion electrode 60 and a reflective layer having good light reflectivity.

Although the second branch electrode 85 is also provided for current spreading, the contact resistance between the additional first electrical connection 77 and the current spreading electrode 60 is reduced and the electrical connection can be interposed between them for stability have.

Since the second branch electrode 85 and the first connection electrode 72 are electrically connected by the additional first electrical connection 77, the current supply path increases without affecting the current flow, Do. That is, the current is concentrated by one electrical connection, and deterioration or interruption due to the current sinking phenomenon can be reduced. Therefore, the current that can be flowed increases, so that the uniformity of the current supply or the uniformity of the light emission can be increased.

8 is a view for explaining another example of the semiconductor light emitting device according to the present disclosure, and is a view for explaining an example of the first branched electrode 75. In Fig.

Referring to FIG. 8, the first branched electrode 75 is formed on the exposed first semiconductor layer 30 from which the second semiconductor layer 50 and the active layer 40 are removed, (88). That is, the first branched electrode 75 extends from below the first pad electrode 70 to below the second pad electrode 80.

The first branched electrode 75 is electrically connected to the second connecting electrode 82 by a second additional electrical connection 87 passing through the non-conductive reflective film 91. The non-conductive reflective film 91 is formed so as to cover the first branched electrode 75.

An additional second electrical connection 87 is located away from the second electrical connection 83 and is not formed overlying each other.

The additional second electrical connection 87 may be located on the same line as the fourth electrical connection 84, but may be located on another line.

As shown in FIG. 8 in the present disclosure, one additional second electrical connection 87 is shown, but not limited thereto, and may be formed as a plurality of one or more.

The size of the opening of the additional second electrical connection 87 may be equal to, less than, or greater than the size of the opening of the second electrical connection 83 and the fourth electrical connection 84.

The additional second electrical connection 87 is in contact with the second island-like Ohmic electrode 86 and is electrically connected to the first branched electrode 75, thereby reducing the contact resistance and improving the stability of the electrical connection. The second island-like Ohmic electrode 86 does not extend differently from the first branched electrode 75, but may be formed in a circular shape, a polygonal shape, or the like.

The first branched electrode 75 may be formed of a plurality of metal layers and may include a contact layer having good electrical contact with the first semiconductor layer 30 and a reflective layer having good light reflectivity.

Although the first branched electrode 75 is also provided for current diffusion, the contact resistance between the additional second electrical connection 87 and the first semiconductor layer 30 can be reduced and the electrical connection can be interposed between them for stability have.

Since the first branch electrode 75 and the second connection electrode 82 are electrically connected by the additional second electrical connection 87, the current supply path increases without affecting the current flow, Do. That is, the current is concentrated by one electrical connection, and deterioration or interruption due to the current sinking phenomenon can be reduced. Therefore, the current that can be flowed increases, so that the uniformity of the current supply or the uniformity of the light emission can be increased.

Although not shown in the drawings, the first branched electrode and the second branched electrode may be formed together.

The first pad electrode 70 is electrically connected to the first connection electrode 72 through a third electrical connection 74 to supply electrons to the first semiconductor layer 30.

The second pad electrode 80 is electrically connected to the second connection electrode 82 through a fourth electrical connection 84 to supply holes to the second semiconductor layer 50.

The first pad electrode 70 and the second pad electrode 80 are electrodes for electrical connection with external electrodes, and may be eutectic-bonded, soldered, or wire-bonded with external electrodes. The external electrode may be a conductive part provided on the submount, a lead frame of the package, an electric pattern formed on the PCB, or the like, and the shape of the lead wire provided independently of the semiconductor light emitting element is not particularly limited. The first pad electrode 70 and the second pad electrode 80 are formed to have a certain area to be a heat dissipation path.

Generally, when ohmic electrodes 71 and 81, branched electrodes 75 and 85, connecting electrodes 72 and 82, and bonding pads 101 and 102 are formed on a semiconductor light emitting device, . The lowermost layer should have a high bonding force with the adhesive surface, and materials such as Cr and Ti are mainly used, and Ni, Ti, TiW and the like can also be used, and there is no particular limitation. For the top layer, Au is used for wire bonding or connection with external electrodes.

The active layer 40, the second semiconductor layer 50, and the current diffusion electrode 60 (for example, the active layer 40, the active layer 40, and the second active layer 40) are formed on the substrate 10, ITO) and mesa-etched to expose a portion of the first semiconductor layer 30 corresponding to the first electrical connection 73. The mesa etching may be performed before or after the current diffusion electrode 60 is formed. The current diffusion electrode 60 may be omitted.

Next, ohmic electrodes 71 and 81 are formed on the current diffusion electrode 60 and the exposed first semiconductor layer 30, respectively. The ohmic electrodes 71 and 81 may be omitted but are preferably provided for stable electrical contact while suppressing an increase in the operating voltage.

It is also conceivable to form the light absorption preventing film corresponding to the ohmic electrode 81 on the second semiconductor layer 50 before the current diffusion electrode 60 is formed.

Next, branched electrodes 75 and 85 extending from the ohmic electrodes 71 and 81 in the direction of the electrode portions 78 and 88 are formed on the current diffusion electrode 60 and the exposed first semiconductor layer 30, respectively.

The first branched electrode 75 is extended from the first ohmic electrode 71 toward the second electrode portion 88 on the first semiconductor layer 30 and the second branched electrode 85 is formed on the first semiconductor layer 30, Is formed to extend from the second ohmic electrode (81) in the direction of the first electrode portion (78) on the second ohmic electrode (50).

Next, a first island-shaped ohmic electrode 76 is formed on the first branched electrode 75 and the second branched electrode 85 in correspondence with an additional first electrical connection 77 and an additional second electrical connection 87, The second island-like Ohmic electrode 86 is formed. The first island-shaped ohmic electrode 76 and the second island-shaped ohmic electrode 86 may be omitted, but are preferably provided for stable electrical contact while suppressing an increase in operating voltage.

Next, a non-conductive reflective film 91 is formed on the current spreading electrode 60.

Next, a first electrical connection 73, a second electrical connection 83, a further first electrical connection 77 made of openings in the non-conductive reflective film 91 by dry etching or wet etching, or a combination thereof, And an additional second electrical connection (87). The first electrical connection 73 and the second electrical connection 83 are formed to contact the first ohmic electrode 71 and the second ohmic electrode 81 respectively and the additional first electrical connection 77 and the additional The second electrical connection 87 is formed in contact with the first island-like ohmic electrode 76 and the second island-like Ohmic electrode 86.

The first electrical connection 73 and the additional second electrical connection 87 are formed up to a portion of the nonconductive reflective film 91, the second semiconductor layer 50, the active layer 40 and the first semiconductor layer 30.

The second electrical connection 83 and the additional first electrical connection 77 are formed to expose a portion of the current spreading electrode 60 through the non-conductive reflective film 91.

The first electrical connection 73, the second electrical connection 83, the additional first electrical connection 77 and the additional second electrical connection 87 may be formed after the formation of the non-conductive reflective film 91, Alternatively, a first electrical connection 73 and an additional second electrical connection 87 may be formed on the plurality of semiconductor layers 30, 40, 50 before forming the non-conductive reflective film 91 or after the non-conductive reflective film 91 is formed, And after the non-conductive reflective film 91 is formed so as to cover the first electrical connection 73 and the additional second electrical connection 87, A connection 73 and an additional second electrical connection 87 are formed and a second electrical connection 83 and a further first electrical connection 77 may be formed at the same time or in a further process.

Next, a first connection electrode 72 and a second connection electrode 82 are formed on the non-conductive reflective film 91. For example, the first connection electrode 72 and the second connection electrode 82 may be deposited using a sputtering equipment, an E-beam device, or the like. The first connecting electrode 72 and the second connecting electrode 82 may be formed using Cr, Ti, Ni, or their alloys for stable electrical contact, and may include a reflective metal layer such as Al or Ag .

The first connecting electrode 72 may be formed to contact the first semiconductor layer 30 through a plurality of first electrical connections 73 and the second branched electrode 72 may be formed through a further first electrical connection 77, 85, respectively.

The second connecting electrode 82 may be formed to contact the current spreading electrode 60 through the second electrical connection 83 and the first branched electrode 75 and / As shown in FIG.

Next, an insulating layer 95 covering the first connection electrode 72 and the second connection electrode 82 is formed. A representative material of the insulating layer 95 is SiO2, and SiN, TiO2, Al2O3, Su-8, and the like may be used without being limited thereto.

Next, a third electrical connection 74 and a fourth electrical connection 84 comprising a plurality of openings are formed in the insulating layer 95 by dry etching or wet etching, or a combination thereof. The plurality of third electrical connections 74 and the fourth electrical connections 84 are formed to contact the first connection electrode 72 and the second connection electrode 82, respectively.

The plurality of third electrical connections 74 and the fourth electrical connections 84 may be formed after the formation of the insulating layer 95 but may alternatively be formed prior to the formation of the insulating layer 95.

The first pad electrode 70 and the second pad electrode 80 may be electrically connected to electrodes provided on the outside (package, COB, submount, etc.) by a method such as a stud bump, a conductive paste, have. It is important that the height difference between the first pad electrode 70 and the second pad electrode 80 does not become large in the case of eutectic bonding. According to the semiconductor light emitting device of this example, since the first pad electrode 70 and the second pad electrode 80 can be formed on the insulating layer 95 by the same process, there is almost no height difference between both electrodes. Therefore, it has an advantage in the case of eutectic bonding. The uppermost portion of the first pad electrode 70 and the second pad electrode 80 may be formed of Au / Sn alloy, Au / Sn / Cu alloy, etc., And may be formed of a tick bonding material.

9 is a view for explaining another example of the semiconductor light emitting device according to the present disclosure, and is a view for explaining an example in which a plurality of the third electrical connection 74 and the fourth electrical connection 84 are formed. Except for the fourth electrical connection 84 formed in plurality in FIG. 9, has the same characteristics as the semiconductor light emitting device described in FIG.

Referring to FIG. 9, the third electrical connection 74 and the fourth electrical connection 84 are formed in a plurality. That is, the number of the third electrical connection 74 and the fourth electrical connection 84 is greater than the number of the first electrical connection 73 and the second electrical connection 83.

Generally, the electrical connection between the pad electrodes 70, 80 and the connection electrodes 72, 82 is formed as one opening. In the case of forming one opening, the flow of current is determined according to the size of the opening, so that there is a problem that a uniform current can not be supplied to a plurality of semiconductor layers due to influence of current diffusion. If the current is non-uniform, the current may be biased in one opening, and deterioration may occur at a position where the current is biased in the long term.

Accordingly, in the present disclosure, the number of the third electrical connection 74 and the fourth electrical connection 84 located between the pad electrodes 70, 80 and the connection electrodes 72, 82 is made up of one or more than one, So that a uniform current can be supplied to the plurality of semiconductor layers.

The sizes of the respective openings of the third electrical connection 74 and the fourth electrical connection 84 may be different from each other, but are not limited thereto and may be of a size having the same diameter.

As described above, the third electrical connection 74 and the fourth electrical connection 84 are formed by a plurality of openings, so that the first electrical connection 73 and the second electrical connection 83, The size of the opening is formed to be larger than the size of the openings of the third electrical connection 74 and the fourth electrical connection 84.

The third electrical connection 74 and the fourth electrical connection 84 are formed in plural. That is, the number of the third electrical connection 74 and the fourth electrical connection 84 is greater than the number of the first electrical connection 73 and the second electrical connection 83.

10 is a cross-sectional view for explaining another example of the semiconductor light emitting device according to the present disclosure, and explaining an example of the nonconductive reflective film 91. In FIG. Except for the nonconductive reflective film 91 described in Fig. 10, has the same characteristics as those of the semiconductor light emitting device described in Fig.

As shown in Fig. 10, the non-conductive reflective film 91 of the semiconductor light emitting element may be composed of a single dielectric layer or may have a multilayer structure. In this example, the non-conductive reflective film 91 is formed of a non-conductive material in order to reduce light absorption by the metal reflective film, and the non-conductive reflective film 91 includes a dielectric film 91b, a distributed Bragg reflector 91a (Distributed Bragg Reflector) and a clad film 91c.

According to this embodiment, in forming the semiconductor light emitting device, a height difference may occur due to the same structure as the ohmic electrodes 71 and 81. Therefore, by forming the dielectric film 91b having a certain thickness prior to the deposition of the distribution Bragg reflector 91a requiring precision, it is possible to stably manufacture the distribution Bragg reflector 91a, You can give.

SiO ₂ is suitable as the material of the dielectric film 91b, and its thickness is preferably 0.2 um to 2.0 um. If the thickness of the dielectric film 91b is too thin, it may be insufficient to sufficiently cover the ohmic electrodes 71 and 81 and the island-shaped Ohmic electrodes 76 and 86 having a height of about 2 to 3 μm. If the dielectric film 91b is too thick, The first electrical connection 73, the second electrical connection 83, the additional first electrical connection 77, and the additional second electrical connection 87 may be burdensome. The thickness of the dielectric film 91b may be thicker than the thickness of the subsequent distributed Bragg reflector 91a. Further, the dielectric film 91b needs to be formed by a method that is more suitable for ensuring reliability of the device. For example, the dielectric film 91b made of SiO ₂ is preferably formed by CVD (Chemical Vapor Deposition), in particular, plasma enhanced chemical vapor deposition (PECVD). This is because chemical vapor deposition is more advantageous than physical vapor deposition (PVD) such as electron beam evaporation (E-Beam Evaporation) in step coverage. Specifically, when the dielectric film 91b is formed by E-Beam Evaporation, the dielectric film 91b is hardly formed in the designed thickness in the height difference region, and the reflectance of light may be lowered , There may be a problem in electrical insulation. Therefore, it is preferable that the dielectric film 91b is formed by a chemical vapor deposition method for reducing the height difference and ensuring insulation. Therefore, it is possible to secure the function of the reflective film while securing the reliability of the semiconductor light emitting element.

The distribution Bragg reflector 91a is formed on the dielectric film 91b. Distributed Bragg reflector (91a) has a reflectivity can be made by repeatedly laminating, for _{example, SiO 2 / TiO 2, SiO} 2 / Ta 2 O 2, or a repeating stack of SiO ₂ / HfO of other materials. In addition, distributed Bragg reflector (91a) can be configured with a combination, such as _{Ta 2 O 5, HfO, ZrO} , SiN , such as high refractive index material than the low dielectric thin film (typically, SiO ₂₎ refractive index. For example, a distributed Bragg reflector (95a) is a SiO ₂ / TiO _2, SiO ₂ / Ta ₂ O _2, or SiO ₂ / can be made by repeated lamination of HfO and, Blue on for SiO ₂ / TiO ₂ the reflection efficiency light , And SiO ₂ / Ta ₂ O ₂ or SiO ₂ / HfO for the UV light will have a good reflection efficiency. When the distributed Bragg reflector 91a is made of SiO2 / TiO2, it is preferable to go through an optimization process in consideration of the incident angle and the reflectance depending on wavelength based on the optical thickness of 1/4 of the wavelength of light emitted from the active layer 40 And the thickness of each layer does not necessarily have to satisfy the optical thickness of 1/4 of the wavelength. The number of combinations is 4 to 40 pairs. In the case where the distribution Bragg reflector 91a has a repetitive layer structure of SiO ₂ / TiO ₂ , the distribution Bragg reflector 91 a may be formed by physical vapor deposition (PVD), E-beam evaporation or sputtering It is preferably formed by sputtering or thermal evaporation.

A clad layer (91c) may be formed of a dielectric film (91b), material of MgF, CaF, such as a metal oxide, SiO _2, SiON, such as Al ₂ O _3. It is preferable that the clad film 91c has a thickness of lambda / 4n to 3.0 um. Where lambda is the wavelength of the light generated in the active layer 40 and n is the refractive index of the material forming the clad film 91c. and 4500/4 * 1.46 = 771A or more when? is 450 nm (4500 A).

Considering that the uppermost layer of the distributed Bragg reflector 91a composed of a large number of pairs of SiO ₂ / TiO ₂ may be TiO ₂ , but considering that it can be made of an SiO ₂ layer having a thickness of λ / 4n, Is preferably thicker than? / 4n so as to be differentiated from the uppermost layer of the distribution Bragg reflector 91a located below. However, it is not only burdensome to the subsequent opening forming process, but also increases the thickness because the cladding film 91c can increase the material cost without contributing to the improvement of the efficiency. Therefore, in order not to burden the subsequent process, it is appropriate that the maximum value of the thickness of the clad film 91c is formed within 1 mu m to 3 mu m.

However, in some cases it is not impossible to form more than 3.0 μm. It is preferable that the effective refractive index of the first distributed Bragg reflector 91a is larger than the refractive index of the dielectric film 91b for light reflection and guidance. When the distribution Bragg reflector 91a directly contacts the pad electrodes 70 and 80, a part of the light traveling through the distribution Bragg reflector 91a can be absorbed by the pad electrodes 70 and 80. Therefore, when the clad film 91c having a refractive index lower than that of the distributed Bragg reflector 91a is introduced, the absorption of light by the pad electrodes 70 and 80 can be greatly reduced. When the refractive index is selected in this way, the dielectric film 91b-distributed Bragg reflector 91a-clad film 91c can be described in terms of an optical waveguide. The optical waveguide is a structure for guiding light by surrounding the propagating portion of the light with a material having a lower refractive index than that of the light guiding portion.

From this viewpoint, the dielectric film 91b and the clad film 91c can be seen as a part of the optical waveguide as a configuration surrounding the propagating portion, when the distributed Bragg reflector 91a is regarded as a propagation portion.

For example, a distributed Bragg reflector (91a) is a light-transmitting material to prevent absorption of light (for example; SiO ₂ / TiO ₂₎ if formed from a dielectric film (91b) has a refractive index distribution of the effective refractive index of the Bragg reflector (91a) Lt; _{RTI ID} = 0.0 &gt; SiO2. &Lt; / RTI &gt;

Here, the effective refractive index means an equivalent refractive index of light that can travel in a waveguide made of materials having different refractive indices. A clad layer (91c) also distributed low material than the effective refraction index of the Bragg reflector (91a): may be made of (for example, _{Al 2 O 3, SiO 2,} SiON, MgF, CaF). If distributed Bragg reflector (91a) is composed of SiO ₂ / TiO _2, and a refractive index of 1.46 of SiO _2, because the refractive index of TiO ₂ is 2.4, the effective refractive index of the distributed Bragg reflector has a value of between 1.46 and 2.4. Therefore, the dielectric film 91b may be made of SiO ₂ , and the thickness thereof is suitably from 0.2 탆 to 1.0 탆.

The clad film 91c may also be formed of SiO ₂ having a refractive index of 1.46 which is smaller than the effective refractive index of the distributed Bragg reflector 91a.

The dielectric film 91b may be omitted from the viewpoint of the entire technical idea of the present disclosure and it is also possible to consider the configuration of the distributed Bragg reflector 91a and the clad film 91c There is no reason to exclude. It may be considered to include a dielectric film 91b made of TiO ₂ which is a dielectric instead of the distributed Bragg reflector 91a. It is also conceivable to omit the clad film 91c when the distributed Bragg reflector 91a has the SiO ₂ layer as the uppermost layer. If the dielectric film 91b and the distributed Bragg reflector 91a are designed in consideration of the reflectance of light traveling substantially in the transverse direction, even if the distributed Bragg reflector 91a has the TiO ₂ layer as the uppermost layer, It is also conceivable to omit the film 91c.

Thus, the dielectric film 91b, the distributed Bragg reflector 91a, and the clad film 91c serve as a non-conductive reflective film 91 as a waveguide, and preferably have a total thickness of 1 to 8 um. The distribution Bragg reflector 91a has a higher reflectance as the light closer to the vertical direction reflects more than 99%.

11 is a view for explaining another example of the semiconductor light emitting device according to the present disclosure, and is a view for explaining an example in which the light absorption preventing film 41 is included. Except for the nonconductive reflective film 91 described in Fig. 11, has the same characteristics as those of the semiconductor light emitting device described in Fig.

11, the semiconductor light emitting element is provided between the second semiconductor layer 50 and the current diffusion electrode 60 in correspondence with the second ohmic electrode 81 and the second electrical connection 83, (41).

The light absorption preventing film 41 may be formed of SiO 2 or TiO 2 and may have a function of reflecting a part or all of the light generated in the active layer 40. The second ohmic electrode 81 and the second electrical connection It may have only the function of preventing the current from flowing directly downward from the electrode 83 and may have both functions.

12 is a view for explaining another example of the semiconductor light emitting device according to the present disclosure, and is a view for explaining an example in which branch electrodes 75 and 85 include extension portions 79 and 89. FIG. Except for the extension portions 79 and 89 shown in FIG. 12, the same characteristics as those of the semiconductor light emitting device described in FIGS.

As shown in Fig. 12, the branch electrodes 85 and 75 include an extension E having a constant width and extensions 79 and 89 having a width wider than the extension E. As described above, the branch electrodes 85 and 75 may have a constant width or vary depending on the position, and include not only a straight branch electrode but also a curved branch electrode.

Various embodiments of the present disclosure will be described below.

(1) A semiconductor light emitting device comprising: a first semiconductor layer having a first conductivity; a second semiconductor layer having a second conductivity different from the first conductivity; and a second semiconductor layer interposed between the first and second semiconductor layers, A plurality of semiconductor layers having active layers for generating light through recombination of the semiconductor layers; A non-conductive reflective film formed on the plurality of semiconductor layers to reflect light generated in the active layer toward the first semiconductor layer; An insulating layer formed on the non-conductive reflective film; A first electrode part electrically connected to the first semiconductor layer and supplying one of electrons and holes; And a second electrode part electrically connected to the second semiconductor layer and supplying the remaining one of electrons and holes, and at least one of the first electrode part and the second electrode part comprises: a connection electrode formed on the non-conductive reflective film; A first electrical connection for electrically connecting the connection electrode and the plurality of semiconductor layers through the non-conductive reflective film; A pad electrode formed on the insulating layer; A second electrical connection for electrically connecting the pad electrode and the connection electrode through the insulating layer; A branched electrode formed between the plurality of semiconductor layers and the non-conductive reflective film; And a further electrical connection for electrically connecting the branch electrode and the connection electrode, wherein the further electrical connection is located in one of the first electrode portion and the second electrode portion.

(2) The semiconductor light emitting device according to claim 1, wherein the additional electrical connection is at least one or more.

(3) The first electrode unit includes: a first conductive connection electrode formed on the non-conductive reflective film; A first electrical connection of a first conductivity through the non-conductive reflective film to electrically connect the first conductive semiconductor first layer and the first conductive first connection electrode; A first conductive pad electrode formed on the insulating layer; And a second electrical connection of a first conductive type that electrically connects the first conductive connection electrode and the first conductive first pad electrode through the insulating layer, and the second electrode portion includes: A second connecting electrode of a second conductive type formed; A first electrical connection of a second conductivity for electrically communicating the second conductive second semiconductor layer and the second conductive second connection electrode through the non-conductive reflective film; A second conductive pad electrode formed on the insulating layer; And a second conductive second electrical connection through the insulating layer to electrically connect the second conductive connection electrode and the second conductive second pad electrode.

(4) a first conductive first ohmic electrode formed between the first semiconductor layer of the first conductivity and the first electrical connection of the first conductivity; And a second conductive ohmic electrode formed between the second conductive semiconductor layer and the first electrical connection of the second conductivity, and the branched electrode comprises a first branched electrode or a second branched electrode extending from the first ohmic electrode, 2 ohmic electrode, and a second branched electrode extending from the ohmic electrode.

(5) a first ohmic electrode formed between the first semiconductor layer of the first conductivity and the first electrical connection of the first conductivity; And a second ohmic electrode formed between the second conductive semiconductor layer and the first electrical connection of the second conductivity, wherein the branched electrode extends from the first ohmic electrode toward the second electrode portion on the first semiconductor layer, Wherein the first branched electrode is electrically connected to the second connection electrode by an additional second electrical connection through the nonconductive reflective film.

(6) A further second electrical connection is located apart from the first electrical connection of the second conductivity.

(7) a first ohmic electrode formed between the first semiconductor layer of the first conductivity and the first electrical connection of the first conductivity; And a second ohmic electrode formed between the second conductive semiconductor layer and the first electrical connection of the second conductivity, wherein the branched electrode is extended from the second ohmic electrode toward the first electrode portion on the second semiconductor layer, And the second branch electrode is electrically connected to the first connection electrode by an additional first electrical connection through the nonconductive reflection film.

(8) A further first electrical connection is located apart from a first electrical connection of the first conductivity.

(9) a first conductive first ohmic electrode formed between the first semiconductor layer of the first conductivity and the first electrical connection of the first conductivity; And a second conductive ohmic electrode formed between the second conductive semiconductor layer and the first electrical connection of the second conductivity, wherein the branched electrode comprises a first branched electrode extending from the first ohmic electrode and a second branched electrode And a second branched electrode extended from the second ohmic electrode.

(10) The number of the second electrical connections is larger than the number of the first electrical connections.

(11) The semiconductor light-emitting device as claimed in any one of the preceding claims, wherein the insulating layer is formed of a dielectric material, and the non-conductive reflective film comprises DBR (Distributed Bragg Reflector) or ODR (Omni-Directional Reflector).

(12) The branched electrodes are: an extension having a constant width; And an extension portion connected to the extension portion and having a larger width than the extension portion.

According to the semiconductor light emitting device of the present disclosure, by electrically connecting the branch electrode of the first conductivity type and the second conductive electrode of the first conductivity type to the electrode of the second conductive type by electrical connection, uniformity of current diffusion .

As a result, the current is concentrated by one electrical connection, and deterioration or interruption due to the current leaking phenomenon is reduced, so that the uniformity of light emission of the semiconductor light emitting device is further improved.

According to the semiconductor light emitting device of the present disclosure, the uniformity of the current diffusion is improved by electrically connecting the upper electrode and the plurality of semiconductor layers through the plurality of openings in the semiconductor light emitting device having the plurality of light emitting portions.

78, 88: electrode portion 71, 81: ohmic electrode
76, 86: island-shaped ohmic electrode 72, 82: connecting electrode
73, 74, 83, 84: electrical connection 77, 87: additional electrical connection
78, 88: branch electrode 70, 80: pad electrode
91: non-conductive reflective film 95: insulating layer

Claims (12)

In the semiconductor light emitting device,
A first semiconductor layer having a first conductivity, a second semiconductor layer having a second conductivity different from the first conductivity, and an active layer disposed between the first and second semiconductor layers and generating light through recombination of electrons and holes, A plurality of semiconductor layers;
A non-conductive reflective film formed on the plurality of semiconductor layers to reflect light generated in the active layer toward the first semiconductor layer;
An insulating layer formed on the non-conductive reflective film;
A first electrode part electrically connected to the first semiconductor layer and supplying one of electrons and holes; And
And a second electrode part electrically connected to the second semiconductor layer and supplying the remaining one of electrons and holes,
At least one of the first electrode portion and the second electrode portion includes:
A connection electrode formed on the non-conductive reflective film;
A first electrical connection for electrically connecting the connection electrode and the plurality of semiconductor layers through the non-conductive reflective film;
A pad electrode formed on the insulating layer;
A second electrical connection for electrically connecting the pad electrode and the connection electrode through the insulating layer;
A branched electrode formed between the plurality of semiconductor layers and the non-conductive reflective film; And
And an additional electrical connection for electrically connecting the branch electrode to the connection electrode,
Wherein the additional electrical connection is located in one of the first electrode portion and the second electrode portion. The method according to claim 1,
Wherein the additional electrical connection is at least one or more than one. The method according to claim 1,
The first electrode portion includes:
A first conductive connection electrode formed on the non-conductive reflective film;
A first electrical connection of a first conductivity through the non-conductive reflective film to electrically connect the first conductive semiconductor first layer and the first conductive first connection electrode;
A first conductive pad electrode formed on the insulating layer; And
And a second electrical connection of a first conductive type that electrically connects the first conductive connection electrode and the first conductive first pad electrode through the insulating layer,
The second electrode portion includes:
A second conductive connection electrode formed on the non-conductive reflective film;
A first electrical connection of a second conductivity for electrically communicating the second conductive second semiconductor layer and the second conductive second connection electrode through the non-conductive reflective film;
A second conductive pad electrode formed on the insulating layer; And
And a second conductive second electrical connection through the insulating layer to electrically connect the second conductive connection electrode and the second conductive second pad electrode. The method of claim 3,
A first conductive first ohmic electrode formed between the first semiconductor layer of the first conductivity and the first electrical connection of the first conductivity; And
And a second conductive ohmic electrode formed between the second semiconductor layer of the second conductivity and the first electrical connection of the second conductivity,
The branched electrode includes at least one of a first branched electrode extending from the first ohmic electrode or a second branched electrode extending from the second ohmic electrode. The method of claim 3,
A first ohmic electrode formed between the first semiconductor layer of the first conductivity and the first electrical connection of the first conductivity; And
And a second ohmic electrode formed between the second semiconductor layer of the second conductivity and the first electrical connection of the second conductivity,
The branch electrode is a first branched electrode extending from the first ohmic electrode toward the second electrode portion on the first semiconductor layer,
Wherein the first branched electrode is electrically connected to the second connection electrode by a second electrical connection through the non-conductive reflective film. The method of claim 5,
And the additional second electrical connection is located away from the first electrical connection of the second electrical conductivity. The method of claim 3,
A first ohmic electrode formed between the first semiconductor layer of the first conductivity and the first electrical connection of the first conductivity; And
And a second ohmic electrode formed between the second semiconductor layer of the second conductivity and the first electrical connection of the second conductivity,
The branch electrode is a second branched electrode extending from the second ohmic electrode on the second semiconductor layer toward the first electrode portion,
And the second branched electrode is electrically connected to the first connection electrode by a further first electrical connection through the non-conductive reflective film. The method of claim 7,
Wherein the further first electrical connection is located away from the first electrical connection of the first electrical conductivity. The method of claim 3,
A first conductive first ohmic electrode formed between the first semiconductor layer of the first conductivity and the first electrical connection of the first conductivity; And
And a second conductive ohmic electrode formed between the second semiconductor layer of the second conductivity and the first electrical connection of the second conductivity,
The branched electrode includes a first branched electrode extending from the first ohmic electrode and a second branched electrode extending from the second ohmic electrode. The method according to claim 1,
Wherein the number of the second electrical connections is larger than the number of the first electrical connections. The method according to claim 1,
The insulating layer is formed of a dielectric,
The non-conductive reflective film includes a DBR (Distributed Bragg Reflector) or an ODR (Omni-Directional Reflector). The method according to claim 1,
Branch electrodes are:
An extension having a constant width; And
And an extension portion connected to the extension portion and having a larger width than the extension portion.

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