KR102331337B1 - Light emitting device - Google Patents

Abstract

A light emitting device is disclosed. The light emitting device includes: a light emitting structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer positioned between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer; a first contact electrode in ohmic contact with the first conductivity-type semiconductor layer; a second contact electrode positioned on the second conductivity-type semiconductor layer; and an insulating layer positioned on the light emitting structure and insulating the first contact electrode and the second contact electrode, wherein the light emitting structure has a non-polar or semi-polar growth surface, and The upper surface includes a non-polar or semi-polar surface, and the second contact electrode includes a conductive oxide layer in ohmic contact with the second conductivity-type semiconductor layer, and a reflective electrode layer disposed on the conductive oxide layer.

Description

Light emitting device {LIGHT EMITTING DEVICE}

The present invention relates to a light emitting device, and more particularly, to a light emitting device having high luminous efficiency due to excellent optical and electrical properties.

Recently, as the demand for a small high-power light-emitting device increases, the demand for a large-area flip-chip type light-emitting diode with high heat dissipation efficiency applicable to the high-power light-emitting device is increasing. The electrode of the flip chip light emitting device is directly bonded to the secondary substrate, and since a wire for supplying external power to the flip chip light emitting device is not used, heat dissipation efficiency is very high compared to that of the horizontal light emitting device. Therefore, even when a high-density current is applied, heat can be effectively conducted to the secondary substrate side, so that the flip-chip type light emitting device is suitable as a light emitting source of a high output light emitting device.

Meanwhile, a general nitride-based light emitting device was manufactured by growing it on a growth substrate such as a sapphire substrate having a C-plane growth surface. However, since the growth plane of the C plane has a polarity with respect to a direction in which electrons and holes are combined, spontaneous polarization and piezoelectric polarization occur in the grown nitride-based semiconductor layer. Due to this polarization phenomenon, the internal quantum efficiency of the light emitting device is lowered, and an efficiency droop occurs. In addition, the sapphire substrate used as the growth substrate has low thermal conductivity, thereby lowering the heating efficiency of the light emitting device, thereby reducing the lifespan and luminous efficiency of the light emitting device. In such a conventional light emitting device, a decrease in efficiency is more pronounced when driving with a high current.

In order to improve this point, a method for manufacturing a light emitting device using a non-polar or semi-polar (homogeneous) growth substrate has been proposed. By growing a non-polar or semi-polar nitride semiconductor on the same substrate, efficiency degradation due to spontaneous polarization and piezoelectric polarization can be minimized. As a non-polar surface of a nitride-based semiconductor, there are a-plane ({11-20}) and m-plane ({1-100}), and a light emitting device manufactured by growing nitride-based semiconductor layers on an m-plane non-polar substrate is conventionally Many have been disclosed in

However, the non-polar nitride-based semiconductor layer grown with the m-plane as the growth plane is different from the non-polar nitride-based semiconductor layer grown with the c-plane as the growth plane, in growth characteristics, optical properties, and the like. Accordingly, there is a limitation in directly applying the technique of growing the nitride-based semiconductor layer with the c-plane as the growth plane to the manufacture of the nitride-based semiconductor layer having the m-plane as the growth plane.

An object of the present invention is to provide a light emitting device having a non-polar or semi-polar growth surface, high internal quantum efficiency, improved ohmic contact characteristics between a semiconductor layer and a contact electrode, and excellent electrical characteristics.

Another problem to be solved by the present invention is to provide a light emitting device having excellent heat dissipation efficiency during high current driving, and improved reliability.

A light emitting device according to an aspect of the present invention is a light emitting structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer positioned between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer. ; a first contact electrode in ohmic contact with the first conductivity-type semiconductor layer; a second contact electrode positioned on the second conductivity-type semiconductor layer; and an insulating layer positioned on the light emitting structure and insulating the first contact electrode and the second contact electrode, wherein the light emitting structure has a non-polar or semi-polar growth surface, and The upper surface includes a non-polar or semi-polar surface, and the second contact electrode includes a conductive oxide layer in ohmic contact with the second conductivity-type semiconductor layer, and a reflective electrode layer disposed on the conductive oxide layer.

The light emitting structure may include a nitride semiconductor, and the non-polar or semi-polar growth plane may include an m-plane.

In addition, the conductive oxide layer may include ITO, and the reflective electrode layer may include Ag.

An area of the conductive oxide layer may be greater than an area of the reflective electrode layer, and the reflective electrode layer may be located within an edge region of the conductive oxide layer.

The conductive oxide layer may cover 90% or more of an upper surface of the second conductivity-type semiconductor layer.

The conductive oxide layer may be covered with the reflective electrode layer.

In some embodiments, the first conductivity type semiconductor layer may include a nitride-based substrate having a non-polar or semi-polar growth surface.

In addition, the nitride-based substrate may be undoped or doped to have the same conductivity type as the first conductivity type semiconductor layer.

The nitride-based substrate may have a thickness of 270 to 330 μm.

A contact resistance between the second conductivity-type semiconductor layer and the conductive oxide may be lower than a contact resistance between the second conductivity-type semiconductor layer and the reflective metal layer.

In addition, in the light emitting structure, the light emitting structure may include a plurality of mesa including the second conductivity type semiconductor layer and the active layer, the second contact electrode is located on the plurality of mesa, and the first The conductive semiconductor layer may be exposed in at least a partial region around the plurality of mesa.

The insulating layer may include a first insulating layer and a second insulating layer, wherein the first insulating layer covers the plurality of mesas and the first conductive type semiconductor layer, a portion of the first conductive type semiconductor layer and the It may include a first opening and a second opening exposing a portion of the second contact electrode, respectively.

The first contact electrode may be in ohmic contact with the first conductivity-type semiconductor layer through the first opening, and the first contact electrode may be positioned on a portion of upper surfaces of the plurality of mesas and side surfaces of the plurality of mesas, It may be insulated from the plurality of mesa.

Furthermore, the second insulating layer may include a third opening and a fourth opening partially covering the first contact electrode and partially exposing the first contact electrode and the second contact electrode, respectively.

The light emitting device may include: a first pad electrode disposed on the second insulating layer and electrically connected to the first contact electrode through the third opening; and a second pad electrode disposed on the second insulating layer and electrically connected to the second contact electrode through the fourth opening.

The insulating layer may cover the plurality of mesas and the first conductivity-type semiconductor layer, and may include first and second openings exposing a portion of the first conductivity-type semiconductor layer and a portion of the second contact electrode, respectively. have.

In addition, the first contact electrode is in ohmic contact with the first conductivity-type semiconductor layer through the first opening, and the first contact electrode is located on a portion of an upper surface of the plurality of mesas and a portion of a side surface of the plurality of mesas. , may be insulated from the plurality of mesa.

The light emitting device may further include a pad electrode disposed on the insulating layer and electrically connected to the second contact electrode through the second opening, wherein the pad electrode and the first contact electrode are spaced apart from each other. can

The light emitting structure may include a first area including one side thereof and a second area including the other side opposite to the one side, wherein the first contact electrode is located in the first area, and The pad electrode may be located in the second region.

In some embodiments, the first contact electrode may be positioned on at least a portion of a region where the first conductivity-type semiconductor layer is exposed.

The insulating layer may cover the plurality of mesas and the first conductivity type semiconductor layer, and may include first and second openings exposing a portion of the first contact electrode and a portion of the second contact electrode, respectively.

The light emitting device may include: a first pad electrode disposed on the insulating layer and electrically connected to a first contact electrode through the first opening; and a second pad electrode disposed on the insulating layer and electrically connected to a second contact electrode through the second opening, wherein the first pad electrode includes the first contact electrode and the plurality of mesa electrodes. It may be positioned on a portion of the upper surface of the plurality of mesas and a portion of the side surfaces of the plurality of mesas, and may be spaced apart from the plurality of mesas by the insulating layer.

The light emitting structure includes a region in which the first conductivity-type semiconductor layer is partially exposed, the insulating layer includes a first insulating layer, and the first insulating layer partially covers the light emitting structure and the second contact electrode. The cover may include a first opening and a second opening exposing a portion of the first conductivity-type semiconductor layer and a portion of the second contact electrode, respectively.

Furthermore, the first insulating layer may include a preliminary insulating layer and a main insulating layer positioned on the preliminary insulating layer, and the preliminary insulating layer may cover a portion of the light emitting structure and a part of the conductive oxide.

The preliminary insulating layer may include an opening partially exposing the conductive oxide, and the reflective electrode layer may be located in the opening.

The main insulating layer may partially cover the reflective electrode layer.

The insulating layer may further include a second insulating layer disposed on the first insulating layer and partially covering the first contact electrode, wherein the first insulating layer may be thicker than the second insulating layer. .

According to the present invention, a light emitting structure having a non-polar or semi-polar growth surface, in particular, a second contact electrode forming an ohmic contact with a low contact resistance with a second conductivity-type semiconductor layer having a non-polar or semi-polar growth surface; , a light emitting device having low forward voltage (Vf) and high reliability may be provided. In addition, the light emitting device according to the embodiments of the present invention includes a first conductivity type semiconductor layer having a predetermined thickness or more, so that the light emitting device has excellent thermal reliability and the current can be evenly distributed in the horizontal direction. may be provided.

1 is a cross-sectional view for explaining a light emitting device according to an embodiment of the present invention.
2 is a cross-sectional view for explaining a light emitting device according to another embodiment of the present invention.
3A and 3B are plan views and cross-sectional views illustrating a light emitting device according to another embodiment of the present invention.
4A and 4B are plan views and cross-sectional views illustrating a light emitting device according to another embodiment of the present invention.
5A and 5B are plan views and cross-sectional views illustrating a light emitting device according to another embodiment of the present invention.
6 is an exploded perspective view illustrating an example in which a light emitting device according to an embodiment of the present invention is applied to a lighting device.
7 is a cross-sectional view illustrating an example in which a light emitting device according to an embodiment of the present invention is applied to a display device.
8 is a cross-sectional view illustrating an example in which a light emitting device according to an embodiment of the present invention is applied to a display device.
9 is a cross-sectional view illustrating an example in which a light emitting device according to an embodiment of the present invention is applied to a head lamp.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments introduced below are provided as examples so that the spirit of the present invention can be sufficiently conveyed to those skilled in the art to which the present invention pertains. Accordingly, the present invention is not limited to the embodiments described below and may be embodied in other forms. And, in the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience. In addition, when one component is described as being “on” or “on” another component, each component is different from each component, as well as when each component is “immediately above” or “directly on” the other component. It includes the case where another component is interposed between them. Like reference numerals refer to like elements throughout.

1 is a cross-sectional view for explaining a light emitting device according to an embodiment of the present invention, Figure 2 is a cross-sectional view for explaining a light emitting device according to another embodiment of the present invention.

First, referring to FIG. 1 , the light emitting device includes a light emitting structure 120 , a first contact electrode 130 , a second contact electrode 140 , and insulating layers 150 and 160 . In addition, the light emitting device may further include a connection electrode 145 , a first pad electrode 171 , and a second pad electrode 173 .

The light emitting structure 120 includes a first conductivity type semiconductor layer 121 , an active layer 123 located on the first conductivity type semiconductor layer 121 , and a second conductivity type semiconductor layer ( 125) may be included. Meanwhile, the first conductivity type semiconductor layer 121 may include a growth substrate 121a and an upper first conductivity type semiconductor layer 121b positioned on the growth substrate 121a.

The first conductivity type semiconductor layer 121 , the active layer 123 , and the second conductivity type semiconductor layer 125 may each include a III-V series compound semiconductor, for example, (Al, Ga, In)N It may include a nitride-based semiconductor such as The first conductivity-type semiconductor layer 121 may include an n-type impurity (eg, Si), and the second conductivity-type semiconductor layer 125 may include a p-type impurity (eg, Mg). have. In particular, the upper first conductivity-type semiconductor layer 121b of the first conductivity-type semiconductor layer 121 may have an n-type conductivity by including artificially doped n-type impurities. Alternatively, the conductivity types of the first and second conductivity type semiconductor layers 121 and 125 may be opposite to those described above. The active layer 123 may include a multiple quantum well structure (MQW).

The growth substrate 121a is not limited as long as it is a substrate capable of growing a nitride-based semiconductor, and may include, for example, a heterogeneous substrate such as a sapphire substrate, a silicon substrate, a silicon carbide substrate, or a spinel substrate. It may include a homogeneous substrate such as a gallium substrate, an aluminum nitride substrate, or the like. In particular, in this embodiment, the growth substrate 121a may include a substrate of the same type as that of the upper first conductivity type semiconductor layer 121b, such as a gallium nitride substrate. When the growth substrate 121a is a nitride-based substrate, the growth substrate 121a may include a single crystal nitride-based semiconductor. The growth substrate 121a may be n-type doped including an n-type dopant, or may be formed in an undoped state without including a dopant. However, since the nitride-based semiconductor has an n-type conductivity even in an undoped state due to its own defects such as a nitrogen vacancy, the growth substrate 121a in an undoped state also has an n-type conductivity. Accordingly, the undoped growth substrate 121a may have the same conductivity type as the n-type doped upper first conductivity type semiconductor layer 121b.

The semiconductor layers of the light emitting structure 120 may be grown from the growth substrate 121a. Accordingly, as will be described later, the growth surfaces of the semiconductor layers of the light emitting structure 120 may all be the same. Meanwhile, the growth substrate 121a is separated from the upper first conductivity type semiconductor layer 121b after growth of the upper first conductivity type semiconductor layer 121b, the active layer 123 and the second conductivity type semiconductor layer 125 . / or may be removed.

The light emitting structure 120 has a non-polar or semi-polar growth surface. Accordingly, the first conductivity-type semiconductor layer 121 , the active layer 123 , and the second conductivity-type semiconductor layer 123 may have non-polar or semi-polar growth surfaces. In particular, the upper surface of the second conductivity type semiconductor layer 123 includes a non-polar or semi-polar surface. Accordingly, separation of energy bands generated in the process of combining electrons and holes in the light emitting structure 120 is reduced. Specifically, the growth surface of the semiconductor layers of the light emitting structure 120 is a non-polar or semi-polar surface such as an a-plane or an m-plane (eg, {20-2-1} or {30-3-1}, etc.) can be The non-polar or semi-polar growth surface of the semiconductor layers of the light emitting structure 120 is an upper first conductivity type semiconductor layer 121 b and an active layer 123 on a growth substrate 121 a having a non-polar or semi-polar growth surface. and growing the second conductivity-type semiconductor layer 125 .

In addition, the upper surface of the growth substrate 121a, that is, the growth surface of the growth substrate 121a may have a predetermined off-cut angle. For example, when the growth substrate 121a has an m-plane growth plane, the c-direction (<0001> family direction) and/or a-direction (<11-20> family direction) with respect to the m-plane It may have a predetermined off-cut angle. In this case, the c-direction and the a-direction are directions perpendicular to the c-plane and the a-plane, respectively. The offcut angle is not limited, but may be, for example, an angle within the range of -10° to +10°. The growth plane with an off-cut angle may also be a non-polar or semi-polar plane. A fine step is formed on the surface of the growth plane (eg, m-plane) having an off-cut angle, and another crystal plane (eg, c-plane) may be exposed on the side of the step. When the nitride semiconductor is grown in the vapor phase on the growth substrate 121a, the bonding energy at the step surface is high, so that the growth of the semiconductor layer is promoted. Accordingly, the growth rate of the nitride semiconductor layer may be increased by adjusting the offcut angle of the surface of the growth substrate 121a.

In this specification, the 'specific growth plane' is described as including a case in which a predetermined off-cut angle is formed from the specific growth plane.

Meanwhile, the thickness T of the growth substrate 121a may be greater than or equal to a predetermined value. The thickness T of the growth substrate 121a may be about 100 μm or more, and may have a thickness within a range of about 200 μm to 500 μm, and further, a thickness within a range of about 270 μm to 330 μm. Since the thickness T of the growth substrate 121a is formed to the above-described thickness, the luminous efficiency of the light emitting device may be improved. In addition, when the growth substrate 121a is a gallium nitride-based substrate, the thickness T of the growth substrate 121a is formed to be greater than or equal to the predetermined value, thereby improving the heat dissipation efficiency and heat distribution efficiency to improve the junction temperature ( T _j , junction temperature) can be lowered. Accordingly, the light emitting power and reliability of the light emitting device are improved.

On the other hand, in this embodiment, the light emitting structure 120 includes a semi-polar or non-polar homogeneous nitride-based substrate, or is described as grown from a semi-polar or non-polar homogeneous nitride-based substrate, but the present invention is not limited thereto no. If the light emitting structure 120 is a substrate on which the light emitting structure 120 can be grown so as to have a semi-polar or non-polar growth surface, the present invention is not limited to the same type of substrate. Furthermore, when the heterogeneous substrate is used as the growth substrate, it may be separated and removed from the light emitting structure 120 after the growth of the light emitting structure 120 is completed. At this time, even when the growth substrate is separated from the light emitting structure 120 , the thickness of the first conductivity-type semiconductor layer 121 grown and formed on the heterogeneous substrate is formed to a thickness greater than or equal to the thickness T of the growth substrate 121a. By doing so, the effect of increasing the light emitting power according to the thickness of the growth substrate 121a may be similarly realized.

Referring back to FIG. 1 , the light emitting structure 120 may include a region in which the upper surface of the first conductivity type semiconductor layer 121 is partially exposed. The region in which the upper surface of the first conductivity-type semiconductor layer 121 is partially exposed may be provided by partially removing the second conductivity-type semiconductor layer 125 and the active layer 123 . As illustrated, a top surface of the first conductivity type semiconductor layer 121 may be partially exposed through a hole passing through the second conductivity type semiconductor layer 125 and the active layer 123 . The hole may have an inclined side surface. A plurality of holes may be formed, and the shape and arrangement of the holes are not limited to the illustrated ones. In addition, in the region where the first conductivity-type semiconductor layer 121 is partially exposed, the second conductivity-type semiconductor layer 125 and the active layer 125 and the active layer ( 123) may be provided.

In addition, the light emitting structure 120 may further include a roughened surface formed by increasing the roughness of the lower surface thereof. The roughened surface may be formed using at least one of wet etching, dry etching, and electrochemical etching, for example, PEC etching or an etching method using an etching solution containing KOH and NaOH. can be Accordingly, the light emitting structure 120 may include protrusions and/or concave portions in a μm to nm scale formed on the lower surface of the first conductivity type semiconductor layer 121 . Light extraction efficiency of light emitted from the light emitting structure 120 may be improved by the roughened surface.

The second contact electrode 140 is positioned on the second conductivity-type semiconductor layer 125 and is in ohmic contact with the second conductivity-type semiconductor layer 125 . The second contact electrode 140 includes a conductive oxide layer 141 and a reflective electrode layer 143 disposed on the conductive oxide layer 141 . In this case, the conductive oxide layer 141 may be in contact with the second conductivity type semiconductor layer 125 , and may be in ohmic contact with the second conductivity type semiconductor layer 125 having a non-polar or semi-polar growth surface. The reflective electrode layer 143 is disposed on the conductive oxide layer 141 , and an area of the reflective electrode layer 143 may be smaller than an area of the conductive oxide layer 141 . Accordingly, the reflective electrode layer 143 may be located in an outer edge region of the conductive oxide layer 141 .

The conductive oxide layer 141 may include ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, IrOx, RuOx, RuOx/ITO, MgO, ZnO, and the like, and in particular, may be formed of ITO. In this case, the contact resistance between the conductive oxide layer 141 and the second conductivity type semiconductor layer 125 may be lower than the contact resistance between the metal (eg, Ag) and the second conductivity type semiconductor layer 125 . Although the thickness of the conductive oxide layer 141 is not limited, the contact resistance between the second contact electrode 140 and the second conductivity-type semiconductor layer 125 may be low, and the thickness of the conductive oxide layer 141 may be optimized at a level that does not significantly decrease the luminous efficiency. For example, the thickness of the conductive oxide layer 141 may be in the range of about 50 Å to 400 Å, in particular, the conductive oxide layer 141 may be formed of ITO having a thickness in the range of 50 Å to 150 Å. However, the present invention is not limited thereto.

The reflective electrode layer 143 may include a metal material having high reflectivity to light, and the metal material may be variously selected and applied according to the emission wavelength of the light emitting device. The reflective electrode layer 143 may include a reflective layer and a cover layer covering the reflective layer. For example, the reflective layer may include at least one of Ni, Pt, Pd, Rh, W, Ti, Al, Mg, Ag, and Au. The reflective layer may be formed through sputtering, electron beam deposition, or the like. For example, when the reflective layer is formed through sputtering, the reflective layer may be formed in such a way that the thickness decreases from the peripheral portion of the outer edge toward the edge. In addition, the reflective layer may include a single layer or multiple layers. The cover layer may prevent mutual diffusion between the reflective layer and other materials, and may prevent other materials from diffusing into the reflective layer from damaging the reflective layer. The cover layer may include, for example, Au, Ni, Ti, Cr, or the like, and may include a single layer or multiple layers.

The second conductivity-type semiconductor layer 125 has a non-polar or semi-polar growth surface, and the p-type nitride-based semiconductor layer having a non-polar or semi-polar growth surface does not form well ohmic contact with a metal material, or ohmic contact Even if this is formed, the contact resistance is high. According to the present embodiment, the second contact electrode 140 includes the conductive oxide layer 141 in contact with the second conductivity type semiconductor layer 125 , and has a non-polar or semi-polar growth surface. An ohmic contact having a low contact resistance may also be formed with respect to the layer 125 . In addition, since the reflective electrode layer 143 does not need to form a direct ohmic contact with the second conductivity-type semiconductor layer 125 , heat treatment is performed so that the reflective electrode layer 143 can make ohmic contact with the second conductivity-type semiconductor layer 125 . The process of performing may be omitted. Accordingly, it is possible to prevent the reflective electrode layer 143 from being damaged during the heat treatment process and thereby reducing the reflectance.

In addition, the second contact electrode 140 may at least partially cover the upper surface of the second conductivity-type semiconductor layer 125 , and further, may be disposed to entirely cover the upper surface of the second conductivity-type semiconductor layer 125 . have. In addition, the light emitting structure 120 may be formed to cover the upper surface of the second conductivity type semiconductor layer 125 as a single body in the remaining regions except for the position where the exposed region of the first conductivity type semiconductor layer 121 is formed. Accordingly, current may be uniformly supplied to the entire light emitting structure 120 , and current dispersion efficiency may be improved. However, the present invention is not limited thereto, and the second contact electrode 140 may include a plurality of unit electrodes.

In particular, the conductive oxide layer 141 of the second contact electrode 140 may cover almost the entire upper surface of the second conductivity-type semiconductor layer 125 . For example, the conductive oxide layer 141 may cover 90% or more of the upper surface of the second conductivity-type semiconductor layer 125 . After the conductive oxide layer 141 is formed on the upper surface of the light emitting structure 120 after the light emitting structure 120 is formed, the second conductivity type semiconductor layer ( 125) and the active layer 123 may be etched simultaneously. On the other hand, when the metal contact electrode is formed on the second conductivity-type semiconductor layer 125 by deposition or plating, the second conductivity-type semiconductor layer 125 is formed from the outer edge of the upper surface 125 due to the process margin of the mask. The contact electrode may be formed only in a region spaced apart by a predetermined distance. Accordingly, when the conductive oxide layer 141 is formed as a portion for forming the ohmic contact of the second contact electrode 140 , the contact electrode and the second conductivity type semiconductor layer 125 are compared to the case where the contact electrode is formed of a metal material. It is possible to reduce the distance to the outer edge of the upper surface of the As the contact area between the second conductivity-type semiconductor layer 125 and the second contact electrode 140 is relatively increased, the forward voltage V _f of the light emitting device may decrease. In addition, since the conductive oxide layer 141 may be located closer to the edge of the second conductivity-type semiconductor layer 125 than the metal material, the second contact electrode 140 and the second conductivity-type semiconductor layer 125 are The shortest distance from the contacting portion to the contacting portion of the first contact electrode 130 and the first conductivity-type semiconductor layer 121 is also reduced, so that the forward voltage V _f of the light emitting device may be further reduced.

However, the present invention is not limited thereto, and as shown in FIG. 2 , the reflective electrode layer 143 may be formed to cover the side surface of the conductive oxide layer 141 . Since the light emitting device of FIG. 2 is substantially the same as the light emitting device of FIG. 1 in other configurations except for the shape of the second contact electrode 140 , a detailed description thereof will be omitted.

Referring back to FIG. 1 , the insulating layers 150 and 160 insulate the first contact electrode 130 and the second contact electrode 140 from each other. The insulating layers 150 and 160 are positioned on the light emitting structure 120 and may partially cover the first and second contact electrodes 130 and 140 . In addition, the insulating layers 150 and 160 may include a first insulating layer 150 and a second insulating layer 160 . Hereinafter, the first insulating layer 150 will be described first, and the contents related to the second insulating layer 160 will be described later.

The first insulating layer 150 may partially cover the upper surface of the light emitting structure 120 and the second contact electrode 140 . In addition, the first insulating layer 150 may cover a side surface of the hole partially exposing the first conductivity type semiconductor layer 121 , and at least partially expose the first conductivity type semiconductor layer 121 exposed to the hole. . The first insulating layer 150 may include an opening positioned at a portion corresponding to the hole and an opening exposing a portion of the second contact electrode 140 . The first conductivity-type semiconductor layer 121 and the second contact electrode 140 may be partially exposed through the openings. In particular, a portion of the reflective electrode layer 143 of the second contact electrode 140 may be exposed.

The first insulating layer 150 may include an insulating material, for example, SiO ₂ , SiN _x , MgF _{2 ,} or the like. Furthermore, the first insulating layer 150 may include multiple layers, and may include a distributed Bragg reflector in which materials having different refractive indices are alternately stacked.

Furthermore, unlike illustrated, the first insulating layer 150 may further cover at least a portion of the side surface of the light emitting structure 120 . The degree to which the first insulating layer 150 covers the side surface of the light emitting structure 120 may vary depending on whether chip unit isolation is performed in the manufacturing process of the light emitting device. That is, as in the present embodiment, the first insulating layer 150 may be formed to cover only the upper surface of the light emitting structure 120 . In contrast, after individualizing the wafer into chip units in the manufacturing process of the light emitting device, the first insulating layer 150 is When the layer 150 is formed, the first insulating layer 150 may cover the side surface of the light emitting structure 120 .

Meanwhile, the first insulating layer 150 may include a pre-insulation layer 150a and a main insulation layer 150b. In the process of forming the first insulating layer 150 , the preliminary insulating layer 150a may be formed before the main insulating layer 150a , and thus the preliminary insulating layer 150a is formed below the first insulating layer 150 . can be located

Specifically, the preliminary insulating layer 150a may cover a portion of the light emitting structure 120 , and further, may cover a portion of an upper surface of the second contact electrode 140 and a side surface of the second contact electrode 140 . In this case, the preliminary insulating layer 150a may cover a portion of the side and top surfaces of the conductive oxide layer 141 of the second contact electrode 140 , and the preliminary insulating layer 150a exposes a portion of the conductive oxide layer 141 . It has an opening that allows A reflective electrode layer 143 may be formed on the conductive oxide layer 141 exposed in the opening. In this case, the reflective electrode layer 143 may be spaced apart from the preliminary insulating layer 150a and may not contact each other, but the preliminary insulating layer 150a and the reflective electrode layer 143 may contact each other depending on the formation process of the reflective electrode layer 143 . The main insulating layer 150b is positioned on the preliminary insulating layer 150a and further partially covers the reflective electrode layer 143 . When the reflective electrode layer 143 does not contact the preliminary insulating layer 150a, the preliminary insulating layer 150a is not interposed between the reflective electrode layer 143 and the main insulating layer 150b.

The preliminary insulating layer 150a and the main insulating layer 150b may be formed of the same material and may include _{, for example, SiO 2 .} The preliminary insulating layer 150a may be formed to have a thickness greater than that of the conductive oxide layer 141 .

The preliminary insulating layer 150a may be formed during the formation of the second contact electrode 140 . For example, the conductive oxide layer 141 is formed on the second conductivity type semiconductor layer 125 , and the preliminary insulating layer 150a is formed before the reflective electrode layer 143 is formed. In this case, it may be formed to a thickness of about 1000 Å. The preliminary insulating layer 150a is formed to cover the side surface of the hole to which the first conductivity type semiconductor layer 121 is exposed and a portion of the conductive oxide layer 141 . In this case, the preliminary insulating layer 150a partially covers the conductive oxide layer 141 except for a region in which the second contact electrode 143 is formed on the conductive oxide layer 141 to form the conductive oxide layer 141 . An opening partly exposed is formed. Thereafter, the reflective electrode layer 143 is formed in the opening through which the conductive oxide layer 141 is exposed. The reflective electrode layer 143 may be spaced apart from the preliminary insulating layer 150a or may be bonded. By forming the preliminary insulating layer 150a before the formation of the reflective electrode layer 143 as described above, the light reflectance and resistance increase of the reflective electrode layer 143 by material diffusion between the reflective electrode layer 143 and the light emitting structure 120 are reduced. can be prevented Next, after forming the reflective electrode layer 143 on the conductive oxide layer 141 , the primary insulating layer 150b partially covering the reflective electrode layer 143 is formed on the preliminary insulating layer 150a to form the first insulation A layer 150 may be formed.

Meanwhile, as in the embodiment of FIG. 2 , when the reflective electrode layer 143 ′ is formed to cover the conductive oxide layer 141 ′, the preliminary insulating layer 150a does not partially cover the conductive oxide layer 141 ′. , may be formed only on the light emitting structure 120 .

The first contact electrode 130 may partially cover the light emitting structure 120 . Also, the first contact electrode 130 is in ohmic contact with the first conductivity type semiconductor layer 121 through the partially exposed surface of the first conductivity type semiconductor layer 121 . As in the present embodiment, when the region where the first conductivity-type semiconductor layer 121 is exposed is formed in the shape of a hole, the first conductivity is formed through the opening of the first insulating layer 150 positioned at a portion corresponding to the hole. It is in ohmic contact with the type semiconductor layer 121 . In addition, the first contact electrode 130 may be formed to entirely cover a portion other than a partial region of the first insulating layer 150 . Accordingly, light may be reflected through the first contact electrode 130 . Also, the first contact electrode 130 may be spaced apart from the second contact electrode 140 by the first insulating layer 150 to be electrically insulated.

Since the first contact electrode 130 is formed to entirely cover the upper surface of the light emitting structure 120 except for a partial region, current dissipation efficiency may be further improved. In addition, since the first contact electrode 130 may cover a portion not covered by the second contact electrode 140 , light may be reflected more effectively to improve the luminous efficiency of the light emitting device.

As described above, the first contact electrode 130 may make an ohmic contact with the first conductivity type semiconductor layer 121 and may serve to reflect light. Accordingly, the first contact electrode 130 may include a highly reflective metal layer such as an Al layer. In this case, the first contact electrode 130 may be formed of a single layer or multiple layers. The highly reflective metal layer may be formed on an adhesive layer such as Ti, Cr, or Ni. However, the present invention is not limited thereto, and the first contact electrode 130 may include at least one of Ni, Pt, Pd, Rh, W, Ti, Al, Mg, Ag, and Au.

Also, unlike illustrated, the first contact electrode 130 may be formed to cover the side surface of the light emitting structure 120 . When the first contact electrode 130 is also formed on the side surface of the light emitting structure 120 , the light emitted from the side surface from the active layer 123 is reflected upward to increase the ratio of light emitted to the upper surface of the light emitting device. When the first contact electrode 130 is formed to cover the side surface of the light emitting structure 120 , the first insulating layer 150 may be interposed between the side surface of the light emitting structure 120 and the first contact electrode 130 . have.

Meanwhile, the light emitting device may further include a connection electrode 145 . The connection electrode 145 may be positioned on the second contact electrode 140 , and may be electrically connected to the second contact electrode 140 through the opening of the first insulating layer 150 . Furthermore, the connection electrode 145 may electrically connect the second contact electrode 140 and the second pad electrode 173 to each other. In addition, the connection electrode 145 may be formed to partially cover the first insulating layer 150 , and may be spaced apart from each other and insulated from the first contact electrode 130 . The upper surface of the connection electrode 145 may be formed to have substantially the same height as the upper surface of the first contact electrode 130 . Also, the connection electrode 145 may be formed in the same process as the first contact electrode 130 , and the connection electrode 145 and the first contact electrode 130 may include the same material. However, the present invention is not limited thereto, and the connection electrode 145 and the first contact electrode 130 may include different materials.

The second insulating layer 160 may partially cover the first contact electrode 130 , and may form a first opening 160a partially exposing the first contact electrode 130 and a second contact electrode 140 . A second opening 160b partially exposed may be included. One or more of the first and second openings 160a and 160b may be formed.

The second insulating layer 160 may include an insulating material, for example, SiO ₂ , SiN _x , MgF ₂ . Furthermore, the second insulating layer 160 may include multiple layers, and may include a distributed Bragg reflector in which materials having different refractive indices are alternately stacked. When the second insulating layer 160 is formed of multiple layers, the uppermost layer of the second insulating layer 160 may be formed _{of SiN x .} Since the uppermost layer of the second insulating layer 160 _{is formed of SiN x} , it is possible to more effectively prevent moisture from penetrating into the light emitting structure 120 . Alternatively, the second insulating layer 160 may be formed of a single SiNx layer. When the first insulating layer 150 _{is formed of SiO 2} and the second insulating layer 160 is formed of SiNx, the light emitting device It is possible to improve the luminous efficiency and at the same time improve reliability. Since _{the first insulating layer 150 formed of SiO 2} is positioned under the first contact electrode 130 , the light reflection efficiency through the first contact electrode 130 and the second contact electrode 140 can be maximized. At the same time, it is possible to efficiently protect the light emitting device from external moisture through the second insulating layer 160 formed of SiNx.

Meanwhile, the thickness of the first insulating layer 150 may be greater than the thickness of the second insulating layer 160 . The first insulating layer 150 may be formed to have a thickness greater than that of the second insulating layer 160 by being formed in two steps including the preliminary insulating layer 150a. In this case, the thickness of the main insulating layer 150b of the first insulating layer 150 may be substantially the same as the thickness of the second insulating layer 160 , but the present invention is not limited thereto.

The first and second pad electrodes 171 and 173 are positioned on the light emitting structure 120 . The first and second pad electrodes 171 and 173 may be electrically connected to the first and second contact electrodes 130 and 140 through the first and second openings 160a and 160b, respectively. The first and second pad electrodes 171 and 173 may serve to supply external power to the light emitting structure 120 .

The first and second pad electrodes 171 and 173 may be formed together in the same process, for example, by using a photolithography and etching technique or a lift-off technique. The first and second pad electrodes 171 and 173 may be formed of a single layer or multiple layers, for example, an adhesive layer such as Ti, Cr, Ni and a high-conductivity metal layer such as Al, Cu, Ag or Au. may include

According to the present embodiment, there is provided a light emitting device including a light emitting structure 120 having a non-polar or semi-polar growth surface and a conductive oxide layer 141 in ohmic contact with the light emitting structure 120 . Accordingly, the horizontal direction current dissipation efficiency is high during high current driving, the forward voltage (V _f ) is relatively low due to low contact resistance between the contact electrode and the semiconductor layers, and the current dissipation efficiency including the nitride-based growth substrate having a predetermined thickness or more and a light emitting device having improved light emitting power due to excellent heat distribution efficiency.

3A and 3B are plan views and cross-sectional views illustrating a light emitting device according to another embodiment of the present invention. 3A (a) is a plan view of the light emitting device of the present embodiment, (b) is the position of the mesa (M) and a contact region in which the first conductivity-type semiconductor layer 121 and the first contact electrode 130 are in ohmic contact. It is a top view which shows 120a. FIG. 3B shows a cross-section of a portion corresponding to line B-B' of FIG. 3A.

Compared to the light emitting device of FIG. 1 in the light emitting device of FIGS. 3A and 3B , the light emitting structure 120 has a plurality of mesas M and the first conductivity type semiconductor layer 121 formed around the mesa M is exposed. There is a difference in that it includes an area where the light emitting structure 120 is formed, and there is a difference in the arrangement of other components according to the structure of the light emitting structure 120 . Hereinafter, the light emitting device of the present embodiment will be described with a focus on the differences, and a detailed description of the overlapping configuration will be omitted.

First, referring to FIGS. 3A and 3B , the light emitting device includes a light emitting structure 120 , a first contact electrode 130 , a second contact electrode 140 , and insulating layers 150 and 160 . In addition, the light emitting device may further include a connection electrode 145 , a first pad electrode 171 , and a second pad electrode 173 .

The light emitting structure 120 includes a first conductivity type semiconductor layer 121 , an active layer 123 located on the first conductivity type semiconductor layer 121 , and a second conductivity type semiconductor layer ( 125) may be included. Meanwhile, the first conductivity type semiconductor layer 121 may include a growth substrate 121a and an upper first conductivity type semiconductor layer 121b positioned on the growth substrate 121a. Meanwhile, the thickness T of the growth substrate 121a may be greater than or equal to a predetermined value. The thickness T of the growth substrate 121a may be greater than or equal to a predetermined value. The thickness T of the growth substrate 121a may be about 100 μm or more, and may have a thickness within a range of about 200 μm to 500 μm, and further, a thickness within a range of about 270 μm to 330 μm. The semiconductor layers of the light emitting structure 120 have non-polar or semi-polar growth surfaces.

In addition, the light emitting structure 120 includes a plurality of mesa M including the second conductivity type semiconductor layer 125 and the active layer 123 . The plurality of mesa M may have inclined side surfaces and may be formed through a patterning process of the light emitting structure 120 . In addition, each mesa M may further include a portion of the first conductivity type semiconductor layer 121 . The plurality of mesa M may be disposed on the first conductivity-type semiconductor layer 121 in various shapes, and, for example, may have an elongated shape that is spaced apart from each other as illustrated and extends substantially parallel to each other in one direction. can However, the shape of the mesa M is not limited thereto. Exposed regions of the first conductivity-type semiconductor layer 121 are formed around the plurality of mesas M.

The second contact electrode 140 is positioned on the plurality of mesas M, and is in ohmic contact with the second conductivity-type semiconductor layer 125 . The second contact electrode 140 includes a conductive oxide layer 141 and a reflective electrode layer 143 disposed on the conductive oxide layer 141 . The reflective electrode layer 143 is disposed on the conductive oxide layer 141 , and an area of the reflective electrode layer 143 may be smaller than an area of the conductive oxide layer 141 . Accordingly, the reflective electrode layer 143 may be located in an outer edge region of the conductive oxide layer 141 . Alternatively, the reflective electrode layer 143 may be formed to cover the side surface of the conductive oxide layer 141 .

The insulating layers 150 and 160 insulate the first contact electrode 130 and the second contact electrode 140 from each other. The insulating layers 150 and 160 are positioned on the light emitting structure 120 and may partially cover the first and second contact electrodes 130 and 140 . In addition, the insulating layers 150 and 160 may include a first insulating layer 150 and a second insulating layer 160 .

The first insulating layer 150 partially covers the upper surface of the light emitting structure 120 and the second contact electrode 140 , and the first insulating layer 150 covers the side surface of the mesa M. Furthermore, the first insulating layer 150 may partially cover a region partially exposing the first conductivity type semiconductor layer 121 , and may expose a portion of the first conductivity type semiconductor layer 121 . That is, the first insulating layer 150 may include openings exposing a portion of the first conductivity-type semiconductor layer 121 and a portion of the second contact electrode 140 .

A partial region of the first conductivity-type semiconductor layer 121 exposed by the opening of the first insulating layer 150 may be in ohmic contact with the first contact electrode 130 and may be defined as the contact region 120a. can The contact area 120a may be located around the plurality of mesas M, and for example, may have an elongated shape extending along the extending direction of the mesas M. As shown in FIG. Also, mesa M may be positioned between the contact regions 120a.

The first insulating layer 150 may include a preliminary insulating layer 150a and a main insulating layer 150b, and the preliminary insulating layer 150a may partially cover the light emitting structure 120 and the conductive oxide layer 141 . can

The first contact electrode 130 may be positioned on the first insulating layer 150 and may partially cover the light emitting structure 120 . In addition, the first contact electrode 130 is in ohmic contact with the first conductivity type semiconductor layer 121 through the partially exposed surface of the first conductivity type semiconductor layer 121 , that is, the contact region 120a. Since the first contact electrode 130 is formed to entirely cover the upper surface of the light emitting structure 120 except for a partial region, current dissipation efficiency may be further improved. Also, unlike illustrated, the first contact electrode 130 may be formed to cover the side surface of the light emitting structure 120 .

Meanwhile, the light emitting device may further include a connection electrode (not shown). The connection electrode may be positioned on the second contact electrode 140 , and may be electrically connected to the second contact electrode 140 through the opening of the first insulating layer 150 . The upper surface of the connection electrode may be formed to have substantially the same height as the upper surface of the first contact electrode 130 . Also, the connection electrode 145 may be formed in the same process as the first contact electrode 130 , and the connection electrode 145 and the first contact electrode 130 may include the same material.

The second insulating layer 160 may partially cover the first contact electrode 130 , and may form a first opening 160a partially exposing the first contact electrode 130 and a second contact electrode 140 . A second opening 160b partially exposed may be included. One or more of each of the first and second openings 160a and 160b may be formed, and the second opening 160b may be located on the mesa M.

The first and second pad electrodes 171 and 173 may be electrically connected to the first and second contact electrodes 130 and 140 through the first and second openings 160a and 160b, respectively. The first and second pad electrodes 171 and 173 may be formed together in the same process, for example, by using a photolithography and etching technique or a lift-off technique. The first and second pad electrodes 171 and 173 may be formed of a single layer or multiple layers, for example, an adhesive layer such as Ti, Cr, Ni and a high-conductivity metal layer such as Al, Cu, Ag or Au. may include

Hereinafter, a method for manufacturing the light emitting device of this embodiment will be described. The manufacturing method of the light emitting device described below is provided to help the understanding of the present invention, but the present invention is not limited thereto.

First, the light emitting structure 120 is formed by growing the first conductivity type semiconductor layer 121 , the active layer 123 , and the second conductivity type semiconductor layer 125 on the growth substrate 121a using a method such as MOCVD. do. Next, a conductive oxide layer 141 including ITO is formed on the light emitting structure 120 by using a method such as electron beam deposition or sputtering. A mask is formed on the conductive oxide layer 141 , and portions of the conductive oxide layer 141 and the light emitting structure 120 are etched using the mask to form a plurality of mesas M . Accordingly, the outer edge of the conductive oxide 141 may be formed to substantially coincide with the outer edge of the upper surface of the mesa M. Next, the reflective electrode layer 143 is formed on the conductive oxide layer 141 to form the second contact electrode 140 , and the first insulating layer 150 covering the light emitting structure 120 and the second contact electrode 140 . ) to form In this case, when the first insulating layer 150 includes the preliminary insulating layer 150a and the main insulating layer 150b, the second contact electrode 140 and the first insulating layer 150 forming process are performed as described above. can be merged Next, the first insulating layer 150 is patterned to expose the contact region 120a partially exposing the first conductivity-type semiconductor layer 121 and a portion of the second contact electrode 140 . Next, the first contact electrode 130 is formed on the first insulating layer 150 by using a method such as plating or deposition. After forming the first contact electrode 130 , a second insulating layer 160 covering the entire first contact electrode 130 is formed, and the second insulating layer 160 is patterned to form first and second openings 160a; 160b). Thereafter, the light emitting device of FIGS. 3A and 3B may be provided by forming the first and second pad electrodes 171 and 173 on the openings 160a and 160b.

According to the present embodiment, by forming the plurality of mesas M and the contact regions 120a positioned around the mesas, current can be more effectively distributed in the horizontal direction during high current driving.

4A and 4B are plan views and cross-sectional views illustrating a light emitting device according to another embodiment of the present invention.

4A and 4B are plan views and cross-sectional views illustrating a light emitting device according to another embodiment of the present invention. 4A (a) is a plan view of the light emitting device of this embodiment, (b) is the position of the mesa (M) and a contact region in which the first conductivity-type semiconductor layer 121 and the first contact electrode 130 are in ohmic contact. It is a top view which shows 120a. FIG. 4B shows a cross-section of a portion corresponding to the line C-C' of FIG. 4A.

Compared to the light emitting device of FIGS. 3A and 3B , the light emitting device of FIGS. 4A and 4B omits the second insulating layer 160 and the first and second pad electrodes 171 and 173 are omitted. There are differences in points. Hereinafter, the light emitting device of the present embodiment will be described with a focus on the differences, and a detailed description of the overlapping configuration will be omitted.

First, referring to FIGS. 4A and 4B , the light emitting device includes a light emitting structure 120 , a first contact electrode 130 , a second contact electrode 140 , a first insulating layer 150 , and a connection electrode 145 . includes

The first insulating layer 150 partially covers the upper surface of the light emitting structure 120 and the second contact electrode 140 , and the first insulating layer 150 covers the side surface of the mesa M. Furthermore, the first insulating layer 150 may partially cover a region partially exposing the first conductivity type semiconductor layer 121 , and may expose a portion of the first conductivity type semiconductor layer 121 . That is, the first insulating layer 150 may include openings exposing a portion of the first conductivity-type semiconductor layer 121 and a portion of the second contact electrode 140 . A partial region of the first conductivity-type semiconductor layer 121 exposed by the opening of the first insulating layer 150 may be in ohmic contact with the first contact electrode 130 and may be defined as the contact region 120a. can The first insulating layer 150 may include a preliminary insulating layer 150a , and the preliminary insulating layer 150a may partially cover the light emitting structure 120 and the conductive oxide layer 141 .

In this case, the first insulating layer 150 forms a partial region of the first conductivity-type semiconductor layer 121 , that is, the first opening 150a exposing the contact region 120a and a partial region of the second contact electrode 140 . A second opening 150b to expose may be included. When the light emitting structure 120 is divided into at least two regions, the first opening 150a and the second opening 150b may be located in different regions.

For example, a plurality of second openings 150b may be positioned on each of the mesas M, and the second openings 150b may be positioned to be biased toward one side of the light emitting structure 120 . . Conversely, the first opening 150a may be located around the relatively long side of the mesas M, but may be biased toward the other side of the light emitting structure 120 opposite to the one side. When the light emitting structure 120 is divided into a first region R1 and a second region R2 based on an imaginary line I defined in a direction perpendicular to the direction in which the mesa M is extended, the first opening ( 150a ) may be located in the first region R1 , and the second openings 150b may be located in the second region R1 . In this case, the first and second regions R1 and R2 do not overlap each other. Accordingly, the first opening 150a and the second opening 150b may not be located in the same area, but may be located in different areas.

The first contact electrode 130 may be positioned on the first insulating layer 150 and may partially cover the light emitting structure 120 . In addition, the first contact electrode 130 is in ohmic contact with the first conductivity type semiconductor layer 121 through the partially exposed surface of the first conductivity type semiconductor layer 121 , that is, the contact region 120a. Meanwhile, the connection electrode 145 may be positioned on the second contact electrode 140 , and may be electrically connected to the second contact electrode 140 through the opening of the first insulating layer 150 . The upper surface of the connection electrode 145 may be formed to have substantially the same height as the upper surface of the first contact electrode 130 . Also, the connection electrode 145 may be formed in the same process as the first contact electrode 130 , and the connection electrode 145 and the first contact electrode 130 may include the same material.

In this case, when the light emitting structure 120 is divided into at least two regions, the first contact electrode 130 and the connection electrode 145 may be located in different regions. For example, as illustrated, the first contact electrode 130 may be located in the first region R1 , the connection electrode 145 may be located in the second region R2 , and the first contact electrode 130 and the connection electrode 145 are spaced apart from each other. As described above, since the first contact electrode 130 and the connection electrode 145 are formed to be spaced apart from each other in different regions, the first contact electrode 130 and the connection electrode 145 are respectively separated from the pad electrodes in the light emitting device. can play the same role. Accordingly, the first contact electrode 130 serves to make an ohmic contact with the first conductivity-type semiconductor layer 121 , and may serve as the first pad electrode, and the connection electrode 145 may make a second contact. It may be electrically connected to the electrode 140 to correspond to the second pad electrode.

Hereinafter, a method for manufacturing the light emitting device of this embodiment will be described. The manufacturing method of the light emitting device described below is provided to help the understanding of the present invention, but the present invention is not limited thereto.

First, the light emitting structure 120 is formed by growing the first conductivity type semiconductor layer 121 , the active layer 123 , and the second conductivity type semiconductor layer 125 on the growth substrate 121a using a method such as MOCVD. do. Next, a conductive oxide layer 141 including ITO is formed on the light emitting structure 120 by using a method such as electron beam deposition or sputtering. A mask is formed on the conductive oxide layer 141 , and portions of the conductive oxide layer 141 and the light emitting structure 120 are etched using the mask to form a plurality of mesas M . Accordingly, the outer edge of the conductive oxide 141 may be formed to substantially coincide with the outer edge of the upper surface of the mesa M. Next, the reflective electrode layer 143 is formed on the conductive oxide layer 141 to form the second contact electrode 140 , and the first insulating layer 150 covering the light emitting structure 120 and the second contact electrode 140 . ) to form In this case, when the first insulating layer 150 includes the preliminary insulating layer 150a and the main insulating layer 150b, the second contact electrode 140 and the first insulating layer 150 forming process are performed as described above. can be merged Next, the first opening 150a exposing the contact region 120a of the first conductivity-type semiconductor layer 121 and a second contact electrode 140 partially exposing the first insulating layer 150 are patterned. 2 An opening 150b is formed. Next, the first contact electrode 130 and the connection electrode 145 are formed on the first insulating layer 150 by using a method such as plating or deposition. In this case, by forming the first contact electrode 130 and the connection electrode 145 to be spaced apart from each other, the light emitting device of FIGS. 4A and 4B may be provided.

According to the present embodiment, the manufacturing process of the second insulating layer and the first and second pad electrodes is omitted, so that the manufacturing process of the light emitting device can be simplified, and in particular, the number of masks required for the process can be reduced.

5A and 5B are plan views and cross-sectional views illustrating a light emitting device according to another embodiment of the present invention.

5A and 5B are plan views and cross-sectional views illustrating a light emitting device according to another embodiment of the present invention. 5A (a) is a plan view of the light emitting device of this embodiment, (b) is the position of the mesa (M) and the contact region in which the first conductivity-type semiconductor layer 121 and the first contact electrode 130 are in ohmic contact. It is a top view which shows 120a. FIG. 5B shows a cross-section of a portion corresponding to the line D-D' of FIG. 5A.

The light emitting device of FIGS. 5A and 5B is different from the light emitting device of FIGS. 4A and 4B in that it further includes a first pad electrode 181 and a second pad electrode 183 . Hereinafter, the light emitting device of the present embodiment will be described with a focus on the differences, and a detailed description of the overlapping configuration will be omitted.

First, referring to FIGS. 5A and 5B , the light emitting device includes a light emitting structure 120 , a first contact electrode 130 , a second contact electrode 140 , a first insulating layer 150 , and first and second It includes pad electrodes 181 and 183 .

The first contact electrode 130 is in ohmic contact with the first conductivity-type semiconductor layer 121 through the contact region 120a. The first contact electrode 130 is positioned on the first conductivity-type semiconductor layer 121 and is positioned in a region between the mesa M. Accordingly, in the light emitting device of this embodiment, the first contact electrode 130 is not positioned on the mesa M, unlike the light emitting devices of the other embodiments described above.

The first pad electrode 181 may be positioned on the first insulating layer 150 and may partially cover the light emitting structure 120 . Also, the first pad electrode 181 may partially cover the mesas M, and may be electrically connected to the first contact electrode 130 positioned on the contact region 120a. The second pad electrode 183 may be positioned on the second contact electrode 140 , and may be electrically connected to the second contact electrode 140 through the second opening 150b of the first insulating layer 150 . have. The top surface of the second pad electrode 183 may be formed to have substantially the same height as the top surface of the first pad electrode 183 . Also, the first and second pad electrodes 181 and 183 may be formed in the same process and may include the same material. Also, the first and second pad electrodes 181 and 183 may be formed of a single layer or multiple layers.

In this case, when the light emitting structure 120 is divided into at least two regions, the first pad electrode 181 and the second pad electrode 183 may be located in different regions. For example, as illustrated, the first pad electrode 181 may be located in the first region R1 , and the second pad electrode 183 may be located in the second region R2 , and the first The pad electrode 181 and the second pad electrode 183 are spaced apart from each other.

Hereinafter, a method for manufacturing the light emitting device of this embodiment will be described. The manufacturing method of the light emitting device described below is provided to help the understanding of the present invention, but the present invention is not limited thereto.

First, the light emitting structure 120 is formed by growing the first conductivity type semiconductor layer 121 , the active layer 123 , and the second conductivity type semiconductor layer 125 on the growth substrate 121a using a method such as MOCVD. do. Next, a conductive oxide layer 141 including ITO is formed on the light emitting structure 120 by using a method such as electron beam deposition or sputtering. A mask is formed on the conductive oxide layer 141 , and portions of the conductive oxide layer 141 and the light emitting structure 120 are etched using the mask to form a plurality of mesas M . Accordingly, the outer edge of the conductive oxide 141 may be formed to substantially coincide with the outer edge of the upper surface of the mesa M. Next, the reflective electrode layer 143 is formed on the conductive oxide layer 141 to form the second contact electrode 140 , and the first contact electrode is formed on a portion of the region where the first conductivity-type semiconductor layer 121 is exposed. form (130). The first contact electrode 130 and the second contact electrode 140 may be formed using plating or deposition, respectively. Next, the first insulating layer 150 covering the light emitting structure 120 and the first and second contact electrodes 130 and 140 is formed. In this case, when the first insulating layer 150 includes the preliminary insulating layer 150a and the main insulating layer 150b, the second contact electrode 140 and the first insulating layer 150 forming process are performed as described above. can be merged Next, by patterning the first insulating layer 150 , the first opening 150a exposing at least a portion of the first contact electrode 130 and the second opening 150b exposing a portion of the second contact electrode 140 ) to form Next, the first pad electrode 181 and the second pad electrode 183 are formed on the first insulating layer 150 using a method such as plating or deposition. In this case, by forming the first and second pad electrodes 181 and 183 to be spaced apart from each other, the light emitting device of FIGS. 5A and 5B may be provided.

According to the present embodiment, since the process of forming the second insulating layer is omitted, the manufacturing process of the light emitting device can be simplified, and in particular, the number of masks required for the process can be reduced.

6 is an exploded perspective view illustrating an example in which a light emitting device according to an embodiment of the present invention is applied to a lighting device.

Referring to FIG. 6 , the lighting device according to the present embodiment includes a diffusion cover 1010 , a light emitting device module 1020 , and a body portion 1030 . The body 1030 may accommodate the light emitting device module 1020 , and the diffusion cover 1010 may be disposed on the body 1030 to cover the upper portion of the light emitting device module 1020 .

The body portion 1030 is not limited as long as it can accommodate and support the light emitting device module 1020 and supply electrical power to the light emitting device module 1020 . For example, as shown, the body 1030 may include a body case 1031 , a power supply device 1033 , a power case 1035 , and a power connection unit 1037 .

The power supply device 1033 is accommodated in the power case 1035 , is electrically connected to the light emitting device module 1020 , and may include at least one IC chip. The IC chip may adjust, convert, or control characteristics of power supplied to the light emitting device module 1020 . The power case 1035 may accommodate and support the power supply 1033 , and the power case 1035 to which the power supply 1033 is fixed therein may be located inside the body case 1031 . . The power connection part 115 may be disposed at the lower end of the power case 1035 to be bound to the power case 1035 . Accordingly, the power connection unit 115 may be electrically connected to the power supply unit 1033 inside the power case 1035 , and may serve as a passage through which external power may be supplied to the power supply unit 1033 .

The light emitting device module 1020 includes a substrate 1023 and a light emitting device 1021 disposed on the substrate 1023 . The light emitting device module 1020 may be provided on the body case 1031 and electrically connected to the power supply 1033 .

The substrate 1023 is not limited as long as it is a substrate capable of supporting the light emitting device 1021 , and may be, for example, a printed circuit board including wiring. The substrate 1023 may have a shape corresponding to the fixing portion of the upper portion of the body case 1031 so as to be stably fixed to the body case 1031 . The light emitting device 1021 may include at least one of the light emitting devices according to the above-described embodiments of the present invention.

The diffusion cover 1010 may be disposed on the light emitting device 1021 , and may be fixed to the body case 1031 to cover the light emitting device 1021 . The diffusion cover 1010 may have a light-transmitting material, and by adjusting the shape and light transmittance of the diffusion cover 1010 , the directional characteristics of the lighting device may be adjusted. Therefore, the diffusion cover 1010 may be modified in various forms according to the purpose of use of the lighting device and the application aspect.

7 is a cross-sectional view illustrating an example in which a light emitting device according to an embodiment of the present invention is applied to a display device.

The display device of the present embodiment includes a display panel 2110 , a backlight unit BLU1 providing light to the display panel 2110 , and a panel guide 2100 supporting a lower edge of the display panel 2110 .

The display panel 2110 is not particularly limited and may be, for example, a liquid crystal display panel including a liquid crystal layer. A gate driving PCB for supplying a driving signal to the gate line may be further positioned at an edge of the display panel 2110 . Here, the gate driving PCBs 2112 and 2113 are not formed on a separate PCB, but may be formed on a thin film transistor substrate.

The backlight unit BLU1 includes a light source module including at least one substrate 2150 and a plurality of light emitting devices 2160 . Furthermore, the backlight unit BLU1 may further include a bottom cover 2180 , a reflective sheet 2170 , a diffusion plate 2131 , and optical sheets 2130 .

The bottom cover 2180 may be opened upward to accommodate the substrate 2150 , the light emitting device 2160 , the reflective sheet 2170 , the diffusion plate 2131 , and the optical sheets 2130 . Also, the bottom cover 2180 may be coupled to the panel guide 2100 . The substrate 2150 may be disposed under the reflective sheet 2170 to be surrounded by the reflective sheet 2170 . However, the present invention is not limited thereto, and when the reflective material is coated on the surface, it may be positioned on the reflective sheet 2170 . In addition, a plurality of substrates 2150 may be formed so that the plurality of substrates 2150 are arranged side by side, but is not limited thereto, and may be formed of a single substrate 2150 .

The light emitting device 2160 may include at least one of the light emitting devices according to the above-described embodiments of the present invention. The light emitting devices 2160 may be regularly arranged in a predetermined pattern on the substrate 2150 . In addition, a lens 2210 may be disposed on each light emitting device 2160 to improve uniformity of light emitted from the plurality of light emitting devices 2160 .

The diffusion plate 2131 and the optical sheets 2130 are positioned on the light emitting device 2160 . The light emitted from the light emitting device 2160 may be supplied to the display panel 2110 in the form of a surface light source through the diffusion plate 2131 and the optical sheets 2130 .

In this way, the light emitting device according to the embodiments of the present invention can be applied to the direct type display device as in the present embodiment.

8 is a cross-sectional view illustrating an example in which a light emitting device according to an embodiment is applied to a display device.

The display device provided with the backlight unit according to the present embodiment includes a display panel 3210 on which an image is displayed, and a backlight unit BLU2 disposed on the rear surface of the display panel 3210 to irradiate light. Furthermore, the display device includes a frame 240 supporting the display panel 3210 and accommodating the backlight unit BLU2 , and covers 3240 and 3280 surrounding the display panel 3210 .

The display panel 3210 is not particularly limited, and may be, for example, a liquid crystal display panel including a liquid crystal layer. A gate driving PCB for supplying a driving signal to the gate line may be further positioned at an edge of the display panel 3210 . Here, the gate driving PCB is not formed on a separate PCB, but may be formed on the thin film transistor substrate. The display panel 3210 is fixed by covers 3240 and 3280 positioned at upper and lower portions thereof, and the lower cover 3280 may be coupled to the backlight unit BLU2 .

The backlight unit BLU2 providing light to the display panel 3210 includes a lower cover 3270 having a partially opened upper surface, a light source module disposed on one side of the inner side of the lower cover 3270, and positioned in parallel with the light source module. and a light guide plate 3250 for converting point light into surface light. In addition, the backlight unit BLU2 of the present embodiment is disposed on the light guide plate 3250 and the optical sheets 3230 for diffusing and condensing light, and is disposed under the light guide plate 3250 and proceeds in the lower direction of the light guide plate 3250 . It may further include a reflective sheet 3260 for reflecting the light to the display panel 3210 direction.

The light source module includes a substrate 3220 and a plurality of light emitting devices 3110 spaced apart from each other at regular intervals on one surface of the substrate 3220 . The substrate 3220 is not limited as long as it supports the light emitting device 3110 and is electrically connected to the light emitting device 3110, and may be, for example, a printed circuit board. The light emitting device 3110 may include at least one light emitting device according to the above-described embodiments of the present invention. Light emitted from the light source module is incident on the light guide plate 3250 and is supplied to the display panel 3210 through the optical sheets 3230 . Through the light guide plate 3250 and the optical sheets 3230 , the point light source emitted from the light emitting devices 3110 may be transformed into a surface light source.

In this way, the light emitting device according to the embodiments of the present invention can be applied to the edge type display device as in the present embodiment.

9 is a cross-sectional view illustrating an example in which a light emitting device according to an embodiment of the present invention is applied to a head lamp.

Referring to FIG. 9 , the head lamp includes a lamp body 4070 , a substrate 4020 , a light emitting device 4010 , and a cover lens 4050 . Furthermore, the head lamp may further include a heat dissipation unit 4030 , a support rack 4060 , and a connection member 4040 .

The substrate 4020 is fixed by the support rack 4060 and spaced apart from the lamp body 4070 . The substrate 4020 is not limited as long as it is a substrate capable of supporting the light emitting device 4010 , and may be, for example, a substrate having a conductive pattern such as a printed circuit board. The light emitting device 4010 is positioned on the substrate 4020 , and may be supported and fixed by the substrate 4020 . Also, the light emitting device 4010 may be electrically connected to an external power source through the conductive pattern of the substrate 4020 . In addition, the light emitting device 4010 may include at least one light emitting device according to the above-described embodiments of the present invention.

The cover lens 4050 is positioned on a path through which light emitted from the light emitting device 4010 travels. For example, as shown, the cover lens 4050 may be disposed to be spaced apart from the light emitting device 4010 by the connecting member 4040 and may be disposed in a direction in which the light emitted from the light emitting device 4010 is to be provided. can A beam angle and/or color of light emitted from the headlamp to the outside may be adjusted by the cover lens 4050 . Meanwhile, the connection member 4040 may serve as a light guide for fixing the cover lens 4050 to the substrate 4020 , as well as surrounding the light emitting device 4010 to provide a light emitting path 4045 . In this case, the connection member 4040 may be formed of a light reflective material or coated with a light reflective material. Meanwhile, the heat dissipation unit 4030 may include a heat dissipation fin 4031 and/or a heat dissipation fan 4033 , and radiates heat generated when the light emitting device 4010 is driven to the outside.

In this way, the light emitting device according to the embodiments of the present invention may be applied to the head lamp as in the present embodiment, in particular, a vehicle head lamp.

In the above, various embodiments of the present invention have been described, but the present invention is not limited to each of the above-described embodiments and features. The invention changed through the combination and substitution of technical features described in the embodiments is also included in the scope of the present invention, and various modifications and changes are possible within the scope without departing from the technical spirit of the claims of the present invention.

Claims (31)

a light emitting structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer positioned between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer;
a first contact electrode in ohmic contact with the first conductivity-type semiconductor layer;
a second contact electrode positioned on the second conductivity-type semiconductor layer; and
an insulating layer disposed on the light emitting structure and insulating the first contact electrode and the second contact electrode;
The light emitting structure has a non-polar or semi-polar growth surface, the upper surface of the second conductivity-type semiconductor layer includes a non-polar or semi-polar surface,
The second contact electrode includes a conductive oxide layer in ohmic contact with the second conductivity-type semiconductor layer, and a reflective electrode layer disposed on the conductive oxide layer,
The area of the conductive oxide layer is larger than the area of the reflective electrode layer,
The reflective electrode layer is a light emitting device located in an edge region of the conductive oxide layer.
a light emitting structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer positioned between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer;
a first contact electrode in ohmic contact with the first conductivity-type semiconductor layer;
a second contact electrode positioned on the second conductivity-type semiconductor layer; and
an insulating layer disposed on the light emitting structure and insulating the first contact electrode and the second contact electrode;
The light emitting structure has a non-polar or semi-polar growth surface, the upper surface of the second conductivity-type semiconductor layer includes a non-polar or semi-polar surface,
The second contact electrode includes a conductive oxide layer in ohmic contact with the second conductivity-type semiconductor layer, and a reflective electrode layer disposed on the conductive oxide layer,
The light emitting structure includes a plurality of mesa including the second conductivity type semiconductor layer and the active layer,
the second contact electrode is positioned on the plurality of mesa, and the first conductivity-type semiconductor layer is exposed in at least a partial region around the plurality of mesa;
The insulating layer includes a first insulating layer and a second insulating layer,
The first insulating layer covers the plurality of mesas and the first conductivity-type semiconductor layer, and includes first and second openings exposing a portion of the first conductivity-type semiconductor layer and a portion of the second contact electrode, respectively. light emitting device.
a light emitting structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer positioned between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer;
a first contact electrode in ohmic contact with the first conductivity-type semiconductor layer;
a second contact electrode positioned on the second conductivity-type semiconductor layer; and
an insulating layer disposed on the light emitting structure and insulating the first contact electrode and the second contact electrode;
The light emitting structure has a non-polar or semi-polar growth surface, the upper surface of the second conductivity-type semiconductor layer includes a non-polar or semi-polar surface,
The second contact electrode includes a conductive oxide layer in ohmic contact with the second conductivity-type semiconductor layer, and a reflective electrode layer disposed on the conductive oxide layer,
The light emitting structure includes a plurality of mesa including the second conductivity type semiconductor layer and the active layer,
the second contact electrode is positioned on the plurality of mesa, and the first conductivity-type semiconductor layer is exposed in at least a partial region around the plurality of mesa;
The insulating layer includes first and second openings covering the plurality of mesas and the first conductivity type semiconductor layer, and exposing a portion of the first conductivity type semiconductor layer and a portion of the second contact electrode, respectively,
The first contact electrode is in ohmic contact with the first conductivity-type semiconductor layer through the first opening, and the first contact electrode is located on a portion of an upper surface of the plurality of mesas and a portion of a side surface of the plurality of mesas, A light emitting device insulated from a plurality of mesa.
a light emitting structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer positioned between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer;
a first contact electrode in ohmic contact with the first conductivity-type semiconductor layer;
a second contact electrode positioned on the second conductivity-type semiconductor layer;
an insulating layer disposed on the light emitting structure and insulating the first contact electrode and the second contact electrode; and
a first pad electrode and a second pad electrode positioned on the insulating layer;
The light emitting structure has a non-polar or semi-polar growth surface, the upper surface of the second conductivity-type semiconductor layer includes a non-polar or semi-polar surface,
The second contact electrode includes a conductive oxide layer in ohmic contact with the second conductivity-type semiconductor layer, and a reflective electrode layer disposed on the conductive oxide layer,
The light emitting structure includes a plurality of mesa including the second conductivity type semiconductor layer and the active layer,
the second contact electrode is positioned on the plurality of mesa, and the first conductivity-type semiconductor layer is exposed in at least a partial region around the plurality of mesa;
The first contact electrode is positioned on at least a portion of an area where the first conductivity-type semiconductor layer is exposed,
The insulating layer covers the plurality of mesas and the first conductivity-type semiconductor layer, and includes first and second openings exposing a portion of the first contact electrode and a portion of the second contact electrode, respectively;
the first pad electrode is electrically connected to the first contact electrode through the first opening;
the second pad electrode is electrically connected to a second contact electrode through the second opening;
The first pad electrode is located on a portion of an upper surface of the plurality of mesas and a portion of a side surface of the plurality of mesas, and is spaced apart from the plurality of mesas by the insulating layer.
a light emitting structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer positioned between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer;
a first contact electrode in ohmic contact with the first conductivity-type semiconductor layer;
a second contact electrode positioned on the second conductivity-type semiconductor layer; and
an insulating layer disposed on the light emitting structure and insulating the first contact electrode and the second contact electrode;
The light emitting structure has a non-polar or semi-polar growth surface, the upper surface of the second conductivity-type semiconductor layer includes a non-polar or semi-polar surface,
The second contact electrode includes a conductive oxide layer in ohmic contact with the second conductivity-type semiconductor layer, and a reflective electrode layer disposed on the conductive oxide layer,
The light emitting structure includes a region in which the first conductivity-type semiconductor layer is partially exposed, the insulating layer includes a first insulating layer,
The first insulating layer partially covers the light emitting structure and the second contact electrode, and includes a first opening and a second opening exposing a portion of the first conductivity-type semiconductor layer and a portion of the second contact electrode, respectively,
The first insulating layer includes a preliminary insulating layer and a main insulating layer positioned on the preliminary insulating layer,
The preliminary insulating layer is a light emitting device covering a portion of the light emitting structure and a portion of the conductive oxide.
The method according to any one of claims 1 to 5,
The light emitting structure includes a nitride semiconductor, and the non-polar or semi-polar growth plane includes an m-plane.
7. The method of claim 6,
The conductive oxide layer includes ITO, and the reflective electrode layer includes Ag.
The method according to any one of claims 2 to 5,
The area of the conductive oxide layer is larger than the area of the reflective electrode layer,
The reflective electrode layer is a light emitting device located in an edge region of the conductive oxide layer.
The method according to claim 1,
The conductive oxide layer covers 90% or more of an upper surface of the second conductivity-type semiconductor layer.
The method according to any one of claims 2 to 5,
The conductive oxide layer is a light emitting device covered with the reflective electrode layer.
The method according to any one of claims 1 to 5,
The first conductivity-type semiconductor layer is a light emitting device comprising a nitride-based substrate having a non-polar or semi-polar growth surface.
12. The method of claim 11,
The nitride-based substrate is undoped or doped to have the same conductivity type as the first conductivity type semiconductor layer.
12. The method of claim 11,
The nitride-based substrate is a light emitting device having a thickness of 270 to 330㎛.
The method according to any one of claims 1 to 5,
A contact resistance between the second conductivity type semiconductor layer and the conductive oxide is lower than a contact resistance between the second conductivity type semiconductor layer and the reflective electrode layer.
The method according to claim 1,
The light emitting structure includes a plurality of mesa including the second conductivity type semiconductor layer and the active layer,
The second contact electrode is positioned on the plurality of mesa, and the first conductivity-type semiconductor layer is exposed in at least a partial region around the plurality of mesa.
16. The method of claim 15,
The insulating layer includes a first insulating layer and a second insulating layer,
The first insulating layer covers the plurality of mesas and the first conductivity-type semiconductor layer, and includes first and second openings exposing a portion of the first conductivity-type semiconductor layer and a portion of the second contact electrode, respectively. light emitting device.
17. The method of claim 16,
the first contact electrode is in ohmic contact with the first conductivity-type semiconductor layer through the first opening;
The first contact electrode is a light emitting device located on a portion of an upper surface of the plurality of mesas and on side surfaces of the plurality of mesas, and insulated from the plurality of mesa.
18. The method of claim 17,
The second insulating layer partially covers the first contact electrode, and includes a third opening and a fourth opening partially exposing the first contact electrode and the second contact electrode, respectively.
19. The method of claim 18,
a first pad electrode disposed on the second insulating layer and electrically connected to the first contact electrode through the third opening; and
The light emitting device further comprising a second pad electrode disposed on the second insulating layer and electrically connected to the second contact electrode through the fourth opening.
16. The method of claim 15,
The insulating layer covers the plurality of mesas and the first conductivity type semiconductor layer, and includes a first opening and a second opening for exposing a portion of the first conductivity type semiconductor layer and a portion of the second contact electrode, respectively. device.
21. The method of claim 20,
The first contact electrode is in ohmic contact with the first conductivity-type semiconductor layer through the first opening, and the first contact electrode is located on a portion of an upper surface of the plurality of mesas and a portion of a side surface of the plurality of mesas, A light emitting device insulated from a plurality of mesa.
22. The method of claim 21,
a pad electrode positioned on the insulating layer and electrically connected to the second contact electrode through the second opening;
The pad electrode and the first contact electrode are spaced apart from each other.
23. The method of claim 22,
The light emitting structure includes a first region including one side thereof, and a second region including the other side opposite to the one side,
The first contact electrode is positioned in the first region, and the pad electrode is positioned in the second region.
16. The method of claim 15,
The first contact electrode is a light emitting device positioned on at least a portion of a region where the first conductivity-type semiconductor layer is exposed.
25. The method of claim 24,
The insulating layer covers the plurality of mesas and the first conductivity-type semiconductor layer, and includes a first opening and a second opening for exposing a portion of the first contact electrode and a portion of the second contact electrode, respectively.
26. The method of claim 25,
a first pad electrode disposed on the insulating layer and electrically connected to a first contact electrode through the first opening; and
a second pad electrode positioned on the insulating layer and electrically connected to a second contact electrode through the second opening;
The light emitting device of the first pad electrode, wherein the first contact electrode is positioned on a portion of an upper surface of the plurality of mesas and a portion of a side surface of the plurality of mesas, and is spaced apart from the plurality of mesas by the insulating layer.
The method according to claim 1,
The light emitting structure includes a region in which the first conductivity-type semiconductor layer is partially exposed, the insulating layer includes a first insulating layer,
The first insulating layer partially covers the light emitting structure and the second contact electrode, and includes a first opening and a second opening for exposing a portion of the first conductivity-type semiconductor layer and a portion of the second contact electrode, respectively. device.
28. The method of claim 27,
The first insulating layer includes a preliminary insulating layer and a main insulating layer positioned on the preliminary insulating layer,
The preliminary insulating layer is a light emitting device covering a portion of the light emitting structure and a portion of the conductive oxide.
29. The method of claim 5 or 28,
The preliminary insulating layer includes an opening partially exposing the conductive oxide, and the reflective electrode layer is located in the opening.
30. The method of claim 29,
The main insulating layer partially covers the reflective electrode layer.
29. The method of claim 5 or 28,
The insulating layer further includes a second insulating layer positioned on the first insulating layer and partially covering the first contact electrode,
The first insulating layer is thicker than the second insulating layer.

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