KR102533825B1 - Semiconductor device - Google Patents

Abstract

In an embodiment, a first conductivity type semiconductor layer, a second conductivity type semiconductor layer disposed on the first conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer. A light emitting structure comprising a; a first electrode electrically connected to the first conductivity type semiconductor layer; and a second electrode electrically connected to the second conductivity type semiconductor layer. Including, the second electrode is a conductive anode disposed under the light emitting structure, a conductive layer electrically connected to the conductive anode, and disposed between the conductive anode and the conductive layer and the conductive anode It includes a diffusion prevention electrode surrounding the bottom and side surfaces of the semiconductor device, and the top surface of the conductive oxide electrode and the top surface of the diffusion prevention electrode are disposed on the same plane.

Description

Semiconductor device {SEMICONDUCTOR DEVICE}

The embodiment discloses a semiconductor device.

Semiconductor devices including compounds such as GaN and AlGaN have many advantages, such as having a wide and easily adjustable band gap energy, and can be used in various ways such as light emitting devices, light receiving devices, and various diodes.

In particular, light emitting devices such as light emitting diodes or laser diodes using group 3-5 or group 2-6 compound semiconductor materials of semiconductors are developed in thin film growth technology and device materials to produce red, green, Various colors such as blue and ultraviolet can be realized, and white light with high efficiency can be realized by using fluorescent materials or combining colors. , safety, and environmental friendliness.

In addition, when light receiving devices such as photodetectors or solar cells are manufactured using group 3-5 or group 2-6 compound semiconductor materials, photocurrent is generated by absorbing light in various wavelength ranges through the development of device materials. By doing so, it is possible to use light in a wide range of wavelengths from gamma rays to radio wavelengths. In addition, it has the advantages of fast response speed, safety, environmental friendliness, and easy control of element materials, so that it can be easily used in power control or ultra-high frequency circuits or communication modules.

Accordingly, the semiconductor device can replace a transmission module of an optical communication means, a light emitting diode backlight that replaces a Cold Cathode Fluorescence Lamp (CCFL) constituting a backlight of an LCD (Liquid Crystal Display) display device, and can replace a fluorescent lamp or an incandescent bulb. Applications are expanding to white light emitting diode lighting devices, automobile headlights and traffic lights, and sensors that detect gas or fire. In addition, applications of semiconductor devices can be expanded to high-frequency application circuits, other power control devices, and communication modules.

In particular, a light emitting element that emits light in the ultraviolet wavelength region can be used for curing, medical, and sterilization purposes by performing a curing or sterilizing action.

Recently, research on UV light emitting devices has been actively conducted, but it is still difficult to implement UV light emitting devices in a vertical type, and there is a problem in that light extraction efficiency is relatively low.

The embodiment provides a semiconductor device with improved light extraction efficiency.

The embodiment provides a semiconductor device with excellent current dissipation efficiency.

The problem to be solved in the embodiment is not limited thereto, and it will be said that the solution to the problem described below or the purpose or effect that can be grasped from the embodiment is also included.

A semiconductor device according to one aspect of the present invention includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer disposed on the first conductivity type semiconductor layer, and the first conductivity type semiconductor layer and the second conductivity type semiconductor layer. A light emitting structure including an active layer disposed between semiconductor layers; a first electrode electrically connected to the first conductivity type semiconductor layer; and a second electrode electrically connected to the second conductivity type semiconductor layer. Including, the second electrode is a conductive anode disposed under the light emitting structure, a conductive layer electrically connected to the conductive anode, and disposed between the conductive anode and the conductive layer and the conductive anode and a diffusion prevention electrode surrounding a lower surface and a side surface thereof, and an upper surface of the conductive anode and an upper surface of the diffusion prevention electrode are disposed on the same plane.

A semiconductor device according to another feature of the present invention includes a first conductivity-type semiconductor layer, a second conductivity-type semiconductor layer, and an active layer disposed between the first conductivity-type semiconductor layer and the second conductivity-type semiconductor layer, a light emitting structure including a plurality of recesses penetrating the second conductivity type semiconductor layer and the active layer and extending to a partial region of the first conductivity type semiconductor layer; a first electrode electrically connected to the first conductivity type semiconductor layer within the plurality of recesses; and a second electrode electrically connected to the second conductivity type semiconductor layer, wherein the second electrode includes a conductive layer including a through hole vertically overlapping the plurality of recesses, the conductive layer and the light emitting structure. a conductive anode disposed therebetween, and a diffusion barrier layer disposed between the conductive anode and the conductive layer, wherein the conductive layer includes a concave groove toward the diffusion barrier layer in the light emitting structure, and the conductive anode , and the anti-diffusion layer is disposed in the groove.

According to the embodiment, light extraction efficiency is improved.

In addition, light output may be improved due to excellent current dissipation efficiency.

Various advantageous advantages and effects of the present invention are not limited to the above description, and will be more easily understood in the process of describing specific embodiments of the present invention.

1 is a conceptual diagram of a semiconductor device according to an embodiment of the present invention;
2 is an enlarged view of part A of FIG. 1;
3A and 3B are views for explaining a configuration in which light output is improved according to a change in the number of recesses;
4 is a view showing the structure of the diffusion prevention electrode,
5 is a view showing a structure in which an intermediate layer is disposed between a second conductive semiconductor layer and a second conductive layer;
6 is a modified example of the structure of the anti-diffusion electrode,
7 is a plan view of a semiconductor device according to an embodiment of the present invention;
8 is an enlarged view of part B of FIG. 7;
9 is a plan view of a semiconductor device according to another embodiment of the present invention;
10 is an enlarged view of part C of FIG. 9;
11 is a modified example of FIG. 9;
12 is a graph measuring the aluminum composition of the light emitting structure,
13 is a conceptual diagram of a semiconductor device package according to an exemplary embodiment.

The present embodiments may be modified in other forms or combined with each other, and the scope of the present invention is not limited to each of the embodiments described below.

Even if a matter described in a specific embodiment is not described in another embodiment, it may be understood as a description related to another embodiment, unless there is a description contrary to or contradictory to the matter in another embodiment.

For example, if the characteristics of component A are described in a specific embodiment and the characteristics of component B are described in another embodiment, the opposite or contradictory description even if the embodiment in which components A and B are combined is not explicitly described. Unless there is, it should be understood as belonging to the scope of the present invention.

In the description of the embodiment, in the case where an element is described as being formed “on or under” of another element, on or under (on or under) or under) includes both elements formed by directly contacting each other or by indirectly placing one or more other elements between the two elements. In addition, when expressed as "on or under", it may include the meaning of not only the upward direction but also the downward direction based on one element.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention.

1 is a conceptual diagram of a semiconductor device according to an exemplary embodiment of the present invention, FIG. 2 is an enlarged view of portion A of FIG. 1, and FIGS. 3A and 3B illustrate a configuration in which light output is improved according to a change in the number of recesses. It is a drawing for

The light emitting structure 120 according to an embodiment of the present invention may output light in an ultraviolet wavelength range. Illustratively, the light emitting structure may output light (UV-A) in a near-ultraviolet wavelength range, may output light (UV-B) in a far-ultraviolet wavelength range, or emit light (UV-C) in a deep ultraviolet wavelength range. can be printed out. The wavelength range may be determined by the composition ratio of aluminum of the light emitting structure 120 .

Illustratively, light (UV-A) in the near ultraviolet wavelength range may have a peak wavelength in the range of 320 nm to 420 nm, and light (UV-B) in the far ultraviolet wavelength range may have a peak wavelength in the range of 280 nm to 320 nm, Light (UV-C) in the deep ultraviolet wavelength range may have a peak wavelength ranging from 100 nm to 280 nm.

Referring to FIGS. 1 and 2 , the semiconductor device according to the embodiment includes a light emitting structure 120 and first electrodes 142 and 165 electrically connected to the first conductive semiconductor layer 124 of the light emitting structure 120 . , and second electrodes 246 , 247 , and 150 electrically connected to the second conductivity type semiconductor layer 127 .

The light emitting structure 120 is disposed between the first conductivity type semiconductor layer 124, the second conductivity type semiconductor layer 127, and the first conductivity type semiconductor layer 124 and the second conductivity type semiconductor layer 127. An active layer 126 may be included.

The first conductivity type semiconductor layer 124 may be implemented with a compound semiconductor such as group III-V or group II-VI, and may be doped with a first dopant. The first conductive semiconductor layer 124 is a semiconductor material having a composition formula of In _x1 Al _y1 Ga _{1 -x1-y1} N (0≤x1≤1, 0≤y1≤1, 0≤x1+y1≤1), eg For example, it may be selected from GaN, AlGaN, InGaN, InAlGaN, and the like. Also, the first dopant may be an n-type dopant such as Si, Ge, Sn, Se, or Te. When the first dopant is an n-type dopant, the first conductivity-type semiconductor layer 124 doped with the first dopant may be an n-type semiconductor layer.

The active layer 126 is disposed between the first conductivity type semiconductor layer 124 and the second conductivity type semiconductor layer 127 . The active layer 126 is a layer where electrons (or holes) injected through the first conductive semiconductor layer 124 and holes (or electrons) injected through the second conductive semiconductor layer 127 meet. The active layer 126 transitions to a lower energy level as electrons and holes recombine, and may generate light having an ultraviolet wavelength.

The active layer 126 may have a structure of any one of a single well structure, a multi-well structure, a single quantum well structure, a multi-quantum well (MQW) structure, a quantum dot structure, or a quantum wire structure, and the active layer 126 ) The structure of is not limited to this.

The second conductivity type semiconductor layer 127 is formed on the active layer 126 and may be implemented with compound semiconductors such as group III-V and group II-VI. Dopants may be doped. The second conductive semiconductor layer 127 is a semiconductor material having a composition formula of In _x5 Al _y2 Ga _{1 -x5- y2} N (0≤x5≤1, 0≤y2≤1, 0≤x5+y2≤1) or AlInN. , AlGaAs, GaP, GaAs, GaAsP, may be formed of a material selected from AlGaInP. When the second dopant is a p-type dopant such as Mg, Zn, Ca, Sr, or Ba, the second conductivity-type semiconductor layer 127 doped with the second dopant may be a p-type semiconductor layer.

A light emitting structure according to an embodiment may include a plurality of recesses 128 .

The plurality of recesses 128 may be disposed from the lower surface 127G of the second conductive semiconductor layer 127 to a partial region of the first conductive semiconductor layer 124 through the active layer 126 . A first insulating layer 131 may be disposed inside the recess 128 to electrically insulate the first conductive layer 165 from the second conductive semiconductor layer 127 and the active layer 126 .

The first electrodes 142 and 165 may include a first contact electrode 142 and a first conductive layer 165 . The first contact electrode 142 may be disposed on the upper surface of the recess 128 and electrically connected to the first conductive semiconductor layer 124 .

When the aluminum composition of the light emitting structure 120 increases, current dissipation characteristics within the light emitting structure 120 may deteriorate. In addition, the active layer increases the amount of light emitted to the side compared to the GaN-based blue light emitting device (TM mode). This TM mode may mainly occur in an ultraviolet semiconductor device.

The UV semiconductor device has poor current dissipation characteristics compared to the blue GaN semiconductor device. Accordingly, the UV semiconductor device needs to have relatively more first contact electrodes 142 than the blue GaN semiconductor device.

Referring to FIG. 3A , current is distributed only to points near each first contact electrode 142 , and current density may rapidly decrease at points far away from each other. Accordingly, the effective light emitting region P2 may be narrowed.

The effective light emitting region P2 may be defined as a region up to a boundary point where the current density is 40% or less based on the current density at the center of the first contact electrode 142 having the highest current density. For example, the effective light emitting region P2 may be adjusted according to the level of the injection current and the composition of Al within a range of 40 μm from the center of the recess 128 .

The low current density region P3 may hardly contribute to light emission due to low current density. Therefore, in the embodiment, the light output can be improved by further disposing the first contact electrode 142 in the low current density region P3 where the current density is low or by using a reflective structure.

In general, since a GaN-based semiconductor device emitting blue light has relatively excellent current dissipation characteristics, it is desirable to minimize the area of the recess 128 and the first contact electrode 142 . This is because the area of the active layer 126 decreases as the area of the recess 128 and the first contact electrode 142 increases. However, in the case of the embodiment, since the composition of aluminum is high and the current dissipation characteristic is relatively poor, even if the area of the active layer 126 is sacrificed, the number of first contact electrodes 142 is increased to reduce the low current density region P3 or , or it may be desirable to dispose a reflective structure in the low current density region P3.

Referring to FIG. 3B , when the number of recesses 128 is 48, the recesses 128 may not be arranged in a straight line in the horizontal and vertical directions, but may be arranged in a zigzag pattern. In this case, the area of the low current density region P3 is further narrowed so that most of the active layer can participate in light emission.

Referring back to FIGS. 1 and 2 , a second electrode pad 166 may be disposed at a corner region of one side of the semiconductor device. The second electrode pad 166 may have a concave portion and a convex portion on an upper surface of the second electrode pad 166 having a depressed central portion. A wire (not shown) may be bonded to the concave portion of the upper surface. Therefore, the bonding area is widened, and the second electrode pad 166 and the wire can be more firmly bonded.

Since the second electrode pad 166 can reflect light, light extraction efficiency can be improved as the second electrode pad 166 is closer to the light emitting structure 120 .

The height of the convex portion of the second electrode pad 166 may be higher than that of the active layer 126 . Therefore, the second electrode pad 166 reflects the light emitted from the active layer 126 in the horizontal direction of the device upward, thereby improving light extraction efficiency and controlling the beam angle.

The first insulating layer 131 is partially opened under the second electrode pad 166 so that the second conductive layer 150 and the second contact electrode 246 can be electrically connected.

The passivation layer 180 may be formed on top and side surfaces of the light emitting structure 120 . The passivation layer 180 may contact the first insulating layer 131 at a region adjacent to the second contact electrode 246 or at a lower portion of the second contact electrode 246 .

The width d22 of the portion where the first insulating layer 131 is opened and the second electrode pad 166 contacts the second conductive layer 150 may be, for example, 40 μm to 90 μm. If it is smaller than 40 μm, there is a problem in that the operating voltage increases, and if it is larger than 90 μm, it may be difficult to secure a process margin for not exposing the second conductive layer 150 to the outside.

The first insulating layer 131 may electrically insulate the first contact electrode 142 from the active layer 126 and the second conductive semiconductor layer 127 . Also, the first insulating layer 131 may electrically insulate the second conductive layer 150 from the first conductive layer 165 .

The first insulating layer 131 may be formed by selecting at least one from the group consisting of SiO ₂ , SixOy, Si ₃ N ₄ , Si _x N _y , SiO _x N _y , Al ₂ O ₃ , TiO ₂ , AlN, and the like. However, it is not limited thereto. The first insulating layer 131 may be formed as a single layer or multiple layers. For example, the first insulating layer 131 may be a multi-layer distributed Bragg reflector (DBR) including silver Si oxide or a Ti compound. However, the first insulating layer 131 is not necessarily limited thereto and may include various reflective structures.

When the first insulating layer 131 performs a reflective function, light emitted from the active layer 126 toward the side surface is upwardly reflected to improve light extraction efficiency. Compared to semiconductor devices emitting blue light, the UV semiconductor device may have more effective light extraction efficiency as the number of recesses 128 increases.

The second electrodes 246 , 247 , and 150 may include a second contact electrode 246 , a diffusion barrier electrode 247 , and a second conductive layer 150 .

The second contact electrode 246 may contact the lower surface 127G of the second conductive type semiconductor layer 127 . The second contact electrode 246 may include a conductive oxide electrode having relatively little absorption of ultraviolet light. Illustratively, the conductive anode may be ITO, but is not necessarily limited thereto.

The second conductive layer 150 may inject current into the second conductive semiconductor layer 127 . Also, the second conductive layer 150 may reflect light emitted from the active layer 126 .

The second conductive layer 150 may cover the second contact electrode 246 . Accordingly, the second electrode pad 166, the second conductive layer 150, and the second contact electrode 246 may form one electrical channel.

The second conductive layer 150 may surround the second contact electrode 246 and contact the side surface and bottom surface of the first insulating layer 131 . The second conductive layer 150 is made of a material having good adhesion to the first insulating layer 131, and includes at least one material selected from the group consisting of materials such as Cr, Al, Ti, Ni, Au, and the like. It may be made of an alloy of, and may be made of a single layer or a plurality of layers. The second conductive layer 150 may include a plurality of through holes TH1 vertically overlapping with the plurality of recesses 128 . That is, the second conductive layer 150 is removed in the region where the recess 128 is disposed so that the first electrode 142 disposed in the recess 128 and the first conductive layer 165 can be electrically connected. can

When the second conductive layer 150 contacts the side surface and bottom surface of the first insulating layer 131, the thermal and electrical reliability of the second contact electrode 246 can be improved. In addition, it may have a reflective function of reflecting light emitted between the first insulating layer 131 and the second contact electrode 246 upward.

The second insulating layer 132 may electrically insulate the second conductive layer 150 from the first conductive layer 165 . The first conductive layer 165 may be electrically connected to the first contact electrode 142 through the second insulating layer 132 .

The first conductive layer 165 and the bonding layer 160 may be disposed along the lower surface of the light emitting structure 120 and the shape of the recess 128 . The first conductive layer 165 may be made of a material having excellent reflectivity. For example, the first conductive layer 165 may include aluminum. When the first conductive layer 165 includes aluminum, it serves to reflect light emitted from the active layer 126 upward, thereby improving light extraction efficiency.

The bonding layer 160 may include a conductive material. For example, the bonding layer 160 may include a material selected from the group consisting of gold, tin, indium, aluminum, silicon, silver, nickel, and copper, or an alloy thereof.

The conductive substrate 170 may be made of a conductive material to inject current into the first conductive semiconductor layer 124 . For example, the conductive substrate 170 may include a metal or semiconductor material. The conductive substrate 170 may be a metal having excellent electrical conductivity and/or thermal conductivity. In this case, the heat generated during operation of the semiconductor device can be quickly dissipated to the outside.

The conductive substrate 170 may include a material selected from the group consisting of silicon, molybdenum, silicon, tungsten, copper, and aluminum, or an alloy thereof.

An upper surface of the light emitting structure 120 may have irregularities formed thereon. These irregularities may improve extraction efficiency of light emitted from the light emitting structure 120 . The irregularities may have different average heights depending on the wavelength of the ultraviolet light. In the case of UV-C, the light extraction efficiency may be improved when the irregularities have a height of about 300 nm to about 800 nm and an average height of about 500 nm to about 600 nm.

Referring to FIG. 2 , the anti-diffusion electrode 247 may be disposed between the second contact electrode 246 and the second conductive layer 150 .

The anti-diffusion electrode 247 can prevent the second conductive layer 150 from being oxidized at the interface with the second contact electrode 246 . For example, when the second contact electrode 246 is a conductive oxide electrode such as ITO, oxygen may diffuse into the second conductive layer 150 and the second conductive layer 150 may be oxidized. When the second conductive layer 150 is Al, it may react with oxygen to form an Al ₂ O ₃ interfacial layer. The Al ₂ O ₃ interfacial layer may have a lower UV reflectance than the Al layer. Accordingly, if the second conductive layer 150 is prevented from being oxidized, the reflectance of ultraviolet light may be increased, and light extraction efficiency may be improved.

According to the embodiment, since the second conductive layer 150 is prevented from being oxidized by the diffusion preventing electrode 247, the problem of the second contact electrode 246 and the second conductive layer 150 being separated can be improved. . When the second conductive layer 150 reacts with oxygen to form an _AlOX oxide layer, adhesive strength with the second contact electrode 246 may be weakened. In addition, since peeling of the second contact electrode 246 and the second conductive layer 246 is prevented, the operating voltage can also be lowered.

The anti-diffusion electrode 247 may include a material having a low oxidation degree among Ni, Cr, Rh, Co, Au, Pt, and Ti. A difference between the Gibbs energy of the anti-diffusion electrode 247 and the Gibbs energy of the second contact electrode 246 may be a positive number.

Gibbs energy is a thermodynamic function defined using enthalpy, entropy, and temperature of a system. When the difference in Gibbs energy is greater than zero, the forward reaction (oxidation reaction) becomes involuntary and the reverse reaction becomes spontaneous. Conversely, if the difference in Gibbs energy is less than zero, the forward reaction is spontaneous. Therefore, when the difference between the Gibbs energy of the anti-diffusion electrode 247 and the Gibbs energy of the second contact electrode 246 is a positive number, the reverse reaction becomes a spontaneous reaction, and thus the oxidation degree can be lowered.

For example, since the Gibbs energy difference between ITO and Al is -375.8 [KJ/mol], an oxidation reaction, which is a forward reaction, may occur spontaneously. On the other hand, since the Gibbs energy difference between ITO and Ni is +65.4 [KJ/mol], and the Gibbs energy difference between ITO and Rh is +252.0 [KJ/mol], oxidation may not occur relatively well.

The anti-diffusion electrode 247 may have an area sufficient to cover the second contact electrode 246 . This is because when the second contact electrode 246 is partially exposed, the adjacent second conductive layer 150 may be oxidized and the reflectance may decrease.

Accordingly, the diffusion prevention electrode 247 can completely cover the bottom and side surfaces of the second contact electrode 246 to block it from the second conductive layer 150 . As a result, the anti-diffusion electrode 247 may contact the lower surface 127G of the second conductive type semiconductor layer 127 .

Accordingly, the upper surface of the second contact electrode 246 and the upper surface of the diffusion prevention electrode 247 may contact the lower surface 127G of the second conductive semiconductor layer 127 . Accordingly, the upper surface of the second contact electrode 246 and the upper surface of the diffusion barrier electrode 247 may be disposed on the same plane. If there is another lowermost semiconductor layer other than the second conductive type semiconductor layer 127 under the light emitting structure, the upper surface of the second contact electrode 246 and the upper surface of the anti-diffusion electrode 247 are in contact with the lowermost semiconductor layer. You may.

The second contact electrode 246 such as ITO may absorb ultraviolet light. Therefore, it is necessary to improve light extraction efficiency while maintaining ohmic contact by the second contact electrode 246 .

According to the embodiment, the reflectance may be increased by reducing the area of the second contact electrode 246 . When the second contact electrode 246 is made of a conductive metal oxide such as ITO, UV light is absorbed and light extraction efficiency may be reduced. Therefore, in the embodiment, light extraction efficiency may be improved by reducing the area of the second contact electrode 246 .

However, if the second contact electrode 246 is reduced, resistance may increase because the ohmic contact area is reduced. In this case, the second conductive layer 150 may be disposed in an area where the lower surface 127G of the second conductive type semiconductor layer 127 is exposed to increase reflectance and be Schottky bonded to serve as a current injection path.

The area S11 in which the second contact electrode 246 contacts the lower portion of the light emitting structure 120 is 30% to 50% of the area S13 in which the anti-diffusion electrode 247 contacts the lower portion of the light emitting structure 120. can be That is, the area S11 in which the second contact electrode 246 contacts the lower portion of the light emitting structure 120 may be smaller than the area S13 in which the anti-diffusion electrode 247 contacts the lower portion of the light emitting structure 120. .

When the area S11 in which the second contact electrode 246 contacts the lower portion of the light emitting structure 120 is 30% or more, the area of the second contact electrode 246 is secured, so the ohmic resistance is lowered and the current injection efficiency can be improved. there is. In addition, when the area is 50% or less, the area of the second contact electrode 246 is reduced, so light extraction efficiency can be improved. At this time, since the area where the anti-diffusion electrode 247 contacts the lower portion of the light emitting structure 120 can also be Schottky junction, it can function as a current injection passage.

The area S11 in which the second contact electrode 246 contacts the lower portion of the light emitting structure 120 is 10% to 30% of the area S14 in which the second conductive layer 150 faces the lower portion of the light emitting structure 120. may be %. When the area is 10% or more, since the area of the second contact electrode 246 is secured, the ohmic resistance is lowered and current injection efficiency can be improved. In addition, when the area is 30% or less, the area where the second conductive layer 150 contacts the second conductive semiconductor layer 127 and performs a reflective function increases, and light extraction efficiency can be improved.

The contact area of the first contact electrode 142 with the first conductivity-type semiconductor layer 124 and the contact area of the second contact electrode 246 with the second conductivity-type semiconductor layer 127 have an inversely proportional relationship. That is, when the number of recesses 128 is increased to increase the number of first contact electrodes 142, the area of the second contact electrode 246 is reduced. Therefore, in order to improve electrical and optical properties, the dispersion characteristics of electrons and holes must be balanced. Therefore, it may be important to adjust the area of the first contact electrode 142 and the area of the second contact electrode 246 at an appropriate ratio.

The area in which the plurality of first contact electrodes 142 contact the first conductivity-type semiconductor layer 124 is 70% to 90% of the area in which the second contact electrode 246 contacts the lower portion of the light emitting structure 120. can When the area is 70% to 90%, the area of the first contact electrode 142 and the area of the second contact electrode 246 are adjusted in an appropriate ratio, so that the current density applied to the semiconductor device can be improved. Thus, light output can be improved.

An area S13 in which the anti-diffusion electrode 247 contacts the lower portion of the light emitting structure 120 may be 57% to 77% of the area of the plurality of recesses 128 . When the area is 57% or more, since the area of the first electrode increases in proportion thereto, current injection efficiency may be improved. In addition, when the area is 77% or less, the area of the first contact electrode 142 is reduced to lower the light absorption rate. In addition, a contact area between the second conductive layer 150 and the second conductive semiconductor layer 127 may increase, thereby increasing reflectance.

Referring to FIG. 4 , the diffusion prevention electrode 247 may have a plurality of prevention electrode layers.

The diffusion prevention electrode 247 includes a first prevention electrode 247a disposed below the second contact electrode 246 and a second prevention electrode disposed between the first prevention electrode 247a and the second conductive layer 150. (247b). In addition, the diffusion prevention electrode 247 may further include a third prevention electrode 247c and a fourth prevention electrode 247d without being limited thereto.

Illustratively, the first prevention electrode 247a may include Cr. The first prevention electrode 247a may improve bonding strength with the second contact electrode 246 . Also, the second prevention electrode 247b may include Ni, the third prevention electrode 247c may include Au, and the fourth prevention electrode 247d may include Ti. However, it is not necessarily limited to this, and each prevention electrode may have various electrode layer structures.

According to the embodiment, since the anti-diffusion electrode 247 includes a plurality of anti-electrode layers, it is possible to improve adhesion and at the same time prevent diffusion of oxygen of the second contact electrode 246 .

The conductive layer 150 may have a concave groove 150a extending from the second conductive semiconductor layer 127 of the light emitting structure toward the conductive layer 150 . The second contact electrode 246 and the diffusion prevention electrode 247 may be disposed in the groove 150a.

The second contact electrode 246 may include a first surface Q1 closest to the light emitting structure, and the anti-diffusion electrode 247 may also include a second surface Q2 closest to the light emitting structure.

When the first surface Q1 and the second surface Q2 contact the second conductive semiconductor layer 127 of the light emitting structure, the first surface Q1 and the second surface Q2 are disposed on the same plane. It can be. However, it is not necessarily limited to this, and if a separate semiconductor layer is further disposed below the second conductivity type semiconductor layer 127, the first surface Q1 and the second surface Q2 may contact the separately disposed semiconductor layer. may be

Referring to FIG. 5 , an intermediate layer 151 may be disposed between the second conductive layer 150 and the second conductive semiconductor layer 127 . The intermediate layer 151 may improve adhesion between the second conductive layer 150 and the second conductive semiconductor layer 127 .

The intermediate layer 151 may have the same composition as the first prevention electrode 247a of the diffusion prevention electrode 247 . Illustratively, the intermediate layer 151 and the first prevention electrode 247a may include Cr. However, it is not necessarily limited thereto, and the intermediate layer 151 and the first prevention electrode 247a may include various materials capable of improving adhesion between the layers.

In this case, the thickness of the intermediate layer 151 may be thinner than that of the first prevention electrode 247a. Since a metal such as Cr absorbs ultraviolet light, when the thickness of the intermediate layer 151 becomes thick, it absorbs most of the ultraviolet light and light extraction efficiency may decrease. In contrast, the first prevention electrode 247a has a relatively small contact area with the second conductive semiconductor layer 127 and most of it is disposed below the second contact electrode, so it needs to be made thick to improve the bonding force rather than the reflection effect. can Illustratively, while the first prevention electrode 247a is 100um to 200um, the intermediate layer 151 may be 2um to 40um.

Referring to FIG. 6 , the second contact electrode 246 may be divided into a plurality of pieces. Accordingly, the second conductive layer 150 may protrude between the adjacent second contact electrodes 246 and be electrically connected to the second conductive semiconductor layer 127 . According to this structure, light extraction efficiency can be improved.

7 is a plan view of a semiconductor device according to an exemplary embodiment, and FIG. 8 is an enlarged view of part B of FIG. 7 .

Referring to FIGS. 7 and 8 , a plurality of second contact electrodes 246 such as conductive oxide electrodes may be disposed between the recesses 128 . In this case, the diameter d2 of the plurality of second contact electrodes 246 may be smaller than the diameter d4 of the recess 128 . The diameter d2 of the plurality of second contact electrodes 246 may be 15% to 40% of the diameter d4 of the recess 128 .

In addition, the diameter d1 of the anti-diffusion electrode 247 may be 28% to 48% of the diameter d4 of the recess 128 . When these conditions are satisfied, the second contact electrode 246 having an appropriate area can be secured, and light extraction efficiency can be improved.

FIG. 9 is a plan view of a semiconductor device according to another exemplary embodiment, FIG. 10 is an enlarged view of portion C of FIG. 9 , and FIG. 11 is a modified example of FIG. 9 .

Referring to FIGS. 9 and 10 , the second contact electrode 246 may have a plurality of lines extending between the plurality of recesses 128 .

The second contact electrode 246 may include a plurality of first cavities H1 in which the recess 128 and the first contact electrode 142 are disposed on a plane. The first cavity H1 may be formed by connecting a plurality of lines.

The shape of the first cavity H1 may be a polygonal shape or a circular shape. Although it is shown that the first cavity H1 has a hexagonal shape, the shape of the first cavity H1 is not particularly limited.

The diffusion barrier electrode 247 may include a second cavity H2 disposed inside the first cavity H1. That is, in order for the anti-diffusion electrode 247 to cover the first cavity H1, the second cavity H2 may be smaller than the first cavity H1. The anti-diffusion electrode 247 may completely overlap the second contact electrode 246 on a plane.

Referring to FIG. 11 , the second contact electrode 246 may include an edge portion 248 extending along the side surface of the light emitting structure 120 . According to this configuration, the current is uniformly distributed even on the sides of the light emitting structure, so that uniform light emission can be achieved. Due to the configuration of the edge portion 248, the plurality of first electrodes 142 may be respectively disposed in cavities formed by the second contact electrodes 246 on a plane view.

12 is a graph measuring the aluminum composition of the light emitting structure.

Referring to FIG. 12 , an electron blocking layer 129 may be disposed between the active layer 126 and the second conductive semiconductor layer 127 . The electron blocking layer 129 blocks the flow of electrons supplied from the first conductivity type semiconductor layer 124 to the second conductivity type semiconductor layer 127, so that electrons and holes recombine in the active layer 126. can increase your odds. An energy bandgap of the electron blocking layer 129 may be larger than that of the active layer 126 and/or the second conductive type semiconductor layer 127 .

The electron blocking layer 129 is a semiconductor material having a composition formula of In _x1 Al _y1 Ga _{1 -x1- y1} N (0≤x1≤1, 0≤y1≤1, 0≤x1+y1≤1), for example AlGaN , InGaN, InAlGaN, etc., but is not limited thereto. In the electron blocking layer 129, a first layer 129b having a high aluminum composition and a second layer 129a having a low aluminum composition may be alternately disposed.

The active layer 126 including the first conductivity type semiconductor layer 124, the barrier layer 126b and the well layer 126a, the 2-1st conductivity type semiconductor layer 127a, and the 2-2nd conductivity type semiconductor layer (127b) may all contain aluminum. Therefore, the first conductivity type semiconductor layer 124, the barrier layer 126b, the well layer 126a, the 2-1st conductivity type semiconductor layer 127a, and the 2-2nd conductivity type semiconductor layer 127b are AlGaN can be However, it is not necessarily limited to this.

The thickness of the 2-1st conductive type semiconductor layer 127a may be greater than 10 nm and less than 200 nm. When the thickness of the 2-1st conductive type semiconductor layer 127a is smaller than 10 nm, resistance may increase and current injection efficiency may decrease. In addition, when the thickness of the 2-1st conductivity type semiconductor layer 127a is greater than 200 nm, crystallinity is lowered by the materials constituting the 2-1st conductivity type semiconductor layer 127a, resulting in reliability, electrical characteristics and optical characteristics. this may deteriorate.

The aluminum composition of the 2-1st conductivity type semiconductor layer 127a may be higher than that of the well layer 126a. In order to generate ultraviolet light, the aluminum composition of the well layer 126a may be about 30% to about 50%. If the aluminum composition of the 2-1st conductivity type semiconductor layer 127a is lower than the aluminum composition of the well layer 126a, light extraction efficiency is reduced because the 2-1st conductivity type semiconductor layer 127a absorbs light. can

The aluminum composition of the 2-1st conductivity type semiconductor layer 127a may be greater than 40% and less than 80%. If the aluminum composition of the 2-1 conductivity type semiconductor layer 127a is less than 40%, there is a problem of absorbing light, and if it is greater than 80%, there is a problem of deteriorating current injection efficiency. For example, when the aluminum composition of the well layer 126a is 30%, the aluminum composition of the 2-1st conductivity type semiconductor layer 127a may be 40%.

The aluminum composition of the 2-2nd conductivity type semiconductor layer 127b may be lower than the aluminum composition of the well layer 126a. When the aluminum composition of the 2-2nd conductivity type semiconductor layer 127b is higher than the aluminum composition of the well layer 126a, the resistance between the second electrode and the 2-2nd conductivity type semiconductor layer 127b increases, so that sufficient current injection is possible. may not be done

The aluminum composition of the 2-2 conductive semiconductor layer 127b may be greater than 1% and less than 50%. If it is greater than 50%, sufficient ohmic with the second electrode may not be achieved, and if the composition is less than 1%, there is a problem in that the composition is close to the GaN composition and absorbs light.

The thickness of the 2-2 conductive semiconductor layer 127b may be greater than 1 nm and less than 30 nm. As described above, the 2-2 conductive semiconductor layer 127b has a low composition of aluminum for ohmic purposes, so it can absorb ultraviolet light. Therefore, controlling the thickness of the 2-2nd conductivity type semiconductor layer 127b as thin as possible may be advantageous in terms of light output.

When the thickness of the 2-2nd conductivity type semiconductor layer 127b is controlled to be 1 nm or less, the 2-2nd conductivity type semiconductor layer 127b is not disposed in some sections, and the 2-1st conductivity type semiconductor layer 127a An area exposed to the outside of the light emitting structure 120 may occur. Therefore, it may be difficult to form one layer, and it may be difficult to perform the role of the 2-2 conductivity type semiconductor layer 127b. In addition, when the thickness is greater than 30 nm, the amount of light absorbed is too large, and thus light output efficiency may decrease.

The 2-2nd conductivity type semiconductor layer 127b may include a 2-3rd conductivity type semiconductor layer 127c and a 2-4th conductivity type semiconductor layer 127d. The 2-3 conductive semiconductor layer 127c may be a surface layer in contact with the second electrode, and the 2-4 conductive semiconductor layer 127d may be a layer that controls the composition of aluminum.

The 2-4th conductivity type semiconductor layer 127d includes the 2-1st conductivity type semiconductor layer 127a with a relatively high aluminum content and the 2-3rd conductivity type semiconductor layer 127c with a relatively low aluminum content. ) can be placed between Therefore, it is possible to prevent a problem in which the crystallinity is deteriorated due to an abrupt change in the aluminum content.

The 2-3 conductive semiconductor layer 127c may have an aluminum composition greater than 1% and less than 20%. Alternatively, the aluminum composition may be greater than 1% and less than 10%.

When the aluminum composition is lower than 1%, there may be a problem in that the light absorption rate is too high in the second-third conductivity type semiconductor layer 127c, and when the aluminum composition is higher than 20%, the contact resistance of the second electrode ( ) increases. There may be a problem of low current injection efficiency.

However, it is not necessarily limited thereto, and the aluminum composition of the second-third conductivity type semiconductor layer 127c may be adjusted in consideration of current injection characteristics and light absorptivity. Alternatively, it may be adjusted according to light output or electrical characteristics required by the product.

For example, when current injection efficiency is more important than light absorption, the composition ratio of aluminum may be adjusted to 1% to 10%. In the case of a product in which light output characteristics are more important than electrical characteristics, the aluminum composition ratio of the second-third conductive type semiconductor layer 127c may be adjusted to 1% to 20%.

When the aluminum composition ratio of the 2-3 conductive semiconductor layer 127c is greater than 1% and less than 20%, the resistance between the 2-3 conductive semiconductor layer 127c and the second electrode decreases, so that the operating voltage can be lowered Therefore, electrical characteristics can be improved. The thickness of the second-third conductive type semiconductor layer 127c may be greater than 1 nm and less than 10 nm. Therefore, the problem of light absorption can be improved.

The thickness of the 2-2nd conductivity type semiconductor layer 127b may be smaller than the thickness of the 2-1st conductivity type semiconductor layer 127a. The thickness ratio of the 2-1st conductivity type semiconductor layer 127a and the 2-2nd conductivity type semiconductor layer 127b may be 1.5:1 to 20:1. When the thickness ratio is less than 1.5:1, the thickness of the 2-1st conductivity type semiconductor layer 127a may be too thin and current injection efficiency may decrease. In addition, when the thickness ratio is greater than 20:1, the thickness of the 2-2 conductive type semiconductor layer 127b is too thin, and thus ohmic reliability may deteriorate.

The aluminum composition of the 2-1st conductivity type semiconductor layer 127a may decrease as the distance from the active layer 126 increases. In addition, the aluminum composition of the 2-2 conductive semiconductor layer 127b may decrease as the distance from the active layer 126 increases. Therefore, the aluminum composition of the second-third conductivity type semiconductor layer 127c may satisfy 1% to 10%.

However, it is not necessarily limited to this, and the aluminum composition of the 2-1st conductivity type semiconductor layer 127a and the 2-2nd conductivity type semiconductor layer 127b does not continuously decrease, but includes a period in which there is no decrease in a certain period. You may.

In this case, the aluminum reduction range of the 2-2nd conductivity type semiconductor layer 127b may be greater than the aluminum reduction range of the 2-1st conductivity type semiconductor layer 127a. That is, the change rate of the Al composition ratio of the 2-2nd conductivity type semiconductor layer 127b in the thickness direction may be greater than the change rate of the Al composition ratio of the 2-1st conductivity type semiconductor layer 127a in the thickness direction. Here, the thickness direction is a direction from the first conductivity type semiconductor layer 124 to the second conductivity type semiconductor layer 127 or a direction from the second conductivity type semiconductor layer 127 to the first conductivity type semiconductor layer 124. can

The thickness of the 2-1st conductivity type semiconductor layer 127a is thicker than that of the 2-2nd conductivity type semiconductor layer 127b, but the aluminum composition should be higher than that of the well layer 126a, so the decrease may be relatively gentle.

However, since the thickness of the 2-2 conductive semiconductor layer 127b is thin and the change range of the aluminum composition is large, the reduction range of the aluminum composition may be relatively large.

Referring to FIG. 13 , the semiconductor device package includes a body 2 having a groove 3, a semiconductor device 1 disposed in the body 2, and a semiconductor device 1 disposed in the body 2 electrically. A pair of connected lead frames 5a and 5b may be included. The semiconductor device 1 may include all of the above configurations.

The body 2 may include a material or coating layer that reflects ultraviolet light. The body 2 may be formed by stacking a plurality of layers 2a, 2b, 2c, 2d, and 2e. The plurality of layers 2a, 2b, 2c, 2d, and 2e may be made of the same material or may include different materials.

The groove 3 may be formed to become wider as it moves away from the semiconductor element, and a step 3a may be formed on the inclined surface.

The light-transmitting layer 4 may cover the groove 3 . The light-transmitting layer 4 may be made of glass, but is not necessarily limited thereto. The light-transmitting layer 4 is not particularly limited as long as it is made of a material capable of effectively transmitting ultraviolet light. The inside of the groove 3 may be an empty space.

Semiconductor devices may be applied to various types of light source devices. For example, the light source device may include a sterilization device, a curing device, a lighting device, a display device, and a vehicle lamp. That is, the semiconductor element may be applied to various electronic devices disposed in a case to provide light.

The sterilization device may sterilize a desired area by including the semiconductor device according to the embodiment. The sterilization device may be applied to household appliances such as water purifiers, air conditioners, and refrigerators, but is not necessarily limited thereto. That is, the sterilization device can be applied to various products (eg, medical devices) requiring sterilization.

Illustratively, the water purifier may include a sterilization device according to the embodiment to sterilize circulating water. The sterilization device may be disposed at a nozzle through which water circulates or an outlet to irradiate ultraviolet rays. In this case, the sterilization device may include a waterproof structure.

The curing device may be provided with a semiconductor device according to an embodiment to cure various types of liquids. Liquid may be the lightest concept that includes all various materials that are hardened when irradiated with ultraviolet rays. Illustratively, the curing device may cure various types of resins. Alternatively, the curing device may be applied to curing cosmetic products such as nail polish.

The lighting device may include a light source module including a substrate and the semiconductor device of the embodiment, a heat dissipation unit dissipating heat from the light source module, and a power supply unit that processes or converts an electrical signal received from the outside and provides it to the light source module. Also, the lighting device may include a lamp, a head lamp, or a street lamp.

The display device may include a bottom cover, a reflector, a light emitting module, a light guide plate, an optical sheet, a display panel, an image signal output circuit, and a color filter. The bottom cover, the reflector, the light emitting module, the light guide plate, and the optical sheet may constitute a backlight unit.

The reflector is disposed on the bottom cover, and the light emitting module can emit light. The light guide plate may be disposed in front of the reflector to guide light emitted from the light emitting module forward, and the optical sheet may include a prism sheet and the like and be disposed in front of the light guide plate. A display panel may be disposed in front of the optical sheet, an image signal output circuit may supply an image signal to the display panel, and a color filter may be disposed in front of the display panel.

When the semiconductor device is used as a backlight unit of a display device, it may be used as an edge-type backlight unit or a direct-type backlight unit.

The semiconductor element may be a laser diode other than the light emitting diode described above.

Like the light emitting device, the laser diode may include the first conductivity type semiconductor layer, the active layer, and the second conductivity type semiconductor layer having the above structure. In addition, an electro-luminescence phenomenon in which light is emitted when a current is passed after bonding a p-type first conductivity type semiconductor and an n-type second conductivity type semiconductor is used, but the directionality of the emitted light There is a difference between and phase. That is, the laser diode can emit light having a specific wavelength (monochromatic beam) with the same phase and in the same direction by using a phenomenon called stimulated emission and constructive interference, etc. Due to this, it can be used for optical communication, medical equipment, and semiconductor processing equipment.

A photodetector, which is a type of transducer that detects light and converts its intensity into an electrical signal, may be exemplified as the light receiving element. As such an optical detector, a photovoltaic cell (silicon, selenium), an optical output device (cadmium sulfide, cadmium selenide), a photodiode (eg, a PD having a peak wavelength in a visible blind spectral region or a true blind spectral region), a photodetector Transistors, photomultiplier tubes, photoelectric tubes (vacuum, gas filled), IR (Infra-Red) detectors, etc., but embodiments are not limited thereto.

In addition, a semiconductor device such as a photodetector may be fabricated using a direct bandgap semiconductor having excellent light conversion efficiency. Alternatively, photodetectors have various structures, and the most common structures include a pin type photodetector using a p-n junction, a Schottky type photodetector using a Schottky junction, and a Metal Semiconductor Metal (MSM) type photodetector. there is.

Like a light emitting device, a photodiode may include a first conductivity-type semiconductor layer, an active layer, and a second conductivity-type semiconductor layer having the above-described structure, and has a pn junction or pin structure. The photodiode operates by applying reverse bias or zero bias, and when light is incident on the photodiode, electrons and holes are generated and current flows. In this case, the size of the current may be substantially proportional to the intensity of light incident on the photodiode.

A photovoltaic cell or solar cell is a type of photodiode and can convert light into electric current. A solar cell, like a light emitting device, may include a first conductivity-type semiconductor layer, an active layer, and a second conductivity-type semiconductor layer having the above structure.

In addition, it can be used as a rectifier of an electronic circuit through the rectification characteristics of a general diode using a p-n junction, and can be applied to an oscillation circuit by being applied to a microwave circuit.

In addition, the above-described semiconductor device is not necessarily implemented as a semiconductor and may further include a metal material in some cases. For example, a semiconductor device such as a light receiving device may be implemented using at least one of Ag, Al, Au, In, Ga, N, Zn, Se, P, or As, and may be implemented using a p-type or n-type dopant. It may be implemented using a doped semiconductor material or an intrinsic semiconductor material.

Although the above has been described with reference to the embodiments, this is only an example and does not limit the present invention, and those skilled in the art to which the present invention belongs will not deviate from the essential characteristics of the present embodiment. It will be appreciated that various variations and applications are possible. For example, each component specifically shown in the embodiment can be modified and implemented. And the differences related to these modifications and applications should be construed as being included in the scope of the present invention as defined in the appended claims.

Claims (20)

A first conductivity type semiconductor layer, a second conductivity type semiconductor layer disposed under the first conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer. light emitting structures;
a first electrode electrically connected to the first conductivity type semiconductor layer; and
a second electrode electrically connected to the second conductivity type semiconductor layer; including,
The second electrode is a conductive anode disposed under the light emitting structure, a conductive layer electrically connected to the conductive anode, and a lower surface and a side surface of the conductive anode disposed between the conductive anode and the conductive layer. Including an anti-diffusion electrode surrounding the,
The top surface of the conductive anode and the top surface of the diffusion prevention electrode are disposed on the same plane,
The diffusion barrier electrode is a semiconductor device spaced apart from an insulating layer disposed under the second conductivity type semiconductor layer.
According to claim 1,
The upper surface of the conductive oxide electrode and the upper surface of the diffusion prevention electrode contact the lower surface of the second conductivity type semiconductor layer.
According to claim 1,
The area in which the conductive oxide electrode contacts the lower portion of the light emitting structure is 30% to 50% of the area in which the anti-diffusion electrode contacts the lower portion of the light emitting structure semiconductor device.
According to claim 1,
The area in which the conductive oxide electrode contacts the lower portion of the light emitting structure is 10% to 30% of the area in which the conductive layer faces the lower portion of the light emitting structure semiconductor device.
According to claim 1,
The light emitting structure includes a plurality of recesses penetrating the second conductivity type semiconductor layer and the active layer and extending to a partial region of the first conductivity type semiconductor layer;
The first electrode includes a plurality of contact electrodes disposed in the plurality of recesses and contacting the first conductivity type semiconductor layer.
According to claim 5,
An area in which the plurality of contact electrodes contact the first conductivity-type semiconductor layer is 70% to 90% of an area in which the conductive oxide electrode contacts the lower portion of the light emitting structure.
According to claim 6,
An area in which the anti-diffusion electrode contacts the lower portion of the light emitting structure is 57% to 77% of an area of the plurality of recesses.
According to claim 6,
The conductive oxide electrode is disposed between the recesses in plurality,
The semiconductor device of claim 1 , wherein diameters of the plurality of conductive anodes are smaller than diameters of the recesses.
According to claim 8,
A diameter of the plurality of conductive anodes is 15% to 40% of a diameter of the recess.
According to claim 9,
The semiconductor device of claim 1 , wherein a diameter of the anti-diffusion electrode is 28% to 48% of a diameter of the recess.
According to claim 5,
The conductive oxide electrode includes a plurality of lines disposed between the plurality of recesses.
According to claim 1,
The conductive anode includes a plurality of first cavities,
The plurality of first electrodes are respectively disposed in the plurality of first cavities on a top view.
According to claim 12,
The plurality of first cavities have a polygonal shape.
According to claim 12,
The diffusion barrier electrode includes a plurality of second cavities disposed inside the plurality of first cavities on a top view.
According to claim 1,
The semiconductor device of claim 1 , wherein a difference between the Gibbs energy of the anti-diffusion electrode and the Gibbs energy of the conductive anode is a positive number.
According to claim 1,
The anti-diffusion electrode includes at least one of Ni, Cr, Rh, Co, Au, Pt, and Ti.
According to claim 1,
The diffusion prevention electrode includes a second prevention electrode disposed between the conductive oxidation electrode and the conductive layer, and a first prevention electrode disposed between the conductive oxidation electrode and the second prevention electrode.
According to claim 17,
And an intermediate layer disposed between the lower portion of the light emitting structure and the conductive layer,
The thickness of the intermediate layer is smaller than the thickness of the first prevention electrode,
The intermediate layer and the first prevention electrode have the same composition.
A first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, wherein the second conductivity type semiconductor layer and the active layer pass through a light emitting structure including a plurality of recesses disposed up to a partial region of the first conductivity type semiconductor layer;
a first electrode electrically connected to the first conductivity type semiconductor layer within the plurality of recesses; and
A second electrode electrically connected to the second conductivity type semiconductor layer,
The second electrode may include a conductive layer including a through hole vertically overlapping with the plurality of recesses, a conductive anode disposed between the conductive layer and the light emitting structure, and disposed between the conductive anode and the conductive layer. Including a diffusion barrier layer that is,
The conductive layer includes a concave groove toward the diffusion barrier layer in the light emitting structure,
The conductive oxide electrode and the anti-diffusion layer are disposed in the groove,
The diffusion preventing electrode is a light emitting element spaced apart from an insulating layer disposed under the second conductivity type semiconductor layer.
According to claim 19,
The conductive oxide electrode includes a first surface closest to the light emitting structure,
The diffusion barrier layer includes a second surface closest to the light emitting structure,
The first surface and the second surface are disposed on the same plane.

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