KR20190129345A - Semiconductor device - Google Patents

Abstract

An embodiment of the present invention provides a semiconductor element which comprises: a light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer arranged on the first conductive semiconductor layer, and an active layer arranged between the first conductive semiconductor layer and the second conductive semiconductor layer; a first electrode electrically connected to the first conductive semiconductor layer; and a second electrode electrically connected to the second conductive semiconductor layer. The second electrode includes: a conductive oxide electrode arranged in a lower part of the light emitting structure; a conductive layer electrically connected to the conductive oxide electrode; and a diffusion prevention electrode arranged between the conductive oxide electrode and the conductive layer and surrounding a lower surface and a side surface of the conductive oxide electrode. An upper surface of the conductive oxide electrode and an upper surface of the diffusion prevention electrode are arranged on the same plane.

Description

Semiconductor device {SEMICONDUCTOR DEVICE}

An embodiment discloses a semiconductor device.

A semiconductor device including a compound such as GaN, AlGaN, etc. has many advantages, such as having a wide and easy-to-adjust band gap energy, and can be used in various ways as a light emitting device, a light receiving device, and various diodes.

Particularly, light emitting devices such as light emitting diodes and laser diodes using semiconductors of Group 3-5 or Group 2-6 compound semiconductors have been developed through the development of thin film growth technology and device materials. Various colors such as blue and ultraviolet light can be realized, and efficient white light can be realized by using fluorescent materials or combining colors.Low power consumption, semi-permanent lifespan, and fast response speed compared to conventional light sources such as fluorescent and incandescent lamps can be realized. It has the advantages of safety, environmental friendliness.

In addition, when a light-receiving device such as a photodetector or a solar cell is also manufactured using a group 3-5 or 2-6 compound semiconductor material of a semiconductor, the development of device materials absorbs light in various wavelength ranges to generate a photocurrent. As a result, light in various wavelengths can be used from gamma rays to radio wavelengths. It also has the advantages of fast response speed, safety, environmental friendliness and easy control of device materials, making it easy to use in power control or microwave circuits or communication modules.

Therefore, the semiconductor device may replace a light emitting diode backlight, a fluorescent lamp, or an incandescent bulb, which replaces a cold cathode tube (CCFL) constituting a backlight module of an optical communication means, a backlight of a liquid crystal display (LCD) display device. Applications are expanding to include white LED lighting devices, automotive headlights and traffic lights, and sensors that detect gas or fire. In addition, the semiconductor device may be extended to high frequency application circuits, other power control devices, and communication modules.

In particular, the light emitting device that emits light in the ultraviolet wavelength region can be used for curing, medical treatment, and sterilization by curing or sterilizing.

Recently, the research on the ultraviolet light emitting device is active, but the ultraviolet light emitting device has a problem that it is difficult to implement a vertical type, and there is a problem that the light extraction efficiency is relatively low.

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

The embodiment provides a semiconductor device having excellent current dispersion efficiency.

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

A semiconductor device according to an aspect of the present invention includes a first conductive semiconductor layer, a second conductive semiconductor layer disposed on the first conductive semiconductor layer, and the first conductive semiconductor layer and the second conductive type. A light emitting structure including an active layer disposed between the semiconductor layers; A first electrode electrically connected to the first conductive semiconductor layer; And a second electrode electrically connected to the second conductive semiconductor layer. Wherein the second electrode is a conductive oxide electrode disposed under the light emitting structure, a conductive layer electrically connected to the conductive oxide electrode, and disposed between the conductive oxide electrode and the conductive layer and the conductive oxide electrode. And a diffusion preventing electrode surrounding the lower surface and the side surface of the upper surface of the conductive oxide electrode and the upper surface of the diffusion preventing electrode.

According to another aspect of the present invention, a semiconductor device includes a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer. A light emitting structure including a second conductive semiconductor layer and a plurality of recesses penetrating through the active layer to a partial region of the first conductive semiconductor layer; A first electrode electrically connected to the first conductive semiconductor layer in the plurality of recesses; And a second electrode electrically connected to the second conductive semiconductor layer, wherein the second electrode includes a through hole vertically overlapping the plurality of recesses, the conductive layer, and the light emitting structure. A conductive oxide electrode disposed therebetween, and a diffusion barrier layer disposed between the conductive oxide electrode and the conductive layer, wherein the conductive layer includes a groove concave toward the diffusion barrier layer in the light emitting structure, and the conductive oxide electrode And the diffusion barrier layer are disposed in the groove.

According to the embodiment, the light extraction efficiency is improved.

In addition, the current dispersion efficiency is excellent, the light output can be improved.

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

1 is a conceptual diagram of a semiconductor device according to an embodiment of the present disclosure;
2 is an enlarged view of a portion 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 a diffusion preventing electrode,
5 is a view showing a structure in which an intermediate layer is disposed between the second conductive semiconductor layer and the second conductive layer,
6 is a modification of the structure of the diffusion preventing electrode,
7 is a plan view of a semiconductor device according to an embodiment of the present disclosure;
8 is an enlarged view of a portion 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 a portion C of FIG. 9;
11 is a modification 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 embodiment of the present invention.

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

Although matters described in a specific embodiment are not described in other embodiments, it may be understood as descriptions related to other embodiments unless there is a description that is contrary to or contradictory to the matters in other embodiments.

For example, if a feature is described for component A in a particular embodiment and a feature for component B in another embodiment, a description that is contrary or contradictory, even if the embodiments in which configuration A and configuration B are combined are not explicitly described. Unless otherwise, it should be understood to fall within the scope of the present invention.

In the description of the embodiment, when one element is described as being formed "on or under" of another element, it is on (up) or down (on). or under) includes both two elements being directly contacted with each other or one or more other elements are formed indirectly between the two elements. In addition, when expressed as "on" or "under", it may include the meaning of the downward direction as well as the upward direction based on one element.

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

1 is a conceptual diagram of a semiconductor device according to an embodiment of the present disclosure, FIG. 2 is an enlarged view of a 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 for the drawing.

The light emitting structure 120 according to the embodiment of the present invention may output light in the ultraviolet wavelength band. For example, the light emitting structure may output light in the near ultraviolet wavelength range (UV-A), may output light in the far ultraviolet wavelength range (UV-B), and emit light in the deep ultraviolet wavelength range (UV-C). You can print The wavelength range may be determined by the composition ratio of aluminum of the light emitting structure 120.

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

1 and 2, a semiconductor device according to an embodiment may include a light emitting structure 120 and first electrodes 142 and 165 electrically connected to a 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 conductive semiconductor layer 124, the second conductive semiconductor layer 127, and the first conductive semiconductor layer 124 and the second conductive semiconductor layer 127. The active layer 126 may be included.

The first conductive semiconductor layer 124 may be formed of a compound semiconductor such as a III-V group or a II-VI group, 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), for example For example, it may be selected from GaN, AlGaN, InGaN, InAlGaN and the like. 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 conductive semiconductor layer 124 doped with the first dopant may be an n-type semiconductor layer.

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

The active layer 126 may have 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 line structure, and the active layer 126. ) Is not limited thereto.

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

The light emitting structure according to the embodiment may include a plurality of recesses 128.

The plurality of recesses 128 may pass through the active layer 126 from the lower surface 127G of the second conductive semiconductor layer 127 to be disposed in a portion of the first conductive semiconductor layer 124. The first insulating layer 131 may be disposed in 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 an upper surface of the recess 128 to be electrically connected to the first conductive semiconductor layer 124.

As the light emitting structure 120 increases in aluminum composition, current dispersing characteristics may decrease in the light emitting structure 120. In addition, the amount of light emitted to the side of the active layer is increased compared to the GaN-based blue light emitting device (TM mode). This TM mode can occur mainly in ultraviolet semiconductor devices.

Ultraviolet semiconductor devices have poor current dissipation characteristics compared to blue GaN semiconductor devices. Accordingly, in the ultraviolet semiconductor device, it is necessary to dispose more first contact electrodes 142 than the blue GaN semiconductor device.

Referring to FIG. 3A, current is distributed only to a nearby point of each first contact electrode 142, and a current density may be sharply lowered at a long distance. Therefore, the effective light emitting area P2 can be narrowed.

The effective light emitting region P2 may be defined as an area up to a boundary point having a current density of 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 have a low current density and hardly contribute to light emission. Therefore, in the exemplary embodiment, the first contact electrode 142 may be further disposed in the low current density region P3 having a low current density, or the light output may be improved by using a reflective structure.

In general, in the case of GaN-based semiconductor devices that emit blue light, it is preferable to minimize the area of the recess 128 and the first contact electrode 142 because of relatively excellent current dispersion characteristics. This is because the larger the area of the recess 128 and the first contact electrode 142 is, the smaller the area of the active layer 126 is. However, in the embodiment, since the composition of aluminum is high and current dispersal characteristics are relatively low, even if the area of the active layer 126 is sacrificed, the number of the first contact electrodes 142 is increased to reduce the low current density region P3. Alternatively, it may be desirable to arrange the reflective structure in the low current density region P3.

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

Referring back to FIGS. 1 and 2, the second electrode pad 166 may be disposed in one corner area of the semiconductor device. The second electrode pad 166 may have a recessed portion and a convex portion at an upper surface thereof because the center portion thereof is recessed. Wires (not shown) may be bonded to the recesses of the upper surface. Therefore, the adhesive area is widened, and the second electrode pad 166 and the wire may be more firmly bonded.

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

The height of the convex portion of the second electrode pad 166 may be higher than that of the active layer 126. Accordingly, the second electrode pad 166 may reflect light emitted in the horizontal direction of the device from the active layer 126 to the top to improve light extraction efficiency and to control the direction angle.

The first insulating layer 131 may be partially opened under the second electrode pad 166 to electrically connect the second conductive layer 150 and the second contact electrode 246.

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

A width d22 of a 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, about 40 μm to about 90 μm. If the thickness is smaller than 40 μm, the operating voltage may be increased. If the thickness 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. In addition, 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 selected 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 in a single layer or multiple layers. For example, the first insulating layer 131 may be a distributed Bragg reflector (DBR) having a multilayer structure including silver Si oxide or a Ti compound. However, the present invention is not limited thereto, and the first insulating layer 131 may include various reflective structures.

When the first insulating layer 131 performs a reflection function, light extraction efficiency may be improved by reflecting light emitted toward the side from the active layer 126 upwardly. In the ultraviolet semiconductor device, as the number of the recesses 128 increases, the light extraction efficiency may be more effective than the semiconductor device emitting blue light.

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 bottom surface 127G of the second conductive semiconductor layer 127. The second contact electrode 246 may include a conductive oxide electrode with relatively low ultraviolet light absorption. For example, the conductive oxide electrode may be ITO, but is not limited thereto.

The second conductive layer 150 may inject a current into the second conductive semiconductor layer 127. In addition, 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 may contact the side and bottom surfaces 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 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, it 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 overlapping the plurality of recesses 128 in the vertical direction. That is, the second conductive layer 150 may be removed in an area where the recess 128 is disposed so that the first electrode 142 and the first conductive layer 165 disposed in the recess 128 are electrically connected to each other. Can be.

When the second conductive layer 150 contacts the side and bottom surfaces of the first insulating layer 131, thermal and electrical reliability of the second contact electrode 246 may be improved. In addition, it may have a reflection function to reflect the light emitted between the first insulating layer 131 and the second contact electrode 246 to the top.

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 shape of the lower surface of the light emitting structure 120 and the recess 128. The first conductive layer 165 may be made of a material having excellent reflectance. For example, the first conductive layer 165 may include aluminum. When the first conductive layer 165 includes aluminum, the light emitting efficiency may be improved by reflecting light emitted from the active layer 126 upward.

The bonding layer 160 may comprise 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 a current into the first conductive semiconductor layer 124. In exemplary embodiments, the conductive substrate 170 may include a metal or a semiconductor material. The conductive substrate 170 may be a metal having excellent electrical conductivity and / or thermal conductivity. In this case, heat generated during the operation of the semiconductor device may be quickly released 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.

Unevenness may be formed on the upper surface of the light emitting structure 120. Such unevenness may improve extraction efficiency of light emitted from the light emitting structure 120. The unevenness may have a different average height according to the ultraviolet wavelength, and in the case of UV-C, the light extraction efficiency may be improved when the UV-C has a height of about 300 nm to 800 nm and an average of about 500 nm to 600 nm.

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

The diffusion preventing electrode 247 may 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 to oxidize the second conductive layer 150. When the second conductive layer 150 is Al, it may react with oxygen to form an Al ₂ O ₃ interface layer. The Al ₂ O ₃ interface layer may have a lower UV reflectance than the Al layer. Therefore, when the second conductive layer 150 is prevented from being oxidized, the reflectance of the ultraviolet light may be increased to improve light extraction efficiency.

According to the embodiment, since the second conductive layer 150 is prevented from being oxidized by the diffusion preventing electrode 247, the problem of peeling the second contact electrode 246 and the second conductive layer 150 may be improved. . When the second conductive layer 150 reacts with oxygen to form an AlO _X oxide layer, the adhesion to 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 may also be lowered.

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

Gibbs energy is a thermodynamic function defined using the enthalpy, entropy and temperature of a system. If the Gibbs energy difference is greater than zero, the forward reaction (oxidation reaction) is involuntary and the reverse reaction is spontaneous. In contrast, if the Gibbs energy difference is less than zero, the forward reaction is spontaneous. Therefore, when the difference between the Gibbs energy of the diffusion barrier electrode 247 and the Gibbs energy of the second contact electrode 246 is positive, the reverse reaction becomes a spontaneous reaction and thus the oxidation degree may be lowered.

For example, since ITO and Al have a difference in Gibbs energy of −375.8 [KJ / mol], a positive oxidation reaction may occur spontaneously. In contrast, ITO and Ni have a difference in Gibbs energy of +65.4 [KJ / mol], and ITO and Rh may have relatively low oxidation because of a difference of Gibbs energy of +252.0 [KJ / mol].

The diffusion barrier electrode 247 may have an area that sufficiently covers the second contact electrode 246. This is because if the second contact electrode 246 is partially exposed, the adjacent second conductive layer 150 may be oxidized to reduce the reflectance.

Accordingly, the diffusion barrier electrode 247 may completely cover the bottom surface and the side surface of the second contact electrode 246 to block the second conductive layer 150. As a result, the diffusion barrier electrode 247 may contact the bottom surface 127G of the second conductive semiconductor layer 127.

Therefore, the upper surface of the second contact electrode 246 and the upper surface of the diffusion barrier electrode 247 may contact the lower surface 127G of the second conductive semiconductor layer 127. Accordingly, the top surface of the second contact electrode 246 and the top 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 semiconductor layer 127 below the light emitting structure, the upper surface of the second contact electrode 246 and the upper surface of the diffusion preventing electrode 247 contact the lowermost semiconductor layer. You may.

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

According to an embodiment, the area of the second contact electrode 246 may be reduced to increase the reflectance. When the second contact electrode 246 is a conductive metal oxide such as ITO, light absorption efficiency may be reduced because ultraviolet light is absorbed. Therefore, in the exemplary embodiment, light extraction efficiency may be improved by reducing the area of the second contact electrode 246.

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

The area S11 where the second contact electrode 246 contacts the bottom of the light emitting structure 120 is 30% to 50% of the area S13 where the diffusion preventing electrode 247 contacts the bottom of the light emitting structure 120. Can be. That is, the area S11 where the second contact electrode 246 contacts the lower portion of the light emitting structure 120 may be smaller than the area S13 where the diffusion preventing electrode 247 contacts the lower portion of the light emitting structure 120. .

If the area (S11) of the second contact electrode 246 in contact with the lower portion of the light emitting structure 120 is 30% or more, the area of the second contact electrode 246 is secured, thereby reducing the ohmic resistance and improving current injection efficiency. have. In addition, when the area is 50% or less, the area of the second contact electrode 246 may be reduced, thereby improving light extraction efficiency. At this time, since the diffusion preventing electrode 247 is in contact with the lower portion of the light emitting structure 120 can also be a Schottky junction can perform the function of the current injection path.

The area S11 where the second contact electrode 246 contacts the lower portion of the light emitting structure 120 is 10% to 30% of the area S14 where the second conductive layer 150 faces the lower portion of the light emitting structure 120. May be%. When the area is 10% or more, the area of the second contact electrode 246 is secured, thereby reducing the ohmic resistance, thereby improving current injection efficiency. In addition, when the area is 30% or less, the area in which the second conductive layer 150 contacts the second conductive semiconductor layer 127 to perform a reflection function may be increased to improve light extraction efficiency.

An area in which the first contact electrode 142 contacts the first conductive semiconductor layer 124 and an area in which the second contact electrode 246 contacts the second conductive semiconductor layer 127 have an inverse relationship. That is, when the number of the recesses 128 is increased in order to increase the number of the first contact electrodes 142, the area of the second contact electrode 246 is reduced. Therefore, in order to increase the electrical and optical characteristics, the dispersion characteristics of electrons and holes should 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 where the plurality of first contact electrodes 142 contact the first conductive semiconductor layer 124 is 70% to 90% of the area where the second contact electrode 246 contacts the lower portion of the light emitting structure 120. Can be. When the area is 70% to 90%, the area of the first contact electrode 142 and the area of the second contact electrode 246 may be adjusted at an appropriate ratio to improve the current density applied to the semiconductor device. Thus, the light output can be improved.

An area S13 of the diffusion preventing electrode 247 in contact with the lower portion of the light emitting structure 120 may be 57% to 77% of the area of the plurality of recesses 128. If the area is 57% or more, the area of the first electrode is increased in proportion to the area, thereby improving current injection efficiency. In addition, when the area is 77% or less, the area of the first contact electrode 142 may be reduced to lower the light absorption rate. In addition, the contact area between the second conductive layer 150 and the second conductive semiconductor layer 127 may increase to increase the reflectance.

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

The diffusion barrier electrode 247 is a first barrier electrode 247a disposed under the second contact electrode 246 and a second barrier electrode disposed between the first barrier electrode 247a and the second conductive layer 150. 247b. In addition, the present disclosure is not limited thereto, and the diffusion barrier electrode 247 may further include a third barrier electrode 247c and a fourth barrier electrode 247d.

In exemplary embodiments, the first protection electrode 247a may include Cr. The first prevention electrode 247a may improve the bonding force with the second contact electrode 246. In addition, the second protection electrode 247b may include Ni, the third protection electrode 247c may include Au, and the fourth protection electrode 247d may include Ti. However, the present disclosure is not necessarily limited thereto, and each prevention electrode may have various electrode layer structures.

According to the embodiment, the diffusion prevention electrode 247 may include a plurality of prevention electrode layers to improve adhesion and prevent oxygen from being diffused in the second contact electrode 246.

The conductive layer 150 may have a groove 150a concave in the direction of the conductive layer 150 in the second conductive semiconductor layer 127 of the light emitting structure. The second contact electrode 246 and the diffusion barrier 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 diffusion barrier 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. Can be. However, the present invention is not limited thereto, 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 semiconductor layer disposed separately. It 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. For example, the intermediate layer 151 and the first protection electrode 247a may include Cr. However, the present disclosure is not limited thereto, and the intermediate layer 151 and the first prevention electrode 247a may include various materials that may improve the adhesion of the layers.

In this case, the thickness of the intermediate layer 151 may be thinner than the first prevention electrode 247a. Since a metal such as Cr absorbs ultraviolet light, when the thickness of the intermediate layer 151 becomes thick, most of the ultraviolet light may be absorbed to reduce light extraction efficiency. On the contrary, since the first protection electrode 247a has a relatively small contact area with the second conductive semiconductor layer 127 and most of the first protection electrodes 247a are disposed under the second contact electrode, the first prevention electrode 247a may be made thicker to improve the bonding force rather than the reflection effect. Can be. For example, the first protection electrode 247a may be 100um to 200um, while the intermediate layer 151 may be 2um to 40um.

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

7 is a plan view of a semiconductor device according to an embodiment of the present invention, and FIG. 8 is an enlarged view of a portion B of FIG. 7.

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 diffusion barrier electrode 247 may be 28% to 48% of the diameter d4 of the recess 128. When the condition is satisfied, the second contact electrode 246 having an appropriate area can be secured, thereby improving light extraction efficiency.

9 is a plan view of a semiconductor device according to another exemplary embodiment of the present invention, FIG. 10 is an enlarged view of a portion C of FIG. 9, and FIG. 11 is a modification of FIG. 9.

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 on which the recess 128 and the first contact electrode 142 are disposed. A plurality of lines of the first cavity H1 may be connected to each other.

The shape of the first cavity H1 may be polygonal or circular. Although 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, the second cavity H2 may be smaller than the first cavity H1 so that the diffusion barrier electrode 247 covers the first cavity H1. The diffusion barrier 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 such a configuration, even current may be uniformly distributed on the side surface of the light emitting structure, thereby enabling uniform light emission. Due to the configuration of the edge portion 248, the plurality of first electrodes 142 may be disposed in the cavity formed by the second contact electrode 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 conductive semiconductor layer 124 to the second conductive semiconductor layer 127 so that electrons and holes can be recombined in the active layer 126. You can increase your chances. The energy band gap of the electron blocking layer 129 may be larger than the energy band gap of the active layer 126 and / or the second conductive 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. may be selected, 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.

An active layer 126 including a first conductive semiconductor layer 124, a barrier layer 126b, and a well layer 126a, a 2-1 conductive semiconductor layer 127a, and a 2-2 conductive semiconductor layer 127b may all comprise aluminum. Accordingly, the first conductive semiconductor layer 124, the barrier layer 126b, the well layer 126a, the second-first conductive semiconductor layer 127a, and the second-second conductive semiconductor layer 127b are formed of AlGaN. Can be. However, it is not necessarily limited thereto.

The thickness of the second-first conductive semiconductor layer 127a may be larger than 10 nm and smaller than 200 nm. If the thickness of the second-first conductive semiconductor layer 127a is smaller than 10 nm, the resistance may increase, thereby decreasing current injection efficiency. In addition, when the thickness of the 2-1 conductive semiconductor layer 127a is greater than 200 nm, crystallinity is degraded by the materials constituting the 2-1 conductive semiconductor layer 127a, thereby reducing reliability, electrical characteristics, and optical characteristics. This can be degraded.

The aluminum composition of the second-first conductive semiconductor layer 127a may be higher than that of the well layer 126a. The aluminum composition of the well layer 126a may be about 30% to 50% to generate ultraviolet light. If the aluminum composition of the 2-1 conductive semiconductor layer 127a is lower than that of the well layer 126a, the light extraction efficiency may decrease because the 2-1 conductive semiconductor layer 127a absorbs light. Can be.

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

The aluminum composition of the second-second conductive semiconductor layer 127b may be lower than that of the well layer 126a. When the aluminum composition of the second conductive semiconductor layer 127b is higher than the aluminum composition of the well layer 126a, the resistance between the second electrode and the second conductive semiconductor layer 127b becomes high and sufficient current injection is achieved. It may not be done.

The aluminum composition of the second-second conductive semiconductor layer 127b may be greater than 1% and less than 50%. If it is larger than 50%, sufficient ohmic may not be achieved with the second electrode. If the composition is smaller than 1%, there is a problem of absorbing light because it is almost close to the GaN composition.

The thickness of the second-2 conductive semiconductor layer 127b may be greater than 1 nm and smaller than 30 nm. As described above, the second conductive semiconductor layer 127b may absorb ultraviolet light because the composition of aluminum is low for ohmic. Therefore, it may be advantageous in terms of light output to control the thickness of the second-second conductive semiconductor layer 127b as thin as possible.

When the thickness of the second-second conductive semiconductor layer 127b is controlled to 1 nm or less, the second-second conductive semiconductor layer 127b is not disposed in some sections, and the second-first conductive semiconductor layer 127a is not disposed. An area exposed to the outside of the light emitting structure 120 may occur. Therefore, it may be difficult to configure one layer, and may be difficult to perform the role of the second-second conductive semiconductor layer 127b. In addition, when the thickness is larger than 30 nm, the amount of light to be absorbed may be too large to reduce the light output efficiency.

The second-second conductive semiconductor layer 127b may include the second-three conductive semiconductor layer 127c and the second-four conductive 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 for controlling the composition of aluminum.

The 2-4 conductive semiconductor layer 127d includes the 2-1 conductive semiconductor layer 127a containing a relatively high aluminum content and the 2-3 conductive semiconductor layer 127c including a relatively low aluminum content. ) May be disposed between. Therefore, it is possible to prevent the problem that the aluminum content changes rapidly and the crystallinity deteriorates.

The second conductive semiconductor layer 127c may have an aluminum composition of greater than 1% and less than 20%. Or the aluminum composition may be greater than 1% and less than 10%.

If the aluminum composition is lower than 1%, there may be a problem that the light absorption rate is too high in the 2-3 conductive semiconductor layer 127c. If the aluminum composition is higher than 20%, the contact resistance of the second electrode () becomes high. There may be a problem that the current injection efficiency is low.

However, the present invention is not limited thereto, and the aluminum composition of the second conductive semiconductor layer 127c may be adjusted in consideration of the current injection characteristic and the light absorption rate. Alternatively, it can be adjusted according to the light output or electrical characteristics required by the product.

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

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

The thickness of the second-second conductive semiconductor layer 127b may be smaller than the thickness of the second-first conductive semiconductor layer 127a. The thickness ratio of the 2-1 conductive semiconductor layer 127a and the 2-2 conductive semiconductor layer 127b may be 1.5: 1 to 20: 1. When the thickness ratio is smaller than 1.5: 1, the thickness of the 2-1 conductive semiconductor layer 127a may be too thin, thereby reducing current injection efficiency. In addition, when the thickness ratio is greater than 20: 1, the thickness of the second-second conductive semiconductor layer 127b may be too thin, thereby reducing ohmic reliability.

The aluminum composition of the second-first conductive semiconductor layer 127a may be smaller as it moves away from the active layer 126. In addition, the aluminum composition of the second-second conductive semiconductor layer 127b may be smaller as it moves away from the active layer 126. Therefore, the aluminum composition of the second conductive semiconductor layer 127c may satisfy 1% to 10%.

However, the present invention is not limited thereto, and the aluminum composition of the 2-1 conductive semiconductor layer 127a and the 2-2 conductive semiconductor layer 127b does not continuously decrease, but includes a section in which there is no decrease in a certain section. You may.

At this time, the aluminum reduction width of the 2-2 conductive semiconductor layer 127b may be greater than the aluminum reduction width of the 2-1 conductive semiconductor layer 127a. That is, the change rate in the thickness direction of the Al composition ratio of the 2-2 conductive semiconductor layer 127b may be greater than the change rate in the thickness direction of the Al composition ratio of the 2-1 conductive semiconductor layer 127a. The thickness direction may be a direction from the first conductive semiconductor layer 124 to the second conductive semiconductor layer 127 or a direction from the second conductive semiconductor layer 127 to the first conductive semiconductor layer 124. Can be.

While the thickness of the second-first conductive semiconductor layer 127a is thicker than that of the second-second conductive semiconductor layer 127b, the aluminum composition should be higher than that of the well layer 126a, so that the decrease may be relatively slow.

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

Referring to FIG. 13, the semiconductor device package is disposed on the body 2 having the groove 3, the semiconductor device 1 disposed on the body 2, and the body 2 to be electrically connected to the semiconductor device 1. It may include a pair of lead frames (5a, 5b) to be connected. The semiconductor device 1 may include all of the above configurations.

The body 2 may include a material or a 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 the same material or may include different materials.

The groove 3 may be wider as it is farther from the semiconductor device, 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 limited thereto. The light transmitting layer 4 is not particularly limited as long as it is a material that can effectively transmit ultraviolet light. The inside of the groove 3 may be an empty space.

The semiconductor device can be applied to various kinds of light source devices. For example, the light source device may be a concept including a sterilizing device, a curing device, a lighting device, and a display device and a vehicle lamp. That is, the semiconductor device may be applied to various electronic devices disposed in a case to provide light.

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

Illustratively, the water purifier may be provided with a sterilizing device according to the embodiment to sterilize the circulating water. The sterilization apparatus may be disposed at a nozzle or a discharge port through which water circulates to irradiate ultraviolet rays. At this time, the sterilization apparatus may include a waterproof structure.

The curing apparatus includes a semiconductor device according to an embodiment to cure various kinds of liquids. Liquids can be the broadest concept that includes all of the various materials that cure when irradiated with ultraviolet light. By way of example, the curing apparatus may cure various kinds of resins. Alternatively, the curing device may be applied to cure a cosmetic product such as a nail polish.

The lighting apparatus may include a light source module including a substrate and the semiconductor device of the embodiment, a heat dissipation unit for dissipating heat of the light source module, and a power supply unit for processing or converting an electrical signal provided from the outside and providing the light source module to the light source module. In addition, the lighting apparatus 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 reflecting plate is disposed on the bottom cover, and the light emitting module may emit light. The light guide plate may be disposed in front of the reflective plate to guide light emitted from the light emitting module to the front, and the optical sheet may include a prism sheet or the like to be disposed in front of the light guide plate. The display panel is disposed in front of the optical sheet, the image signal output circuit supplies an image signal to the display panel, and the color filter may be disposed in front of the display panel.

The semiconductor device may be used as an edge type backlight unit or a direct type backlight unit when used as a backlight unit of a display device.

The semiconductor element may be a laser diode in addition to the above-described light emitting diode.

Like the light emitting device, the laser diode may include the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer having the above-described structure. In addition, although the p-type first conductive semiconductor and the n-type second conductive semiconductor are bonded to each other, an electro-luminescence phenomenon is used in which light is emitted when an electric current flows, but the direction of the emitted light is used. There is a difference in and phase. That is, a laser diode may emit light having a specific wavelength (monochromatic beam) in the same direction with the same phase by using a phenomenon called excited emission and a constructive interference phenomenon. Therefore, it can be used for optical communication, medical equipment and semiconductor processing equipment.

For example, a photodetector may be a photodetector, which is a type of transducer that detects light and converts its intensity into an electrical signal. Such photodetectors include photovoltaic cells (silicon, selenium), photoelectric devices (cadmium sulfide, cadmium selenide), photodiodes (eg PDs with peak wavelengths in visible blind or true blind spectral regions) Transistors, photomultipliers, phototubes (vacuum, gas encapsulation), infrared (Infra-Red) detectors, and the like, but embodiments are not limited thereto.

In addition, a semiconductor device such as a photodetector may generally be manufactured using a direct bandgap semiconductor having excellent light conversion efficiency. Alternatively, the photodetector has various structures, and the most common structures include a pin photodetector using a pn junction, a Schottky photodetector using a Schottky junction, a metal semiconductor metal (MSM) photodetector, and the like. have.

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

Photovoltaic cells or solar cells are a type of photodiodes that can convert light into electrical current. The solar cell may include the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer having the above-described structure, similarly to the light emitting device.

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

In addition, the semiconductor device described above 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 by a p-type or n-type dopant. It may also be implemented using a doped semiconductor material or an intrinsic semiconductor material.

Although described above with reference to the embodiments are only examples and are not intended to limit the present invention, those skilled in the art to which the present invention pertains are not exemplified above within the scope not departing from the essential characteristics of the present embodiment. It will be appreciated that many variations and applications are possible. For example, each component specifically shown in the embodiment can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

Claims (20)

Light emission comprising 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. structure;
A first electrode electrically connected to the first conductive semiconductor layer; And
A second electrode electrically connected to the second conductive semiconductor layer; Including,
The second electrode is a conductive oxide electrode disposed under the light emitting structure, a conductive layer electrically connected to the conductive oxide electrode, and a lower surface and a side surface of the conductive oxide electrode disposed between the conductive oxide electrode and the conductive layer. Includes a diffusion preventing electrode surrounding the
And a top surface of the conductive oxide electrode and a top surface of the diffusion preventing electrode are disposed on the same plane.
The method of claim 1,
And a top surface of the conductive oxide electrode and a top surface of the diffusion preventing electrode contact the bottom surface of the second conductive semiconductor layer.
The method of claim 1,
And an area where the conductive oxide electrode contacts a lower portion of the light emitting structure is 30% to 50% of an area where the diffusion preventing electrode contacts a lower portion of the light emitting structure.
The method of claim 1,
The area of the conductive oxide electrode in contact with the lower portion of the light emitting structure is 10% to 30% of the area of the conductive layer facing the lower portion of the light emitting structure.
The method of claim 1,
The light emitting structure includes a plurality of recesses formed through the second conductive semiconductor layer and the active layer to a part of the first conductive semiconductor layer.
And the first electrode includes a plurality of contact electrodes disposed in the plurality of recesses to contact the first conductive semiconductor layer.
The method of claim 5,
The area of the plurality of contact electrodes in contact with the first conductivity type semiconductor layer is 70% to 90% of the area of the conductive oxide electrode in contact with the lower portion of the light emitting structure.
The method of claim 6,
The area of the diffusion preventing electrode in contact with the lower portion of the light emitting structure is 57% to 77% of the area of the plurality of recesses.
The method of claim 6,
The conductive oxide electrode is arranged in plurality between recesses,
And a diameter of the plurality of conductive oxide electrodes is smaller than a diameter of the recess.
The method of claim 8,
The diameter of the plurality of conductive oxide electrodes is 15% to 40% of the diameter of the recess.
The method of claim 9,
The diffusion preventing electrode has a diameter of 28% to 48% of the diameter of the recess.
The method of claim 5,
And the conductive oxide electrode includes a plurality of lines disposed in the plurality of recesses.
The method of claim 1,
The conductive oxide electrode includes a plurality of first cavities,
And the plurality of first electrodes are respectively disposed in the plurality of first cavities on a top view.
The method of claim 12,
The plurality of first cavities are polygonal shape.
The method of claim 12,
The diffusion preventing electrode includes a plurality of second cavities disposed inside the plurality of first cavities in a top view.
The method of claim 1,
The difference between the Gibbs energy of the diffusion preventing electrode and Gibbs energy of the conductive oxide electrode is positive.
The method of claim 1,
The diffusion preventing electrode includes at least one of Ni, Cr, Rh, Co, Au, Pt, Ti.
The method of claim 1,
The diffusion barrier electrode includes a second barrier electrode disposed between the conductive oxide electrode and the conductive layer, and a first barrier electrode disposed between the conductive oxide electrode and the second barrier electrode.
The method of claim 17,
An intermediate layer disposed between the lower portion of the light emitting structure and the conductive layer,
The thickness of the intermediate layer is thinner than the thickness of the first prevention electrode,
And the intermediate layer and the first prevention electrode have the same composition.
A first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer, and penetrating the second conductive semiconductor layer and the active layer. A light emitting structure including a plurality of recesses disposed to a part of the first conductivity type semiconductor layer;
A first electrode electrically connected to the first conductive semiconductor layer in 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 the plurality of recesses, a conductive oxide electrode disposed between the conductive layer and the light emitting structure, and between the conductive oxide electrode and the conductive layer. Including a diffusion barrier layer,
The conductive layer includes a groove concave toward the diffusion barrier layer in the light emitting structure,
And the conductive oxide electrode and the diffusion barrier layer are disposed in the groove.
The method of 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 light emitting device having the first surface and the second surface disposed on the same plane.

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