KR20120045537A - Light emitting device and fabrication method there of - Google Patents

Abstract

PURPOSE: A light emitting device and a manufacturing method thereof are provided to improve light extraction efficiency by forming a uniform concavo-convex shape. CONSTITUTION: A metal layer is located on a conductive support substrate. A reflective layer(120) is located on the metal layer. An ohmic layer(130) is located on the reflective layer. A light emitting structure layer(150) comprises a first semiconductor layer arranged on the metal layer, the ohmic layer, an active layer, and a second semiconductor layer. A first protection layer(170) is arranged on a side surface of the light emitting structure layer. A part of the metal layer is exposed to the outside of the light emitting structure layer and comprises a second protection layer which is arranged on a side surface or an exposed upper part.

Description

Light emitting device and fabrication method thereof

The embodiment relates to a light emitting device having a protective layer and a method of manufacturing the same.

LED (Light Emitting Diode) is a device that converts an electric signal into infrared, visible light or light by using the characteristics of compound semiconductor.It is used in home appliances, remote controls, electronic signs, indicators, and various automation devices. Increasingly, the usage area is expanding.

On the other hand, the external quantum efficiency, which is the light efficiency of the light emitting device, is determined by the product of the internal quantum efficiency and the light extraction efficiency, and the internal quantum efficiency is determined by the quality of the semiconductor and the efficiency of current injection. The light extraction efficiency is reduced by total internal reflection due to the difference in refractive index between gallium nitride (GaN) and air in the light emitting device. In order to increase light extraction efficiency, a vertical light emitting device has been developed, and a method of forming surface irregularities has been developed. Unevenness of the surface may improve the light extraction efficiency of the light emitting device by minimizing the amount of light totally reflected from the surface.

However, it is difficult to form uniform surface irregularities due to the presence of the metal layer exposed to the outside of the light emitting structure layer.

Accordingly, an object of the present invention is to provide a light emitting device and a method for manufacturing the same, which include a nitride film or an oxide film to form uniform surface irregularities.

According to an embodiment of the present invention, a light emitting device includes a conductive support substrate, a metal layer positioned on the conductive support substrate, a reflective layer positioned on the metal layer, an ohmic layer positioned on the reflective layer, an ohmic layer, A light emitting structure layer comprising a first semiconductor layer, an active layer, and a second semiconductor layer on the metal layer, and a first protective layer positioned on the side of the light emitting structure layer, wherein the metal layer is at least partially exposed to the outside of the light emitting structure layer; And a second protective layer disposed on the top or side surfaces thereof.

In addition, a method of manufacturing a light emitting device according to an embodiment for solving the above problems, the step of forming a light emitting structure layer on a separate substrate, the step of forming an ohmic layer and a reflective layer on the light emitting structure layer, the metal layer Forming a conductive support substrate on the substrate, separating the detachable substrate from the light emitting structure layer, and plasma treating the upper and side surfaces of the metal layer exposed to the outside of the light emitting structure layer to form a second protective layer. Method of manufacturing a light emitting device.

According to the embodiment, the metal layer portion exposed to the outside by performing the plasma treatment is surrounded by a second protective layer made of a nitride film or an oxide film, so that the metal group of the metal layer can no longer come into contact with the OH-group, and the second protection By forming the layer, the etching rate of the semiconductor layer may be increased, and the light extraction efficiency may increase as the etching is performed uniformly, thereby increasing the light emission efficiency of the entire light emitting device.

1 is a cross-sectional view showing the structure of a light emitting device according to the embodiment.
2 to 7 illustrate a method of manufacturing the light emitting device of FIG. 1.
8 (a) to 8 (b) are diagrams showing changes in the light extraction effect according to the formation of unevenness.

In the description of embodiments, each layer, region, pattern, or structure is “under” a substrate, each layer (film), region, pad, or “on” of a pattern or other structure. In the case of being described as being formed on the upper or lower, the "on", "under", upper, and lower are "direct" "directly" or "indirectly" through other layers or structures.

In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. Also, the size of the component does not fully reflect its actual size.

Hereinafter, embodiments will be described in more detail with reference to FIGS. 1 to 8.

1 is a cross-sectional view showing the structure of a light emitting device according to the embodiment.

Referring to FIG. 1, the light emitting device 100 includes a conductive support substrate 110, a bonding layer 112 positioned on the conductive support substrate 110, a metal layer 140 positioned on the bonding layer 112, and a metal layer. Light emitting structure disposed on the reflective layer 120 and the reflective layer 120 and the ohmic layer 130 and the ohmic layer 130 and the metal layer 140 having the same width as the reflective layer 120. The layer 150, the second passivation layer 180 formed on the portion of the metal layer 140 where the light emitting structure layer 150 is not located, and the first passivation layer located on the side of the light emitting structure layer 150 ( 180).

The first passivation layer 170 may be formed of an insulating material, and may form the light emitting structure layer 150 along the side surface of the light emitting structure layer 150 from an upper portion of the metal layer 140 that does not vertically overlap with the light emitting structure layer 150. Up to a portion of the upper part).

By forming the first protective layer 170, the semiconductor layer and the chip can be protected and the leakage current can be suppressed.

The second passivation layer 180 may be formed by performing plasma treatment using nitrogen or oxygen gas. In the plasma treated region, a nitride film or an oxide film may be formed. The nitride film or oxide film may have a thickness of several tens of microwatts. In addition, it may have the effect of avoiding a short circuit between the metal layer 140 and the active layer 152 which is a metal.

The conductive support substrate 110 may be formed using a material having excellent thermal conductivity, and may be formed of a conductive material, and may be formed using a metal material or a conductive ceramic. The conductive support substrate 110 may be formed of a single layer and may be formed of a double or more multiple structures.

That is, the conductive support substrate 110 may be formed of any one selected from, for example, Au, Ni, W, Mo, Cu, Al, Ta, Ag, Pt, and Cr, or may be formed of two or more alloys. The above materials can be laminated and formed.

The conductive support substrate 110 may be formed to have a thickness of 30 μm to 200 μm, and may easily release heat generated from the light emitting device 100 to improve thermal stability of the light emitting device 100.

The bonding layer 112 is laminated to attach the conductive support substrate 110 to the metal layer 140, and the bonding layer 112 is formed of indium (In), tin (Sn), silver (Ag), and niobium (A). Nb), nickel (Ni), gold (Au), copper (Cu) may be made of at least one or an alloy thereof.

In this case, when the conductive support substrate 110 is coupled between the metal layer 140 and the reflective layer 120 and between the reflective layer 120 and the ohmic layer 130, diffusion is performed to prevent the metal from being transferred to the lower layer. A barrier wall (not shown) may be formed.

The ohmic layer 130 may include, for example, indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), and indium gallium (IGTO). tin oxide), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IrOx, RuOx, RuOx / ITO, Ni / IrOx / Au, and Ni / IrOx / Au / ITO, Pt, It may include at least one of Ni, Au, Rh, Pd.

Meanwhile, the reflective layer 120 and the ohmic layer 130 may have the same width, and as described below, the reflective layer 120 and the ohmic layer 130 may be formed through a simultaneous firing process, and thus may have excellent bonding force. have.

The reflective layer 120 is made of at least one of silver (Ag), aluminum (Al), lead (Pb), and rhodium (Rh) or an alloy thereof to reflect light moving toward the conductive support substrate 110. Therefore, the luminous efficiency of the light emitting device 100 that emits light through the light emitting structure layer can be increased.

As illustrated in FIG. 1, the reflective layer 120 and the ohmic layer 130 are described as having the same width and length, but at least one of the width and the length may be different, but is not limited thereto.

In this case, the metal layer 140 may be in contact with the outer peripheral side surfaces of the reflective layer 120 and the ohmic layer 130. The metal layer 140 may include at least one of a metal material and an insulating material. In the case of the metal material, the metal layer 140 is applied to the ohmic layer 130 using a material having a lower electrical conductivity than the material forming the ohmic layer 130. The power may be prevented from being applied to the metal layer 140.

The metal layer 140 includes titanium (Ti), nickel (Ni), platinum (Pt), lead (Pb), rhodium (Rh), iridium (Ir), tungsten (W), iron (Fe), and molybdenum (Mo). ) And vanadium (V). Or aluminum oxide (Al 2 O 3), silicon oxide (SiO 2), silicon nitride (Si 3 N 4) and titanium oxide (TiO x), indium tin oxide (ITO), aluminum zinc oxide (AZO) and aluminum zinc oxide It may include at least one of (IZO, Indium Zinc Oxide).

In this case, the metal layer 140 may include a metal material or an insulating material to form a plurality of layers.

In other words, the metal layer 140 may be made of a metal material. As the metal layer 140 is made of a metal material, an addition is improved, and the function of the current blocking layer (CBL) is improved. The CBL may be located below the upper electrode and vertically.

In addition, the metal layer 140 may prevent the material in the bonding layer 112 from being diffused into the ohmic layer 130 and the reflective layer 120.

The light emitting structure layer 150 may contact the ohmic layer 130 and the metal layer 140, and may include a first semiconductor layer 151, an active layer 152, and a second semiconductor layer 153. The active layer 152 may be interposed between the 151 and the second semiconductor layer 153.

In the first semiconductor layer 151, the n-type semiconductor layer is a semiconductor material having a composition formula of In _x Al _y Ga _1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), For example, it may be selected from GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like, and an n-type dopant such as Si, Ge, Sn, or the like may be doped.

Meanwhile, the electrode pad 160 may be formed of nickel (Ni) on the first semiconductor layer 151, and the entire or partial region of the surface of the first semiconductor layer 151 on which the electrode pad 160 is not formed. Concave-convex 158 can be formed in the region to improve light extraction efficiency by a predetermined etching method. The electrode pad 160 may be formed on a flat surface on which the unevenness 158 is not formed, or may be formed on an upper surface on which the unevenness 158 is formed, but is not limited thereto.

An active layer 152 may be formed under the first semiconductor layer 151. The active layer 152 is an area where electrons and holes are recombined. The active layer 152 may transition to a low energy level as the electrons and holes recombine, and may generate light having a corresponding wavelength.

An active layer 152, e.g., including a semiconductor material having a compositional formula of _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1) It may be formed, and may be formed of a single quantum well structure or a multi quantum well structure (MQW).

Therefore, more electrons are collected at the lower energy level of the quantum well layer, and as a result, the probability of recombination of electrons and holes can be increased, thereby improving the light emitting effect. In addition, a quantum wire structure or a quantum dot structure may be included.

The second semiconductor layer 153 may be formed under the active layer 152. The second semiconductor layer 153 may be implemented as a p-type semiconductor layer to inject holes into the active layer 152. For example, the p-type semiconductor layer is a semiconductor material having a composition formula of In _x Al _y Ga _{1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1), for example For example, it may be selected from GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like, and p-type dopants such as Mg, Zn, Ca, Sr, and Ba may be doped.

In addition, a third semiconductor layer (not shown) may be formed under the second semiconductor layer 153. The third semiconductor layer may be implemented as an n-type semiconductor layer.

On the other hand, since the external quantum efficiency, which is the light efficiency of the light emitting device, is determined by the product of the internal quantum efficiency and the light extraction efficiency, in order to increase the light extraction efficiency, surface texturing, flip-chip structure, and photonic crystal (Photo-Crystal), anti-reflection layer, etc. are used.

In an embodiment, an electrolyte solution of KOH and NaOH may be used using a photochemical etching method for forming surface irregularities. The principle of GaN photochemical etching is as follows.

That is, when ultraviolet rays are irradiated on the surface of GaN, holes which are a small charge are generated, and these holes move toward the surface, where OH-groups in the electrolyte react with GaN to form an oxide.

This oxide again reacts with the OH-group to dissolve and separate into the electrolyte. In other words, the GaN semiconductor is wet etched through the redox process in the electrolyte. Irradiating ultraviolet light may increase the etching rate by eventually supplying the excess holes to promote the redox reaction.

 At this time, the OH-group of the KOH and NaOH solution may react with the metal element constituting the metal layer 140, thereby preventing uniform etching of the light emitting structure layer 150, and ultimately, preventing the light extraction effect.

In order to increase the light extraction effect, the second protective layer 180 made of an insulating material including a nitride film or an oxide film is disposed on the exposed metal layer 140, thereby uniformly performing the above-described etching process. Can be etched.

In detail, the second passivation layer 180 may be formed by performing plasma treatment using nitrogen or oxygen gas. In the plasma treated region, a nitride film or an oxide film may be formed. The nitride film or oxide film may have a thickness of several tens of microwatts. In addition, it may have the effect of avoiding a short circuit between the metal layer 140 and the active layer 152 which is a metal.

In addition, the first passivation layer 170 may be further formed on the second passivation layer 180 including the nitride layer or the oxide layer.

That is, the first passivation layer 170 may be formed using an insulating material such as silicon oxide (SiO 2) or silicon nitride (Si 3 N 4), and the metal layer 140 may not overlap with the light emitting structure layer 150. The upper surface of the first semiconductor layer 151 may be formed to surround the second passivation layer 180 along the side surface of the light emitting structure layer 150 from above.

On the other hand, in the case of a nitride semiconductor such as GaN, the bonding force is high and the etching rate is low, so that the reactivity between the nitride semiconductor and the etching electrolyte may be increased by irradiating external light.

The first semiconductor layer 151, the active layer 152, and the second semiconductor layer 153 may be formed of metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), and plasma. Plasma-Enhanced Chemical Vapor Deposition (PECVD), Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), Sputtering But it is not limited thereto.

In addition, unlike the above-described embodiments, the first semiconductor layer 151 may be implemented as a p-type semiconductor layer, and the second semiconductor layer 153 may be implemented as an n-type semiconductor layer.

  2 to 7 illustrate a method of manufacturing the light emitting device of FIG. 1.

Referring to FIG. 2, the light emitting structure layer 150 is formed on the detachable substrate 101.

The detachable substrate 101 may be selected from the group consisting of a sapphire (Al ₂ O ₃ ) substrate, GaN, SiC, ZnO, Si, GaP, InP, and GaAs. A buffer layer (not shown) may be formed to mitigate lattice mismatch between the substrate 101 and the first semiconductor layer 151 and to easily grow the semiconductor layers.

The buffer layer (not shown) is formed using a metal material having excellent adhesion to the underlying material, and the metal material having excellent adhesion used as the buffer layer (not shown) includes indium (In), tin (Sn), and silver (Ag). , At least one of niobium (Nb), nickel (Ni), aluminum (Au), and copper (Cu), and in the form of a combination of Group 3 and Group 5 elements, among GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN. It may be made of either, and the dopant may be doped.

The buffer layer (not shown) includes AlNN / GaN stacked structure including AlN, GaN, In _x Ga _{1 - x} N / GaN stacked structure, Al _x In _y Ga _{1 -x- y} N / In _x Ga _{1 - x} N / It may be formed of a structure such as a laminated structure of GaN.

An undoped semiconductor layer (not shown) may be formed on the separation substrate 101 or the buffer layer (not shown).

Both the buffer layer (not shown) and the undoped semiconductor layer may be formed on the separation substrate 101, or may be formed in a structure in which only one layer is formed or both layers are removed. It doesn't work.

The light emitting structure layer 150 may include at least a first semiconductor layer 151, an active layer 152, and a second semiconductor layer 153, which are the same as described above with reference to FIG. 1, and thus a detailed description thereof will be omitted.

Although the ohmic layer 130 and the reflective layer 120 are simultaneously formed on the second semiconductor layer 153 of the light emitting structure layer 150, the present invention is not limited thereto.

That is, the ohmic layer 130 and the reflective layer 120 may be formed by successive simultaneous firing by a method such as sputtering.

Etching is performed on the outer regions of the ohmic layer 130 and the reflective layer 120. The mesa etching may be performed by dry etching, and since the ohmic layer 130 and the reflective layer 120 are simultaneously etched, the ohmic layer 130 and the reflective layer 120 may have the same width.

In addition, the reflective layer 120 may have a larger area than the ohmic layer 130, and may maximize the reflection characteristics of the reflective layer 120, thereby improving external luminous efficiency of the light emitting device 100.

In addition, due to mesa etching of the ohmic layer 130 and the reflective layer 120, the reflective layer 120 and the metal layer 140 may be partially overlapped or not overlapped vertically, but are not limited thereto.

As such, when the ohmic layer 130 and the reflective layer 120 are formed by firing at the same time, the adhesion between the ohmic layer 130 and the reflective layer 120 may be improved.

Subsequently, as illustrated in FIG. 3, the metal layer 140 may be formed on the second semiconductor layer 153, the etched reflective layer 120, and the ohmic layer 130 by using a method such as sputtering. It may be formed according to the method.

Subsequently, referring to FIG. 4, the conductive support substrate 110 may be formed on the reflective layer 120. The conductive support substrate 110 may be bonded to the metal layer 140 by the bonding layer 112.

When the conductive support substrate 110 is formed, the above-described separation substrate 101 is removed after the conductive support substrate 110 is positioned as a base.

Referring to FIG. 5, the separating substrate 101 is removed.

The separation substrate 101 may be removed by a physical or / and chemical method, and the physical method may be removed by, for example, a laser lift off (LLO) method.

The separation process of the separation substrate 101 is performed using a laser. For example, the laser lift-off (LLO) process irradiates an KrF excimer laser beam having a wavelength of 248 nm or an ArF excimer laser beam having a wavelength of 193 nm to an interface between the sapphire substrate and the light emitting structure through the sapphire substrate. do.

Light of this wavelength is not absorbed by the sapphire substrate, but is absorbed by the GaN-based semiconductor layer of the light emitting structure 150, so that the laser beam passing through the sapphire substrate is absorbed by the GaN-based semiconductor layer and rapidly absorbs the GaN-based semiconductor layer. Heat. After the heated GaN-based semiconductor layer is melted, it starts to generate high pressure and high temperature surface plasma. The plasma generation phenomenon appears only at the interface between the sapphire substrate and the GaN series semiconductor layer.

Thereafter, the plasma generated by melting the GaN-based semiconductor layer rapidly expands to the periphery thereof, thereby exerting a physical force on the sapphire substrate and the GaN-based semiconductor layer in opposite directions. Through this process, the substrate and the GaN-based semiconductor layer are separated.

In order to remove the sapphire substrate, a support structure (not shown) such as a metal or a semiconductor wafer may be attached on the upper side of the device on which the electrode is formed. A bonding layer 112 may be stacked to facilitate bonding of the support structure (not shown).

For example, a support structure (not shown) is stacked on the P-type electrode. The bonding layer 112 may be stacked first so that the metal support may adhere to the P-type electrode, and then a support structure (not shown) may be formed.

The support structure (not shown) may use any one of copper (Cu), gold (Au), nickel (Ni), aluminum (Al), or an alloy thereof. The thickness of the support structure (not shown) is preferably formed to 30 ~ 200μm.

The bonding layer 112 may use any one of titanium (Ti), platinum (Pt), gold (Au), nickel (Ni), aluminum (Al), or an alloy thereof.

Next, referring to FIG. 6, the detachable substrate 101 is removed and then turned upside down to perform etching on the outer region of the light emitting structure layer 150.

By mesa etching of the light emitting structure layer 150, the width of the metal layer 140 may be wider than that of the active layer 152.

Although not shown, a buffer layer (not shown) disposed on the light emitting structure layer 150 may be removed after the separation substrate 101 is removed. In this case, the buffer layer (not shown) may be removed through a dry or wet etching method or a polishing process.

Meanwhile, the unevenness 158 may be formed on a portion or the entire surface of the first semiconductor layer 151 by a predetermined etching method, and the electrode pad 160 may be formed on the surface of the first semiconductor layer 151. Form

The shape in which the unevenness 158 is formed is not limited to the shape shown in FIG. 6, and the unevenness 158 may be formed using a wet etching method.

When using a wet etching method to etch a portion or the entire region of the surface of the light emitting structure layer 150, KOH, NaOH electrolyte may be used. In the etching process, Ga 3+ ions on the surface of the light emitting structure layer 150 are combined with OH ions of KOH or NaOH solution to be decomposed into the solution. When Ga3 + ions are separated, N3- ions are bonded to N2 to form bubbles, and electrons are released through the electrode.

That is, the gallium nitride (GaN) element of the gallium (Ga) element of the semiconductor layer is combined with OH- group of KOH, NaOH, and must be decomposed into a solution to complete the etching. However, when the reactivity of the metal ions included in the metal layer 140 is greater than that of gallium (Ga), the OH-group and the metal ions included in the metal layer 140 react to reduce the etch rate of the light emitting structure layer 150. have. That is, when the metal ions of the metal layer 140 float on the surface layer, the reaction density of the OH-group with Ga decreases, and when the etching rate is reduced, the light extraction efficiency decreases, thereby reducing the overall light emission efficiency of the light emitting device 100. Can be reduced.

Therefore, when the light emitting structure layer 150 is etched, the metal layer 140 having a larger area than the light emitting structure layer 150 and thus not covered with the light emitting structure layer 150 may not react with the OH-group of NaOH or KOH. Plasma treatment is performed on the upper and side surfaces of the metal layer exposed to the outside using nitrogen or oxygen to form the second protective layer 180 having a predetermined thickness. The supply of nitrogen and oxygen uses a chamber, and plasma treatment means that the material supplies the energy necessary for bonding. The thickness of the oxide film or nitride film formed by plasma treatment using nitrogen or oxygen may be tens of ohms or more.

When the plasma treatment is performed, portions of the metal layer 140 exposed to the outside are stacked by the second protective layer 180 made of a nitride film or an oxide film so that the metal elements of the metal layer 140 can no longer come into contact with the OH-group. do. Accordingly, by forming the second passivation layer 180, the etching rate of the light emitting structure layer 150 is increased, and the light extraction efficiency is increased as the etching is performed uniformly, thereby increasing the light emitting efficiency of the entire light emitting device 100. have.

However, the etching electrolyte is not limited to NaOH and KOH electrolyte, and in the case of an electrolyte having an element capable of reacting with a metal element of the metal layer 140, all embodiments are applicable.

On the other hand, the electrode pad 160 is preferably formed corresponding to the position of the current blocking layer (CBL) (not shown). That is, the current limiting layer (not shown) is formed to correspond to the position of the electrode pad 160, thereby preventing the clustering phenomenon in which electrons provided through the electrode pad 160 are concentrated only on the lower portion of the electrode pad 160. FIG. have.

That is, a current limiting layer (not shown) may be formed on the other surface of the light emitting structure layer 150 so that at least a portion thereof corresponds to the position of the electrode pad 160. In addition, a groove may be formed in the ohmic layer 130 to correspond to at least a portion of the current limiting layer (not shown).

The current limiting layer (not shown) is, for example, when the first semiconductor layer 151 is implemented as an n-type semiconductor layer, a current in which electrons provided through the electrode pad 160 are concentrated only under the electrode pad 160. Can prevent clustering.

The current limiting layer (not shown) may be formed of at least two layers including silicon dioxide (SiO 2) and aluminum oxide (Al 2 O 3).

Next, referring to FIG. 7, after forming the second protective layer 180, the first protective layer 170 may be formed on the side surface of the light emitting structure.

The first passivation layer 170 may be formed of an insulating material, and may form the light emitting structure layer 150 along the side surface of the light emitting structure layer 150 from an upper portion of the metal layer 140 that does not vertically overlap with the light emitting structure layer 150. Up to a portion of the upper part).

By forming the first protective layer 170, the semiconductor layer and the chip can be protected and the leakage current can be suppressed.

8 (a) to 8 (b) are diagrams showing changes in the light extraction effect according to the formation of unevenness.

When the light generated from the multi quantum well (MQW) inside the light emitting device is emitted to the outside, the refractive index of GaN is 2.4 and the refractive index of air is 1, so that the critical angle due to the difference in refractive index decreases, resulting in total internal reflection. Loss of light may occur.

This reduces the light efficiency of the light emitting device 100. For example, when the semiconductor layer of the light emitting structure layer 150 is made of GaN, the critical angle of the light generated inside the light emitting device 100 is only 23 °, so that only a part of the generated light is emitted to the outside of the light emitting device 100. do.

Referring to the drawing, in the case of the light emitting device 100 in which the light generated from the light emitting structure layer 150 is not formed with the unevenness 158 or more, the amount of light emitted by the total reflection is emitted to the outside. In the case of forming the unevenness 158, the light path may be changed, and thus the amount of light emitted to the outside may increase.

However, it is specified that the shape of the unevenness 158 and the path of the light shown in the drawings are not limited. Depending on the shape of the unevenness 158, the light path and the light extraction efficiency may change.

The light emitting device 100 according to the embodiment may be mounted in a package. A plurality of light emitting device packages on which the light emitting device 100 is mounted may be arranged on a substrate, and a light guide plate may be an optical member on an optical path of the light emitting device package. Prism sheets, diffusion sheets, and the like may be disposed. The light emitting device package, the substrate, and the optical member may function as a light unit. Another embodiment may be implemented as a display device, an indicator device, or a lighting system including the light emitting device or the light emitting device package described in the above embodiments, and for example, the lighting system may include a lamp or a street lamp.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It should be understood that various modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention.

100 light emitting element 101 separation substrate
110: conductive support substrate 112: bonding layer
120: reflective layer 130: ohmic layer
140: metal layer 150: light emitting structure layer
160: electrode pad 170: first protective layer
180: second protective layer

Claims (13)

Conductive support substrate;
A metal layer on the conductive support substrate;
A reflective layer on the metal layer;
An ohmic layer positioned on the reflective layer;
A light emitting structure layer including a first semiconductor layer, an active layer, and a second semiconductor layer on the ohmic layer and the metal layer; and
And a first passivation layer positioned on a side of the light emitting structure layer.
The metal layer includes a second protective layer at least partially exposed to the outside of the light emitting structure layer and disposed on the exposed top or side surfaces. The method of claim 1,
The second protective layer,
An insulating light emitting device comprising a nitride film or an oxide film. The method of claim 1,
Light emitting device comprising an electrode pad on the light emitting structure layer. The method of claim 1,
The ohmic layer is made of at least one of indium (In), zinc (Zn), tin (Sn), nickel (Ni), lead (Pt), silver (Ag) or an alloy thereof. The method of claim 1,
The light emitting device layer, the light emitting device comprising a concave-convex on the top. The method of claim 1,
The light emitting device further comprises a bonding layer for coupling the conductive support substrate and the metal layer. The method of claim 1,
The reflective layer,
A light emitting device comprising at least one of silver (Ag), aluminum (Al), lead (Pb), rhodium (Rh) or an alloy thereof. The method of claim 1,
The metal layer,
A light emitting device comprising at least one of nickel (Ni), lead (Pb), titanium (Ti), tungsten (W), V (vanadium), iron (Fe), and molybdenum (Mo). Forming a light emitting structure layer on the separated substrate;
Forming an ohmic layer and a reflective layer on the light emitting structure layer;
Forming a metal layer on the reflective layer;
Forming a conductive support substrate on the metal layer;
Separating the detachable substrate from the light emitting structure layer; and
And forming a second passivation layer by performing plasma treatment on the upper and side surfaces of the metal layer exposed to the outside of the light emitting structure layer. The method of claim 9,
The second protective layer,
A method of manufacturing a light emitting device, which is an insulating material including a nitride film or an oxide film. The method of claim 9,
And forming a first passivation layer on side surfaces of the light emitting structure layer and an upper surface of the second passivation layer. The method of claim 9,
And etching the light emitting structure layer separated from the separated substrate, and forming an electrode pad on the light emitting structure layer having irregularities formed by the etching. The method of claim 9,
Forming the light emitting structure layer,
Forming a first semiconductor layer on the separated substrate, forming an active layer on the first semiconductor layer, and forming a second semiconductor layer on the active layer.

Images