KR102350784B1 - Uv light emitting device and lighting system - Google Patents

Abstract

The ultraviolet light emitting device according to the embodiment includes a first conductive type second semiconductor layer 112; a second conductivity type fourth semiconductor layer 116 disposed under the first conductivity type second semiconductor layer 112; an active layer 114 disposed between the first conductivity type second semiconductor layer 112 and the second conductivity type fourth semiconductor layer 116; A portion of the first conductivity type second semiconductor layer 112 penetrates through the second conductivity type fourth semiconductor layer 116 and the active layer 114 from the bottom surface of the second conductivity type fourth semiconductor layer 116 . a plurality of holes (H) exposing the; a first contact electrode 160 electrically connected to the first conductivity type second semiconductor layer 112 from the bottom surface of the second conductivity type fourth semiconductor layer 116 through the plurality of holes H; an insulating layer 140 disposed between the first contact electrode 160 and the plurality of holes H; and a first conductivity type third semiconductor layer 113 disposed between the first contact electrode 160 and the first conductivity type second semiconductor layer 112 .

Description

UV light emitting device and lighting system {UV LIGHT EMITTING DEVICE AND LIGHTING SYSTEM}

The embodiment relates to a light emitting device, a method for manufacturing a light emitting device, a light emitting device package, and a lighting system.

Light Emitting Diode is a pn junction diode having a characteristic in which electric energy is converted into light energy. Various colors can be realized by adjusting.

For example, nitride semiconductors are receiving great attention in the field of developing optical devices and high-power electronic devices due to their high thermal stability and wide bandgap energy. In particular, ultraviolet (UV) light-emitting devices, blue light-emitting devices, green light-emitting devices, and red light-emitting devices using nitride semiconductors have been commercialized and widely used.

For example, in the case of an ultraviolet light emitting device (UV LED), it is a light emitting device that generates light distributed in a wavelength range of 200 nm to 400 nm. Or it may be used in a curing machine and the like.

For example, a near UV light emitting device (Near UV LED) is used for counterfeit detection, resin curing, or UV treatment, and is also used in lighting devices that realize visible light of various colors in combination with a phosphor.

On the other hand, the ultraviolet light emitting device has a problem in that light acquisition efficiency and light output are inferior compared to the blue light emitting device. This is acting as a barrier to the practical use of the ultraviolet light emitting device.

For example, a group III nitride used in an ultraviolet light emitting device can be widely used from visible light to ultraviolet light, but there is a problem in that the efficiency of ultraviolet light compared to visible light is lowered. The reason is that group III nitride absorbs ultraviolet rays as the wavelength of ultraviolet rays increases, and the internal quantum efficiency decreases due to low crystallinity.

Accordingly, according to the conventional UV LED technology, in order to prevent UV absorption in group III nitride, a growth substrate, a GaN layer, an AlGaN layer, an active layer, etc. are sequentially grown, and then a GaN layer with a potential for UV absorption is removed and an AlGaN layer. It is manufactured in the form of a vertical light emitting device that exposes

On the other hand, among the light emitting devices according to the prior art, there is a horizontal type light emitting device in which an electrode layer is disposed in one direction of the epitaxial layer. As (Vf) increases, the current efficiency decreases, and in order to improve the luminous intensity (Po) and solve the problem of being vulnerable to electrostatic discharge, a via hole type vertical light emitting device in which an electrode is disposed by forming a via hole under the epi layer is being developed

In order to manufacture such a via hole type vertical light emitting device, a plurality of mesa etchings for n-contact are performed, and an insulating layer is formed between the n-contact and the mesa etching hole. can be formed

However, when a via hole type vertical light emitting device is applied to a UV light emitting device, the contact electrode passing through the via hole is in direct contact with the exposed AlGaN layer, and since the AlGaN layer has a large bandgap energy, there is a problem in that the operating voltage is increased.

Embodiments are to provide an ultraviolet light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system in which the operating voltage is improved while the luminous intensity is improved.

The ultraviolet light emitting device according to the embodiment includes a first conductive type second semiconductor layer 112; a second conductivity type fourth semiconductor layer 116 disposed under the first conductivity type second semiconductor layer 112; an active layer 114 disposed between the first conductivity type second semiconductor layer 112 and the second conductivity type fourth semiconductor layer 116; A portion of the first conductivity type second semiconductor layer 112 penetrates through the second conductivity type fourth semiconductor layer 116 and the active layer 114 from the bottom surface of the second conductivity type fourth semiconductor layer 116 . a plurality of holes (H) exposing the; a first contact electrode 160 electrically connected to the first conductivity type second semiconductor layer 112 from the bottom surface of the second conductivity type fourth semiconductor layer 116 through the plurality of holes H; an insulating layer 140 disposed between the first contact electrode 160 and the plurality of holes H; and a first conductivity type third semiconductor layer 113 disposed between the first contact electrode 160 and the first conductivity type second semiconductor layer 112 .

The lighting system according to the embodiment may include a light emitting unit including the light emitting device.

According to the embodiment, it is an object of the present invention to provide an ultraviolet light emitting device in which an operating voltage is improved while luminous intensity is improved, a method for manufacturing an ultraviolet light emitting device, a light emitting device package, and a lighting system.

1 is a plan view of a light emitting device according to an embodiment;
2 is an enlarged cross-sectional view of a light emitting device according to the embodiment;
3 to 11 are cross-sectional views illustrating a method of manufacturing a light emitting device according to an embodiment.
12 is a cross-sectional view of a light emitting device package according to the embodiment;
13 is an exploded perspective view of a lighting device according to the embodiment;

In the description of embodiments, each layer (film), region, pattern or structure is “on/over” or “under” the substrate, each layer (film), region, pad or pattern. In the case of being described as being formed on, “on/over” and “under” include both “directly” or “indirectly” formed through another layer. do. In addition, the reference for the upper / upper or lower of each layer will be described with reference to the drawings.

(Example)

1 is a plan view of a light emitting device 100 according to an embodiment, and FIG. 2 is an enlarged cross-sectional view taken along line A-A' of FIG. 1 .

The ultraviolet light emitting device according to the embodiment includes a first conductivity type second semiconductor layer 112 , a second conductivity type fourth semiconductor layer 116 , an active layer 114 , a first contact electrode 160 , and an insulating layer 140 . , the first conductivity type third semiconductor layer 113 may be included.

For example, the ultraviolet light emitting device according to the embodiment may include a first conductive type second semiconductor layer 112 ; a second conductivity type fourth semiconductor layer 116 disposed under the first conductivity type second semiconductor layer 112; an active layer 114 disposed between the first conductivity type second semiconductor layer 112 and the second conductivity type fourth semiconductor layer 116; A portion of the first conductivity type second semiconductor layer 112 passes through the second conductivity type fourth semiconductor layer 116 and the active layer 114 from the bottom surface of the second conductivity type fourth semiconductor layer 116 . a plurality of holes (H) exposing the; a first contact electrode 160 electrically connected to the first conductivity type second semiconductor layer 112 from the bottom surface of the second conductivity type fourth semiconductor layer 116 through the plurality of holes H; an insulating layer 140 disposed between the first contact electrode 160 and the plurality of holes H; and a first conductivity type third semiconductor layer 113 disposed between the first contact electrode 160 and the first conductivity type second semiconductor layer 112 .

In addition, the embodiment may include a first electrode layer 150 electrically connected to the first contact electrode 160 and a second contact electrode 132 electrically connected to the second conductivity-type fourth semiconductor layer 116 . have.

The first electrode layer 150 may include a bonding layer 156 electrically connected to the first contact electrode 160 and a support member 158 disposed under the bonding layer 156 .

The embodiment may include a first conductivity type third semiconductor layer 113 disposed between the first contact electrode 160 and the first conductivity type second semiconductor layer 112 .

The first contact electrode 160 may directly contact the first conductivity-type third semiconductor layer 113 .

The first conductivity-type second semiconductor layer 112 may include an n-type AlGaN-based semiconductor layer, and the first conductivity-type third semiconductor layer 113 may include an n-type GaN-based semiconductor layer.

The first conductivity-type fourth semiconductor layer 116 may include a p-type AlGaN-based semiconductor layer.

According to the prior art, when a via hole type vertical light emitting device is applied to a UV light emitting device, there is a problem in that the operating voltage increases as the contact electrode passing through the via hole is in direct contact with the AlGaN layer having high bandgap energy.

According to this embodiment, a first conductivity type third semiconductor layer 113 is disposed between the first contact electrode 160 and the first conductivity type second semiconductor layer 112 , and the first contact electrode ( The luminous intensity of 160 may be improved without increasing the operating voltage by making it come into contact with the third semiconductor layer 113 of the first conductivity type.

Hereinafter, a method of manufacturing a light emitting device according to an embodiment will be described with reference to FIGS. 3 to 11 .

First, as shown in FIG. 3 , the light emitting structure layer 110 may be formed on the growth substrate 105 . The light emitting structure layer 110 may include a first conductivity type second semiconductor layer 112 , an active layer 114 , and a second conductivity type fourth semiconductor layer 116 .

The growth substrate 105 may be loaded into a growth device and formed in a layer or pattern form using a compound semiconductor of a group II to group VI element thereon.

The growth equipment includes an electron beam evaporator, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma laser deposition (PLD), dual-type thermal evaporator sputtering, and metal organic chemical vapor (MOCVD). deposition) may be employed, but is not limited to such equipment.

The growth substrate 105 may be a conductive substrate or an insulating substrate. For example, the growth substrate 105 may be selected from the group consisting _{of a sapphire substrate (Al 2} 0 ₃ ), GaN, SiC, ZnO, Si, GaP, InP, Ga ₂ 0 _{3 , and GaAs.}

A buffer layer (not shown) may be formed on the growth substrate 105 . The buffer layer reduces the difference in lattice constant between the growth substrate 105 and the nitride semiconductor layer, and the material thereof is GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP. can be selected from

An undoped semiconductor layer (not shown) may be formed on the buffer layer, and the undoped semiconductor layer may be formed of an undoped GaN-based semiconductor, and may be formed of a semiconductor layer having lower conductivity than the n-type semiconductor layer. .

Thereafter, a first conductivity type first semiconductor layer 111 may be formed on the buffer layer or the undoped semiconductor layer.

The first conductivity type first semiconductor layer 111 may include a first conductivity type GaN-based semiconductor material. For example, the first conductivity type first semiconductor layer 112 may be formed of any one of a GaN semiconductor layer and an InGaN semiconductor layer.

Next, a first conductivity type second semiconductor layer 112 may be formed on the first conductivity type first semiconductor layer 111 , and an active layer 114 may be formed on the first conductivity type second semiconductor layer 112 . ) may be formed, and a second conductivity-type fourth semiconductor layer 116 may be sequentially stacked on the active layer 114 .

Other layers may be further disposed above or below each of the semiconductor layers, and may be formed in a superlattice structure using, for example, a group III-V compound semiconductor layer, but is not limited thereto.

The first conductivity-type second semiconductor layer 112 may be an AlGaN-based semiconductor layer doped with a first conductivity-type dopant. For example, the first conductivity type second semiconductor layer 112 may be selected from AlN, AlGaN, InAlGaN, AlInN, AlGaAs, AlGaInP, and the like.

The first conductivity-type second semiconductor layer 112 may be an n-type semiconductor layer, and the first conductivity-type dopant may include an n-type dopant such as Si, Ge, Sn, Se, Te, or the like.

The first conductivity-type second semiconductor layer 112 may be an n-type AlGaN-based semiconductor layer, and the Al composition may be about 4% to about 10%. In the first conductivity type second semiconductor layer 112, when the Al composition is less than 4%, the luminous intensity (Po) may decrease due to light absorption, and when it exceeds 10%, cracks occur in the light emitting structure layer due to crystal quality deterioration or resistance may increase.

The embodiment may include a first conductivity type third semiconductor layer 113 disposed on the first conductivity type second semiconductor layer 112 .

The first conductivity type third semiconductor layer 113 may be a first conductivity type GaN-based semiconductor layer. For example, the first conductivity-type third semiconductor layer 112 may be formed of any one of a GaN semiconductor layer and an InGaN semiconductor layer.

After the first conductive type second semiconductor layer 112 is first formed, the first conductive type third semiconductor layer 113 is selectively formed in the exposed region using a predetermined mask (not shown), and then the mask is removed The first conductivity-type second semiconductor layer 112 may be formed secondary.

For example, the mask may be an insulating mask as a mask exposing a region where the first conductivity-type third semiconductor layer 113 is to be formed. For example, the mask may be an oxide such as _{SiO 2 or a nitride such as Si 3} N ₄ , but is not limited thereto. Alternatively, according to an embodiment, as shown in FIG. 4 , the second conductivity type fourth semiconductor layer ( 116) and a plurality of holes H penetrating through the active layer 114 and exposing a portion of the first conductivity type second semiconductor layer 112 are formed, and then the exposed first conductivity type second semiconductor layer 112 is formed. A first conductivity type third semiconductor layer 113 may be formed thereon, but is not limited thereto.

The active layer 114 may be formed of at least one of a single quantum well structure, a multi quantum well (MQW) structure, a quantum-wire structure, or a quantum dot structure.

For example, in the active layer 114, trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and trimethyl indium gas (TMIn) are injected to form a multi-quantum well structure. The present invention is not limited thereto.

The active layer 114 may include a quantum well and a quantum wall. For example, the active layer 114 may include InGaN/AlGaN, InAlGaN/AlGaN, AlGaN/GaN, AlGaN/AlGaN, InGaN/GaN, InGaN/InGaN, InAlGaN/GaN, GaAs/AlGaAs, InGaAs/AlGaAs, GaP/AlGaP, It may be formed in any one or more pair structures of InGaP AlGaP, but is not limited thereto.

In an embodiment, the active layer 114 may be formed of an InGaN quantum well having an In composition of 3% or less and an AlGaN quantum wall having an Al composition of 5% or more, but is not limited thereto. In addition, when the quantum well is made of InAlGaN, the In content may be about 3% or more depending on the Al composition. For example, as the composition of Al increases, the composition of In may be about 3% or more. In an embodiment, the thickness of the quantum well may be about 2 nm to about 10 nm, and the thickness of the quantum well may be about 2 nm to about 20 nm, but is not limited thereto. If the thickness of the quantum well is less than 2 nm, the light emitting function may be lowered, so that the luminous efficiency may be lowered, and if the thickness is more than 10 nm, the crystal quality may be deteriorated. If the thickness of the quantum well is less than 2 nm, the function as a barrier may be deteriorated, and if it exceeds 20 nm, the crystal quality may be deteriorated.

The second conductivity type fourth semiconductor layer 116 may be a second conductivity type AlGaN-based semiconductor layer.

For example, the second conductivity type fourth semiconductor layer 116 may include a semiconductor material having a composition formula of _{Al q} Ga _{1-q N (0≤q≤1).} When the second conductivity-type fourth semiconductor layer 116 is a p-type semiconductor layer, the second conductivity-type dopant is a p-type dopant and may include Mg, Zn, Ca, Sr, Ba, or the like.

In the embodiment, the second conductivity type fourth semiconductor layer 116 may contain Al to prevent a decrease in luminosity (Po Drop) due to light absorption, unlike a blue chip, and the Al composition is about It may be between 3% and about 10%. When the Al composition in the second conductivity-type fourth semiconductor layer 116 is less than 3%, the luminous intensity may decrease, and if it exceeds 10%, the crystal quality may decrease.

In the embodiment, a p-GaN layer (not shown) may be further formed on the second conductivity-type fourth semiconductor layer 116 to lower the contact resistance to prevent an increase in the operating voltage. The p-GaN layer may have a thickness of about 10 nm or less, and a Mg doping concentration of about 1×10 ²⁰ (atoms/cm 3 ) or more. When the thickness of the p-GaN layer (not shown) is greater than 10 nm or when the Mg doping concentration is ^{less than about 1X10 20} (atoms/cm 3 ), it may be difficult to contribute to lowering of the contact resistance.

In the embodiment, an electron blocking layer (not shown) having an Al composition in the range of 15% to 35% may be formed between the second conductivity type fourth semiconductor layer 116 and the active layer 114, and the electron blocking layer is p -Can be formed of AlGaN. When the Al composition of the electron blocking layer is less than 15%, the bandgap energy level is low, so it may be difficult to function as an electron blocking layer, and when it exceeds 35%, the crystal quality may be deteriorated.

The first conductivity type second semiconductor layer 112 , the active layer 114 , and the second conductivity type fourth semiconductor layer 116 may be defined as a light emitting structure layer 110 . In addition, a third conductivity type semiconductor layer (not shown), for example, a semiconductor layer having a polarity opposite to that of the second conductivity type may be formed on the second conductivity type fourth semiconductor layer 116 .

Accordingly, the light emitting structure layer 110 may include at least one of an n-p junction, a p-n junction, an n-p-n junction, and a p-n-p junction structure. In the following description, a structure in which the second conductive type fourth semiconductor layer 116 is disposed on the uppermost layer of the light emitting structure layer 110 will be described as an example.

Next, as shown in FIG. 4 , a mesa etching process for removing a portion of the light emitting structure may be performed.

For example, a portion of the first conductivity type second semiconductor layer 112 or the first conductivity type third semiconductor layer 113 penetrating through the second conductivity type fourth semiconductor layer 116 and the active layer 114 . ) exposing a plurality of holes (H) may be formed.

According to an embodiment, when the first conductivity type third semiconductor layer 113 is not previously formed, the first conductivity type third semiconductor layer 113 is formed on the exposed first conductivity type second semiconductor layer 112 . can be formed.

In an embodiment, the plurality of holes H are formed at a predetermined angle from the first conductivity type second semiconductor layer 112 to the upper surface of the second conductivity type fourth semiconductor layer 116 , for example, the light emitting structure layer 110 . It may be formed at an obtuse angle with respect to the upper surface of the , but is not limited thereto.

In an embodiment, the horizontal width of the plurality of holes H may decrease toward the lower side. Meanwhile, in FIG. 2 , the horizontal widths of the plurality of holes H may decrease toward the upper side.

2, according to the embodiment, the area of the active layer 114 and the first conductivity type second semiconductor layer 112 that are removed by decreasing the horizontal width of the plurality of holes H toward the upper side is reduced. It can contribute to the luminous efficiency.

Next, as shown in FIG. 5 , the channel layer 120 may be formed on the plurality of holes H. The channel layer 120 may not be formed in a region where the first contact electrode 160 to be formed later will be formed.

The channel layer 120 may function as an electrical insulating layer between the first contact electrode 160 , the active layer 114 , and the second conductivity-type fourth semiconductor layer 116 to be formed later.

The channel layer 120 may be formed of at least one material selected _{from SiO x} , SiO _x N _y , Al ₂ O ₃ , and TiO _{2 .}

Also, in an embodiment, the reflectance of the channel layer 120 may be greater than 50%. For example, the channel layer 120 may be formed of a material selected from among _{SiO 2} , SiO _x , SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ , and TiO _{2 , and the insulating material has a reflective material} It may be formed in a mixed form.

For example, the channel layer 120 may be formed in a form in which one or more of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, or Hf is mixed with an insulating material. can

According to the embodiment, when the emitted light moves downward, it is reflected by the channel layer 120 to minimize light absorption and increase light efficiency.

Next, a second contact electrode 132 may be formed on the second conductivity-type fourth semiconductor layer 116 .

The second contact electrode 132 is in ohmic contact with the second conductivity-type fourth semiconductor layer 116 , includes at least one conductive material, and may be formed of a single layer or multiple layers.

For example, the second contact electrode 132 may include at least one of a metal, a metal oxide, and a metal nitride.

The second contact electrode 132 includes a light-transmitting material, for example, indium tin oxide (ITO), indium zinc oxide (IZO), IZO nitride (IZON), indium zinc tin oxide (IZTO), or indium aluminum (IAZO). zinc oxide), IGZO (indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IrOx, RuOx, RuOx/ITO, Ni It may include at least one of /IrOx/Au, Ni/IrOx/Au/ITO, Pt, Ni, Au, Rh, or Pd.

Next, a reflective layer 134 may be formed on the second contact electrode 132 .

The reflective layer 134 is disposed on the second contact electrode 132 , and may reflect light incident through the second contact electrode 132 .

The reflective layer 134 includes a metal, for example, one layer or a plurality of materials made of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, and alloys of two or more thereof. It can be formed in layers.

Next, a capping layer 136 may be formed on the reflective layer 134 . The second electrode layer 130 including the second contact electrode 132 , the reflective layer 134 , and the capping layer 136 may be referred to as a second electrode layer 130 , the power supplied from the pad electrode 180 . may be supplied to the second conductivity-type fourth semiconductor layer 116 .

The capping layer 136 is disposed on the reflective layer 134 and may supply power supplied from the pad electrode 180 to the reflective layer 134 . The capping layer 136 may function as a current diffusion layer.

The capping layer 136 includes a metal and is a material with high electrical conductivity, for example, Sn, Ga, In, Bi, Cu, Ni, Ag, Mo, Al, Au, Nb, W, Ti, Cr, Ta, Al, Pd, Pt, Si and at least one of an optional alloy thereof may be formed as a single layer or a multi-layer.

Next, as shown in FIG. 6 , an insulating layer 140 may be formed on the capping layer 136 and the channel layer 120 .

The insulating layer 140 may be formed to expose the first contact electrode 160 .

The insulating layer 140 electrically insulates between the first contact electrode 160 and another semiconductor layer.

In addition, the insulating layer 140 may be disposed between the first electrode layer 150 and the channel layer 120 to be formed later to block electrical contact.

The insulating layer 140 may be formed of a material selected _{from SiO 2} , SiO _x , SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ , and TiO _{2 .}

The insulating layer 140 may have a reflectance greater than 50%. For example, the insulating layer 140 _{may be formed of a material selected from among SiO 2} , SiO _x , SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ , and TiO ₂ , and the insulating material has a reflective material. It may be formed in a mixed form.

For example, the insulating layer 140 may be formed of a mixture of any one or more of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, or Hf.

According to the embodiment, the physical properties of the insulating layer 140 formed between the first contact electrode 160 and the plurality of holes H are formed of a reflective layer material to reduce light absorption in the insulating layer 140 having a passivation function. It is possible to increase the light efficiency by minimizing it.

Next, a first contact electrode 160 may be formed on the first conductivity-type third semiconductor layer 113 .

The first contact electrode 160 may have a circular or polygonal shape when viewed from above, but is not limited thereto.

In an embodiment, the first contact electrode 160 may be in contact with the first conductivity-type third semiconductor layer 113 .

According to the embodiment, a first conductivity type third semiconductor layer 113 is disposed between the first contact electrode 160 and the first conductivity type second semiconductor layer 112 , and the first contact electrode 160 ) may be brought into contact with the third semiconductor layer 113 of the first conductivity type, thereby improving the luminous intensity without increasing the operating voltage.

Referring to FIG. 6 , in the embodiment, the width of the first contact electrode 160 may increase from the bottom surface to the top surface. Meanwhile, with reference to FIG. 2 , the width of the first contact electrode 160 may decrease from the top surface to the bottom surface.

Through this, the possibility of the first contact electrode 160 being short-circuited with the material of the second electrode layer 130 to be formed thereafter is reduced, and the region where the first contact electrode 160 is in contact with the third semiconductor layer 113 of the first conductivity type. The light efficiency may be increased by maximizing the luminance and decreasing the area occupied by the first contact electrode 160 .

Meanwhile, when explaining with reference to FIG. 2 , the horizontal width of the bottom surface of the first contact electrode 160 and the horizontal width of the diffusion barrier layer 154 in contact with the first contact electrode 160 are made to match. (154), while minimizing the area occupied by the first contact electrode 160, electrical characteristics may not be deteriorated.

Next, as shown in FIG. 7 , a diffusion barrier layer 154 is formed on the insulating layer 140 and the first contact electrode 160 , and a bonding layer 156 is formed on the diffusion barrier layer 154 . can

The diffusion barrier layer 154 or the bonding layer 156 may include at least one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, or Ta as a single layer or a multilayer.

The diffusion barrier layer 154 or the bonding layer 156 may be formed by at least one of a deposition method, a sputtering method, and a plating method, or may be attached as a conductive sheet.

The bonding layer 156 may not be formed, but is not limited thereto.

Next, a support member 158 may be formed on the bonding layer 156 as shown in FIG. 8 .

The diffusion barrier layer 154 , the bonding layer 156 , and the support member 158 may be referred to as a first electrode layer 150 , and the first electrode layer 150 controls power supplied from the lower electrode 159 . It may be supplied to the first conductivity type second semiconductor layer 112 .

The support member 158 may be bonded to the bonding layer 156, but is not limited thereto.

The support member 158 may be a conductive support member, and as a base substrate, at least one of copper (Cu), gold (Au), nickel (Ni), molybdenum (Mo), copper-tungsten (Cu-W), and the like. can be one

In addition, the support member 158 may be implemented as a carrier wafer (eg, Si, Ge, GaAs, ZnO, SiC, SiGe, Ga ₂ O ₃ , GaN, etc.), etc., on a circuit pattern of a board or a lead frame of a package. can be soldered to

Next, as shown in FIG. 9 , the growth substrate 105 may be removed. In this case, the surface of the first conductivity-type first semiconductor layer 111 may be exposed by removing the undoped semiconductor layer (not shown) remaining after the growth substrate 105 is removed.

The growth substrate 105 may be removed by physical and/or chemical methods. For example, the removal method of the growth substrate 105 may be performed by a laser lift off (LLO) process. For example, the growth substrate 105 is lifted off by irradiating a laser having a wavelength of a predetermined region to the growth substrate 105 .

Alternatively, the growth substrate 105 may be separated by removing a buffer layer (not shown) disposed between the growth substrate 105 and the first conductivity-type second semiconductor layer 112 using a wet etching solution. .

When the growth substrate 105 is removed and the buffer layer is removed by etching or polishing, an upper surface of the first conductivity-type first semiconductor layer 111 may be exposed.

Next, as shown in FIG. 10 , the first conductivity-type first semiconductor layer 111 may be removed by wet or dry etching to expose the first conductivity-type second semiconductor layer 112 .

Next, a portion of the light emitting structure layer 110 may be removed to expose a portion of the channel layer 120 .

For example, portions of the first conductivity type second semiconductor layer 112 , the active layer 114 , and the second conductivity type fourth semiconductor layer 116 in the region where the pad electrode 180 is to be formed may be removed.

For example, by performing wet etching or dry etching, the periphery of the light emitting structure layer 110 , that is, a channel region or an isolation region that is a boundary region between a chip and a chip may be removed, and the channel layer 120 may be exposed. can be

A light extraction structure may be formed on the upper surface of the first conductivity-type second semiconductor layer 112 , and the light extraction structure may be formed in roughness or a pattern. The light extraction structure may be formed by a wet or dry etching method.

Next, as shown in FIG. 11 , a passivation layer 170 may be formed on the exposed channel layer 120 and the light emitting structure layer 110 .

Thereafter, portions of the passivation layer 170 and the channel layer 120 in the region where the pad electrode 180 is to be formed may be removed to expose a portion of the capping layer 136 .

Next, the pad electrode 180 may be formed on the exposed capping layer 136 .

The pad may be formed as a single layer or a multilayer, but is not limited thereto. For example, the electrode 180 may include an ohmic layer, a reflective layer, a bonding layer, and the like. For example, the electrode 180 may include titanium (Ti), chromium (Cr), nickel (Ni), aluminum (Al), platinum (Pt), gold (Au), tungsten (W), molybdenum (Mo), or It may be formed of at least one of semiconductor substrates doped with impurities, but is not limited thereto.

The pad electrode 180 is a portion to be bonded with a wire, and may be disposed on a predetermined portion of the light emitting structure layer 110 , and may be formed in one or a plurality.

Also, as shown in FIG. 2 , a first electrode 159 may be formed under the first electrode layer 150 , and the first electrode 159 may be formed of a material with high conductivity, for example, Ti, Al, Ni, or the like. It may be formed as a single layer or a multilayer including a material, but is not limited thereto.

According to the embodiment, it is possible to provide an ultraviolet light emitting device in which the operating voltage is improved while the luminous intensity is improved.

12 is a view showing a light emitting device package to which a light emitting device according to an embodiment is applied.

12 , the light emitting device package according to the embodiment includes a body 205 , first and second lead electrodes 213 and 214 disposed on the body 205 , and the body 205 . It may include a light emitting device 100 provided to and electrically connected to the first lead electrode 213 and the second lead electrode 214 , and a molding member 240 surrounding the light emitting device 100 . .

The body 205 may be formed of a silicon material, a synthetic resin material, or a metal material, and an inclined surface may be formed around the light emitting device 100 .

The first lead electrode 213 and the second lead electrode 214 are electrically isolated from each other, and provide power to the light emitting device 100 . In addition, the first lead electrode 213 and the second lead electrode 214 reflect the light generated by the light emitting device 100 to increase light efficiency, and the heat generated by the light emitting device 100 . It may also play a role in discharging to the outside.

The light emitting device 100 may be disposed on the body 205 or disposed on the first lead electrode 213 or the second lead electrode 214 .

The light emitting device 100 may be electrically connected to the first lead electrode 213 and the second lead electrode 214 by any one of a wire method, a flip chip method, and a die bonding method.

In the embodiment, the light emitting device 100 is mounted on the second lead electrode 214 and may be connected to the first lead electrode 213 and the wire 250, but the embodiment is not limited thereto.

The molding member 240 may surround the light emitting device 100 to protect the light emitting device 100 . In addition, the molding member 240 may include a phosphor 232 to change the wavelength of light emitted from the light emitting device 100 . The molding member 240 may have a flat, concave, or convex top surface, but is not limited thereto.

A plurality of light emitting devices or light emitting device packages according to the embodiment may be arrayed on a substrate, and optical members such as lenses, light guide plates, prism sheets, diffusion sheets, etc. may be disposed on a light path of the light emitting device package. Such a light emitting device package, a substrate, and an optical member may function as a light unit. The light unit may be implemented as a top view or side view type, and may be provided in display devices such as portable terminals and notebook computers, or may be variously applied to lighting devices and indicating devices. Another embodiment may be implemented as a lighting device including the light emitting device or the light emitting device package described in the above-described embodiments. For example, the lighting device may include a lamp, a street lamp, an electric billboard, and a headlamp.

13 is an exploded perspective view of a lighting device according to the embodiment.

The lighting device according to the embodiment may include a cover 2100 , a light source module 2200 , a heat sink 2400 , a power supply unit 2600 , an inner case 2700 , and a socket 2800 . In addition, the lighting device according to the embodiment may further include any one or more of the member 2300 and the holder 2500 . The light source module 2200 may include a light emitting device or a light emitting device package according to an embodiment.

The light source module 2200 may include a light source unit 2210 , a connection plate 2230 , and a connector 2250 . The member 2300 is disposed on the upper surface of the heat sink 2400 , and has guide grooves 2310 into which a plurality of light source units 2210 and a connector 2250 are inserted.

The holder 2500 blocks the receiving groove 2719 of the insulating part 2710 of the inner case 2700 . Accordingly, the power supply unit 2600 accommodated in the insulating unit 2710 of the inner case 2700 is sealed. The holder 2500 has a guide protrusion 2510 .

The power supply unit 2600 may include a protrusion part 2610 , a guide part 2630 , a base 2650 , and an extension part 2670 . The inner case 2700 may include a molding unit together with the power supply unit 2600 therein. The molding part is a part where the molding liquid is hardened, and allows the power supply unit 2600 to be fixed inside the inner case 2700 .

Features, structures, effects, etc. described in the above embodiments are included in at least one embodiment, and are not necessarily limited to only one embodiment. Furthermore, features, structures, effects, etc. illustrated in each embodiment can be combined or modified for other embodiments by those of ordinary skill in the art to which the embodiments belong. Accordingly, the contents related to such combinations and modifications should be interpreted as being included in the scope of the embodiments.

In the above, the embodiment has been mainly described, but this is only an example and does not limit the embodiment, and those of ordinary skill in the art to which the embodiment pertains may find several not illustrated above within the range that does not deviate from the essential characteristics of the embodiment. It can be seen that variations and applications of branches are possible. For example, each component specifically shown in the embodiment can be implemented by modification. And differences related to such modifications and applications should be construed as being included in the scope of the embodiments set forth in the appended claims.

A first conductivity type first semiconductor layer 111 , a first conductivity type second semiconductor layer 112 ,
A first conductivity type third semiconductor layer 113 , a second conductivity type fourth semiconductor layer 116 ,
The active layer 114 , the plurality of holes H, the first contact electrode 160 , the insulating layer 140 ,
The bonding layer 156 , the support member 158 , the second contact electrode 132 ,

Claims (9)

a second semiconductor layer of a first conductivity type;
a second conductivity type fourth semiconductor layer disposed under the first conductivity type second semiconductor layer;
an active layer disposed between the first conductivity type second semiconductor layer and the second conductivity type fourth semiconductor layer;
a plurality of holes penetrating through the second conductivity type fourth semiconductor layer and the active layer from a bottom surface of the second conductivity type fourth semiconductor layer to expose a portion of the first conductivity type second semiconductor layer;
a first contact electrode electrically connected from a bottom surface of the second conductivity type fourth semiconductor layer to the first conductivity type second semiconductor layer through the plurality of holes;
an insulating layer disposed between the first contact electrode and the plurality of holes;
and a first conductivity type third semiconductor layer disposed between the first contact electrode and the first conductivity type second semiconductor layer. According to claim 1,
The first contact electrode is an ultraviolet light emitting device in direct contact with the third semiconductor layer of the first conductivity type. According to claim 1,
The first conductivity-type second semiconductor layer is an n-type AlGaN-based semiconductor layer,
The first conductive type third semiconductor layer is an n-type GaN-based semiconductor layer, the ultraviolet light emitting device. 4. The method of claim 3,
The second conductivity-type fourth semiconductor layer is a p-type AlGaN-based semiconductor layer, an ultraviolet light emitting device. According to claim 1,
a bonding layer electrically connected to the first contact electrode;
a support member disposed under the bonding layer; and
The ultraviolet light emitting device further comprising a; a second contact electrode electrically connected to the second conductive type fourth semiconductor layer. According to claim 1,
The ultraviolet light emitting device further comprising a channel layer surrounding the first contact electrode. 7. The method of claim 6,
The channel layer is
An ultraviolet light emitting device comprising a reflective material. According to claim 1,
Further comprising an electrode layer,
The electrode layer is
a diffusion barrier layer on the first contact electrode; and
An ultraviolet light emitting device comprising a bonding layer on the diffusion barrier layer. A lighting system comprising a light emitting unit having the ultraviolet light emitting device according to any one of claims 1 to 8.

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