KR102299735B1 - Light emitting device and lighting system - Google Patents

Abstract

The embodiment relates to a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system.
The light emitting device according to the embodiment includes a first conductivity type semiconductor layer 112; a second conductivity type semiconductor layer 116 disposed under the first conductivity type semiconductor layer 112; an active layer 114 disposed between the first conductivity type semiconductor layer 112 and the second conductivity type semiconductor layer 116; A plurality of holes passing through the second conductivity type semiconductor layer 116 and the active layer 114 from the bottom surface of the second conductivity type semiconductor layer 116 and exposing a portion of the first conductivity type semiconductor layer 112 (H); a first contact electrode 160 electrically connected from a bottom surface of the second conductivity type semiconductor layer 116 to the first conductivity type semiconductor layer 112 through the plurality of holes H; an insulating layer 140 disposed between the first contact electrode 160 and the plurality of holes H; a first current spreading layer 122 extending to a side surface of the first contact electrode 160; 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 semiconductor layer 116 .

Description

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

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

Light Emitting Diode is a pn junction diode that converts electric energy into light energy. possible.

When a forward voltage is applied, the electrons of the n-layer and the holes of the p-layer combine to emit energy corresponding to the band gap energy of the conduction band and the valence band. is mainly emitted in the form of heat or light, and when emitted in the form of light, it becomes a light emitting device.

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, a blue light emitting device, a green light emitting device, and an ultraviolet (UV) light emitting device using a nitride semiconductor have been commercialized and widely used.

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 an epitaxial layer. ) increases, the current efficiency decreases, and there is a problem of being vulnerable to electrostatic discharge.

In order to solve this problem, conventionally, a via hole type vertical light emitting device in which an electrode is disposed by forming a via hole under the epitaxial layer has been developed.

Meanwhile, in order to manufacture such a via hole type vertical light emitting device, a plurality of mesa etchings for n-contact are performed and passivation is performed between the n-contact and the mesa etching hole. A passivation layer is formed. According to the prior art, electrons injected through the via hole cause electron clouding around the via hole, which is the n-type pad electrode region, and the electrons mainly flow around the via hole. Carrier recombination occurs only in a part of the active layer area around it, so that light is mainly emitted only around the via hole, so there is a problem in that the luminous flux is low.

Also, according to the prior art, in order to manufacture a via hole type vertical light emitting device, a plurality of mesa etchings for the n-contact are performed, but there is a problem in that the VF increases according to the n-contact region.

The embodiment is intended to provide a light emitting device having an improved luminous flux by improving carrier injection efficiency, a method of manufacturing the light emitting device, a light emitting device package, and a lighting system.

In addition, the embodiment is to provide a light emitting device with improved electrical characteristics, a method of manufacturing the light emitting device, a light emitting device package, and a lighting system.

The light emitting device according to the embodiment includes a first conductivity type semiconductor layer 112; a second conductivity type semiconductor layer 116 disposed under the first conductivity type semiconductor layer 112; an active layer 114 disposed between the first conductivity type semiconductor layer 112 and the second conductivity type semiconductor layer 116; A plurality of holes passing through the second conductivity type semiconductor layer 116 and the active layer 114 from the bottom surface of the second conductivity type semiconductor layer 116 and exposing a portion of the first conductivity type semiconductor layer 112 (H); a first contact electrode 160 electrically connected from a bottom surface of the second conductivity type semiconductor layer 116 to the first conductivity type semiconductor layer 112 through the plurality of holes H; an insulating layer 140 disposed between the first contact electrode 160 and the plurality of holes H; a first current spreading layer 122 extending to a side surface of the first contact electrode 160; 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 semiconductor layer 116 .

In addition, the lighting system according to the embodiment may include a light emitting unit including the light emitting device.

According to the embodiment, it is possible to provide a light emitting device having an improved luminous flux by improving carrier injection efficiency by current diffusion, a method of manufacturing the light emitting device, a light emitting device package, and a lighting system.

Further, according to the embodiment, it is possible to provide a light emitting device with improved electrical characteristics, a method for manufacturing a 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 a partially enlarged cross-sectional view of the light emitting device according to the first embodiment;
3 is a partially enlarged cross-sectional view of a light emitting device according to a second embodiment;
4 to 16 are cross-sectional views of a method of manufacturing a light emitting device according to an embodiment.
17 is a cross-sectional view of a light emitting device package according to the embodiment;
18 is an exploded perspective view of a lighting device according to the embodiment;

In the description of an embodiment, 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 criteria for the upper / upper or lower of each layer will be described with reference to the drawings.

(Example)

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

The light emitting device 100 according to the embodiment includes a first conductive semiconductor layer 112 , a second conductive semiconductor layer 116 , an active layer 114 , a first contact electrode 160 , an insulating layer 140 , and a second conductive semiconductor layer 116 . One current diffusion layer 122 , a first electrode layer 150 , and a second contact electrode 132 may be included.

For example, the light emitting device according to the embodiment includes a first conductivity type semiconductor layer 112; a second conductivity type semiconductor layer 116 disposed under the first conductivity type semiconductor layer 112; an active layer 114 disposed between the first conductivity type semiconductor layer 112 and the second conductivity type semiconductor layer 116; A plurality of holes passing through the second conductivity type semiconductor layer 116 and the active layer 114 from the bottom surface of the second conductivity type semiconductor layer 116 and exposing a portion of the first conductivity type semiconductor layer 112 (H); a first contact electrode 160 electrically connected to the first conductivity type semiconductor layer 112 from the bottom surface of the second conductivity type semiconductor layer 116 through the plurality of holes H (see FIG. 4 ); An insulating layer 140 disposed between the first contact electrode 160 and the plurality of holes H, a first current spreading layer 122 disposed extending to a side surface of the first contact electrode 160, the It 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 semiconductor layer 116 .

In an embodiment, the first current diffusion layer 122 may be disposed to extend to both sides of the first contact electrode 160 .

The first current diffusion layer 122 may be made of oxide, nitride, or amorphous material. For example, the first current diffusion layer 122 may be SiO ₂ , Si ₃ N ₄ , an amorphous semiconductor layer, or the like, but is not limited thereto.

In the prior art, electrons injected through a contact electrode formed in a via hole cause electron agglomeration in the contact electrode region, which causes luminescent recombination only in some active layer regions around the via hole, resulting in a low luminous flux.

According to the embodiment, the current injection is spread to the side of the first contact electrode 160 by the first current spreading layer 122 extending to the side of the first contact electrode 160 and spreading the current to the first contact By preventing current concentration around the electrode 160 , current diffusion efficiency is improved, thereby improving light output.

In an embodiment, the first current diffusion layer 122 may be disposed on one side or both sides of the first contact electrode 160 , respectively.

In an embodiment, the first current diffusion layer 122 may be disposed at the same height as the first contact electrode 160 , but is not limited thereto.

In the embodiment, the channel layer 120 is formed on the plurality of holes H, but the channel layer 120 may not be formed in the region where the first contact electrode 160 is to be formed. A portion of the conductive semiconductor layer 112 may be exposed.

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

In an embodiment, the first current diffusion layer 122 may be formed in a region overlapping the channel layer 120 and the upper and lower portions. Through this, the light emission efficiency can be improved through current diffusion without reducing the light emission area by utilizing the region of the channel layer 120 in which light emission does not occur substantially as a current diffusion path.

The embodiment may include a protrusion 160p extending to the first conductivity-type semiconductor layer 112 .

A top surface of the protrusion 160p of the first contact electrode may be disposed higher than a top surface of the insulating layer 140 .

Accordingly, since the first contact electrode 160 also contacts the first conductivity-type semiconductor layer 112 at the protrusion 160p, the contact area is widened and contact resistance can be reduced, thereby improving electrical characteristics.

FIG. 3 is a partially enlarged cross-sectional view taken along line A-A' of FIG. 1 as a second embodiment.

The second embodiment may employ the features of the first embodiment.

According to the second embodiment, a second current diffusion layer 123 disposed on the first conductivity-type semiconductor layer 112 above the first contact electrode 160 may be included. For example, the second current diffusion layer 123 may be disposed in the first conductivity type semiconductor layer 112 , but is not limited thereto.

A horizontal width of the second current diffusion layer 123 may be formed to correspond to a horizontal width of the first contact electrode 160 . For example, the horizontal width of the second current diffusion layer 123 is formed to be equal to or greater than the horizontal width of the first contact electrode 160 , so that the first conductivity type semiconductor layer 112 is diffused laterally rather than in the upper direction. By doing so, the horizontal current spreading efficiency is improved, and the light output can be further improved.

The second current spreading layer 123 may be formed to be thicker than the first current spreading layer 122 . Through this, the concentrated current supplied from the first contact electrode 160 may not pass through the second current diffusion layer 123 and may be spread in the horizontal direction.

The second current diffusion layer 123 may be formed of nitride, oxide, or amorphous material. For example, the second current diffusion layer 123 may be Si ₃ N ₄ , SiO ₂ , an amorphous semiconductor layer, or the like, and may be formed as a single layer or a multilayer, but is not limited thereto.

According to the embodiment, including the second current diffusion layer 123 disposed on the first conductivity-type semiconductor layer 112 on the upper side of the first contact electrode 160, the carrier is the first conductivity-type semiconductor layer 112 ), the horizontal current diffusion efficiency is improved by spreading it to the side rather than the upward direction, thereby further improving the light output.

Hereinafter, while describing a method of manufacturing a light emitting device according to an embodiment with reference to FIGS. 4 to 16 , the features of the present invention will be described in detail. Meanwhile, the following manufacturing process drawings will be described with reference to FIG. 2, but the manufacturing method of the embodiment is not limited thereto.

First, the light emitting structure layer 110 may be formed on the growth substrate 105 as shown in FIG. 4 . The light emitting structure layer 110 may include a first conductivity type semiconductor layer 112 , an active layer 114 , and a second conductivity type 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. .

A first conductivity type semiconductor layer 112 may be formed on the buffer layer or the undoped semiconductor layer. Thereafter, an active layer 114 may be formed on the first conductivity-type semiconductor layer 112 , and a second conductivity-type semiconductor layer 116 may be sequentially stacked on the active layer 114 .

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

The first conductivity type semiconductor layer 112 is a compound semiconductor of a group III-V element doped with a first conductivity type dopant, for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, It may be selected from GaAsP, AlGaInP, and the like. For example, the first conductivity type semiconductor layer 112 is _{a semiconductor having a composition formula of In x} Al _y Ga _1-xy N (0≤x≤1, 0≤y≤1, 0≤x+y≤1) It can be formed in layers.

The first conductivity-type 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 semiconductor layer 112 may be formed as a single layer or a multilayer, and alternate two layers of GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP. It may include a superlattice structure arranged as

For example, according to the embodiment, the first current diffusion layer 122 may be formed in the first conductivity type semiconductor layer 112 . The first current diffusion layers 122 may be formed to be spaced apart from each other.

The first current diffusion layer 122 may be made of oxide, nitride, or amorphous material. For example, the first current diffusion layer 122 may be SiO ₂ , Si ₃ N ₄ , an amorphous semiconductor layer, or the like, but is not limited thereto.

For example, after the first conductivity-type semiconductor layer 112 is primarily formed, the first current diffusion layer 122 may be formed, and then the first conductivity-type semiconductor layer 112 may be formed secondarily.

According to the embodiment, the first current diffusion layer 122 is formed to extend to the side surface of the first contact electrode 160 to be formed later, and the current injection is diffused to the side surface of the first contact electrode 160 to be formed by current diffusion. By preventing current concentration around the first contact electrode 160 , current diffusion efficiency is improved, thereby improving light output.

The active layer 114 may include a single quantum well structure, a multiple quantum well structure, a quantum wire structure, or a quantum dot structure. The active layer 114 may be formed in a cycle of a well layer and a barrier layer using a compound semiconductor material of a group III-V element. The well layer includes _{a semiconductor layer having a compositional formula of In x} Al _y Ga _1-xy N (0≤x≤1, 0≤y≤1, 0≤x+y≤1), and the barrier layer includes In _x It may be formed of a semiconductor layer having a composition formula of Al _y Ga _{1-xy N (0≤x≤1, 0≤y≤1, 0≤x+y≤1).} The barrier layer may be formed of a material having a band gap higher than that of the well layer.

The active layer 114 may include, for example, at least one period of a period of an InGaN well layer/GaN barrier layer, a period of an InGaN well layer/AlGaN barrier layer, and a period of an InGaN well layer/InGaN barrier layer. .

The second conductivity type semiconductor layer 116 is formed on the active layer 114, and the second conductivity type semiconductor layer 116 is a compound semiconductor of a group III-V element doped with a second conductivity type dopant, for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP, and the like. The second conductivity type semiconductor layer 116 may be formed of a semiconductor layer having a composition formula _{of In x} Al _y Ga _{1-xy N (0≤x≤1, 0≤y≤1, 0≤x+y≤1).} can

The second conductivity-type semiconductor layer 116 may be a p-type semiconductor layer, and the second conductivity-type dopant includes a p-type dopant such as Mg, Zn, Ca, Sr, Ba, or the like. The second conductivity type semiconductor layer 116 may be formed as a single layer or a multilayer, but is not limited thereto.

The second conductivity type semiconductor layer 116 may include a superlattice structure in which two different layers of GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP are alternately arranged. can

The first conductivity type semiconductor layer 112 , the active layer 114 , and the second conductivity type 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 semiconductor layer 116 .

Accordingly, the light emitting structure layer 110 may include at least one of an np junction, a pn junction, an npn junction, and a pnp junction structure. In the following description, a structure in which the second conductivity type semiconductor layer 116 is disposed on the uppermost layer of the light emitting structure layer 110 will be described as an example.

Next, an etching process for removing a portion of the light emitting structure may be performed.

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

According to an embodiment, the first conductivity-type semiconductor layer 112 between the first current diffusion layers 122 may be partially removed.

In an embodiment, the plurality of holes H are formed at a predetermined angle from the first conductivity-type semiconductor layer 112 to the upper surface of the second conductivity-type semiconductor layer 116 , for example, with respect to the upper surface of the light emitting structure layer 110 . It may be formed at an obtuse angle, 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.

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

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. Through this, a portion of the first conductivity type semiconductor layer 112 may be exposed.

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

The channel layer 120 may be formed of one or more materials selected _{from SiO x} , SiO _x N _y , Al ₂ O ₃ , and TiO _{2 as a single layer or a multilayer.}

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 single layer or multiple layers of a material selected _{from SiO 2} , SiO _x , SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ , and TiO _{2 , and such an insulating material} The reflective material may be formed in a mixed form.

For example, the channel layer 120 is a single layer or a mixture of any one or more materials of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, or Hf in an insulating material. It may be formed in multiple layers.

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

Next, a second hole H2 may be formed inside the first conductivity type semiconductor layer 112 . The channel layer 120 may function as a mask for forming the second hole H2, but is not limited thereto. The second hole H2 may be formed to have a narrower width than the plurality of holes H. The second hole H2 may be a region where the protrusion 160p of the first contact electrode 160 will be formed in a subsequent process.

Meanwhile, according to the second exemplary embodiment, the second current flows in the region where the second hole H2 is formed, that is, the first contact electrode 160 to be formed later and the first conductivity type semiconductor layer 112 overlapping up and down. A diffusion layer 123 may be formed. For example, the second current diffusion layer 123 may be formed in the first conductivity type semiconductor layer 112 , but is not limited thereto. The second current diffusion layer 123 may be formed of nitride, oxide, or amorphous material. For example, the second current diffusion layer 123 may be Si ₃ N ₄ , SiO ₂ , an amorphous semiconductor layer, or the like, and may be formed as a single layer or a multilayer, but is not limited thereto.

According to the second embodiment, including a second current diffusion layer 123 disposed on the first conductivity-type semiconductor layer 112 on the upper side (refer to FIG. 2 ) of the first contact electrode 160 to be formed thereafter, including a carrier By allowing the first conductivity type semiconductor layer 112 to diffuse in the lateral direction rather than in the upper direction, the horizontal current diffusion efficiency is improved, thereby further improving the light output.

In an embodiment, the horizontal width of the second current diffusion layer 123 may be formed to correspond to the horizontal width of the first contact electrode 160 to be formed later. For example, the horizontal width of the second current diffusion layer 123 is formed to be equal to or greater than the horizontal width of the first contact electrode 160 , so that the first conductivity type semiconductor layer 112 is diffused laterally rather than in the upper direction. By doing so, the horizontal current spreading efficiency is improved, and the light output can be further improved.

The second current spreading layer 123 may be formed to be thicker than the first current spreading layer 122 . Through this, the concentrated current supplied from the first contact electrode 160 may not pass through the second current diffusion layer 123 and may be spread in the horizontal direction. Next, as shown in FIG. 6 , a second contact electrode 132 may be formed on the second conductivity-type semiconductor layer 116 .

The second contact electrode 132 is in ohmic contact with the second conductivity type 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 material.

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, as shown in FIG. 7 , a protrusion 160p may be formed in the second hole H2 , and a first contact electrode 160 may be formed on the protrusion 160p.

A top surface of the protrusion 160p of the first contact electrode may be disposed higher than a top surface of the insulating layer 140 (refer to FIG. 2 ). Accordingly, since the first contact electrode 160 also contacts the first conductivity-type semiconductor layer 112 at the protrusion 160p, the contact area is widened and contact resistance can be reduced, thereby improving electrical characteristics.

The protrusion 160p of the first contact electrode may be in ohmic contact with the exposed first conductivity-type semiconductor layer 112 .

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

The top surface of the first contact electrode 160 may be disposed between the top surface of the active layer 114 and the top surface of the first conductivity-type semiconductor layer 112 .

The surface of the first conductivity type semiconductor layer 112 to which the first contact electrode 160 is in contact is a Ga-face, and may be formed in a flat structure, but is not limited thereto.

Referring to FIG. 7 , in the embodiment, the width of the first contact electrode 160 may decrease from the bottom surface to the top surface. Meanwhile, with reference to FIG. 2 , the width of the first contact electrode 160 may increase from the bottom surface to the top surface.

Through this, the possibility of a short circuit between the first contact electrode 160 and the material of the second electrode layer 130 formed thereafter is reduced, and the area in which the first contact electrode 160 contacts the first conductivity-type semiconductor layer 112 is maximized. While reducing the area occupied by the first contact electrode 160 , light efficiency may be increased.

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. At 154 , an area occupied by the first contact electrode 160 may be minimized and electrical characteristics may not be deteriorated.

Next, as shown in FIG. 8 , 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, as shown in FIG. 9 , a capping layer 136 may be formed on the reflective layer 134 .

The second electrode layer 130 may include the second contact electrode 132 , the reflective layer 134 , and the capping layer 136 , and the second electrode layer 130 is the power supplied from the pad electrode 180 . may be supplied to the second conductivity type 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, At least one of Al, Pd, Pt, Si and an alloy thereof may be formed as a single layer or a multilayer.

Next, as shown in FIG. 10 , 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 first contact electrode 160 may be electrically connected to the first conductivity type semiconductor layer 112 , and the insulating layer 140 includes the first contact electrode 160 , the active layer 114 , and the second conductivity type semiconductor layer 112 . It may be electrically insulated from the semiconductor layer 116 .

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 .}

As described above, 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 a reflective material is formed on the insulating material. It may be formed in a mixed form.

For example, the insulating layer 140 may be formed in a form in which any 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, 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, as shown in FIG. 11 , 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 and/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 multi-layer. have.

The diffusion barrier layer 154 and/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 with a conductive sheet.

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

Next, as shown in FIG. 12 , a support member 158 may be formed on the bonding layer 156 .

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 includes power supplied from the lower electrode (see FIG. 2 ). may be supplied to the first conductivity type 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. 13 , the growth substrate 105 may be removed. In this case, the surface of the first conductivity type semiconductor layer 112 may be exposed by removing the undoped semiconductor layer (not shown) remaining after the removal of the growth substrate 105 .

The growth substrate 105 may be removed by a physical and/or chemical method. For example, the method of removing the growth substrate 105 may be performed through 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, a buffer layer (not shown) disposed between the growth substrate 105 and the first conductivity type semiconductor layer 112 may be removed using a wet etching solution to separate the growth substrate 105 .

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 semiconductor layer 112 may be exposed.

A top surface of the first conductivity type semiconductor layer 112 may be an N-face, and may be a surface closer to the growth substrate.

The upper surface of the first conductivity-type semiconductor layer 112 may be etched using an inductively coupled plasma/reactive ion etching (ICP/RIE) method or polished with a polishing device.

Next, as shown in FIG. 14 , 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 semiconductor layer 112 , the active layer 114 , and the second conductivity type 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 is exposed. can be

A light extraction structure may be formed on the upper surface of the first conductivity type 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. 15 , 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 .

The passivation layer 170 may be formed of a material selected _{from SiO x} N _y , Si ₃ N ₄ , Al ₂ O ₃ , and TiO _{2 .}

Next, as shown in FIG. 16 , the pad electrode 180 may be formed on the exposed capping layer 136 .

The pad electrode 180 may include at least one of titanium (Ti), chromium (Cr), nickel (Ni), aluminum (Al), platinum (Pt), gold (Au), tungsten (W), and molybdenum (Mo). Alternatively, it may be formed as a single layer or a multilayer through a combination thereof, 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 a light emitting device with improved electrical characteristics, a method for manufacturing a light emitting device, a light emitting device package, and a lighting system.

Further, according to the embodiment, it is possible to provide a light emitting device having an improved luminous flux by improving carrier injection efficiency, a method of manufacturing the light emitting device, a light emitting device package, and a lighting system.

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

Referring to FIG. 17 , 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 in a top view or side view type, and may be provided to 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.

18 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 includes a plurality of light source units 2210 and guide grooves 2310 into which the connector 2250 is 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 not limiting the embodiment, and those of ordinary skill in the art to which the embodiment pertains are provided with several examples not illustrated above in the range that does not depart 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.

The first conductivity type semiconductor layer 112 , the second conductivity type semiconductor layer 116 , the active layer 114 ,
a plurality of holes H, a first contact electrode 160 , an insulating layer 140 ,
The first electrode layer 150 , the second contact electrode 132 , the protrusion 160p,
First current spreading layer 122, second current spreading layer 123

Claims (8)

a first conductivity type semiconductor layer;
a second conductivity type semiconductor layer disposed under the first conductivity type semiconductor layer;
an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer;
a plurality of holes (H) penetrating the second conductivity type semiconductor layer and the active layer from the bottom surface of the second conductivity type semiconductor layer and exposing a portion of the first conductivity type semiconductor layer;
a first contact electrode electrically connected from a bottom surface of the second conductivity type semiconductor layer to the first conductivity type semiconductor layer through the plurality of holes;
an insulating layer disposed between the first contact electrode and the plurality of holes;
a first current spreading layer extending to a side surface of the first contact electrode;
a channel layer disposed between the first contact electrode and the first current diffusion layer;
a first electrode layer electrically connected to the first contact electrode; and
a second contact electrode electrically connected to the second conductivity-type semiconductor layer; and
The first current diffusion layer is a light emitting device disposed in a region overlapping the channel layer and the upper and lower sides. According to claim 1,
The first current diffusion layer is a light emitting device disposed to extend to both sides of the first contact electrode. According to claim 1,
the first contact electrode includes a protrusion extending to the first conductivity-type semiconductor layer and in contact with the first conductivity-type semiconductor layer;
An upper surface of the protrusion of the first contact electrode is disposed above an upper surface of the insulating layer. According to claim 1,
Further comprising a second current diffusion layer disposed on the first conductivity-type semiconductor layer above the first contact electrode,
A horizontal width of the second current diffusion layer is greater than or equal to a horizontal width of the first contact electrode. A lighting system comprising a light emitting unit having the light emitting device according to any one of claims 1 to 4. delete delete delete

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