KR102385943B1 - Light emitting device and light emitting device package - Google Patents

Abstract

The embodiment relates to a light emitting device and a light emitting device package.
The light emitting device of the embodiment includes a light emitting structure including a first conductivity type semiconductor layer, an active layer located on the first conductivity type semiconductor layer, and a second conductivity type semiconductor layer located on the active layer, and a first region of the first conductivity type semiconductor layer A first electrode pad positioned on the, a second electrode pad positioned on the second conductivity-type semiconductor layer, and a current blocking layer positioned in the second region of the first conductivity-type semiconductor layer and overlapping the second electrode pad, The current blocking layer prevents light loss due to light absorption of the active layer by contacting the exposed first conductivity-type semiconductor layer by removing the active layer, thereby improving light efficiency.

Description

Light emitting device and light emitting device package {LIGHT EMITTING DEVICE AND LIGHT EMITTING DEVICE PACKAGE}

The embodiment relates to a light emitting device and a light emitting device package.

A light emitting device (Light Emitting Device) is a p-n junction diode with a characteristic in which electric energy is converted into light energy. It is possible.

GaN-based light emitting devices (LEDs) are being used in various applications such as natural color LED displays, LED traffic signals, and white LEDs. Recently, the luminous efficiency of a high-efficiency white LED is superior to that of a conventional fluorescent lamp, so it is expected to replace the fluorescent lamp in the general lighting field.

In a conventional light emitting device of a horizontal type, a nitride semiconductor layer is formed on a substrate, and an electrode layer is positioned above the nitride semiconductor layer.

On the other hand, in order to solve the problem of current dispersion in the conventional light emitting device, a technology for preventing current from being concentrated around an electrode pad located on the electrode layer by forming a current blocking layer between the electrode layer and the semiconductor layer is being studied.

However, the conventional light emitting device has a problem in that light extraction efficiency is lowered due to light absorption in which emitted light is re-entered into the active layer located around the current blocking layer.

The embodiment provides a light emitting device and a light emitting device package that improve light extraction efficiency.

The embodiment provides a light emitting device and a light emitting device package that fundamentally block an area in which light is absorbed by removing the active layer.

The embodiment provides a light emitting device and a light emitting device package capable of improving light extraction without an additional process by forming a current blocking layer on the first conductivity type semiconductor layer exposed by removing the active layer in the mesa etching process.

A light emitting device according to an embodiment includes: a light emitting structure including a first conductivity type semiconductor layer, an active layer disposed on the first conductivity type semiconductor layer, and a second conductivity type semiconductor layer disposed on the active layer; a first electrode pad disposed on a first region of the first conductivity-type semiconductor layer; a concave portion penetrating a portion of the second conductivity type semiconductor layer and the active layer and the first conductivity type semiconductor layer; a current blocking layer disposed in the recess; and a second electrode pad electrically connected to the second conductivity-type semiconductor layer and vertically overlapped with the current blocking layer.

A light emitting device according to another embodiment includes a first conductivity type semiconductor layer; an active layer positioned on the first conductivity-type semiconductor layer; and a light emitting structure including a second conductivity type semiconductor layer positioned on the active layer; a first electrode pad positioned in a first region of the first conductivity-type semiconductor layer; a second electrode pad positioned on the second conductivity-type semiconductor layer; and a current blocking layer positioned in a second region of the first conductivity-type semiconductor layer and overlapping the second electrode pad, wherein a lower surface of the current blocking layer is positioned below a lower surface of the first electrode pad. can

In the light emitting device according to the embodiment, the current blocking layer overlapping the second electrode pad is formed on the first conductivity type semiconductor layer exposed by removing the active layer and the second conductivity type semiconductor layer to prevent light loss due to light absorption of the active layer Therefore, the light efficiency can be improved.

In the light emitting device according to the embodiment, the current concentrated around the second electrode pad is dispersed by the current blocking layer, thereby maintaining reliability and improving light efficiency.

In the light emitting device according to the embodiment, light extraction may be improved by a current blocking layer having an inclined surface in the concave portion of the light emitting structure.

1 is a perspective view illustrating a light emitting device according to an embodiment.
FIG. 2 is a plan view illustrating the light emitting device of FIG. 1 .
3 is a cross-sectional view illustrating the light emitting device according to the first embodiment taken along line I-I' of FIG. 2 .
4 is a cross-sectional view illustrating A of FIG. 3 .
5 is a cross-sectional view illustrating a light emitting device according to a second embodiment taken along line I-I' of FIG. 2 .
FIG. 6 is a cross-sectional view taken along line A of FIG. 5 .
7 is a cross-sectional view illustrating a light emitting device according to a third embodiment taken along line I-I' of FIG. 2 .
8 is a cross-sectional view illustrating a light emitting device according to a fourth embodiment.
9 is a view illustrating a light emitting device package including a light emitting device according to an embodiment.

Hereinafter, a light emitting device and a light emitting device package according to an embodiment will be described in detail with reference to the accompanying drawings. In the description of the embodiment, each layer (film), region, pattern or structures are formed “on” or “under” each layer (film), region, pad or pattern of the substrate, When described as being, "on" and "under" include both "directly" or "indirectly" formed through another layer. In addition, the reference for the upper / upper or lower of each layer will be described with reference to the drawings.

1 is a perspective view illustrating a light emitting device according to an embodiment, and FIG. 2 is a plan view illustrating the light emitting device of FIG. 1 .

1 and 2 , the light emitting device 100 includes a substrate 111 , a buffer layer 113 , a light emitting structure 120 , an electrode layer 131 , a first electrode pad 141 , and a first auxiliary electrode 143 . ), a second electrode pad 151 and a second auxiliary electrode 153 .

The substrate 111 is a growth substrate capable of growing a gallium nitride-based semiconductor layer, and a light-transmitting, insulating, or conductive substrate may be used, for example, sapphire (Al ₂ O ₃ ), SiC, Si, GaAs, GaN, ZnO, Any one of Si, GaP, InP, Ge, Ga ₂ O ₃ , LiGaO ₃ , and quartz may be used. A plurality of protrusions may be formed on the upper surface of the substrate 111 , and the plurality of protrusions may be formed by etching the substrate 111 or formed as a light extraction structure such as a separate roughness. can The protrusion may have a stripe shape, a hemispherical shape, or a dome shape. The buffer layer 113 is positioned on the substrate 111 and may be formed to alleviate a difference in lattice constant between the substrate 111 and the nitride-based semiconductor layer, and may function as a defect control layer. . The buffer layer 113 may have a value between the lattice constant between the substrate 111 and the nitride-based semiconductor layer. The buffer layer 113 may be formed of an oxide such as a ZnO layer, but is not limited thereto.

The light emitting structure 120 is positioned on the substrate 111 . The light emitting structure 120 includes a first conductivity type semiconductor layer 115 , an active layer 117 , and a second conductivity type semiconductor layer 119 .

The first conductivity type semiconductor layer 115 may be formed as a single layer or multiple layers. When the first conductivity-type semiconductor layer 115 is an n-type semiconductor layer, it may be a Group III-5 compound semiconductor doped with a first conductivity-type dopant. The first conductivity-type dopant is an n-type dopant and may include Si, Ge, Sn, Se, and Te, but is not limited thereto. The first conductivity type semiconductor layer 115 may include 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). can The first conductivity type semiconductor layer 115 may be formed of any one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, and InP.

The active layer 117 may have any one of a single quantum well structure, a multi quantum well (MQW) structure, a quantum-wire structure, or a quantum dot structure. The active layer 117 may include a well layer and a barrier layer formed of a gallium nitride-based semiconductor layer.

For example, the active layer 117 may include any one or more pairs of InGaN/GaN, InGaN/InGaN, GaN/AlGaN, InAlGaN/GaN, GaAs/AlGaAs, InGaAs/AlGaAs, GaInP/AlGaInP, GaP/AlGaP, and InGaP/AlGaP. It may be formed in a structure, but is not limited thereto. The well layer may be formed of a material having a band gap lower than a band gap of the barrier layer.

The barrier layer and the well layer of the active layer 117 may be formed as undoped layers that are not doped with impurities in order to improve the crystal quality of the active layer, but some or all of the active regions may be doped with impurities to lower the forward voltage. there is.

The second conductivity-type semiconductor layer 119 is positioned on the active layer 117 and may be formed as a single layer or multiple layers. When the second conductivity-type semiconductor layer 119 is a p-type semiconductor layer, it may be a Group III-5 compound semiconductor doped with a second conductivity-type dopant. The second conductivity-type dopant is a p-type dopant and may include, but is not limited to, Mg, Zn, Ca, Sr, Ba, or the like. The second conductivity type semiconductor layer 119 may be formed of, for example, any one of compound semiconductors such as GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP, and GaP.

The first electrode pad 141 and the first auxiliary electrode 143 are positioned on the first conductivity-type semiconductor layer 115 .

The second electrode pad 151 and the second auxiliary electrode 153 are positioned on the second conductivity-type semiconductor layer 119 .

The first electrode pad 141 , the first auxiliary electrode 143 , the second electrode pad 151 , and the second auxiliary electrode 153 are Ti, Ru, Rh, Ir, Mg, Zn, Al, In, and Ta. , Pd, Co, Ni, Si, Ge, Ag and Au and optional alloys thereof.

The electrode layer 131 is a current diffusion layer and may be formed of a material having transparency and electrical conductivity. The electrode layer 131 may have a refractive index lower than that of the compound semiconductor layer.

The electrode layer 131 may be formed on the second conductivity type semiconductor layer 119 to be in ohmic contact with the second conductivity type semiconductor layer 119 . The electrode layer 131 may be a transparent conductive oxide or a transparent metal layer. For example, the electrode layer 131 may include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), or indium gallium tin (IGTO). oxide), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), ZnO, IrOx, RuOx, NiO, and the like, and may be formed as at least one layer.

FIG. 3 is a cross-sectional view illustrating the light emitting device according to the first embodiment cut along line I-I' of FIG. 2 , and FIG. 4 is a cross-sectional view illustrating A of FIG. 3 .

3 and 4 , the light emitting device according to the first embodiment includes a current blocking layer 160 located in the light emitting structure 120 . The current blocking layer 160 has a function of preventing current from being concentrated under the second electrode pad 151 .

Here, the first conductivity type semiconductor layer 115 may include first and second regions 115a and 115b. The first region of the first conductivity-type semiconductor layer 115 may be defined as a region exposed from the second conductivity-type semiconductor layer 119 and the active layer 117 . The first electrode pad 141 is positioned on the first area. The second region 115b of the first conductivity-type semiconductor layer 115 may be defined as a region exposed from the second conductivity-type semiconductor layer 119 and the active layer 117 . The current blocking layer 160 is located on the second region 115b. The first and second regions 115a and 115b may be spaced apart from each other by a predetermined interval. The current blocking layer 160 and the first electrode pad 141 may be spaced apart from each other by a predetermined interval. The first and second regions 115a and 115b are formed through a mesa etching process exposing the first conductivity-type semiconductor layer 115 so that the first and second regions 115a and 115b have the same thickness or the same thickness. It may be a depth, but is not limited thereto.

The light emitting structure 120 includes a concave portion, and the concave portion corresponds to the second region 115b. The concave portion has a structure in which the active layer 117 and the second conductivity type semiconductor layer 119 are removed to expose a portion of the upper surface of the first conductivity type semiconductor layer 115 . The concave portion has a width that gradually increases toward the top. That is, the concave portion has a side inclined from the top surface of the first conductivity type semiconductor layer 115 .

The current blocking layer 160 may be formed in the concave portion. That is, the current blocking layer 160 is formed on the side surface of the first conductivity type semiconductor layer 115, the active layer 117 and the side surface of the second conductivity type semiconductor layer 119 inside the recess, and It may extend to the upper surface of the two-conductivity type semiconductor layer 119 . The current blocking layer 160 has a function of preventing light loss by removing the active layer absorbing light by being located in the region where the active layer 117 is removed.

The current blocking layer 160 may be formed to be inclined with respect to the upper surface of the second conductivity-type semiconductor layer 119 to correspond to the inclined side surface of the concave portion.

The current blocking layer 160 may be formed of, for example, an insulating material such as oxide or nitride. For example, the current blocking layer 160 may be formed by selecting at least one from the group consisting of Si _x O _y , Si _x N _y , SiO _x N _y , Al ₂ O ₃ , TiO ₂ , AlN, etc. However, the present invention is not limited thereto.

Alternatively, the current blocking layer 160 may include a distributed Bragg reflector (DBR) in which layers having different refractive indices are alternately stacked, but is not limited thereto. The current blocking layer 160 of the distributed Bragg reflector (DBR) is inclined in the concave portion to reflect light, so that light extraction of the light emitting device can be improved.

The current blocking layer 160 may overlap the second electrode pad 151 positioned on the second conductivity-type semiconductor layer 119 . The entirety of the current blocking layer 160 may overlap the second electrode pad 151 . Also, the entirety of the current blocking layer 160 may overlap the second auxiliary electrode ( 153 in FIG. 2 ).

More specifically, in FIG. 4 , the width W2 of the current blocking layer 160 is shown to be the same as the width W1 of the second electrode pad 151 , but the present invention is not limited thereto, and the current blocking layer ( The width W2 of 160 may be equal to or wider than the width W1 of the second electrode pad 151 so that current is not concentrated around the second electrode pad 151 .

Also, the width W2 of the current blocking layer 160 may be equal to or wider than the width (not shown) of the second auxiliary electrode 153 . That is, the width of the current blocking layer 160 may be different from the area overlapping the second electrode pad 151 and the area overlapping the second auxiliary electrode (153 in FIG. 2 ).

The electrode layer 131 is disposed on the current blocking layer 160 and the second conductivity type semiconductor layer 119 . That is, the electrode layer 131 may cover the current blocking layer 160 exposed to the outside and cover the upper surface of the second conductivity-type semiconductor layer 119 . The electrode layer 131 positioned in the recess has a cross-sectional shape corresponding to the cross-sectional shape of the current blocking layer 160 . That is, the electrode layer 131 located in the concave portion may be inclined with respect to the upper surface of the second conductivity-type semiconductor layer 119 .

The second electrode pad 151 and the second auxiliary electrode 153 may be positioned on the electrode layer 131 and overlap the current blocking layer 160 . Here, the entire current blocking layer 160 may overlap the second electrode pad 151 and the second auxiliary electrode 153 . The second electrode pad 151 and the second auxiliary electrode 153 formed in the recessed portion correspond to the shape of the current blocking layer 160 and are based on the upper surface of the second conductivity-type semiconductor layer 119 . has sloping sides.

In the light emitting device according to the first embodiment, the current blocking layer 160 overlapping the second electrode pad 151 and the second auxiliary electrode 153 includes the active layer 117 and the second conductivity type semiconductor layer 119 . ) is removed and formed on the exposed first conductivity-type semiconductor layer 115 to prevent light loss due to light absorption of the active layer 117, thereby improving light efficiency.

In addition, in the light emitting device according to the first embodiment, the current concentrated around the second electrode pad 151 and the second auxiliary electrode 153 may be dispersed by the current blocking layer 160 .

In addition, in the light emitting device according to the first embodiment, light extraction may be improved by the current blocking layer 160 having an inclined surface in the concave portion of the light emitting structure 120 .

FIG. 5 is a cross-sectional view illustrating a light emitting device according to a second embodiment taken along line I-I' of FIG. 2 , and FIG. 6 is a cross-sectional view taken along line A of FIG. 5 .

The second embodiment may adopt the technical features of the first embodiment.

5 and 6, since the light emitting device according to the second embodiment has the same configuration as the light emitting device according to the first embodiment except for the current blocking layer 260, the same reference numerals are used and a detailed description thereof will be omitted. , the main features of the second embodiment will be mainly described.

The current blocking layer 260 is in contact with the first conductivity type semiconductor layer 115 , and is in contact with the side surface of the active layer 117 and the side surface of the second conductivity type semiconductor layer 119 . The current blocking layer 160 may overlap the second electrode pad 151 positioned on the second conductivity type semiconductor layer 119 .

The current blocking layer 260 has a cup-shaped cross-section including an inclined side surface. An end of the current blocking layer 260 may be positioned on the same plane as an upper surface of the second conductivity-type semiconductor layer 119 . More specifically, the current blocking layer 260 is in contact with the first conductivity-type semiconductor layer 115 exposed from the active layer 117 and the second conductivity-type semiconductor layer 119 , and a side surface of the active layer 117 . and a side surface of the second conductivity type semiconductor layer 119 . An end surface of the current blocking layer 260 is positioned parallel to an upper surface of the second conductivity-type semiconductor layer 119 . The current blocking layer 260 has a function of preventing light loss due to light absorbed by the active layer by being located in the region from which the active layer 117 is removed.

The width W2 of the current blocking layer 260 is illustrated to be the same as the width W1 of the second electrode pad 151, but is not limited thereto, and the width W2 of the current blocking layer 260 is may be formed to be equal to or wider than the width W1 of the second electrode pad 151 .

The current blocking layer 260 may be formed to be inclined with respect to the upper surface of the second conductivity-type semiconductor layer 119 .

The current blocking layer 260 may be formed of, for example, an insulating material such as oxide or nitride. For example, the current blocking layer 260 may be formed by selecting at least one from the group consisting of Si _x O _y , Si _x N _y , SiO _x N _y , Al ₂ O ₃ , TiO ₂ , AlN, etc. However, the present invention is not limited thereto.

Alternatively, the current blocking layer 260 may include a distributed Bragg reflector (DBR) in which layers having different refractive indices are alternately stacked, but is not limited thereto. The current blocking layer 260 of the distributed Bragg reflector DBR may be inclined in the concave portion to improve light extraction.

In the light emitting device according to the second embodiment, the current blocking layer 260 overlapping the second electrode pad 151 and the second auxiliary electrode 153 includes the active layer 117 and the second conductivity type semiconductor layer 119 . ) is formed on the removed first conductivity-type semiconductor layer 115 to prevent light loss due to light absorption of the active layer 117, thereby improving light efficiency.

In addition, in the light emitting device according to the second embodiment, the current concentrated around the second electrode pad 151 and the second auxiliary electrode 153 may be dispersed by the current blocking layer 260 .

In addition, in the light emitting device according to the second embodiment, light extraction may be improved by the current blocking layer 260 having an inclined surface in the concave portion of the light emitting structure 120 .

7 is a cross-sectional view illustrating a light emitting device according to a third embodiment taken along line I-I' of FIG. 2 .

The third embodiment may adopt the technical features of the first or second embodiment, and the main features of the third embodiment will be mainly described below.

The current blocking layer 360 contacts the first conductivity-type semiconductor layer 115 , and contacts the side surface of the active layer 117 and the side surface of the second conductivity type semiconductor layer 119 . The current blocking layer 360 may overlap the second electrode pad 151 positioned on the second conductivity-type semiconductor layer 119 .

The first conductivity type semiconductor layer 115 includes first and second regions 115a and 115b. The first and second regions 115a and 115b may be defined as regions in which upper surfaces of the first conductivity-type semiconductor layer 115 are exposed from the second conductivity-type semiconductor layer 119 and the active layer 117 . . The first electrode pad 141 is positioned in the first region 115a, and the current blocking layer 360 is positioned in the second region 115b.

The first and second regions 115a and 115b may be spaced apart from each other by a predetermined distance, and the second region 115b may be positioned below the first region 115a. That is, the lower surface of the current blocking layer 360 may be located below the lower surface of the first electrode pad 141 .

The first conductivity-type semiconductor layer 115 corresponding to the first region 115a may have a greater thickness than the first conductivity-type semiconductor layer 115 in the second region 115b. Since the current blocking layer 360 is located in the region where the active layer 117 is removed, it has a function of preventing light loss due to light absorbed by the active layer located below the general current blocking layer.

The width of the current blocking layer 360 is illustrated to be the same as the width of the second electrode pad 151 , but the present invention is not limited thereto, and the width of the current blocking layer 360 is equal to the width of the second electrode pad 151 . It can be formed equal to or wider than the width of

The current blocking layer 360 may be formed to be inclined with respect to the upper surface of the second conductivity-type semiconductor layer 119 .

The current blocking layer 360 may be formed of, for example, an insulating material such as oxide or nitride. For example, the current blocking layer 360 may be formed by selecting at least one from the group consisting of Si _x O _y , Si _x N _y , SiO _x N _y , Al ₂ O ₃ , TiO ₂ , AlN, etc. However, the present invention is not limited thereto.

Also, the current blocking layer 360 may include a distributed Bragg reflector (DBR) in which layers having different refractive indices are alternately stacked, but is not limited thereto. The current blocking layer 360 of the distributed Bragg reflector DBR may be inclined in the concave portion of the second region 115b to improve light extraction. Furthermore, since the current blocking layer 360 minimizes the thickness of the first conductivity-type semiconductor layer 115 in the second region 115b, the area that reflects the light increases, thereby further improving light extraction.

In addition, in the light emitting device according to the third embodiment, the current concentrated around the second electrode pad 151 and the second auxiliary electrode 153 may be dispersed by the current blocking layer 360 .

8 is a cross-sectional view illustrating a light emitting device according to a fourth embodiment.

Referring to FIG. 8 , the light emitting device 400 according to the fourth embodiment includes a first electrode pad 441 having a plurality of conductive layers 442 , 443 , 445 under the light emitting structure 420 in a vertical type, the A second electrode pad 451 disposed on the light emitting structure 420 , a current blocking layer positioned between the light emitting structure 420 and the first electrode pad 441 , and corresponding to the second electrode pad 451 in a vertical direction 460 , and a support member 423 .

The first electrode pad 441 may include a contact layer 442 , a reflective layer 443 , and a bonding layer 445 positioned under the second conductivity-type semiconductor layer 419 of the light emitting structure 420 . .

The contact layer 442 is in contact with the lower surface of the second conductivity-type semiconductor layer 419 , and a portion thereof may extend to the lower surface of the current blocking layer 460 . The contact layer 442 may be a conductive material such as ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, or a metal of Ni or Ag.

A reflective layer 443 may be formed under the contact layer 442 , and the reflective layer 443 may include Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, or a combination thereof. It may be formed in a structure including at least one layer made of a material selected from the group consisting of The reflective layer 443 may be in contact under the second conductivity type semiconductor layer 419 and may be in ohmic contact with a metal or a conductive material such as ITO, but is not limited thereto.

A bonding layer 445 may be formed under the reflective layer 443, and the bonding layer 445 may be used as a barrier metal or a bonding metal, and the material is, for example, Ti, Au, Sn, Ni, It may include at least one of Cr, Ga, In, Bi, Cu, Ag and Ta and an optional alloy.

A channel layer 470 may be disposed under the light emitting structure 420 . The channel layer 470 is formed along the lower surface edge of the second conductivity-type semiconductor layer 419 and may be formed in a ring shape, a loop shape, or a frame shape. The channel layer 470 is at least one of ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, SiO ₂ , SiO _x , SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ , TiO ₂ may include An inner portion of the channel layer 470 is disposed under the second conductivity-type semiconductor layer 419 , and an outer portion of the channel layer 470 is disposed more outside than a side surface of the light emitting structure 420 .

A support member 423 is formed under the bonding layer 445 , and the support member 423 may be formed of a conductive member, and the material is copper (Cu-copper), gold (Au-gold), or nickel. It may be formed of a conductive material such as (Ni-nickel), molybdenum (Mo), copper-tungsten (Cu-W), or a carrier wafer (eg, Si, Ge, GaAs, ZnO, SiC, etc.).

As another example, the support member 423 may be implemented as a conductive sheet. The first electrode pad 441 may include the support member 423 , and at least one or a plurality of layers of the first electrode pad 441 are formed to have the same width as the support member 423 . can be

A light extraction structure such as roughness may be formed on the upper surface of the first conductivity type semiconductor layer 415 . The second electrode pad 451 may be disposed on a flat top surface of the first conductivity-type semiconductor layer 415 , but is not limited thereto. An insulating layer (not shown) may be further formed on the side and top surfaces of the light emitting structure 420 , but the present invention is not limited thereto.

The current blocking layer 460 overlaps the second electrode pad 451 and has a function of preventing current from being concentrated under the second electrode pad 451 .

The light emitting structure 420 includes a concave portion in the central portion, and the concave portion has a structure in which the active layer 417 and the second conductivity type semiconductor layer 419 are removed to expose the first conductivity type semiconductor layer 415 . have The concave portion has a width that gradually becomes narrower toward the top. That is, the concave portion has a side inclined with respect to the lower surface of the first conductivity-type semiconductor layer 415 .

The current blocking layer 460 may be formed in the recess. That is, the current blocking layer 460 is formed on the side surfaces of the first conductivity-type semiconductor layer 415 , the active layer 417 and the second conductivity-type semiconductor layer 419 inside the concave portion, and It may be in contact with the two-conductivity semiconductor layer 419 . The current blocking layer 460 has a function of preventing light loss by removing the active layer absorbing light by being located in the region where the active layer 417 is removed.

The current blocking layer 460 may be formed of, for example, an insulating material such as oxide or nitride. For example, the current blocking layer 460 may be formed by selecting at least one from the group consisting of Si _x O _y , Si _x N _y , SiO _x N _y , Al ₂ O ₃ , TiO ₂ , AlN, etc. However, the present invention is not limited thereto.

Alternatively, the current blocking layer 460 may include a distributed Bragg reflector (DBR) in which layers having different refractive indices are alternately stacked, but is not limited thereto. The current blocking layer 460 of the distributed Bragg reflector (DBR) is inclined in the concave portion to reflect light, so that light extraction of the light emitting device can be improved.

The width of the current blocking layer 460 may be equal to or wider than the width of the second electrode pad 451 .

In the light emitting device according to the fourth embodiment, the current blocking layer 460 overlapping the second electrode pad 451 has the first conductivity type in which the active layer 417 and the second conductivity type semiconductor layer 419 are removed. Since it is formed on the semiconductor layer 415 to prevent light loss due to light absorption by the active layer 417 , light efficiency can be improved.

In addition, in the light emitting device according to the fourth embodiment, the current concentrated in the periphery of the second electrode pad 451 may be dispersed by the current blocking layer 460 .

In addition, in the light emitting device according to the fourth embodiment, light extraction may be improved by the current blocking layer 460 having an inclined surface in the concave portion of the light emitting structure 420 .

9 is a view illustrating a light emitting device package including the light emitting device of FIG. 8 .

Referring to FIG. 9 , the light emitting device package includes a body 510 , first and second lead electrodes 521 and 523 at least partially disposed on the body 510 , and on the body 510 . The light emitting device 400 electrically connected to the first lead electrode 521 and the second lead electrode 523 in the body 510 , and a molding member 530 surrounding the light emitting device 400 on the body 510 . ) is included.

The body 510 may be formed of a silicon material, a synthetic resin material, or a metal material.

The first lead electrode 521 and the second lead electrode 523 may be electrically separated from each other and formed to penetrate the inside of the body 510 . That is, a part of the first lead electrode 521 and the second lead electrode 523 may be disposed inside the cavity, and the other part may be disposed outside the body 510 .

The first lead electrode 521 and the second lead electrode 523 may supply power to the light emitting device 400 and reflect light generated from the light emitting device 400 to increase light efficiency, It may also function to discharge the heat generated by the light emitting device 400 to the outside.

The light emitting device package may include the light emitting device 400 according to the fourth embodiment having excellent light efficiency as shown in FIG. 8 . Accordingly, the light emitting device package has an advantage of improved light efficiency. In addition, the light emitting device package of the embodiment may include the light emitting device according to the first to third embodiments shown in FIGS. 3, 4 and 7 . The light emitting device or the light emitting device package according to the embodiment includes a light It can be applied to units. The light unit includes a structure in which a plurality of light emitting devices or light emitting device packages are arrayed, and may include a lighting lamp, a traffic light, a vehicle headlamp, an electric sign, and the like.

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 belongs are provided with several examples 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.

115: first conductivity type semiconductor layer 117: active layer
119: second conductivity type semiconductor layer 160, 260, 360, 460: current blocking layer
141, 441: first electrode pad 151, 451: second electrode pad

Claims (13)

a light emitting structure including a first conductivity type semiconductor layer, an active layer disposed on the first conductivity type semiconductor layer, and a second conductivity type semiconductor layer disposed on the active layer;
a first concave portion penetrating through the second conductivity type semiconductor layer and the active layer in the first region of the light emitting structure, a portion of the first conductivity type semiconductor layer being removed, and having a first depth;
In a second region of the light emitting structure spaced apart from the first region, it is formed to penetrate the second conductivity-type semiconductor layer and the active layer, and a partial region of the first conductivity-type semiconductor layer is removed, and the first depth a second recess having a second, greater depth;
a first electrode pad disposed on the first conductivity-type semiconductor layer in the first concave portion;
A current blocking portion extending into the second concave portion to directly contact the upper surface of the first conductivity type semiconductor layer exposed by the second concave portion, the side surface of the active layer, and the side surface of the second conductivity type semiconductor layer floor;
an electrode layer formed on the current blocking layer and the second conductivity-type semiconductor layer;
a second electrode pad disposed on the electrode layer to vertically overlap the current blocking layer and electrically connected to the second conductivity-type semiconductor layer; and
a second auxiliary electrode disposed on the electrode layer and extending to the second electrode pad;
The width of the current blocking layer is greater than or equal to the width of the second electrode pad,
The end of the current blocking layer is disposed on the same plane as the upper surface of the second conductivity type semiconductor layer,
the current blocking layer vertically overlaps the second auxiliary electrode;
A width of the current blocking layer in a region where the second electrode pad and the current blocking layer overlap is different from a width of the current blocking layer in a region where the second auxiliary electrode and the current blocking layer overlap. According to claim 1,
The current blocking layer is a light emitting device disposed on an upper surface of a second region of the first conductivity-type semiconductor layer exposed by the concave portion, an inner surface of the active layer, and an inner surface of the second conductivity-type semiconductor layer. delete According to claim 1,
The current blocking layer is a light emitting device having a cup-shaped cross section. According to claim 1,
The recess comprises an inclined side,
A width of the concave portion increases from an upper surface of the first conductivity-type semiconductor layer to an upper surface of the second conductivity-type semiconductor layer. delete delete delete delete delete delete delete delete

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