KR20160133647A - Light emitting device and light unit having thereof - Google Patents

Abstract

An embodiment relates to a light emitting device. The light emitting device according to the embodiment includes a first conductive semiconductor layer; an active layer disposed on the first conductive semiconductor layer and having a plurality of well layers and a plurality of barrier layers; an electron blocking layer disposed on the active layer; a second conductive semiconductor layer disposed on the electron blocking layer; a plurality of holes disposed in the active layer; and a contact part disposed in the plurality of holes. The contact part includes a conductive semiconductor and touches the inner surfaces of the well layers and the barrier layers. So, contact areas can be increased.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a light emitting device,

An embodiment relates to a light emitting element.

An embodiment relates to an ultraviolet light emitting element.

An embodiment relates to a light unit having an ultraviolet light emitting element.

In general, a nitride semiconductor material including a Group V source such as nitrogen (N) and a Group III source such as gallium (Ga), aluminum (Al), or indium (In) has excellent thermal stability, Has a band structure and is widely used as a nitride semiconductor device, for example, a nitride semiconductor light emitting device in an ultraviolet region and a material for a solar cell.

The nitride-based material has a wide energy band gap of 0.7 eV to 6.2 eV, and is thus widely used as a material for a solar cell device due to its characteristics matching the solar spectrum region. In particular, ultraviolet light emitting devices have been utilized in various industrial fields such as a curing apparatus, a medical analyzer, a therapeutic apparatus, and a sterilizing, water purification, and purification system.

Embodiments provide a light emitting device capable of increasing a contact area between an active layer and a second conductive semiconductor layer, and a light unit having the same.

Embodiments provide a light emitting device and a light unit having the same that can increase a contact area between an active layer and an electron blocking layer.

Embodiments provide a light emitting device capable of reducing contact resistance in a path between an active layer and a second conductive semiconductor layer, and a light unit having the same.

Embodiments provide a light emitting device that emits ultraviolet light and a light unit having the same.

A light emitting device according to an embodiment includes: a first conductive semiconductor layer; An active layer disposed on the first conductive semiconductor layer and having a plurality of well layers and a plurality of barrier layers; An electron blocking layer disposed on the active layer; A second conductive semiconductor layer disposed on the electron blocking layer; A plurality of holes disposed in the active layer; And a contact portion disposed in the plurality of holes, wherein the contact portion includes a conductive semiconductor, and contacts the inner surfaces of the plurality of well layers and the plurality of barrier layers.

A light emitting device package according to an embodiment includes: a body having a cavity; The light emitting element disposed in the cavity; And a window layer on the cavity.

According to the light emitting device according to the embodiment, the operating voltage can be reduced by improving the contact area between the second conductive semiconductor layer and the active layer.

According to the light emitting device according to the embodiment, the light output can be improved.

According to the embodiment, an ultraviolet light emitting element having a low operating voltage can be provided.

The embodiment can improve the reliability of the ultraviolet light emitting device.

Embodiments can provide a light emitting device package having an ultraviolet light emitting element and a light unit such as an ultraviolet lamp.

1 is a side sectional view showing a light emitting device according to a first embodiment.
2 is a partial enlarged view of the light emitting device of Fig.
3 is a view showing a top view shape of the light emitting device of FIG.
4 (a) - (c) are views showing other shapes of the holes of the light emitting device of FIG.
5 is a view illustrating a light emitting device according to the second embodiment.
6 is a partially enlarged view of the light emitting device of Fig.
7 is a side sectional view of the light emitting device according to the third embodiment.
8 is another example of the light emitting device of Fig.
9 is a side sectional view of the light emitting device according to the fourth embodiment.
10 is another example of the light emitting device of Fig.
11 is a side sectional view of the light emitting device according to the fifth embodiment.
12 is another example of the light emitting device of Fig.
13 is a side sectional view of the light emitting device according to the sixth embodiment.
14 is an example in which electrodes are arranged in the light emitting device according to the embodiment.
15 is another example in which electrodes are arranged in the light emitting device according to the embodiment.
16 is a view illustrating a light emitting device package having a light emitting device according to an embodiment.

In the description of the embodiments, it is to be understood that each layer (film), region, pattern or structure may be referred to as being "on / over" or "under / under" Quot; on " and "under" are to be understood as being "directly" or "indirectly & . In addition, the criteria for the top / bottom or bottom / bottom of each layer are described with reference to the drawings.

≪ Light emitting element &

FIG. 1 is a cross-sectional view of a light emitting device according to a first embodiment, FIG. 2 is a partially enlarged view of the light emitting device of FIG. 1, and FIG. 3 is a view showing a top view shape of the light emitting device of FIG.

1 to 3, a light emitting device according to an embodiment includes a substrate 21, a buffer layer 31 disposed on the substrate 21, a first conductive semiconductor layer 31 disposed on the buffer layer 31, An active layer 51 disposed on the first conductive semiconductor layer 41; a plurality of holes 53 in the active layer 51; A contact portion 63 disposed in the plurality of holes 53 and a second conductive semiconductor layer 71 disposed on the electron blocking layer 61. [

The light emitting device emits light of ultraviolet wavelength. The light emitting device can emit a wavelength of 300 nm or less. As another example, the light emitting device may emit blue green or red light, but the invention is not limited thereto.

The substrate 21 may be, for example, a translucent, conductive substrate or an insulating substrate. For example, the substrate 21 may include at least one of sapphire (Al ₂ O ₃ ), SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, and Ga ₂ O ₃ . (Not shown) may be provided on the upper surface and / or the lower surface of the substrate 21. Each of the plurality of protrusions may include at least one of a side surface, a hemispherical shape, a polygonal shape, and an elliptical shape, Or in the form of a matrix. The protrusions can improve the light extraction efficiency.

A plurality of compound semiconductor layers may be grown on the substrate 21. The plurality of compound semiconductor layers may be grown using an electron beam evaporator, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma laser deposition (PLD) A dual-type thermal evaporator, sputtering, metal organic chemical vapor deposition (MOCVD), or the like. However, the present invention is not limited thereto. The plurality of compound semiconductor layers may be formed of a compound semiconductor of group II to VI elements, for example, a group II-VI or a group III-V compound semiconductor.

A buffer layer 31 may be disposed between the substrate 21 and the first conductive semiconductor layer 41. The buffer layer 31 may be formed of at least one layer using Group II to VI compound semiconductors. The buffer layer 31 includes a semiconductor layer using a Group III-V compound semiconductor, for example, In _x Al _y Ga _1-xy N (0? _X? 1, 0? Y? Lt; = 1). The buffer layer 31 includes at least one of materials such as GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP and ZnO.

The buffer layer 31 may be formed in a super lattice structure by alternately arranging different semiconductor layers. The buffer layer 31 may be formed to reduce the difference in lattice constant between the substrate 21 and the nitride-based semiconductor layer, and may be defined as a defect control layer. The buffer layer 31 may have a value between lattice constants between the substrate 21 and the nitride semiconductor layer. The buffer layer 31 may not be formed, but the present invention is not limited thereto.

A conductive layer (not shown) may be disposed between the buffer layer 31 and the first conductive semiconductor layer 41. The conductive layer is an undoped semiconductor layer and may have lower electrical conductivity than the first conductive semiconductor layer 41. The conductive layer may be formed of a Group II-VI compound semiconductor, for example, a Group III-V compound semiconductor. For example, the conductive layer may include GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, , AlGaInP, < / RTI > The conductive layer may not be formed, but the present invention is not limited thereto.

The first conductive semiconductor layer 41 may be disposed between the active layer 51 and at least one of the substrate 21, the buffer layer 31, and the conductive layer. The first conductive semiconductor layer 41 may be formed of at least one of Group III-V and Group II-VI compound semiconductors doped with a first conductivity type dopant.

The first conductive semiconductor layer 41 is formed of 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) . The first conductive semiconductor layer 41 may include at least one of GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, , Se, Te, or the like doped with an n-type dopant.

The first conductive semiconductor layer 41 may be a single layer or a multilayer. The first conductive semiconductor layer 41 may have a superlattice structure in which at least two different layers are alternately arranged. The first conductive semiconductor layer 41 may be a contact layer of the first electrode.

A first clad layer (not shown) may be disposed between the first conductive semiconductor layer 41 and the active layer 51. The first clad layer may include a GaN semiconductor, For example, an n-type semiconductor layer having an n-type dopant. The first clad layer may include at least one of GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP and AlGaInP. Type dopant may be an n-type semiconductor layer doped with a dopant.

Here, the semiconductor layer between the active layer 51 and the substrate 21, for example, the first conductive semiconductor layer 41 may be arranged as an AlGaN-based semiconductor in order to prevent absorption of ultraviolet wavelength, but the present invention is not limited thereto .

The active layer 51 may be formed of at least one of a single well, a single quantum well, a multi-well, a multi quantum well (MQW), a quantum-wire structure, or a quantum dot structure .

The active layer 51 is formed in such a manner that electrons (or holes) injected through the first conductive semiconductor layer 41 and holes (or electrons) injected through the second conductive semiconductor layer 71 meet with each other, 51 is a layer that emits light due to a band gap difference of an energy band according to a forming material of the light emitting device.

The active layer 51 may be formed of a compound semiconductor. The active layer 51 may be formed of at least one of Group II-VI and Group III-V compound semiconductors.

When the active layer 51 is implemented as a multi-well structure, it includes a plurality of well layers 5 and a plurality of barrier layers 6 as shown in FIG. In the active layer 51, a well layer 5 and a barrier layer 6 are alternately arranged. The pair of the well layer 5 and the barrier layer 6 may be formed in 2 to 30 cycles.

The well layer 5 may be arranged as 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) . The barrier layer 6 may be formed of 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) .

InGaN / AlGaN, InGaN / AlGaN, InGaN / InGaN, AlGaAs / GaAs, InGaAs / GaAs, InGaP / GaN , AlInGaP / InGaP, and InP / GaAs.

The well layer 5 of the active layer 51 according to the embodiment may be formed of an AlGaN-based semiconductor, and the barrier layer 6 may be formed of an AlGaN-based semiconductor. The active layer 51 may emit ultraviolet light. The aluminum layer of the barrier layer 6 has a higher composition than the aluminum layer of the well layer 5. The aluminum composition of the well layer 5 may range from 20% to 40%, and the aluminum composition of the barrier layer 6 may range from 40% to 95%. The composition of aluminum in the well layer (5) may be lower than the composition of aluminum in the barrier layer (6). The energy band gap of the barrier layer 6 may be larger than the energy band gap of the barrier layer 5.

The thickness of the well layer 5 may range from 3 nm to 5 nm, for example ranging from 2 nm to 4 nm. If the thickness of the well layer 5 is thinner than the above range, the constraining efficiency of the carrier is lowered, and if it is thicker than the above range, the carrier is excessively confined. The thickness of the barrier layer 6 may range from 4 nm to 20 nm, for example, from 4 nm to 10 nm. When the thickness of the barrier layer 6 is thinner than the above range, the electron blocking efficiency is lowered. If the thickness is larger than the above range, electrons are excessively blocked. Each carrier can be effectively restrained to the well layer 5 according to the thickness of the barrier layer 6, the wavelength of the light, and the quantum well structure.

The barrier layer 6 may include a dopant, for example, an n-type dopant. Since the barrier layer 6 is doped with an n-type dopant, the barrier layer 6 may be an n-type semiconductor layer. When the barrier layer 6 is an n-type semiconductor layer, the injection efficiency of electrons injected into the active layer 51 can be increased.

The uppermost side of the active layer 51 may be the barrier layer 6 and the uppermost barrier layer 6 may be in contact with the electron blocking structure layer 61. The last barrier layer 6 may have a different thickness or a different aluminum composition than the other barrier layers, but is not limited thereto.

The electron blocking layer 61 may be disposed on the active layer 51. The electron blocking layer 61 may be formed of a GaN-based semiconductor, for example, an AlGaN-based semiconductor, and may have a higher aluminum composition than the barrier layer 6 of the active layer 51. The composition of aluminum in the electron blocking layer 61 may be 50% or more.

The electron blocking layer 61 may be a p-type semiconductor layer having a second conductivity type dopant, for example, a p-type dopant. The p-type dopant may include dopants such as Mg, Zn, Ca, Sr, and Ba.

As another example, the electron blocking layer 61 may include at least one or two or more of GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, or AlGaInP.

The electron blocking layer 61 may include a plurality of semiconductor layers having different compositions of aluminum, for example, and at least one of the layers may have a composition of aluminum of 50% or more.

The second conductive semiconductor layer 71 is disposed on the electron blocking layer 61. The second conductive semiconductor layer 71 is formed of 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? . The second conductive semiconductor layer 71 may include at least one of GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP, Type semiconductor layer.

The second conductive semiconductor layer 71 may be a single layer or a multilayer. The second conductive semiconductor layer 71 may have a superlattice structure in which at least two different layers are alternately arranged. The second conductive semiconductor layer 71 may be a contact layer of the second electrode 81.

The second conductive semiconductor layer 71 may include a GaN-based semiconductor, for example, an AlGaN-based semiconductor. The second conductive semiconductor layer 71 may have a composition of aluminum of 50% or more, and a p-type dopant may be added.

In the embodiment, the layer structure from the first conductive semiconductor layer 31 to the second conductive semiconductor layer 71 can be defined as a light emitting structure layer. In the embodiment, the first conductivity is n-type and the second conductivity is p-type. As another example, the first conductivity may be p-type and the second conductivity may be n-type. Accordingly, the light emitting structure layer may include any one of an n-p junction structure, a p-n junction structure, an n-p-n junction structure, and a p-n-p junction structure.

A second electrode 81 may be disposed on the second conductive semiconductor layer 71. The second electrode 81 may include a single layer or a multilayer structure and may include a metal such as Ti, Ru, Rh, Ir, Mg, Zn, Al, In, Ta, Pd, Co, Ni, And Au and alloys thereof.

A current diffusion layer (not shown) may be disposed between the second electrode 81 and the second conductive semiconductor layer 71. The current diffusion layer may be formed of a metal or a non-metallic material. For example, an ITO ), IZO (indium zinc oxide), IZTO (indium zinc tin oxide), IZO (indium aluminum zinc oxide), IGZO (indium gallium zinc oxide), IGTO (indium gallium tin oxide) antimony tin oxide, gallium zinc oxide (GZO), ZnO, IrOx, RuOx, NiO, Al, Ag, Pd, Rh, Pt and Ir.

Meanwhile, the active layer 51 may have a plurality of holes 53 spaced from one another. The upper surface 41A of the first conductive semiconductor layer 41 may be exposed to the bottom of the hole 53. [ The inner side surfaces of the active layer 51, such as the well layer 5 and the barrier layer 6, may be exposed to the side walls of the holes 53, as shown in FIG.

The hole 53 may have a circular top view, and may be a polygonal shape such as a hexagon, a triangle, or a quadrangle as shown in FIGS. 4A, 4B, and 4C, or an elliptical shape. The hole 53 may have a shape in which the top and bottom lengths are different from each other, but the present invention is not limited thereto.

A plurality of contact portions 63 may be disposed in the hole 53. The contact portion 63 may be the same semiconductor as the electron blocking layer 61 or a different semiconductor, but is not limited thereto. The contact portion 63 may be formed of a conductive semiconductor, for example, a semiconductor having a second conductivity type dopant, for example, a p-type semiconductor. For convenience of explanation, the contact portion 63 will be described as a portion projecting from the electron blocking layer 61. [

The contact portions 63 of the electron blocking layer 61 are respectively disposed in the holes 53 and may contact the inner surface of the active layer 51. The contact portions 63 of the electron blocking layer 61 are formed on the inner surface of the plurality of well layers 5 and the plurality of barrier layers 6 and contacted with the well layer 5 and the barrier layer 6, And can be electrically connected.

The contact portion 63 of the electron blocking layer 61 may be in contact with the upper surface of the first conductive semiconductor layer 41. The contact portion 63 of the electron blocking layer 61 may be in contact with the upper surface 41A of the first conductive semiconductor layer 41, for example.

Here, since the uppermost barrier layer 6 of the active layer 51 is formed of an AlGaN-based semiconductor having a large aluminum composition, it has a high resistance. If the electron blocking layer is brought into contact with the upper surface of the uppermost barrier layer in the active layer of the comparative example without the hole 53 as in the embodiment and the operating voltage is supplied thereto, the operating voltage is increased. Such an increase in the operating voltage can lower the hole injection efficiency.

The contact area between the electron blocking layer 61 and the active layer 51 may be wider than in the case where the hole is not provided by the plurality of holes 53 in the embodiment. The contact portions 63 of the electron blocking layer 61 can be brought into contact with the inner surfaces of the plurality of well layers 5 and the plurality of barrier layers 6 through the plurality of holes 53 of the active layer 51 . Accordingly, the operating voltage applied between the active layer 51 and the electron blocking layer 61 can be lowered, and the efficiency of injecting holes into the active layer 51 can be improved.

The hole 53 may be disposed at a predetermined depth from the top surface of the active layer 51. The depth of the hole 53 may be the same as or different from the thickness of the active layer 51. The depth of the hole 53 may be greater than the thickness of the at least one barrier layer 6 of the active layer 51, but the present invention is not limited thereto.

Referring to FIGS. 2 and 3, the width D1 of the hole 53 may be 200 nm or less, for example, 20 nm to 200 nm. Even if the contact portion 63 of the electron blocking layer 61 is formed through the hole 53 when the width D1 of the hole 53 is smaller than the above range, the distance between the electron blocking layer 61 and the active layer 51 There is a problem that the contact area is reduced and the contact resistance is not reduced and the hole injection efficiency is not improved. In addition, when the width D1 of the hole 53 is larger than the above range, not only the light emitting area of the active layer 51 is reduced but also the current does not flow through the active layer 51, There is a problem that the first conductive semiconductor layer 41 is leaked through the second conductive semiconductor layer 63.

The density of the holes 53 includes a 1E + 9cm ² or less, for example, 1E + 8 / cm ² to about 1E + 9cm ² range. The distance D2 between the holes 53 may be in a range of 1 mu m or less, for example, 0.316 mu m to 1 mu m. When the density of the holes 53 exceeds the above range and the distance D2 between the holes 53 is less than the above range, there is a problem that the light emitting area is further reduced than the effect of reducing the operating voltage. If the density of the holes 53 is less than the above range and the distance D2 between the holes 53 is larger than the above range, the effect of reducing the operating voltage may be insignificant.

The active layer 51 may be divided into a non-emission region in which the hole 53 exists and a light emission region in which the hole 53 is not present. The area ratio of the non-emission area / light emitting area may vary depending on the density of the holes 53 and the spacing D2 between the holes 53, and may be, for example, in the range of 0.314 or less, for example, in the range of 0.001 to 0.314. The ratio of the area of the non-emission area / emission area can be set to a ratio considering the reduction ratio of the emission area and the operation voltage.

The hole 53 may be formed by forming the active layer 51 and then performing a nano patterning process or patterning a predetermined film such as polymethyl methacrylate (PMMA), followed by a dry etching process But the present invention is not limited thereto.

The contact portion 63 of the electron blocking layer 61 may include a recess when disposed along the surface of the hole 53. The protruding portion 73 of the second conductive semiconductor layer 71 may be disposed on the contact portion 63 of the electron blocking layer 61. The contact portion 63 of the electron blocking layer 61 and the protruding portion 73 of the second conductive semiconductor layer 71 may protrude in the same direction, for example, in the direction of the first conductive semiconductor layer. The projecting portion 73 can be brought into contact with the contact portion 63. [ The protrusion 73 protrudes or extends in the direction of the first conductive semiconductor layer 41 and may be disposed lower than the top surface of the active layer 51.

When current is supplied through the second conductive semiconductor layer 71, the current flows through the electron blocking layer 61 to the upper surfaces of the active layer 51 and the inner surfaces of the active layer 51 Lt; / RTI > Accordingly, carriers, for example, holes may be supplied to the barrier layer 6 and the well layer 5 through the upper surface and the side surface of the active layer 51. The layers adjacent to the lower surface of the active layer 51 from the upper surface of the active layer 51 among the plurality of well layers 5 are also connected to the electrons through the contact portions 63 of the electron blocking layer 61 . Hence, the hole injection efficiency can be improved.

Accordingly, the well layers 5 adjacent to the lower surface of the active layer 51 also generate light, so that the internal quantum efficiency can also be improved. In the case of an ultraviolet light emitting device, the operating voltage can be lowered and reliability can be improved.

1 and 3, the second electrode 81 may include a current diffusion pattern having at least one or a plurality of arm structures or a finger structure. The second electrode 81 having the current diffusion pattern may be disposed in a region that does not overlap the holes 53 in the vertical direction. Accordingly, the current supplied to the second electrode 81 is diffused by the current diffusion pattern, and the current intensity through the holes 53 can be controlled.

FIG. 5 is a side sectional view showing a light emitting device according to a second embodiment, and FIG. 6 is a partial enlarged view of the light emitting device of FIG. In the description of the second embodiment, the same parts as those described above will be described with reference to the above description.

5 and 6, the light emitting device includes a substrate 21, a buffer layer 31 disposed on the substrate 21, a first conductive semiconductor layer 41 disposed on the buffer layer 31, An active layer 51 disposed on the first conductive semiconductor layer 41; a plurality of holes 53 in the active layer 51; an electron blocking layer 61 disposed on the active layer 51; An insulating layer 55 disposed between the contact portion 63 and the first conductive semiconductor layer 41 and an insulating layer 55 disposed between the contact portion 63 and the first conductive semiconductor layer 41, And a second conductive semiconductor layer 71 disposed on the second conductive semiconductor layer 71.

The active layer 51 includes a plurality of holes 53 and the inner surfaces of the well layer 5 and the barrier layer 6 may be exposed to the plurality of holes 53 as shown in FIG.

The electron blocking layer 61 includes a plurality of contact portions 63 and the contact portions 63 are disposed in the holes 53 and are formed on the inner surfaces of the plurality of well layers 5 and the barrier layer 6 Can be contacted.

An insulating layer 55 may be disposed in the hole 53 and the insulating layer 55 may be disposed between the contact portion 63 and the first conductive semiconductor layer 41. The contact portion 63 may be spaced apart from the upper surface of the first conductive semiconductor layer 41. The insulating layer 55 may be in contact with the well layer 5 and the barrier layer 6 adjacent to the bottom surface of the active layer 51. The insulating layer 55 may be in contact with the upper surface 41A of the first conductive semiconductor layer 41.

The insulating layer 55 may be formed of an insulating material such as SiO ₂ , Si ₃ N ₄ , Al ₂ O ₃ , and TiO ₂ , either singly or in multiple layers. The insulating layer 55 may be an undoped semiconductor layer, but is not limited thereto. This insulating layer 55 can function as a current blocking layer.

The insulating layer 55 prevents the contact portion 63 of the electron blocking layer 61 from contacting the first conductive semiconductor layer 41. When the insulating layer 55 is disposed between the contact portion 63 of the electron blocking layer 61 and the first conductive semiconductor layer 41, leakage of current through the hole 53 is not considered , The width or the size of each of the holes 53 may be changed.

The thickness of the insulating layer 55 may be less than 1/2 of the thickness of the active layer 51. If the thickness of the insulating layer 55 exceeds 1/2 of the thickness of the active layer 51, the effect of reducing the contact resistance with respect to the active layer 51 is insignificant and the operation voltage can not be lowered.

Since the contact portion 63 of the electron blocking layer 61 is in contact with the inner surface of the active layer 51 on the insulating layer 55, the leakage current of the light emitting device can be blocked, And the operating voltage of the light emitting element can be lowered.

FIG. 7 is a side sectional view showing a light emitting device according to a third embodiment, and FIG. 8 is another example of FIG. In the description of the third embodiment, the same parts as those described above will be described with reference to the above description.

7 and 8, a region of any one of the well layer 5 and the barrier layer 6 adjacent to the upper surface of the first conductive semiconductor layer 41 is disposed at the bottom of the hole 53 of the active layer 51 And the bottom of the contact portion 63 may be in contact with any one of the well layer and the barrier layer.

7, the light emitting device includes a substrate 21, a buffer layer 31 disposed on the substrate 21, a first conductive semiconductor layer 41 disposed on the buffer layer 31, A plurality of holes (53) in the active layer (51), an electron blocking layer (61) disposed on the active layer (51), and a plurality of holes And a second conductive semiconductor layer 71 disposed on the electron blocking layer 61. The first conductive semiconductor layer 71 may be formed of a metal such as aluminum,

The active layer 51 includes a plurality of holes 53. The plurality of holes 53 may be disposed at a depth lower than the thickness of the active layer 51. Any one of the well layers 5 of the active layer 51, for example, the first region 5A of the lowermost well layer 5, may be disposed in the plurality of holes 53. [ The first region 5A may be in contact with the first conductive semiconductor layer 41 as a part of the well layer 5 which is the lowermost layer of the active layer 51. [

The contact portion 63 of the electron blocking layer 61 may be in contact with the plurality of well layers 5 and the plurality of barrier layers 6 through the holes 53 of the active layer 51, May be in contact with the first region 5A of the well layer 5 disposed at the bottom of the hole 53. [

The first region 5A of the well layer 5 may be disposed in the hole 53 and may be in contact with the contact portion 63 of the electron blocking layer 61. [ The first region 5A of the well layer 5 may serve as current blocking.

The contact portion 63 of the electron blocking layer 61 can be in contact with the plurality of well layers 5 and the plurality of barrier layers through the holes 53 of the active layer 51, The injection efficiency can be increased and the operation voltage of the light emitting device can be lowered.

8 is another example of the light emitting device of Fig.

Referring to FIG. 8, the active layer 51 includes a plurality of holes 53. The plurality of holes 53 may be disposed at a depth lower than the thickness of the active layer 51. A second region 6A of the barrier layer 6 of the active layer 51 may be disposed in the plurality of holes 53. [ The second region 6A may be a portion of one of the barrier layers 6 of the active layer 51, for example, a portion of the barrier layer 6 disposed on the lowermost side. A portion of the well layer 5 may be disposed below the second region 6A.

A contact portion 63 of the electron blocking layer 61 is disposed in the hole 53. The contact portion 63 contacts the plurality of barrier layers 6 and the plurality of well layers 5 through the hole 53, As shown in FIG. The contact portion 63 may be contacted on the second region 6A of the barrier layer 6. A second region 6A of the barrier layer 6 and a partial region of the well layer 5 disposed under the contact portion 63 can generate light under the hole 53. [

The contact portion 63 may have a larger contact area with the barrier layer 6 than a contact area with the well layer 5. [ Whereby the hole injection efficiency through the barrier layer 6 can be improved.

The contact portion 63 of the electron blocking layer 61 can be in contact with the plurality of well layers 5 and the plurality of barrier layers 6 through the holes 53 of the active layer 51 so that the active layer 53 ) Can be increased and the operation voltage of the light emitting device can be lowered.

9 is a side sectional view showing a light emitting device according to a fourth embodiment. In the description of the fourth embodiment, the same parts as those described above will be described with reference to the above description.

9, the light emitting device includes a substrate 21, a buffer layer 31 disposed on the substrate 21, a first conductive semiconductor layer 41 disposed on the buffer layer 31, A plurality of holes (53) in the active layer (51), an electron blocking layer (61) disposed on the active layer (51), and a plurality of holes And a second conductive semiconductor layer 71 disposed on the electron blocking layer 61. The first conductive semiconductor layer 71 may be formed of a metal such as aluminum,

The active layer 51 includes a plurality of holes 53. The plurality of holes 53 may be disposed at a depth greater than the thickness of the active layer 51. For example, the bottom of the hole 53 may be disposed lower than the top surface 41 A of the first conductive semiconductor layer 41.

The contact portion 63 of the electron blocking layer 61 may be disposed in the hole 53 and the contact portion 63 may contact the inner surface of the active layer 51 through the hole 53. [ The contact portion 63 may be disposed in the first conductive semiconductor layer 41. The bottom of the contact portion 63 may extend to the upper region 43 of the first conductive semiconductor layer 41 which is lower than the upper surface 41A of the first conductive semiconductor layer 41. [ The upper region 43 of the first conductive semiconductor layer 41 may be formed by adjusting the etching depth of the holes 53.

The contact area of the contact portion 63 of the electron blocking layer 61 with the active layer 51 can be increased by the hole 53 so that the hole injection efficiency of the active layer 51 can be increased, The operating voltage of the device can be lowered.

10 is another example of the light emitting device of Fig.

Referring to FIG. 10, the active layer 51 includes a plurality of holes 53, and the holes 53 may be disposed at a depth greater than the thickness of the active layer 51. The bottom of the hole 53 may extend to the upper region 43 of the first conductive semiconductor layer 41. An insulating layer 57 may be disposed on the upper region 43. The insulating layer 57 may prevent contact between the first conductive semiconductor layer 41 and the contact portion 63 of the electron blocking layer 61 at the bottom of the hole 53. The insulating layer 57 may be a current blocking layer.

The contact portion 63 of the electron blocking layer 61 is disposed in the hole 53 and the contact portion 63 is in contact with the inner surface of the active layer 51 and the insulating layer 57 through the hole 53 . The contact area of the contact portion 63 of the electron blocking layer 61 with the active layer 51 is increased so that the hole injection efficiency of the active layer 51 can be increased and the operating voltage of the light emitting device can be lowered .

11 is a side sectional view of the light emitting device according to the fifth embodiment, and Fig. 12 is a partial enlarged view of the light emitting device of Fig. In the description of the fifth embodiment, the same components as those described above will be described with reference to the above description.

11 and 12, the light emitting device includes a substrate 21, a buffer layer 31 disposed on the substrate 21, a first conductive semiconductor layer 41 disposed on the buffer layer 31, An active layer 51 disposed on the first conductive semiconductor layer 41; a plurality of holes 53 in the active layer 51; an electron blocking layer 61 disposed on the active layer 51; A contact portion 63 disposed in the plurality of holes 53 and a second conductive semiconductor layer 71 disposed on the electron blocking layer 61. [

A plurality of holes 53 may be disposed in the active layer 51 and a contact portion 64 of the electron blocking layer 61 may be disposed in the holes 53. Here, the contact portion 64 of the electron blocking layer 61 may be filled in the hole 53. The contact portion 64 may have the same width as the width of the hole 53 and may have the same height as the depth of the hole 53.

The contact portion 64 of the electron blocking layer 61 may be grown by an epitaxial lateral overgrowth (ELOG) growth method during growth, but the present invention is not limited thereto.

The region 62 corresponding to the contact portion 64 may be formed in a concave region lower than the upper surface of the electron blocking layer 61. However, the present invention is not limited thereto. This concave region 62 can improve the contact area with the second conductive semiconductor layer 71.

The contact area of the contact portion 64 of the electron blocking layer 61 with the active layer 51 is increased so that the hole injection efficiency of the active layer 51 can be increased and the operating voltage of the light emitting device can be lowered.

13 is a side sectional view of the light emitting device according to the sixth embodiment. The sixth embodiment can be selectively applied to the above-described embodiments, and in the description of the sixth embodiment, the same parts as those described above will be described with reference to the description of the embodiments disclosed above.

13, the light emitting device includes a substrate 21, a buffer layer 31 disposed on the substrate 21, a first conductive semiconductor layer 41 disposed on the buffer layer 31, A plurality of holes (53) in the active layer (51), an electron blocking layer (61) disposed on the active layer (51), and a plurality of holes And a second conductive semiconductor layer 71 disposed on the electron blocking layer 61. The first conductive semiconductor layer 71 may be formed of a metal such as aluminum,

The active layer 51 may include a plurality of holes 53. At least one or all of the plurality of holes 53 may have a wide width at the top and a narrow width at the bottom. At least one or all of the plurality of holes 53 may be gradually narrowed toward the first conductive semiconductor layer 41. The top surface 41A of the first conductive semiconductor layer 41 may not be exposed or exposed to the bottom of the hole 53, but the present invention is not limited thereto.

The contact portion 63 of the electron blocking layer 61 is disposed in the hole 53. The contact portion 63 may contact the inner surface of the active layer 51 through the hole 53, for example, the inner surfaces of the plurality of well layers 5 and the barrier layer 6. Here, the inclined side surfaces of the holes 53 allow the inner surfaces of the well layer 5 and the barrier layer 6 to be provided as inclined surfaces, and the inclined surfaces of the well layers 5 and The contact area of the barrier layer 6 with the contact portion 63 can be increased.

An insulating layer may be further disposed under the contact portion 63, but the present invention is not limited thereto.

Since the contact portion 63 of the electron blocking layer 61 increases the contact area with the active layer 51, the hole injection efficiency of the active layer 51 can be increased and the operating voltage of the light emitting device can be lowered.

A current diffusion layer 83 may be disposed between the second conductive semiconductor layer 71 and the second electrode 81. The current diffusion layer 83 may be a transparent electrode layer or a reflective electrode layer. This current diffusion layer 83 can diffuse the current supplied from the second electrode 81. The current diffusion layer 83 may not be formed.

14 is an example in which electrodes are arranged in the light emitting device according to the embodiment, for example, the light emitting device in Fig.

14, the light emitting device 100 includes a first electrode 91 disposed on the first conductive semiconductor layer 41, a second electrode 81 formed on the second conductive semiconductor layer 71, .

The first and second electrodes 91 and 81 are formed of a metal such as Ti, Ru, Rh, Ir, Mg, Zn, Al, In, Ta, Pd, Co, Ni, Si, Ge, May be selected from the optional alloys and may be formed as a single layer or a multilayer.

The first electrode 91 and the second electrode 81 may further have a current diffusion pattern of an arm structure or a finger structure. The first electrode 91 and the second electrode 81 may be made of a metal having the characteristics of an ohmic contact, an adhesive layer, and a bonding layer, and may not be transparent.

The contact area between the active layer 51 and the electron blocking layer 61 is increased in the light emitting device 100 having the ultraviolet wavelength so that the hole injection efficiency of the active layer 51 can be increased and the operating voltage of the light emitting device is lowered You can give.

15 is another example in which electrodes are arranged in the light emitting device according to the embodiment, for example, the light emitting device in Fig.

15, a light emitting device includes a first conductive semiconductor layer 41, a first electrode 91 on the first conductive semiconductor layer 41, and an active layer 51 under the first conductive semiconductor layer 41. [ A plurality of holes 53 in the active layer 51; an electron blocking layer 61 on the active layer 51; a contact portion 63 in the hole 53; 2 conductive semiconductor layer (71).

The current blocking layer 161, the passivation layer 163, and the second electrode 170 are disposed under the second conductive semiconductor layer 71. The current blocking layer 161 may be made of an insulating material or a low conductive material and may include at least one of SiO ₂ , SiO _x , SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ and TiO ₂ , And may be formed in multiple layers. At least one or a plurality of the current blocking layers 161 may be formed in the inner region of the protective layer 163.

The current blocking layer 161 may overlap the first electrode 91 disposed on the second conductive semiconductor layer 71 in the vertical direction. The current blocking layer 161 may cut off current supplied from the second electrode 170 and diffuse the current blocking layer 161 to another path.

The protective layer 163 is formed along the lower edge of the second conductive semiconductor layer 71 and may be formed in a ring shape, a loop shape, or a frame shape. The protective layer 163 may include a conductive material or an insulating material such as ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, SiO ₂ , SiO _x , SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ , and TiO ₂ , and may be formed as a single layer or a multilayer. The inner side of the protective layer 163 is disposed below the second conductive semiconductor layer 71 and the outer side of the protective layer 163 is located further outward than the side surfaces of the semiconductor layers 41-71.

A second electrode 170 may be formed under the second conductive semiconductor layer 71. The second electrode 170 may include a plurality of conductive layers 165, 167, and 169.

The second electrode 170 includes a contact layer 165, a reflective layer 167, and a bonding layer 169. The contact layer 165 may be formed of a low conductive material such as ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, or ATO, or may be formed of single or multiple layers using metals such as Ni and Ag. A reflective layer 167 is formed under the contact layer 165 and the reflective layer 167 is formed of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, And at least one layer made of a material selected from the group consisting of a single layer or a multilayer. The reflective layer 167 may be in contact with the second conductive semiconductor layer 71 and may be in ohmic contact with a metal or ohmic contact with a conductive material such as ITO.

A bonding layer 169 is formed under the reflection layer 167 and the bonding layer 169 may be used as a barrier metal or a bonding metal. The material may be Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, and Ta and an optional alloy.

A support member 173 is formed under the bonding layer 169 and the support member 173 may be formed of a conductive material made of a metal or a semiconductor material. The material may be copper (Cu), gold (e.g., Si, Ge, GaAs, ZnO, SiC, and the like), nickel (Ni), molybdenum (Mo), copper-tungsten . As another example, the support member 173 may be embodied as a conductive sheet.

Here, the substrate of FIG. 1 may be removed. The growth substrate may be removed by a physical method such as laser lift off or chemical method such as wet etching to expose the first conductive semiconductor layer 41. The first electrode 91 is formed on the first conductive semiconductor layer 41 by performing the isolation etching through the direction in which the substrate is removed.

A light extraction structure 47 such as a roughness may be formed on the upper surface of the first conductive semiconductor layer 117. Accordingly, a light emitting device having a vertical electrode structure having the first electrode 181 and the supporting member 173 below the semiconductor layer 41-71 can be provided.

≪ Light emitting device package &

16 is a side sectional view showing a light emitting device package having the light emitting element of Fig.

16, the light emitting device package includes a body 121, a first lead electrode 111 and a second lead electrode 113 disposed on the body 121, and a second lead electrode 111 disposed on the body 121 A light emitting device 100 according to an embodiment electrically connected to the first lead electrode 111 and the second lead electrode 113 and a window layer 140 disposed on the light emitting device 100 .

The body 121 may include a ceramic material. The body 121 may provide a cavity 125 having an inclined surface around the light emitting device 100. As another example, the body 121 may include a resin material, and a molding member may be disposed in the cavity 125, but the present invention is not limited thereto.

The first lead electrode 111 and the second lead electrode 113 are electrically isolated from each other and provide power to the light emitting device 100. [ The first lead electrode 111 and the second lead electrode 113 may be disposed on the bottom of the cavity 125 and may reflect light generated from the light emitting device 100 to increase light efficiency And may discharge the heat generated from the light emitting device 100 to the outside.

And is connected to the first lead electrode 111 by a wire 143. The first lead electrode 111 is connected to the second lead electrode 113 of the light emitting device 100 by a wire 143. The light emitting device 100 may be arranged in a flip chip manner, but the present invention is not limited thereto.

The window layer 140 may be disposed on the cavity 125. The window layer 140 may be bonded or bonded to the upper surface of the body 121. The window layer 140 includes a glass material such as quartz glass. The window layer 140 emits light emitted from the light emitting device 100. The window layer 140 may include a phosphor layer, but the present invention is not limited thereto.

A plurality of light emitting devices or light emitting device packages according to the embodiments may be arrayed on a substrate, and a lens, a light guide plate, a prism sheet, a diffusion sheet, etc., which are optical members, may be disposed on the light path of the light emitting device package. Such a light emitting device package, a substrate, and an optical member can function as a light unit. The light unit may be implemented as a top view or a side view type and may be provided in a display device such as a portable terminal and a notebook computer, or may be variously applied to a lighting device and a pointing device. Still another embodiment may be embodied as a lighting device including the light emitting device or the light emitting device package described in the above embodiments. For example, the lighting device may include a lamp, a streetlight, an electric signboard, and a headlight.

The features, structures, effects and the like described in the embodiments are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects and the like illustrated in the embodiments can be combined and modified by other persons skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of illustration, It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

21: substrate 31: buffer layer
41: first conductive semiconductor layer 51: active layer
53: hole 61: electron blocking layer
63, 64: contact portion 71: second conductive semiconductor layer
91: first electrode 81: second electrode

Claims (11)

A first conductive semiconductor layer;
An active layer disposed on the first conductive semiconductor layer and having a plurality of well layers and a plurality of barrier layers;
An electron blocking layer disposed on the active layer;
A second conductive semiconductor layer disposed on the electron blocking layer;
A plurality of holes disposed in the active layer;
And a contact disposed in the plurality of holes,
Wherein the contact portion comprises a conductive semiconductor and is in contact with the plurality of well layers and the plurality of barrier layers. The method according to claim 1,
Wherein the well layer, the barrier layer, and the electron blocking layer comprise an AlGaN-based semiconductor. 3. The method of claim 2,
And the contact portion protrudes from the electron blocking layer. The method of claim 3,
And the contact portion is in contact with or spaced from the first conductive semiconductor layer. The method according to claim 3 or 4,
And an insulating layer disposed between the contact portion and the first conductive semiconductor layer. The method according to claim 3 or 4,
Wherein at least one of a well layer and a barrier layer adjacent to the upper surface of the first conductive semiconductor layer is disposed on the bottom of the hole,
And the bottom of the contact portion is in contact with any one of the well layer and the barrier layer. 5. The method of claim 4,
Wherein the hole is disposed at a lower depth than an upper surface of the first conductive semiconductor layer. 5. The method according to any one of claims 1 to 4,
Wherein at least one or both of the plurality of holes have an upper width larger than a lower width. The method of claim 3,
And the second conductive semiconductor layer includes a protrusion disposed on the contact portion. 5. The method according to any one of claims 1 to 4,
And an electrode having a current diffusion pattern disposed on the second conductive semiconductor layer,
And the electrode is disposed in a region that does not overlap with the plurality of holes in the vertical direction. A body having a cavity;
A light emitting element according to any one of claims 1 to 3 arranged in the cavity;
And a window layer on the cavity.

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