KR20180018095A - Uv light emitting device and lighting system - Google Patents

Abstract

Embodiments relate to a light emitting device, a method of fabricating the light emitting device, a light emitting device package, and a lighting apparatus. An ultraviolet (UV) light emitting device comprises: a first conductivity-type first AlGaN-based layer (112); a first conductivity-type second AlGaN-based layer (113) on the first conductivity-type first AlGaN-based layer (112); a GaN/AlGaN-based superlattice layer (115) on the first conductivity-type second AlGaN-based layer (113); an active layer (114) on the GaN/AlGaN-based superlattice layer (115); and a second conductivity-type AlGaN-based layer (116) on the active layer (114). The active layer (114) may include an InGaN-based quantum well (114W) and an AlGaN-based quantum wall (114B). The AlGaN-based quantum wall (114B) may include an Al _yGa_(1-y)N layer (0<y<1). The first conductivity-type second AlGaN-based layer (113) may include a first conductivity-type Al_(x2)Ga_(1-x2)N layer (0<x2<1).

Description

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

Embodiments relate to an ultraviolet light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and a lighting device.

Semiconductor devices including compounds such as GaN and AlGaN have many merits such as wide and easy bandgap energy, and can be used variously as light emitting devices, light receiving devices, and various diodes.

Particularly, a light emitting device such as a light emitting diode or a laser diode using a semiconductor material of Group 3-5 or 2-6 group semiconductors can be applied to various devices such as a red, Blue, and ultraviolet rays. By using fluorescent materials or combining colors, it is possible to realize a white light beam with high efficiency. Also, compared to conventional light sources such as fluorescent lamps and incandescent lamps, low power consumption, , Safety, and environmental friendliness. In addition, when a light-receiving element such as a photodetector or a solar cell is manufactured using a semiconductor material of Group 3-5 or Group 2-6 compound semiconductor, development of a device material absorbs light of various wavelength regions to generate a photocurrent , It is possible to use light in various wavelength ranges from the gamma ray to the radio wave region. It also has advantages of fast response speed, safety, environmental friendliness and easy control of device materials, so it can be easily used for power control or microwave circuit or communication module.

Therefore, a transmission module of the optical communication means, a light emitting diode backlight replacing a cold cathode fluorescent lamp (CCFL) constituting a backlight of an LCD (Liquid Crystal Display) display device, a white light emitting element capable of replacing a fluorescent lamp or an incandescent lamp Diode lighting devices, automotive headlights, traffic lights, and gas and fire sensors. Further, applications can be extended to high frequency application circuits, other power control devices, and communication modules.

The light emitting device may be formed by combining a group III-V element or a group II-VI element in the periodic table with a pn junction diode in which electric energy is converted into light energy, So that various colors can be realized.

For example, nitride semiconductors have received great interest in the development of optical devices and high power electronic devices due to their high thermal stability and wide bandgap energy. Particularly, a blue light emitting element, a green light emitting element, an ultraviolet (UV) light emitting element, and a red (RED) light emitting element using a nitride semiconductor are commercially available and widely used.

For example, in the case of an ultraviolet light emitting device, it is a light emitting diode that emits light distributed in a wavelength range of 200 nm to 400 nm. It is used for sterilization and purification in the above wavelength range and short wavelength, .

For example, ultraviolet rays can be divided into UV-A (315 to 400 nm), UV-B (280 to 315 nm) and UV-C The UV-B (280 ~ 315nm) area is used for various applications such as UV curing for industrial use, curing of printing ink, exposure machine, discrimination of counterfeit, photocatalytic disinfection and special illumination (aquarium / UV-C (200 ~ 280nm) is applied to air purification, water purification, and sterilization products.

On the other hand, the ultraviolet light-emitting device has a problem that the light-receiving efficiency and the light output are lower than that of the blue light-emitting device. This serves as a barrier to practical use of the ultraviolet light emitting element.

For example, the Group-III nitride used in an ultraviolet light-emitting device can be widely used from visible light to ultraviolet light, but the efficiency of ultraviolet light compared to visible light is inferior. The reason is that Group III nitride absorbs ultraviolet rays toward the wavelength of ultraviolet rays and degradation of internal quantum efficiency due to low crystallinity.

Accordingly, in order to prevent the ultraviolet absorption in the Group-III nitride, the growth substrate, the GaN layer, the AlGaN layer, the active layer and the like are successively grown, and then the GaN layer capable of absorbing ultraviolet rays is removed and the AlGaN layer is exposed However, the problem of lowering the internal quantum efficiency due to the low crystallinity of the AlGaN layer is difficult to solve.

Recently, in order to improve the quality of the active layer of the UV light emitting device, a technique including a small amount of indium (In) has been proposed.

However, when indium is contained in the active layer, it is difficult to realize a desired wavelength region of UV light. For example, the tendency of exposure and curing companies is to require a wavelength of 365 nm or less, for example, a wavelength of 360 nm. In the case of an active layer containing indium, it is difficult to realize a short wavelength due to low band gap energy (Eg) It is difficult to implement the following UV chip.

On the other hand, in the case of a light emitting device using a nitride, many carriers (carriers) are injected at the time of high current injection due to the non-symmetry of injection efficiency and concentration of electrons and holes (for example, Are not recombined with each other and overflow, resulting in a decrease in luminous efficiency such as an efficiency droop.

One of the objects of the embodiment is to provide an ultraviolet light emitting device and a lighting apparatus including the same, which can realize a high quality active layer not containing aluminum (Al) in a quantum well and a wavelength of 365 nm or less.

In addition, one of the problems of the embodiment is to provide an ultraviolet light-emitting device and an illumination device including the ultraviolet light-emitting device capable of improving the operating voltage and improving the light output.

In addition, one of the problems of the embodiments is to provide an ultraviolet light emitting device capable of mitigating or eliminating the droop phenomenon and a lighting apparatus including the ultraviolet light emitting device.

The object of the present invention is not limited to the contents described in this item, but an objective technical problem to be solved based on the contents of the entire description of the invention can be described.

The ultraviolet light-emitting device includes a first conductive type first AlGaN layer 112; A first conductive type second AlGaN layer 113 on the first conductive type first AlGaN layer 112; A GaN / AlGaN superlattice layer 115 on the first conductive type second AlGaN layer 113; An active layer 114 on the GaN / AlGaN-based superlattice layer 115; And a second conductive AlGaN layer 116 on the active layer 114.

The active layer 114 may include an InGaN-based quantum well 114W and an AlGaN-based quantum wall 114B.

The AlGaN-based quantum wall 114B may include an Al _y Ga _{1 - y} N layer (0 <y <1).

The first conductive type second AlGaN layer 113 may include a first conductive type Al _{x 2} Ga _{1 - x 2} N layer (0 <x 2 <1).

In addition, the ultraviolet light emitting device according to the embodiment includes a first conductive type first AlGaN layer 112; A first conductive type second AlGaN layer 113 on the first conductive type first AlGaN layer 112; A GaN / AlGaN superlattice layer 115 on the first conductive type second AlGaN layer 113; An active layer 114 on the GaN / AlGaN-based superlattice layer 115; And a second conductive AlGaN series layer 116 on the active layer 114. The active layer 114 includes an InGaN series quantum well 114W and an AlGaN series quantum wall 114B, The InGaN-based quantum well 114W and the AlGaN-based quantum wall 114B may be formed of a plurality of pairs, and the thickness of the InGaN-based quantum well 114W may be 2 nm to 4 nm.

The lighting apparatus according to the embodiment may include a light emitting unit having the light emitting element.

The embodiment can provide an ultraviolet light emitting device having a technical effect in which a quantum well is a high-quality active layer not containing aluminum (Al) and a wavelength of 365 nm or less, and a lighting apparatus including the same.

In addition, the embodiment can provide an ultraviolet light emitting element having a technical effect of improving the operating voltage and improving the light output, and a lighting apparatus including the ultraviolet light emitting element.

Also, the embodiment can provide an ultraviolet light emitting element having a technical effect that can mitigate or eliminate a droop phenomenon, and a lighting apparatus including the ultraviolet light emitting element.

1 is a planar projection view of an ultraviolet light emitting device according to an embodiment.
2 is a cross-sectional view of an ultraviolet light-emitting device according to an embodiment.
3A is a partially enlarged cross-sectional view of an ultraviolet light emitting device according to an embodiment.
3B is a view showing an Al concentration gradient of the first conductive type second AlGaN layer 113 in the ultraviolet light emitting device according to the embodiment.
4 is a diagram illustrating an example of a bandgap diagram of an ultraviolet light-emitting device according to the prior art.
Fig. 5 is an illustration of a bandgap diagram of an ultraviolet light-emitting device according to an embodiment; Fig.
6 is an enlarged view of an active layer of an ultraviolet light emitting device according to another embodiment.
7 to 17 are process sectional views of a method of manufacturing a light emitting device according to an embodiment.
18 is a sectional view of a light emitting device package according to an embodiment.
19 is a perspective view of a lighting apparatus according to an embodiment.

Hereinafter, embodiments will be described with reference to the accompanying drawings. In the description of the embodiments, it is to be understood that each layer (film), area, pattern or structure may be referred to as being "on" or "under" the substrate, each layer Quot; on "and" under "are intended to include both" directly "or" indirectly " do. In addition, the criteria for the top, bottom, or bottom of each layer will be described with reference to drawings, but the embodiment is not limited thereto.

The embodiment will be described mainly with respect to a via-hole type vertical light emitting device, but the embodiment is not limited thereto. The light emitting device of the embodiment can be applied to a horizontal type light emitting device, a vertical type light emitting device, and the like.

(Example)

1 is a planar projection view of an ultraviolet light-emitting device 100 according to an embodiment, and Fig. 2 is a cross-sectional view of an embodiment along line A-A 'in Fig. The configurations shown in FIG. 1 are also shown in FIG. 2, and will be described with reference to FIG.

Referring to FIG. 2, the light emitting device 100 includes a light emitting structure layer 110, a first electrode layer 150, a second electrode layer 130, a contact layer 160, a lower electrode 159, An electrode 180, an insulating layer 140, and a passivation layer 170, as shown in FIG.

For example, the light emitting device 100 according to the embodiment includes a light emitting structure layer 110 including a first conductive AlGaN layer 112, an active layer 114, and a second conductive AlGaN layer 116 A first electrode layer 150 disposed under the light emitting structure layer 110; a second electrode layer 130 electrically connected to the second conductive AlGaN layer 116 of the light emitting structure layer 110; A contact layer 160 electrically connecting the first electrode layer 150 to the first conductive type first AlGaN layer 112 of the light emitting structure layer 110 and a second contact layer 160 disposed below the second electrode layer 130 A lower electrode 159 and a pad electrode 180 electrically connected to the first conductive type second AlGaN layer 113 of the light emitting structure layer 110. The second electrode layer 130 and the first electrode layer And a passivation layer 170 disposed on the light emitting structure layer 110. The passivation layer 170 may be formed on the light emitting structure layer 110, The light extracting structure P may be formed on the upper surface of the light emitting structure layer 110 to improve light extraction efficiency.

Hereinafter, technical features of the ultraviolet light emitting device according to the embodiment will be described with reference to FIG.

<First electrode layer>

The first electrode layer 150 may include a diffusion barrier layer 154 disposed on a side surface of the contact layer 160 and a bonding layer 156 disposed under the diffusion barrier layer 154 and a bonding layer 156 disposed below the bonding layer 156. [ And a support member 158 disposed on the support member 158. [ The diffusion preventing layer 154 and / or the bonding layer 156 may be a single layer or a plurality of layers including at least one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, have.

The diffusion preventing layer 154 of the first electrode layer 150 may be in contact with the side surface of the contact layer 160 and the bonding layer 156 may be in contact with the contact layer 160, The contact area between the contact layers 160 can be enlarged.

Accordingly, according to the embodiment, the contact resistance between the contact layer 160 and the first electrode layer 150 is reduced, thereby preventing an increase in the operating voltage, thereby improving the light output Po and improving the electrical reliability.

According to the embodiment, the luminous flux can be improved by improving the current injection efficiency according to the increase of the contact area between the contact layer 160 and the first electrode layer 150.

<Contact layer>

The contact layer 160 of the embodiment may be formed of a plurality of holes H (see FIG. 9) extending through the active layer 114 and exposing a part of the first conductive type first AlGaN layer 112, The first electrode layer 150 and the second electrode layer 150, respectively.

For example, the contact layer 160 may extend from the bottom of the second conductive AlGaN layer 116 through the second conductive AlGaN layer 116 and the active layer 114, And may be electrically connected to the first conductive type first AlGaN layer 112 through a plurality of holes H (see FIG. 9) that expose a portion of the first AlGaN layer 112.

The upper surface of the contact layer 160 may be disposed higher than the active layer 114 and the lower surface of the contact layer 160 may be disposed lower than the second conductive AlGaN layer 116 have.

The contact layer 160 may be formed of a conductive metal material or a semiconductor material. For example, the contact layer 160 may include at least one of Ti, Cr, Ta, Al, Pd, Pt, Cu, Ni, Ag, Mo, Al, Au, Nb, .

The contact layer 160 may be formed of a semiconductor layer having a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + y? have. For example, the contact layer 160 may be selected from a group III-V element compound semiconductor such as GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP, .

In the embodiment, the lower region of the contact layer 160 may be inclined to the side surface to widen the surface area, and the diffusion prevention layer 154 may contact the side surface of the contact layer 160, The rise of the operating voltage can be prevented by reducing the resistance.

According to an embodiment of the present invention, the current injection efficiency between the first electrode layer 150 and the contact layer 160 is improved by widening the contact area between the inclined side surface of the contact layer 160 and the diffusion prevention layer 154, Can be improved.

<Second electrode layer>

The second electrode layer 130 may include a second contact electrode 132, a reflective layer 134, and a capping layer 136. The second electrode layer 130 may be provided from the pad electrode 180 Can be supplied to the second conductivity type AlGaN series layer 116. [

The second contact electrode 132 may be in ohmic contact with the second conductive AlGaN layer 116 of the light emitting structure layer 110. The second contact electrode 132 may include at least one conductive material and may be a single layer or multi- have.

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

The reflective layer 134 is disposed on the second contact electrode 132 and may reflect light incident through the second contact electrode 132. The reflective layer 134 may include one or more layers of materials selected from the group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, Layer.

The capping layer 136 may be disposed on the reflective layer 134 and may supply power to the reflective layer 134 from the pad electrode 180 formed thereafter. The capping layer 136 may function as a current diffusion layer. The capping layer 136 may be made of a material having high electrical conductivity such as Sn, Ga, In, Bi, Cu, Ni, Ag, Mo, Al, Au, Nb, W, Ti, Al, Pd, Pt, Si and an optional alloy thereof.

<Channel layer>

Embodiments may include a channel layer 120 disposed between the upper side of the contact layer 160 and the first conductive type first AlGaN layer 112.

The channel layer 120 may also be disposed between the upper side of the contact layer 160 and the active layer 116 and the second conductive AlGaN layer 116. Accordingly, the channel layer 120 can prevent a short circuit between the contact layer 160 and the active layer 114 and the second conductive AlGaN layer 116.

In an embodiment, the reflectance of the channel layer 120 may exceed 50%. For example, the channel layer 120 may be formed of one or more materials selected from SiO _x , SiO ₂ , SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ and TiO ₂ , A reflective material may be mixed with the reflective layer.

For example, the channel layer 120 may be formed of a mixture of at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, And may be formed as a single layer or a multilayer, but is not limited thereto.

The channel layer 120 including the reflective material is disposed on the side surface of the contact layer 160 functioning as a contact layer, thereby preventing light absorption by the contact layer 160, unlike the prior art, The luminous flux can be improved by improving the efficiency.

<Light-emitting structure layer>

The light emitting element of the embodiment may be an infrared light emitting element. Accordingly, the light emitting structure layer 110 of the embodiment may include a first conductive type first AlGaN layer 112, an active layer 114, and a second conductive type AlGaN series layer 116.

3A is an enlarged cross-sectional view of a portion (E) of an ultraviolet light-emitting device according to an embodiment.

Hereinafter, description will be made on the technical characteristics of the ultraviolet light emitting device according to the embodiment with reference to the characteristic of the light emitting structure layer 110 with reference to FIG. 3A.

One of the objects of the embodiment is to provide an ultraviolet light emitting device and a lighting apparatus including the same, which can realize a high quality active layer not containing aluminum (Al) in a quantum well and a wavelength of 365 nm or less.

The light emitting device 100 includes a first conductive type first AlGaN layer 112 and a first conductive type first AlGaN layer 112 on the first conductive type AlGaN AlGaN-based superlattice layer 115 on the first conductive type second AlGaN-based layer 113 and a GaN / AlGaN-based superlattice layer 115 on the first conductive type second AlGaN- And a second conductivity type AlGaN series layer 116 on the active layer 114. [

In an embodiment, the first conductive type first AlGaN layer 112 may be selected from compound semiconductors of Group III-V elements doped with a first conductive dopant, such as AlN, AlGaN, InAlGaN, AlInN, AlGaAs, AlGaInP, have. For example, the first conductive type first AlGaN-based layer 112 has a first conductivity type Al _x1 Ga _{1 -} may include _x1 N layer (0 <x1 <1).

The first conductive type first AlGaN layer 112 may be a single layer or multiple layers and may include a superlattice structure in which two different layers of AlN, AlGaN, InAlGaN, AlInN, AlGaAs, and AlGaInP are alternately arranged .

The first conductive type first AlGaN layer 112 may be an n-type semiconductor layer, and the first conductive type dopant may include n-type dopants such as Si, Ge, Sn, Se, and Te.

In the embodiment, the GaN / AlGaN superlattice layer 115 may be formed of a plurality of pairs of a combination of a GaN / AlGaN layer, an InGaN / AlGaN layer, or the like, and contributes to current diffusion, have. The electrical characteristics of the AlGaN layer of the GaN / AlGaN-based superlattice layer 115 can be improved by injecting an n-type dopant.

In an embodiment, the active layer 114 may include an InGaN-based quantum well 114W and an AlGaN-based quantum wall 114B. In the embodiment, the InGaN-based quantum well 114W may not include aluminum (Al) to realize a high-quality active layer.

The InGaN-based quantum well 114W has a composition of In _p Ga _{1 - p} N ( _{0 ? P} ? 0.02), thereby achieving high efficiency chip implementation and droop improvement. In an embodiment, the AlGaN-based quantum wall 114B may include an Al _y Ga _{1 - y} N layer (0 <y <1).

For example, in the embodiment, the InGaN-based quantum well 114W may have a composition of In _p Ga _{1 - p} N (0 < _p ? 0.02). For example, in the InGaN-based quantum well 114W, In may be doped with a composition of about 2% or less. In the InGaN-based quantum well 114W, In can be doped to a treatment level. The doping of the above composition level may not necessarily result in the formation of a tri-atomic compound.

As a result, the InGaN quantum well 114W is positioned in a vacancy of vacancy, thereby reducing defects and improving the crystal quality of the quantum well, so that the brightness can be improved.

Further, in the embodiment, the InGaN-based quantum well 114W may have a composition of In _p Ga _{1 - p} N (p 0). For example, the InGaN-based quantum well 114W may be a GaN layer not doped with In.

In the prior art, in the case of an ultraviolet light emitting device including Al and having a wavelength of 365 nm or less, the light output of about 90% is reduced compared to the light output Po of the embodiment, and the light output is less than about 1/10.

In an embodiment of the present invention, a first conductive type second AlGaN layer 113 is interposed between the first conductive type first AlGaN layer 112 and the GaN / AlGaN series superlattice layer 115, It is possible to provide an ultraviolet light emitting device having a technical effect in which a high quality active layer containing no aluminum (Al) in a quantum well and a wavelength of 365 nm or less is realized. The first conductive type second AlGaN layer 113 may include a first conductive type Al _{x 2} Ga _{1 - x 2} N layer (0 <x 2 <1).

Specifically, in order to solve the above technical problem, the embodiment of the present invention is characterized in that a first AlGaN layer 113 of a first conductivity type, which is a high Al concentration layer, is formed before the growth of the GaN / AlGaN superlattice layer 115 , A compressive strain may intentionally be generated in the active layer 114. This leads to a technical effect in which the wavelength (Wp) of light emitted from the active layer is shortened by the piezo effect by the compressive strain to realize a high-quality active layer containing no aluminum (Al) in the quantum well and a wavelength of 365 nm or less The ultraviolet light emitting device can be provided.

4 is a diagram illustrating an example of a bandgap diagram of an ultraviolet light emitting device according to the related art. Specifically, a conduction band CR in the prior art ultraviolet light emitting device, and the active layer MR is in a relatively less strain state.

5 is a diagram illustrating a bandgap diagram of an ultraviolet light emitting device according to an embodiment. Specifically, the conductive layer CE in the ultraviolet light-emitting device of the embodiment is shown, and the active layer ME has a relatively large strain.

According to the embodiment, in order to realize a wavelength of 365 nm or less while being a high-quality active layer not containing aluminum (Al) in the quantum well, the first conductive type first AlGaN layer 112 and the GaN / AlGaN series superlattice layer 115 and the first conductive type second AlGaN layer 113 is disposed between the first conductive type AlGaN layer 115 and the second conductive type second AlGaN layer 113. As a result,

Accordingly, the decrease (Po1) of the luminous intensity which can be reduced by the piezo effect due to the intrinsic compressive strain in the active layer 114 according to the embodiment can be obtained from the quantum well without Al in the active layer (Po1 < Po2) as compared with the light intensity increase (Po2).

Therefore, the embodiment can provide an ultraviolet light emitting device having a technical effect in which a wavelength of 365 nm or less is realized with a high luminous intensity (Po) according to a high-quality active layer not containing aluminum (Al) in a quantum well.

Referring again to FIG. 3A, in an embodiment, the first conductive type second AlGaN layer 113 may include a first conductive type Al _{x 2} Ga _{1 - x 2} N layer (0 <x 2 <1) The series quantum wall 114B may include an Al _y Ga _{1 -yN} layer (0 <y <1).

In this case, the composition (x2) of Al of the first conductive type second AlGaN layer 113 is larger than the composition (y) of Al of the AlGaN-based quantum wall 114B but less than 0.5 (y <x2 <0.5 ). If the composition (x2) of Al in the first conductive type second AlGaN layer 113 is not larger than the composition (y) of Al in the AlGaN-based quantum wall 114B, an intrinsic compressive strain ( Compressive Strain effect may not occur. Also, when the composition (x2) of Al in the second AlGaN-based layer 113 is more than 0.5 (50%), the film quality of the epilayer may be deteriorated or the injection efficiency of the carrier may be lowered.

The composition (x2) of Al in the first conductive type second AlGaN layer 113 may be 30% to 40%. If the composition (x2) of Al in the first conductive type second AlGaN layer 113 is less than 30%, an intrinsic compressive strain effect may not occur in the active layer 114, When the composition (x2) of Al in the AlGaN-based layer 113 is more than 40%, the light efficiency may be lowered due to a decrease in the carrier injection efficiency or a decrease in the quality of the epi layer.

In an embodiment the first conductive type first AlGaN-based layer 112 has a first conductivity type Al _x1 Ga _{1 -} comprises _x1 N layer (0 <x1 <1), the first conductive claim 2 AlGaN-based layer The composition x2 of Al of the first conductive type AlGaN layer 113 may be in a range (x1 < x2) larger than the composition (x1) of Al of the first conductive type first AlGaN layer 112. [

For example, the composition (x1) of Al of the first conductive type first AlGaN layer 112 may be about 3% to 6%, and the Al of the first conductive type first AlGaN layer 112 may be about 3% (X2) of the first conductive type AlGaN layer 112 is controlled to be in a range (x1 < x2) that is larger than the composition (x1) of Al of the first conductive type first AlGaN layer 112. Accordingly, unlike the prior art, the intrinsic compressive strain The present invention can provide an ultraviolet light emitting device having a high-quality active layer containing no aluminum (Al) in a quantum well and having a wavelength of 365 nm or less, and a lighting apparatus including the same.

In an embodiment, the thickness of the first conductive type second AlGaN layer 113 may range from 10 nm to 40 nm. If the thickness of the first conductive type second AlGaN layer 113 is less than 10 nm, the volume of the layer may be small, the compression strain induced in the active layer may be small, and the effect of shortening the wavelength may be low. 2 AlGaN layer 113 is more than 40 nm, the film quality of the epi layer may be deteriorated, or the light-emitting efficiency may be lowered due to the lowered carrier injection efficiency.

Also, in the embodiment, when the thickness of the first conductive type second AlGaN layer 113 is in the range of 20 nm to 30 nm, the compressive strain induced in the active layer is effective, thereby increasing the effect of shortening the wavelength to 365 nm or less, As the quality is increased and the carrier injection efficiency is increased, there is a technical effect that a high luminance is exhibited according to a high quality active layer.

3B is a diagram showing the Al concentration gradient of the first conductive type second AlGaN layer 113 in the direction of the active layer 114 in the ultraviolet light emitting device according to the embodiment.

Embodiments can provide grading of the Al concentration in the first conductive type second AlGaN layer 113 for effective electron injection.

For example, in the early stage of the first conductive type second AlGaN layer 113, a grading-up structure in which the concentration of Al gradually increases in a state where the concentration of Al is low is applied, So that the electron injection efficiency can be increased.

For example, the first conductive type second AlGaN layer 113 may include a first region 113A in which the concentration of Al is relatively low, and a first region 113A in which the concentration of Al is relatively low. 2 region 113B to prevent an abrupt increase in the concentration of Al, so that the electron injection efficiency can be increased.

In an embodiment, the first region 113A may be 0.5 times to twice or less than the second region 113B. For example, when the first region 113A is less than 0.5 times the thickness of the second region 113B, the thickness of the first conductive type second AlGaN layer in the bulk form is thinned to intentionally compress the active layer The strain can not be effectively added and the effect of shortening the wavelength may be deteriorated. On the other hand, when the first region 113A is more than twice as large as the second region 113B, the gradation range of the Al concentration may be small and the injection efficiency of the carrier may be lowered.

Referring again to FIG. 3A, in the embodiment, a second conductive AlInGaN-based semiconductor layer 118 may be formed on the active layer 114. The bandgap energy level of the second conductive AlInGaN-based semiconductor layer 118 may be greater than the bandgap energy level of the second conductive AlGaN-based layer 116 formed later. The second conductive AlInGaN-based semiconductor layer 118 may function as an electron blocking layer to prevent carriers from overflowing. For example, the second conductive AlInGaN-based semiconductor layer 118 can prevent electrons from overflowing.

Embodiments may include a second conductive AlGaN-based layer 116 on a second conductive AlInGaN-based semiconductor layer 118.

The second conductivity type AlGaN layer 116 may be selected from compound semiconductors of Group III-V elements doped with a second conductivity type dopant, such as AlN, AlGaN, InAlGaN, AlInN, AlGaAs, AlGaInP, The second conductive AlGaN-based layer 116 is formed of a semiconductor layer having a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + As shown in FIG.

The second conductive AlGaN layer 116 may be a p-type semiconductor layer, and the second conductive dopant may include a p-type dopant such as Mg, Zn, or the like. The second conductive AlGaN series layer 116 may be formed as a single layer or a multilayer, but is not limited thereto.

In an exemplary embodiment, a third conductive type semiconductor layer (not shown), for example, a semiconductor layer having a polarity opposite to that of the second conductive type may be formed on the second conductive type AlGaN layer 116, but the present invention is not limited thereto.

Accordingly, the light emitting structure layer 110 may include at least one of an n-p junction, a p-n junction, an n-p-n junction, and a p-n-p junction structure.

6 is an enlarged view of an active layer of an ultraviolet light emitting device according to another embodiment.

Other embodiments may include the technical features described above and will now be described with focus on features of other embodiments shown in FIG.

In order to manufacture an ultraviolet light emitting device having a wavelength of 360 nm or less while maintaining the thickness of the quantum well in the conventional ultraviolet light emitting device, the AlGaN quantum well (Al: 2% to 4% There is a problem that the quality (Qw Quality) of the quantum well is remarkably deteriorated and the luminous intensity Po is rapidly lowered. For example, a brightness lowering phenomenon of about 90% or more is occurring.

Accordingly, in a light emitting device according to another embodiment, a thin quantum well is applied to realize a wavelength of 360 nm or less without using Al, thereby shortening the emission wavelength, improving the quality of the active layer, For the sake of uniformity, the InGaN-based quantum well itself in the active layer 114 may be made very thin, and the InGaN-based quantum well and the AlGaN-based quantum wall may be formed of a plurality of pairs.

For example, in the embodiment, the active layer 114 includes a first InGaN-based quantum well layer 114W1 / a first AlGaN-based quantum wall 114B1, a second InGaN-based quantum well layer 114W2 / a second AlGaN- An n-type InGaN-based quantum well layer 114WN, and an n-th AlGaN-based quantum wall 114BN.

In an embodiment, the thickness of any one of the quantum well layers 114W1, 114W2, 114WN may be between about 2 nm and 4 nm. When the thickness of the quantum well layer is less than 2 nm, the light efficiency may be lowered because the carrier can not be confined because it is too thin in the quantum well, and when the thickness of the quantum well layer is more than 4 nm, . As the thickness of any one of the InGaN quantum well layers is controlled to be as thin as 2 nm to 4 nm in the embodiment, the probability that the probability distribution of photons distributed in quantum wells is distributed at a high energy level is increased, The photons emitted from the InGaN-based quantum well layer can emit light with a short wavelength.

In an embodiment, the number of pairs of the InGaN-based quantum well and the AlGaN-based quantum wall may be 10 pairs to 20 pairs. If the number of pairs is less than 10 pairs, the volume efficiency of the quantum wells may decrease and the light efficiency may decrease or the droop may deteriorate. If the number of pairs exceeds 20 pairs, the carrier injection efficiency may decrease or the operating voltage may increase.

In addition, the InGaN-based quantum well may include a pair of InGaN / GaN, whereby the light intensity may be further increased as the quality of the active layer is improved. The InGaN / GaN pair of the InGaN-based quantum well may be about 1.5 to 3 pairs. When the pair of InGaN / GaN in the InGaN-based quantum well is less than 1.5 pairs, the uniformity of indium in the quantum well itself is lowered by indium segregation and an In cluster is generated at the end of the active layer, Can be lengthened, and the light intensity can also be lowered. If the InGaN / GaN pair is more than three pairs, the carrier injection efficiency may be lowered.

The embodiment can provide an ultraviolet light emitting device having a technical effect in which a quantum well is a high-quality active layer not containing aluminum (Al) and a wavelength of 365 nm or less, and a lighting apparatus including the same.

In addition, the embodiment can provide an ultraviolet light emitting element having a technical effect of improving the operating voltage and improving the light output, and a lighting apparatus including the ultraviolet light emitting element.

Also, the embodiment can provide an ultraviolet light emitting element having a technical effect that can mitigate or eliminate a droop phenomenon, and a lighting apparatus including the ultraviolet light emitting element.

<Manufacturing Method>

Hereinafter, a method of manufacturing a light emitting device according to an embodiment will be described with reference to FIGS. The description of the manufacturing method will be described with reference to the embodiments, but the manufacturing method is not limited to the following description.

First, as shown in FIG. 7, a light emitting structure layer 110 may be formed on a growth substrate 105. The light emitting structure layer 110 may include a first conductive type first AlGaN layer 112, an active layer 114, and a second conductive type AlGaN layer 116.

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

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

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

A buffer layer (not shown) may be formed on the growth substrate 105. AlN, AlGaN, InGaN, InN, InAlGaN, AlInN (AlN), InGaN, AlN, InN, InN, InN, , AlGaAs, GaP, GaAs, GaAsP, and AlGaInP.

An undoped semiconductor layer (not shown) may be formed on the buffer layer. The undoped semiconductor layer may be formed of an undoped GaN-based semiconductor, but the n-type doping element Type semiconductor layer by diffusion of the n-type semiconductor layer, but the present invention is not limited thereto.

Next, a first conductivity type semiconductor layer 111 may be formed on the first substrate 105. For example, the first conductive semiconductor layer 111 may be formed of a compound semiconductor such as a Group III-V, a Group II-VI, or the like, and may be doped with a first conductive type dopant, As shown in FIG.

When the first conductivity type semiconductor layer 111 is an n-type semiconductor layer, the first conductivity type dopant may include Si, Ge, Sn, Se, and Te as an n-type dopant.

The first conductive semiconductor layer 111 may be a GaN-based semiconductor layer, and may be In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + Lt; RTI ID = 0.0 &gt; of &lt; / RTI &gt; For example, the first conductive semiconductor layer 111 may be formed of one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, .

Accordingly, according to the embodiment, the first conductivity type first AlGaN layer 112 following the formation of the first conductivity type semiconductor layer 111, which is a GaN-based semiconductor layer, may have less lattice constant difference, The first conductive semiconductor layer 111 having a possibility of being removed can be removed together with the removal process of the substrate 105.

8A is an enlarged view of a portion (E) of an ultraviolet light emitting device according to an embodiment. Hereinafter, the technical features of the embodiment will be described in more detail with reference to FIG. 8A.

The light emitting device 100 includes a first conductive type first AlGaN layer 112 and a first conductive type second AlGaN layer 113 on the first conductive type first AlGaN layer 112, , A GaN / AlGaN superlattice layer 115 on the first conductive type second AlGaN layer 113, an active layer 114 on the GaN / AlGaN superlattice layer 115, The second conductivity type AlGaN series layer 116 may be formed on the second conductive type AlGaN layer 114.

In an embodiment, the first conductive type first AlGaN layer 112 may be selected from compound semiconductors of Group III-V elements doped with a first conductive dopant, such as AlN, AlGaN, InAlGaN, AlInN, AlGaAs, AlGaInP, have. For example, the first conductive type first AlGaN-based layer 112 has a first conductivity type Al _x1 Ga _{1 -} may include _x1 N layer (0 <x1 <1).

The first conductive type first AlGaN layer 112 may be a single layer or multiple layers and may include a superlattice structure in which two different layers of AlN, AlGaN, InAlGaN, AlInN, AlGaAs, and AlGaInP are alternately arranged . The first conductive type first AlGaN layer 112 may be an n-type semiconductor layer, and the first conductive type dopant may include n-type dopants such as Si, Ge, Sn, Se, and Te.

Next, a first conductive type second AlGaN layer 113 may be formed on the first conductive type first AlGaN layer 112. The first conductive type second AlGaN layer 113 may include a first conductive type Al _{x 2} Ga _{1 - x 2} N layer (0 <x 2 <1).

The composition (x2) of Al in the first conductive type second AlGaN layer 113 may be 30% to 40%. If the composition (x2) of Al in the first conductive type second AlGaN layer 113 is less than 30%, an intrinsic compressive strain effect may not occur in the active layer 114, When the composition (x2) of Al in the AlGaN-based layer 113 is more than 40%, the light efficiency may be lowered due to a decrease in the carrier injection efficiency or a decrease in the quality of the epi layer.

First conductivity type first AlGaN-based layer 112 has a first conductivity type Al _x1 Ga ₁ in an _{embodiment-includes} a _x1 N layer (0 <x1 <1), the first conductive claim 2 AlGaN-based layer ( 113 may be in a range (x1 < x2) that is larger than the composition (x1) of Al of the first conductive type first AlGaN layer 112.

For example, the composition (x1) of Al of the first conductive type first AlGaN layer 112 may be about 3% to 6%, and the Al of the first conductive type first AlGaN layer 112 may be about 3% (X2) of the first conductive type AlGaN layer 112 is controlled to be in a range (x1 < x2) that is larger than the composition (x1) of Al of the first conductive type first AlGaN layer 112. Accordingly, unlike the prior art, the intrinsic compressive strain The present invention can provide an ultraviolet light emitting device having a high-quality active layer containing no aluminum (Al) in a quantum well and having a wavelength of 365 nm or less, and a lighting apparatus including the same.

In an embodiment, the thickness of the first conductive type second AlGaN layer 113 may range from 10 nm to 40 nm. If the thickness of the first conductive type second AlGaN layer 113 is less than 10 nm, the volume of the layer may be small, the compression strain induced in the active layer may be small, and the effect of shortening the wavelength may be low. 2 AlGaN layer 113 is more than 40 nm, the film quality of the epi layer may be deteriorated, or the light-emitting efficiency may be lowered due to the lowered carrier injection efficiency.

Also, in the embodiment, when the thickness of the first conductive type second AlGaN layer 113 is in the range of 20 nm to 30 nm, the compressive strain induced in the active layer is effective, thereby increasing the effect of shortening the wavelength to 365 nm or less, As the quality is increased and the carrier injection efficiency is increased, there is a technical effect that a high luminance is exhibited according to a high quality active layer.

Referring to FIG. 3B, the embodiment may provide gradation of Al concentration in the first conductive type second AlGaN layer 113 for effective electron injection.

For example, in the early stage of the first conductive type second AlGaN layer 113, a grading-up structure in which the concentration of Al gradually increases in a state where the concentration of Al is low is applied, So that the electron injection efficiency can be increased.

For example, the first conductive type second AlGaN layer 113 may include a first region 113A in which the concentration of Al is relatively low, and a first region 113A in which the concentration of Al is relatively low. 2 region 113B to prevent an abrupt increase in the concentration of Al, so that the electron injection efficiency can be increased.

In an embodiment, the first region 113A may be 0.5 times to twice or less than the second region 113B. For example, when the first region 113A is less than 0.5 times the thickness of the second region 113B, the thickness of the first conductive type second AlGaN layer in the bulk form is thinned to intentionally compress the active layer The strain can not be effectively added and the effect of shortening the wavelength may be deteriorated. On the other hand, when the first region 113A is more than twice as large as the second region 113B, the gradation range of the Al concentration may be small and the injection efficiency of the carrier may be lowered.

Next, a GaN / AlGaN superlattice layer 115 may be formed on the first conductive type second AlGaN layer 113. The GaN / AlGaN-based superlattice layer 115 may be formed of a plurality of pairs of a combination of a GaN / AlGaN layer, an InGaN / AlGaN layer, or the like and contributes to current diffusion, thereby contributing to improvement of electrical characteristics and brightness. The electrical characteristics of the AlGaN layer of the GaN / AlGaN-based superlattice layer 115 can be improved by injecting an n-type dopant.

The embodiment is characterized in that a first conductive type second AlGaN series layer 113 is disposed between the first conductive type first AlGaN layer 112 and the GaN / AlGaN series superlattice layer 115 so that aluminum (Al Can be provided, and a wavelength of 365 nm or less can be realized, and an ultraviolet light emitting device having a technical effect can be provided

Specifically, in order to solve the above technical problem, the embodiment of the present invention is characterized in that a first AlGaN layer 113 of a first conductivity type, which is a high Al concentration layer, is formed before the growth of the GaN / AlGaN superlattice layer 115 , A compressive strain may intentionally be generated in the active layer 114. This leads to a technical effect in which the wavelength (Wp) of light emitted from the active layer is shortened by the piezo effect by the compressive strain to realize a high-quality active layer containing no aluminum (Al) in the quantum well and a wavelength of 365 nm or less The ultraviolet light emitting device can be provided.

Next, the active layer 114 may be formed on the GaN / AlGaN superlattice layer 115. In an embodiment, the active layer 114 may include an InGaN-based quantum well 114W and an AlGaN-based quantum wall 114B.

In the embodiment, the InGaN-based quantum well 114W may not include aluminum (Al) to realize a high-quality active layer.

The InGaN-based quantum well 114W has a composition of In _p Ga _{1 - p} N ( _{0 ? P} ? 0.02), thereby achieving high efficiency chip implementation and droop improvement. In an embodiment, the AlGaN-based quantum wall 114B may include an Al _y Ga _{1 - y} N layer (0 <y <1).

For example, in the embodiment, the InGaN-based quantum well 114W may have a composition of In _p Ga _{1 - p} N (0 < _p ? 0.02). For example, in the InGaN-based quantum well 114W, In may be doped with a composition of about 2% or less. In the InGaN-based quantum well 114W, In can be doped to a treatment level. The doping of the above composition level may not necessarily result in the formation of a tri-atomic compound.

As a result, the InGaN quantum well 114W is positioned in a vacancy of vacancy, thereby reducing defects and improving the crystal quality of the quantum well, so that the brightness can be improved.

Further, in the embodiment, the InGaN-based quantum well 114W may have a composition of In _p Ga _{1 - p} N (p 0). For example, the InGaN-based quantum well 114W may be a GaN layer not doped with In.

According to the embodiment, the composition (x2) of Al in the first conductive type second AlGaN layer 113 is larger than the composition (y) of Al in the AlGaN-based quantum wall 114B, x2 < 0.5). If the composition (x2) of Al in the first conductive type second AlGaN layer 113 is not larger than the composition (y) of Al in the AlGaN-based quantum wall 114B, an intrinsic compressive strain ( Compressive Strain effect may not occur. Also, when the composition (x2) of Al in the second AlGaN-based layer 113 is more than 0.5 (50%), the film quality of the epilayer may be deteriorated or the injection efficiency of the carrier may be lowered.

Referring again to FIG. 8A, in the embodiment, a second conductive AlInGaN-based semiconductor layer 118 may be formed on the active layer 114. The bandgap energy level of the second conductive AlInGaN-based semiconductor layer 118 may be greater than the bandgap energy level of the second conductive AlGaN-based layer 116 formed later. The second conductive AlInGaN-based semiconductor layer 118 may function as an electron blocking layer to prevent carriers from overflowing. For example, the second conductive AlInGaN-based semiconductor layer 118 can prevent electrons from overflowing.

Next, a second conductive AlGaN-based layer 116 may be formed on the second conductive AlInGaN-based semiconductor layer 118.

The second conductivity type AlGaN layer 116 may be selected from compound semiconductors of Group III-V elements doped with a second conductivity type dopant, such as AlN, AlGaN, InAlGaN, AlInN, AlGaAs, AlGaInP, The second conductive AlGaN-based layer 116 is formed of a semiconductor layer having a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + As shown in FIG.

The second conductive AlGaN layer 116 may be a p-type semiconductor layer, and the second conductive dopant may include a p-type dopant such as Mg, Zn, or the like. The second conductive AlGaN series layer 116 may be formed as a single layer or a multilayer, but is not limited thereto.

In an exemplary embodiment, a third conductive type semiconductor layer (not shown), for example, a semiconductor layer having a polarity opposite to that of the second conductive type may be formed on the second conductive type AlGaN layer 116, but the present invention is not limited thereto. Accordingly, the light emitting structure layer 110 may include at least one of an n-p junction, a p-n junction, an n-p-n junction, and a p-n-p junction structure.

8B is an enlarged view of an active layer of an ultraviolet light emitting device according to another embodiment.

In order to realize a wavelength of 360 nm or less without using Al in the light emitting device according to another embodiment, a thin quantum well is applied to shorten the emission wavelength, improve the quality of the active layer, and improve the uniformity of indium The InGaN-based quantum well itself in the active layer 114 may be made very thin, and the InGaN-based quantum well and the AlGaN-based quantum wall may be formed of a plurality of pairs.

For example, in the embodiment, the active layer 114 includes a first InGaN-based quantum well layer 114W1 / a first AlGaN-based quantum wall 114B1, a second InGaN-based quantum well layer 114W2 / a second AlGaN- An n-type InGaN-based quantum well layer 114WN, and an n-th AlGaN-based quantum wall 114BN.

In an embodiment, the thickness of any one of the quantum well layers 114W1, 114W2, 114WN may be between about 2 nm and 4 nm. When the thickness of the quantum well layer is less than 2 nm, the light efficiency may be lowered because the carrier can not be confined because it is too thin in the quantum well, and when the thickness of the quantum well layer is more than 4 nm, . As the thickness of any one of the InGaN quantum well layers is controlled to be as thin as 2 nm to 4 nm in the embodiment, the probability that the probability distribution of photons distributed in quantum wells is distributed at a high energy level is increased, The photons emitted from the InGaN-based quantum well layer can emit light with a short wavelength.

In an embodiment, the number of pairs of the InGaN-based quantum well and the AlGaN-based quantum wall may be 10 pairs to 20 pairs. If the number of pairs is less than 10 pairs, the volume efficiency of the quantum wells may decrease and the light efficiency may decrease or the droop may deteriorate. If the number of pairs exceeds 20 pairs, the carrier injection efficiency may decrease or the operating voltage may increase.

Also, in the embodiment, the InGaN-based quantum well may include a pair of InGaN / GaN, and the luminous intensity may be further increased as the quality of the active layer is improved. The InGaN / GaN pair of the InGaN-based quantum well may be about 1.5 to 3 pairs. When the pair of InGaN / GaN in the InGaN-based quantum well is less than 1.5 pairs, the uniformity of indium in the quantum well itself is lowered by indium segregation and an In cluster is generated at the end of the active layer, Can be lengthened, and the light intensity can also be lowered. If the InGaN / GaN pair is more than three pairs, the carrier injection efficiency may be lowered.

Next, as shown in FIG. 9, a mesa etching process for removing a part of the light emitting structure layer 110 may be performed. For example, a plurality of holes (H) exposing a part of the first conductive type first AlGaN layer (112) through the second conductive AlGaN layer (116) and the active layer (114) are formed .

The plurality of holes H may be formed at a predetermined angle from the first conductive AlGaN layer 112 to the upper surface of the second conductive AlGaN layer 116, But the present invention is not limited thereto. The plurality of holes H may also penetrate the first conductive type second AlGaN layer 113 and the GaN / AlGaN superlattice layer 115.

In the embodiment, the horizontal width of the plurality of holes H may be reduced toward the lower side. On the other hand, with reference to FIG. 2, the horizontal width of the plurality of holes H can be reduced toward the upper side.

Referring to FIG. 9 again, according to the embodiment, the active layer 114 and the first conductive type first AlGaN layer 112 regions, which are removed by decreasing the horizontal width of the plurality of holes H downward, Thereby contributing to the luminous efficiency.

Next, as shown in FIG. 10, the channel layer 120 may be formed on a part of the plurality of holes H and the second conductive AlGaN layer 116. At this time, the channel layer 120 may not be formed in a region where the contact layer 160 to be formed is to be formed. Accordingly, a part of the first conductive type first AlGaN layer 112 exposed by the plurality of holes H can be exposed.

The channel layer 120 electrically insulates the contact layer 160 from the active layer 114 and the second conductive AlGaN layer 116.

In an embodiment, the reflectivity of the channel layer 120 may be greater than 50%. For example, the channel layer 120 may be formed of an insulating material selected from SiO ₂ , SiO _x , SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ , TiO ₂ , May be formed in a mixed form.

For example, the channel layer 120 may be formed of a mixture of at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, .

A channel layer 120 including a reflective material is disposed on a side surface of a contact layer 160 to be formed later to prevent light absorption by the contact layer 160 to improve light extraction efficiency, Can be improved.

Next, as shown in FIG. 11, a second contact electrode 132 may be formed on the second conductive AlGaN layer 116. The second contact electrode 132 is in ohmic contact with the second conductive AlGaN layer 116 and may include at least one conductive material and may be a single layer or multiple layers.

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

Next, as shown in FIG. 12, a reflective layer 134 may be formed on the second contact electrode 132. The reflective layer 134 is disposed on the second contact electrode 132 and may reflect light incident through the second contact electrode 132.

The reflective layer 134 may include one or more layers of materials selected from the group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, Layer.

Next, a capping layer 136 may be formed on the reflective layer 134.

The second electrode layer 130 may be referred to as a second electrode layer 130 including the second contact electrode 132, the reflective layer 134 and the capping layer 136. The second electrode layer 130 may be referred to as a pad electrode 180 And the supplied power can be supplied to the second conductivity type AlGaN series layer 116.

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

The capping layer 136 may be made of a material having high electrical conductivity such as Sn, Ga, In, Bi, Cu, Ni, Ag, Mo, Al, Au, Nb, W, Ti, Al, Pd, Pt, Si and an optional alloy thereof.

Next, as shown in FIG. 13, a contact layer 160 may be formed on the exposed first conductive type first AlGaN layer 112. For example, the contact layer 160 may be formed by performing a re-growth process on the exposed first conductive type first AlGaN layer 112 by MOCVD.

The contact layer 160 may be formed of a metal layer or a semiconductor layer. For example, the contact layer 160 may be formed of the same material as the first conductive type first AlGaN layer 112. For example, the contact layer 160 may be a semiconductor layer having a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + .

In addition, the contact layer 160 may be formed of a compound semiconductor of group III-V elements such as GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP and AlGaInP.

In an embodiment, the contact layer 160 may be doped with a first conductive type element, for example, an n-type doped element, and the doping concentration of the first conductive type element doped in the contact layer 160 may be less than the doping concentration of the first May be higher than the doping concentration of the first conductive type doping element doped in the conductive type first AlGaN layer 112.

For example, the contact layer 160 may be an n-type semiconductor layer, and the first conductive dopant may include n-type dopants such as Si, Ge, Sn, Se, and Te.

Accordingly, the doping concentration of the first conductive type element doped in the contact layer 160 is higher than the doping concentration of the first conductive type first AlGaN layer 112, thereby improving the current injection efficiency have.

The contact layer 160 may extend upward from a plurality of holes H that penetrate the active layer 114 and expose a portion of the first conductive type first AlGaN layer 112 .

The upper portion of the contact layer 160 may have a trapezoidal shape to increase the contact area with the first electrode layer 150 formed later, but the present invention is not limited thereto.

이하로 형성될 수 있다. 상기 컨택층(160)의 수평 폭이 약 100

이후 형성되는 제2 전극층(130)과 접촉하여 통전될 수 있기 때문에 제2 전극층(130)과 통전되지 않는 범위에서 수평 폭을 구비할 수 있다. 또한, 상기 컨택층(160)의 수평폭은 상기 비아홀(H)의 폭보다 크게 형성될 수 있으며, 예를 들어 상기 비아홀(H)의 수평폭이 약 24

상기 컨택층(160)은 약 24

초과의 수평 폭으로 형성될 수 있으나 이에 한정되는 것은 아니다.In the embodiment, the horizontal width of the contact layer 160 is larger than the horizontal width of the holes H (based on the bottom horizontal width)

Or less. When the horizontal width of the contact layer 160 is about 100

The second electrode layer 130 may be electrically connected to the second electrode layer 130 formed thereafter, so that the second electrode layer 130 may have a horizontal width in a range not to be energized. The horizontal width of the contact layer 160 may be greater than the width of the via hole H. For example, when the horizontal width of the via hole H is about 24

The contact layer 160 has a thickness of about 24

But the present invention is not limited thereto.

Next, an insulating layer 140 may be formed on the capping layer 136 and the channel layer 120. The insulating layer 140 may be formed to expose the semiconductor contact layer 160. Accordingly, the diffusion preventing layer 154, which will be formed later, is in contact with the side surface of the contact layer 160 to enlarge the mutual contact area, thereby reducing the electrical resistance and improving the current injection efficiency.

The insulating layer 140 may electrically isolate the contact layer 160 from the second conductive AlGaN layer 116. The insulating layer 140 may be formed of a material selected from SiO ₂ , SiO _x , SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ , and TiO ₂ .

Next, a diffusion preventing layer 154 may be formed on the insulating layer 140 and the side surfaces of the contact layer 160, and a bonding layer 156 may be formed on the diffusion preventing layer 154.

The diffusion preventing layer 154 and / or the bonding layer 156 may be a single layer or a plurality of layers including at least one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, have.

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

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

The diffusion preventing layer 154 may be in contact with the side surface of the contact layer 160 and the bonding layer 156 may be in contact with the contact layer 160 to form the first electrode layer 150 and the contact layer 160. [ It is possible to expand the contact area between the first electrode 160 and the second electrode 160.

Accordingly, according to the embodiment, the contact resistance between the contact layer 160 and the first electrode layer 150 is reduced, thereby preventing an increase in the operating voltage, thereby improving light output and improving electrical reliability.

According to the embodiment, the luminous flux can be improved by improving the current injection efficiency according to the increase of the contact area between the contact layer 160 and the first electrode layer 150.

The upper surface of the contact layer 160 may have a tapered side surface to widen the surface area of the contact layer 160 and the diffusion prevention layer 154 may be formed on the upper surface of the contact layer 160 It is possible to prevent the rise of the operating voltage due to the reduction of the contact resistance.

According to an embodiment of the present invention, the current injection efficiency between the first electrode layer 150 and the contact layer 160 is improved by widening the contact area between the inclined side surface of the contact layer 160 and the diffusion prevention layer 154, Can be improved.

Next, a support member 158 may be formed on the bonding layer 156. The first electrode layer 150 may be referred to as a first electrode layer 150 including the diffusion preventing layer 154, the bonding layer 156 and the support member 158. The first electrode layer 150 may be referred to as a lower electrode 159 ) To the first conductive type first AlGaN layer 112. The first conductive type first AlGaN layer 112 may be formed of a metal such as AlGaN.

The support member 158 may be bonded to the bonding layer 156, but is not limited thereto. The support member 158 may be a conductive support member and may be formed of at least one of copper (Cu), gold (Au), nickel (Ni), molybdenum (Mo), copper-tungsten It can be one.

The support member 158 may be implemented as a carrier wafer, for example, Si, Ge, GaAs, ZnO, SiC, SiGe, Ga ₂ O ₃ , GaN, It can be bonded with solder.

Next, as shown in FIG. 14, the growth substrate 105 can be removed. At this time, the surface of the first conductive type first AlGaN layer 112 may be exposed by removing the remaining undoped semiconductor layer (not shown), the first conductive type semiconductor layer 111, and the like after removing the growth substrate 105 have.

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

Alternatively, a buffer layer (not shown) disposed between the growth substrate 105 and the first conductive type first AlGaN layer 112 may be removed using a wet etching solution to separate the growth substrate 105 have.

The upper surface of the first conductive type first AlGaN layer 112 may be exposed by removing the growth substrate 105 and etching or polishing and removing the buffer layer.

The upper surface of the first conductive type first AlGaN layer 112 may be an N-face, which is closer to the growth substrate. The upper surface of the first conductive type first AlGaN layer 112 may be etched by an ICP / RIE (Inductively Coupled Plasma / Reactive Ion Etching) method or may be polished by a polishing apparatus.

Next, as shown in FIG. 15, a part of the light emitting structure layer 110 may be removed and a part of the channel layer 120 may be exposed. For example, portions of the first conductive type first AlGaN layer 112, the active layer 114, and the second conductive type AlGaN layer 116 in the region where the pad electrode 180 is to be formed may be removed.

For example, wet etching or dry etching may be performed to remove the periphery of the light emitting structure layer 110, that is, the channel region or the isolation region, which is a boundary region between the chip and the chip, .

The upper surface of the first conductive type first AlGaN layer 112 may be formed with a light extracting structure P and the light extracting structure may be formed with a roughness or a pattern. The light extracting structure may be formed by a wet or dry etching method.

Next, as shown in FIG. 16, a passivation layer 170 may be formed on the exposed channel layer 120 and the light emitting structure layer 110. The passivation layer 170 may have a pattern corresponding to the pattern of the light extracting structure P. The passivation layer 170 may be formed of a material selected from SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ , and TiO ₂ .

A portion of the capping layer 136 may be exposed by forming a passivation layer 170 in a region where the pad electrode 180 is to be formed and a second hole H2 in which a part of the channel layer 120 is removed.

17, a pad electrode 180 may be formed on the exposed capping layer 136 and a lower electrode 159 may be formed under the first electrode layer 150, The device 100 can be manufactured.

The pad electrode 180 or the lower electrode 159 may be formed of a material such as Ti / Au, but is not limited thereto. The pad electrode 180 is a portion to be bonded with a wire and may be disposed on a predetermined portion of the light emitting structure layer 110 and may be formed of one or more.

&Lt; Light emitting device package &

18 is a view illustrating a light emitting device package 200 to which the light emitting device according to the embodiment is applied.

The light emitting device package 200 according to the embodiment includes a body 205, a first lead electrode 213 and a second lead electrode 214 disposed on the body 205, and a second lead electrode 214 provided on the body 205 A light emitting device 100 electrically connected to the first lead electrode 213 and the second lead electrode 214 and a molding member 240 surrounding the light emitting device 100.

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

The first lead electrode 213 and the second lead electrode 214 are electrically isolated from each other and provide power to the light emitting device 100. [ The first lead electrode 213 and the second lead electrode 214 may increase the light efficiency by reflecting the light generated from the light emitting device 100. The heat generated from the light emitting device 100 To the outside.

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

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

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

The molding member 240 surrounds the light emitting device 100 to protect the light emitting device 100. In addition, the molding member 240 may include a phosphor 232 to change the wavelength of light emitted from the light emitting device 100. The upper surface of the molding member 240 may have a flat or convex or concave shape in cross section, but 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.

<Lighting device>

19 is an exploded perspective view of a lighting apparatus according to an embodiment.

The lighting apparatus according to the embodiment may include a cover 2100, a light source module 2200, a heat discharger 2400, a power supply unit 2600, an inner case 2700, and a socket 2800. Further, the illumination device according to the embodiment may further include at least one of the member 2300 and the holder 2500. The light source module 2200 may include a light emitting device or a light emitting device package according to the embodiment.

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

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

The power supply unit 2600 may include a protrusion 2610, a guide 2630, a base 2650, and an extension 2670. The inner case 2700 may include a molding part together with the power supply part 2600. The molding part is a hardened portion of the molding liquid so that the power supply unit 2600 can be fixed inside the inner case 2700.

The features, structures, effects, and the like described in the embodiments are included in at least one embodiment 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. Accordingly, the contents of such combinations and modifications should be construed as being included in the scope of the embodiments.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. It can be seen that the modification and application of branches are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

The first conductive type first AlGaN series layer 112, the first conductive type second AlGaN series layer 113,
A GaN / AlGaN superlattice layer 115, an active layer 114, a second conductivity type AlGaN series layer 116,
An InGaN-based quantum well 114W, an AlGaN-based quantum wall 114B,

Claims (12)

A first conductive type first AlGaN series layer;
A first conductive type second AlGaN series layer on the first conductive type first AlGaN series layer;
A GaN / AlGaN superlattice layer on the first conductive type second AlGaN series layer;
An active layer on the GaN / AlGaN superlattice layer;
And a second conductive AlGaN-based layer on the active layer,
Wherein the active layer includes an InGaN-based quantum well and an AlGaN-based quantum wall,
Wherein the AlGaN-based quantum wall comprises an Al _y Ga _{1 - y} N layer (0 <y <1)
Wherein the first conductive type second AlGaN-based layer comprises a first conductive type Al _{x 2} Ga _{1 - x 2} N layer (0 <x 2 <1).
The method according to claim 1,
The composition (x2) of Al in the first conductive type second AlGaN-based layer is,
(Y < x2 < 0.5) which is larger than the composition (y) of Al in the AlGaN-based quantum wall but is less than 0.5.
The method according to claim 1,
Wherein the first conductive type first AlGaN layer includes a first conductive type Al _x Ga _{1 - x1} N layer (0 < x1 < 1)
The composition (x2) of Al in the first conductive type second AlGaN-based layer is,
(X1 < x2) larger than the composition (x1) of Al of the first conductive type first AlGaN-based layer.
The method according to claim 1,
The thickness of the first conductive type second AlGaN-
The ultraviolet light-emitting element is in the range of 10 nm to 40 nm.
The method according to claim 1,
And the composition of the InGaN-based quantum well is In _p Ga _{1 - p} N ( _{0 ? P} ? 0.02).
The method according to claim 1,
Wherein the first conductive type second AlGaN-based layer includes a first region having an Al concentration of a first concentration and a second region having a concentration of Al gradually higher than a first concentration.
The method according to claim 1,
The InGaN-based quantum well and the AlGaN-based quantum well in the active layer are formed of a plurality of pairs,
Wherein the thickness of the one InGaN-based quantum well is 2 nm to 4 nm.
8. The method of claim 7,
The InGaN-based quantum well
An ultraviolet light-emitting device comprising a pair of InGaN / GaN.
A first conductive type first AlGaN series layer;
A first conductive type second AlGaN series layer on the first conductive type first AlGaN series layer;
A GaN / AlGaN superlattice layer on the first conductive type second AlGaN series layer;
An active layer on the GaN / AlGaN superlattice layer;
And a second conductive AlGaN-based layer on the active layer,
Wherein the active layer includes an InGaN-based quantum well and an AlGaN-based quantum wall,
The InGaN-based quantum well and the AlGaN-based quantum well in the active layer are formed of a plurality of pairs,
The thickness of the InGaN-based quantum well is 2 nm to 4 nm.
10. The method of claim 9,
The InGaN-based quantum well
An ultraviolet light-emitting device comprising a pair of InGaN / GaN.
10. The method of claim 9,
Wherein the AlGaN-based quantum wall comprises an Al _y Ga _{1 - y} N layer (0 <y <1)
Wherein the first conductive type second AlGaN-based layer comprises a first conductive type Al _{x 2} Ga _{1 - x 2} N layer (0 <x 2 <1).
A lighting apparatus comprising a light-emitting unit including the light-emitting element according to any one of claims 1 to 11.

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