KR102251238B1 - Uv light emitting device and lighting system - Google Patents

Abstract

The embodiment relates to a light emitting device, a method of manufacturing a light emitting device, a light emitting device package and a lighting system.
The ultraviolet light emitting device according to the embodiment includes a first conductivity type semiconductor layer 112; An active layer 114 disposed on the first conductivity type semiconductor layer 112 including a quantum well 114W and a quantum wall 114B; And a second conductivity type semiconductor layer 116 disposed on the active layer 114. _{The quantum wall 114B is undoped on the n-type Al x} GaN layer (0≤x≤ 1) 114BB and the n-type Al _x GaN layer 114BB on the first conductivity-type semiconductor layer 112 It may include an Al _y GaN layer (0≦y≦1) 114BA.

Description

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

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

A light emitting device (Light Emitting Device) is a pn junction diode that converts electric energy into light energy, and can be produced by combining a group 3-5 element or a group 2-6 element on the periodic table, and the composition ratio of the compound semiconductor Various colors can be realized by adjusting.

For example, nitride semiconductors are attracting great interest in the development of optical devices and high-power electronic devices due to their high thermal stability and wide bandgap energy. In particular, an ultraviolet (UV) light emitting device, a blue light emitting device, a green light emitting device, and a red light emitting device using a nitride semiconductor are commercialized and widely used.

For example, in the case of an ultraviolet light-emitting device (UV LED), it is a light-emitting device that generates light distributed in a wavelength range of 200 nm to 400 nm, and is used for sterilization and purification in the above wavelength range, in the case of a short wavelength, and an exposure machine in the case of a long wavelength. Alternatively, it may be used in a curing machine or the like.

For example, near-ultraviolet light emitting devices (Near UV LEDs) are used for counterfeit detection, resin curing, or ultraviolet treatment, and are also used in lighting devices that are combined with phosphors to realize visible light of various colors.

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

In addition, according to the prior art, the ultraviolet light emitting device introduces an AlGaN layer to prevent light absorption. Tensile stress occurs due to the difference in lattice constants between the AlGaN layer and the GaN layer, causing cracks. As it occurs, there is a problem that the crystal quality is deteriorated and the luminous intensity is deteriorated.

The embodiment is to provide an ultraviolet light emitting device having excellent quality, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system.

The ultraviolet light emitting device according to the embodiment includes a first conductivity type semiconductor layer 112; An active layer 114 disposed on the first conductivity type semiconductor layer 112 including a quantum well 114W and a quantum wall 114B; And a second conductivity type semiconductor layer 116 disposed on the active layer 114. _{The quantum wall 114B is undoped on the n-type Al x} GaN layer (0≤x≤ 1) 114BB and the n-type Al _x GaN layer 114BB on the first conductivity-type semiconductor layer 112 It may include an Al _y GaN layer (0≦y≦1) 114BA.

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

The embodiment can provide a light emitting device having excellent quality, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system.

1 is a cross-sectional view of a light emitting device according to an embodiment.
2 is an exemplary diagram of a band gap of a light emitting device according to the first embodiment.
3 is an exemplary diagram of a band gap of a light emitting device according to a second embodiment.
4 to 7 are cross-sectional views illustrating a method of manufacturing a light emitting device according to the embodiment.
8 is a cross-sectional view of a light emitting device package according to an embodiment.
9 is a perspective view of a lighting device according to the embodiment.

In the description of the embodiment, each layer (film), region, pattern, or structure is "on/over" or "under" of the substrate, each layer (film), region, pad, or patterns. In the case of being described as being formed in, "on/over" and "under" include both "directly" or "indirectly" formed. do. In addition, the criteria for the top/top or bottom of each layer will be described based on the drawings.

(Example)

1 is a cross-sectional view of a light emitting device 100 according to an embodiment.

The light emitting device 100 according to the embodiment includes a first conductivity-type semiconductor layer 112, a quantum well 114W, and a quantum wall 114B, and an active layer disposed on the first conductivity-type semiconductor layer 112 It may include 114 and a second conductivity type semiconductor layer 116 disposed on the active layer 114. The first conductivity type semiconductor layer 112, the active layer 114, and the second conductivity type semiconductor layer 116 may constitute the light emitting structure 110. Among the configurations shown in FIG. 1, unexplained reference numerals will be described in the following manufacturing method. In the prior art, the ultraviolet light emitting device has a problem in that the light acquisition efficiency and light output are lower than that of the blue light emitting device. This acts as a barrier to the practical use of ultraviolet light emitting devices.

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

For example, in the case of about 365nm UV LED in the prior art, in order to reduce light absorption by GaN, nAlGaN having a higher bandgap energy (Bandgap E) than that of n-GaN is used as the N-side.

Specifically, according to the prior art, in order to prevent UV absorption in the group III nitride, after sequentially growing a growth substrate, a GaN layer, an AlGaN layer, an active layer, etc., the GaN layer with the possibility of UV absorption is removed, and the AlGaN layer is exposed. However, it is difficult to solve the problem of lowering the internal quantum efficiency due to the low crystallinity of the AlGaN layer.

That is, according to the prior art, when the AlGaN layer is grown on the GaN layer, the AlGaN layer has a smaller lattice than the GaN layer and has a higher thermal expansion rate, so that a tensile stress occurs in the AlGaN layer during growth and cracks. ), there is a problem that the luminosity decreases due to the decrease in crystal quality.

In addition, in the prior art, when the composition ratio of Al increases, the ionization energy (Ionization E) from which Si becomes Si ions (Si-) increases, and the carrier concentration decreases, so a high concentration of doping is avoided. However, since Si also has a difference in lattice constants from GaN, there is a problem that a crack may occur and the quality may be deteriorated.

Accordingly, the embodiment is to provide an ultraviolet light emitting device having improved crystal quality.

2 is an exemplary diagram illustrating a band gap diagram of a light emitting device according to the first embodiment.

In the first embodiment, the quantum wall 114B includes an n-type Al _x GaN layer (0≤x≤ 1) 114BB and the n-type Al _x GaN layer 114BB on the first conductivity-type semiconductor layer 112. ) May include an undoped Al _y GaN layer (0≦y≦1) 114BA.

In the quantum wall 114B, the n-type Al _x GaN layer 114BB may be interposed between the _{undoped Al y GaN layer 114BA.}

In addition, in the embodiment, the quantum wall 114B may have an undoped Al _y GaN layer 114BA/n-type Al _x GaN layer 114BB/ an undoped Al _y GaN layer 114BA. The structure of the Al _y GaN layer 114BA/n-type Al _x GaN layer 114BB/the undoped Al _y GaN layer 114BA may be formed in at least one or a plurality of cycles. The quantum wall (114B) has a plurality of sentence prompt Al _y GaN layer (114BA) between the n-type Al _x GaN layer (114BB) sentence is interposed in a sandwich structure soft Al _y GaN layer (114BA) / n-type Al _x GaN layer (114BB) / undoped Al _y GaN layer (114BA) may include a sandwich structure, but is not limited thereto.

In the embodiment, the Al composition (x) in the n-type Al _x GaN layer (0≦x≦1) (114BB) is the Al composition in _{the undoped Al y GaN layer (0≦y≦1) (114BA) (} can be greater than y).

Accordingly, the band gap energy level of the n-type Al _{x GaN layer (0≦x} ≦1) 114BB may be greater than that of the undoped Al y GaN layer (0≦y≦1) 114BA.

In an embodiment, the n-type Al _x GaN layer (0≦x≦1) 114BB may function as a reflective layer for light emitted from the quantum well 114W.

Accordingly, by using the quantum wall serving as a reflector in the embodiment, light emitted from the quantum well 114W does not move to the bottom side of the light emitting device chip, but moves to the top side, Since the necessity of the n-side AlGaN layer, which was employed to solve the light absorption problem in the GaN layer by reducing or eliminating the light moving downward, can be reduced, the Al composition in the AlGaN layer can be reduced or replaced with GaN altogether.

In the embodiment, the band gap energy level of the n-type Al _x GaN layer (0 ≤ x ≤ 1) (114BB) is set to be 0.7 eV or more larger than _{the undoped Al y GaN layer (0 ≤ y ≤ 1) (114BA).} The light reflection function can be secured by the difference in the relative refractive index.

The Al composition (x) in the n-type Al _x GaN layer (0≦x≦1) 114BB may be 0.3 to 1. When the Al composition (x) in the n-type Al _x GaN layer (0≦x≦1) 114BB is less than 0.3, the difference in refractive index may be insufficient and thus reflective performance may be low.

In an embodiment, the n-type Al _x GaN layer (0≤x≤1) 114BB is doped with an n-type dopant to increase carrier injection efficiency.

In addition, according to the embodiment, since the quantum wall 114B includes an n-type Al _x GaN layer (0≦x≦1) 114BB, a current spreading effect is achieved by a 2DEG (tow-dimensional electron gas) effect. have.

In an embodiment, the thickness of the n-type Al _x GaN layer 114BB may be about 1 nm to about 3 nm. If the thickness of the n-type Al _x GaN layer 114BB is thinner than 1 nm, the reflection effect may be weak, and if it exceeds 3 nm, electron injection into the quantum well 114W may be adversely affected.

Alternatively, in the embodiment, the Al composition (y) in the undoped Al _{y GaN layer (0≦y≦1) 114BA may be 0 to 0.15.} When the Al composition (y) is greater than 0.15 in the undoped Al _y GaN layer (0≦y≦1) 114BA, carrier injection may be impaired.

In an embodiment, the thickness of the undoped AlyGaN layer (0≦y≦1) 114BA may be about 1 nm to about 3 nm. When the thickness of the undoped AlyGaN layer 114BA is less than 1 nm, the reflective function may be weak, and when it exceeds 3 nm, carrier injection may be adversely affected.

In the embodiment, the quantum wall 114B may have an undoped Al _y GaN layer 114BA/n-type Al _x GaN layer 114BB superlattice structure, and the dislocation due to the superlattice shape of two layers having different lattice constants The crystal quality of the last quantum well 114W in which most of the light emission occurs due to bending of (Dislocation) can be greatly improved.

In an embodiment _{, the thickness of the quantum wall 114B including the undoped Al y} GaN layer 114BA/n-type Al _x GaN layer 114BB superlattice structure may be about 10 nm to about 25 nm.

For example, the quantum wall 114B is a first quantum wall 114B1 closest to the first conductivity type semiconductor layer 112, and a last quantum wall closest to the second conductivity type semiconductor layer 116 ( 114BL) and a third quantum wall 114B3 between the first quantum wall 114B1 and the last quantum wall 114BL. In addition, the quantum wall 114B may further include a second quantum wall 114B2 between the third quantum wall 114B3 and the last quantum wall 114BL.

In this case, the first quantum wall 114B1 may have a thickness of about 10 nm to about 25 nm.

In the embodiment, when the thickness of the first quantum wall 114B1 is less than 10 nm, the role of a barrier and the reflection effect may be deteriorated, and when the thickness is more than 25 nm, carrier injection may become more difficult.

In the quantum wall 114B of the embodiment, the last quantum wall 114BL may be an undoped Al _z GaN bulk layer. Since the Al composition (z) of the last quantum wall 114BL may be about 10% to 20%, it is not limited thereto.

The composition (z) of Al in the last quantum wall 114BL is set to be smaller than the composition (x) of Al in the _{n-type Al x GaN layer 114BB, so that the light reflection function in the last quantum wall 114BL is performed.} It can be suppressed, and through this, the luminous efficiency in the upward direction can be improved.

3 is an exemplary diagram of a band gap diagram of a light emitting device according to a second embodiment.

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

2 The light emitting device according to the embodiment includes a first quantum wall 114B1 closest to the first conductivity type semiconductor layer 112, a last quantum wall 114BL closest to the second conductivity type semiconductor layer 116, and A third quantum wall 114B3 may be included between the first quantum wall 114B1 and the last quantum wall 114BL.

In this case, the band gap energy level of the first quantum wall 114B1 may be higher than the band gap energy level of the third quantum wall 114B3.

In addition, the embodiment may include a second quantum wall 114B2 disposed between the first quantum wall 114B1 and the third quantum wall 114B3.

The band gap energy level of the second quantum wall 114B2 may be between the band gap energy level of the first quantum wall 114B1 and the band gap energy level of the third quantum wall 114B3.

According to the second embodiment, as the band gap energy level of the quantum wall 114B decreases from the first conductivity type semiconductor layer 112 to the second conductivity type semiconductor layer 116, the first conductivity type semiconductor layer 112 ), by increasing the reflectance of the first quantum wall 114B1 adjacent to the second conductivity type semiconductor layer 116, and lowering the reflectivity of the third quantum wall 114B3 adjacent to the second conductivity type semiconductor layer 116. It is possible to improve the light extraction efficiency in the direction of the layer 116.

Hereinafter, a method of manufacturing a light emitting device according to an embodiment will be described with reference to FIGS. 4 to 9.

First, a substrate 105 is prepared as shown in FIG. 4. The substrate 105 may be formed of a material having excellent thermal conductivity, and may be a conductive substrate or an insulating substrate. For example, the substrate 105 may use at least one _{of sapphire (Al 2} O ₃ ), SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, and Ga ₂ 0 _3. An uneven structure P may be formed on the substrate 105, but the embodiment is not limited thereto.

A buffer layer 113 may be formed on the substrate 105. The buffer layer 113 may alleviate lattice mismatch between the material of the light emitting structure 110 and the substrate 105 to be formed later, and the material of the buffer layer 113 is a group 3-5 or 2-6 compound A semiconductor, for example, may be formed of at least one of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN.

Next, a first conductivity type semiconductor layer 112 may be formed on the first substrate 105 or the buffer layer 113. For example, the first conductivity type semiconductor layer 112 may be implemented as a compound semiconductor such as group 3-5, group 2-6, or the like, and may be doped with a first conductivity type dopant.

When the first conductivity-type semiconductor layer 112 is an n-type semiconductor layer, the first conductivity-type dopant is an n-type dopant, and may include Si, Ge, Sn, Se, and Te, but is not limited thereto.

The first conductivity type semiconductor layer 112 may include _{a semiconductor material having a composition formula of In x} Al _y Ga _1-xy N (0≤x≤1, 0≤y≤1, 0≤x+y≤1). I can. For example, the first conductivity type semiconductor layer 112 is formed of one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, InP. Can be.

In the embodiment, unlike the prior art, the first conductivity type semiconductor layer 112 may be formed without forming an AlGaN layer on the first substrate 105 or the buffer layer 113.

Next, the active layer 114 may be formed on the first conductivity type semiconductor layer 112.

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

For example, in the active layer 114, trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and trimethyl indium gas (TMIn) may be injected to form a multiple quantum well structure. It is not limited thereto.

The active layer 114 may include a quantum well 114W and a quantum wall 114B. For example, the active layer 114 has a pair structure of at least one of AlGaN/GaN, AlGaN/AlGaN, InGaN/GaN, InGaN/InGaN, InAlGaN/GaN, GaAs/AlGaAs, InGaAs/AlGaAs, GaP/AlGaP, InGaP AlGaP It may be formed of, but is not limited thereto.

Hereinafter, features of the light emitting device according to the embodiment will be described in more detail with reference to FIG. 2 or 3.

As shown in FIG. 2, in the first embodiment, the quantum wall 114B includes an n-type Al _x GaN layer (0≤x≤ 1) 114BB and the n-type Al on the first conductivity-type semiconductor layer 112. _{An undoped Al y} GaN layer (0≦y≦1) 114BA may be included on the x GaN layer 114BB.

In the quantum wall 114B, the n-type Al _x GaN layer 114BB may be interposed between the _{undoped Al y GaN layer 114BA.}

In addition, in the embodiment, the quantum wall 114B may have an undoped Al _y GaN layer 114BA/n-type Al _x GaN layer 114BB/ an undoped Al _y GaN layer 114BA. The structure of the Al _y GaN layer 114BA/n-type Al _x GaN layer 114BB/the undoped Al _y GaN layer 114BA may be formed in at least one or a plurality of cycles.

The quantum wall (114B) has a plurality of sentence prompt Al _y GaN layer (114BA) between the n-type Al _x GaN layer (114BB) sentence is interposed in a sandwich structure soft Al _y GaN layer (114BA) / n-type Al _x GaN layer (114BB) / undoped Al _y GaN layer (114BA) may include a sandwich structure, but is not limited thereto.

In the embodiment, the Al composition (x) in the n-type Al _x GaN layer (0≦x≦1) (114BB) is the Al composition in _{the undoped Al y GaN layer (0≦y≦1) (114BA) (} can be greater than y). Accordingly, the band gap energy level of the n-type Al _{x GaN layer (0≦x} ≦1) 114BB may be greater than that of the undoped Al y GaN layer (0≦y≦1) 114BA.

In an embodiment, the n-type Al _x GaN layer (0≦x≦1) 114BB may function as a reflective layer for light emitted from the quantum well 114W.

Accordingly, by using the quantum wall serving as a reflector in the embodiment, light emitted from the quantum well 114W does not move to the bottom side of the light emitting device chip, but moves to the top side, Since the necessity of the n-side AlGaN layer, which was employed to solve the light absorption problem in the GaN layer by reducing or eliminating the light moving downward, can be reduced, the Al composition in the AlGaN layer can be reduced or replaced with GaN altogether.

In the embodiment, the band gap energy level of the n-type Al _x GaN layer (0 ≤ x ≤ 1) (114BB) is set to be 0.7 eV or more larger than _{the undoped Al y GaN layer (0 ≤ y ≤ 1) (114BA).} The light reflection function can be secured by the difference in the relative refractive index.

The Al composition (x) in the n-type Al _x GaN layer (0≦x≦1) 114BB may be 0.3 to 1. When the Al composition (x) in the n-type Al _x GaN layer (0≦x≦1) 114BB is less than 0.3, the difference in refractive index may be insufficient and thus reflective performance may be low.

In an embodiment, the n-type Al _x GaN layer (0≤x≤1) 114BB is doped with an n-type dopant to increase carrier injection efficiency.

In addition, according to the embodiment, since the quantum wall 114B includes an n-type Al _x GaN layer (0≦x≦1) 114BB, a current spreading effect is achieved by a 2DEG (tow-dimensional electron gas) effect. have.

In an embodiment, the thickness of the n-type Al _x GaN layer 114BB may be about 1 nm to about 3 nm. If the thickness of the n-type Al _x GaN layer 114BB is thinner than 1 nm, the reflection effect may be weak, and if it exceeds 3 nm, electron injection into the quantum well 114W may be adversely affected.

Alternatively, in the embodiment, the Al composition (y) in the undoped Al _{y GaN layer (0≦y≦1) 114BA may be 0 to 0.15.} When the Al composition (y) is greater than 0.15 in the undoped Al _y GaN layer (0≦y≦1) 114BA, carrier injection may be impaired.

In an embodiment, the thickness of the undoped AlyGaN layer (0≦y≦1) 114BA may be about 1 nm to about 3 nm. When the thickness of the undoped AlyGaN layer 114BA is less than 1 nm, the reflection function may be weak, and when the thickness of the undoped AlyGaN layer 114BA is less than 3 nm, carrier injection may be adversely affected.

In the embodiment, the quantum wall 114B may have an undoped Al _y GaN layer 114BA/n-type Al _x GaN layer 114BB superlattice structure, and the dislocation due to the superlattice shape of two layers having different lattice constants The crystal quality of the last quantum well 114W in which most of the light emission occurs due to bending of (Dislocation) can be greatly improved.

In an embodiment _{, the thickness of the quantum wall 114B including the undoped Al y} GaN layer 114BA/n-type Al _x GaN layer 114BB superlattice structure may be about 10 nm to about 25 nm.

For example, the quantum wall 114B is a first quantum wall 114B1 closest to the first conductivity type semiconductor layer 112, and a last quantum wall closest to the second conductivity type semiconductor layer 116 ( 114BL) and a third quantum wall 114B3 between the first quantum wall 114B1 and the last quantum wall 114BL. In addition, the quantum wall 114B may further include a second quantum wall 114B2 between the third quantum wall 114B3 and the last quantum wall 114BL.

In this case, the first quantum wall 114B1 may have a thickness of about 10 nm to about 25 nm. In the embodiment, when the thickness of the first quantum wall 114B1 is less than 10 nm, the role of a barrier and the reflection effect may be deteriorated, and when the thickness is more than 25 nm, carrier injection may become more difficult.

In the quantum wall 114B of the embodiment, the last quantum wall 114BL may be an undoped Al _z GaN bulk layer. Since the Al composition (z) of the last quantum wall 114BL may be about 10% to 20%, it is not limited thereto.

The composition (z) of Al in the last quantum wall 114BL is set to be smaller than the composition (x) of Al in the _{n-type Al x GaN layer 114BB, so that the light reflection function in the last quantum wall 114BL is performed.} It can be suppressed, and through this, the luminous efficiency in the upward direction can be improved.

In contrast, as shown in FIG. 3, the light emitting device according to the second embodiment is the first quantum wall 114B1 closest to the first conductivity type semiconductor layer 112 and the second conductivity type semiconductor layer 116. A third quantum wall 114B3 may be included between the adjacent last quantum wall 114BL and the first quantum wall 114B1 and the last quantum wall 114BL.

In this case, the band gap energy level of the first quantum wall 114B1 may be higher than the band gap energy level of the third quantum wall 114B3. In addition, the embodiment may include a second quantum wall 114B2 disposed between the first quantum wall 114B1 and the third quantum wall 114B3.

The band gap energy level of the second quantum wall 114B2 may be between the band gap energy level of the first quantum wall 114B1 and the band gap energy level of the third quantum wall 114B3.

According to the second embodiment, as the band gap energy level of the quantum wall 114B decreases from the first conductivity type semiconductor layer 112 to the second conductivity type semiconductor layer 116, the first conductivity type semiconductor layer 112 ), by increasing the reflectance of the first quantum wall 114B1 adjacent to the second conductivity type semiconductor layer 116, and lowering the reflectivity of the third quantum wall 114B3 adjacent to the second conductivity type semiconductor layer 116. It is possible to improve the light extraction efficiency in the direction of the layer 116.

Next, as shown in FIG. 4, an electron blocking layer 115 is formed on the active layer 114 to serve as electron blocking and MQW cladding of the active layer, thereby improving luminous efficiency. For example, the electron blocking layer 115 may be formed of an Al _x In _y Ga _(1-xy) N (0≦x≦1,0≦y≦1) based semiconductor, and the active layer 114 It may have a higher energy band gap than the energy band gap.

Next, a second conductivity type semiconductor layer 116 may be formed on the electron blocking layer 124. The second conductivity type semiconductor layer 116 may be implemented with a semiconductor compound, for example, a compound semiconductor such as group 3-5, group 2-6, or the like, and may be doped with a second conductivity type dopant.

For example, it may include a semiconductor material having the second conductivity type semiconductor layer of the composition formula _{(116) InpAlqGa1 -pq N (0≤p≤1} , 0≤q≤1). When the second conductivity-type semiconductor layer 116 is a p-type semiconductor layer, the second conductivity-type dopant is a p-type dopant and may include Mg, Zn, Ca, Sr, Ba, or the like.

In an embodiment, the first conductivity-type semiconductor layer 112 may be implemented as an n-type semiconductor layer, and the second conductivity-type semiconductor layer 116 may be implemented as a p-type semiconductor layer, but is not limited thereto.

In addition, a third semiconductor layer 125 having a polarity opposite to that of the second conductivity type, for example, an n-type third semiconductor layer 125 may be formed on the second conductivity type semiconductor layer 116. Accordingly, the light emitting structure 110 may be implemented in 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.

Next, as shown in FIG. 5, a component disposed above the first conductivity type first semiconductor layer 112 may be partially exposed so that a part of the configuration may be removed. Such a process may be performed by wet etching or dry etching, but is not limited thereto.

Next, as shown in FIG. 6, a current blocking layer 130 may be formed at a location where the second electrode 152 is to be formed. The current blocking layer 130 may include a non-conductive region, a first conductivity type ion implantation layer, a first conductivity type diffusion layer, an insulating material, an amorphous region, and the like.

Next, a light-transmitting electrode layer 140 may be formed on the second conductivity type semiconductor layer 116 on which the current blocking layer 130 is formed. The translucent electrode layer 140 may include an ohmic layer, and may be formed by stacking a single metal, a metal alloy, or a metal oxide in multiple layers so that hole injection can be efficiently performed.

For example, the light-transmitting electrode layer 140 may be formed of an excellent material that is in electrical contact with a semiconductor. For example, the light-transmitting electrode layer 140 may include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), and IGTO. (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IZON (IZO Nitride), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), ZnO, IrOx, RuOx, NiO, RuOx/ITO, Ni/IrOx/Au, and Ni/IrOx/Au/ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt , Au, and may be formed including at least one of Hf, but is not limited to these materials.

Thereafter, the passivation layer 160 may be formed as an insulating layer or the like on the side of the light emitting structure 110 and on a part of the light-transmitting electrode layer 140. The passivation layer 160 may expose a region where the first electrode 151 is to be formed.

Next, as shown in FIG. 7, a second electrode 152 is formed on the light-transmitting electrode layer 140 so as to overlap the current blocking layer 130, and on the exposed first conductivity type first semiconductor layer 112 The red light emitting device according to the embodiment may be manufactured by forming the first electrode 151. The first electrode 151 or the second electrode 152 is titanium (Ti), chromium (Cr), nickel (Ni), aluminum (Al), platinum (Pt), gold (Au), tungsten (W), It may be formed of at least one of molybdenum (Mo), but is not limited thereto.

Ultraviolet light emitting devices are divided into three types: UV-A ((315~400nm)), UV-B (280~315nm), and UV-C (200~280nm) in the order of their longest wavelength.

According to the wavelength of the Jawa ray light emitting device (UV LED) according to the embodiment, the UV-A (315-400 nm) region is industrial UV curing, printing ink curing, exposure machine, counterfeit detection, photocatalytic sterilization, special lighting (aquarium/agricultural use, etc.) ), etc., and the UV-B (280~315nm) region can be used for medical purposes, and the UV-C (200~280nm) region can be applied to air purification, water purification, and sterilization products.

A plurality of light emitting devices according to the embodiment may be arrayed on a substrate in the form of a package, and an optical member, such as a light guide plate, a prism sheet, a diffusion sheet, and a fluorescent sheet, may be disposed on a path of light emitted from the light emitting device package.

The light emitting device according to the embodiment may be applied to a backlight unit, a lighting unit, a display device, an indication device, a lamp, a street light, a vehicle lighting device, a vehicle display device, a smart watch, etc., but is not limited thereto.

8 is a diagram illustrating a light emitting device package 200 in which an ultraviolet light emitting device is installed according to embodiments.

The light emitting device package 200 according to the embodiment includes a package body part 205, a third electrode layer 213 and a fourth electrode layer 214 installed on the package body part 205, and the package body part 205 A molding member 230 which is provided in and surrounds the light emitting device 100 by having an ultraviolet light emitting device 100 and a phosphor 232 electrically connected to the third electrode layer 213 and the fourth electrode layer 214 and electrically connected to the third electrode layer 213 and the fourth electrode layer 214. ) Can be included.

The third electrode layer 213 and the fourth electrode layer 214 are electrically separated from each other, and serve to provide power to the ultraviolet light emitting device 100. In addition, the third electrode layer 213 and the fourth electrode layer 214 may serve to increase light efficiency by reflecting light generated from the ultraviolet light emitting device 100, and in the ultraviolet light emitting device 100 It can also play a role of discharging the generated heat to the outside.

The ultraviolet light emitting device 100 may be electrically connected to the third electrode layer 213 and/or the fourth electrode layer 214 by any one of a wire method, a flip chip method, or a die bonding method.

The ultraviolet light emitting device according to the embodiment may be applied to a backlight unit, a lighting unit, a display device, an indication device, a lamp, a street light, a vehicle lighting device, a vehicle display device, a smart watch, etc., but is not limited thereto.

9 is an exploded perspective view of a lighting system according to an embodiment.

The lighting device according to the embodiment may include a cover 2100, a light source module 2200, a radiator 2400, a power supply unit 2600, an inner case 2700, and a socket 2800. In addition, the lighting device according to the embodiment may further include 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 radiator 2400 and has guide grooves 2310 into which a plurality of light source units 2210 and a connector 2250 are inserted.

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

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

Features, structures, effects, and the like described in the embodiments above 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 each embodiment may be combined or modified for other embodiments by a person having ordinary knowledge in the field to which the embodiments belong. Therefore, contents related to such combinations and modifications should be construed as being included in the scope of the embodiments.

Features, structures, effects, and the like described in the embodiments above 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 each embodiment may be combined or modified for other embodiments by a person having ordinary knowledge in the field to which the embodiments belong. Therefore, contents related to such combinations and modifications should be construed as being included in the scope of the embodiments.

Although the embodiments have been described above, these are only examples and are not intended to limit the embodiments, and those of ordinary skill in the field to which the embodiments belong are not departing from the essential characteristics of the present embodiment. It will be seen that branch transformation and application are possible. For example, each component specifically shown in the embodiment can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the embodiments set in the appended claims.

First conductivity type semiconductor layer 112, active layer 114, quantum well 114W, quantum wall 114B,
n-type Al _x GaN layer (0 ≤ x ≤ 1) (114BB), undoped Al _y GaN layer (0 ≤ y ≤ 1) (114BA)
Second conductivity type semiconductor layer 116

Claims (12)

A first conductivity type semiconductor layer;
An active layer disposed on the first conductivity type semiconductor layer including a quantum well and a quantum wall;
Including; a second conductivity type semiconductor layer disposed on the active layer,
The quantum wall,
A first quantum wall closest to the first conductivity type semiconductor layer;
A last quantum wall closest to the second conductivity type semiconductor layer;
A second quantum wall disposed between the first quantum wall and the last quantum wall; And
And a third quantum wall disposed between the second quantum wall and the last quantum wall,
A band gap energy level of each of the first to third quantum walls and the last quantum wall is greater than a band gap energy level of the first and second conductivity-type semiconductor layers,
Each of the first to third quantum walls,
_{A plurality of undoped Al y} GaN layers (0≦y≦1) disposed on the first conductivity type semiconductor layer;
A plurality of n-type Al _x GaN layers (0≦x≦1) disposed between the plurality of undoped Al _{y GaN layers (0≦y≦1),}
Al composition (x) in the n-type Al _x GaN layer (0≤x≤1) is greater than the Al composition (y) _{in the undoped Al y GaN layer (0≤y≤1),}
The band gap energy level of the n-type Al _{x GaN layer (0≦x} ≦1) is 0.7 eV or more greater than that of the undoped Al y GaN layer (0≦y≦1),
The band gap energy level of each of the n-type Al _x GaN layer (0≦x≦1) and the Al _y GaN layer (0≦y≦1) is greater than the band gap energy level of the quantum well,
The last quantum wall is an undoped Al _z GaN bulk layer, and an ultraviolet light emitting device having a bandgap energy level smaller than that of _{the n-type Al x GaN layer (0≦x≦1).} The method of claim 1,
Each of the first to third quantum walls is an ultraviolet light emitting device having an _{undoped Al y} GaN layer/n-type Al _{x GaN layer superlattice structure.} The method of claim 1,
An ultraviolet light emitting device having an Al composition (z) of 10% to 20% of the last quantum wall. The method of claim 1,
The thickness of the first quantum wall is 10 nm to 25 nm,
The thickness of the n-type Al _x GaN layer is 1 nm to 3 nm,
The undoped Al _y GaN layer (0≦y≦1) has a thickness of 1 nm to 3 nm. The method of claim 1,
The first band gap energy level of the n-type Al _x GaN layer (0≤x≤1) contained in both the wall and the second of the n-type Al _x GaN layer (0≤x≤1) included in the quantum wall Is greater than the bandgap energy level of
Wherein the second band gap energy level of the n-type Al _x GaN layer (0≤x≤1) contained in both the wall of the n-type Al _x GaN layer (0≤x≤1) contained in said third quantum wall Ultraviolet light emitting device that is larger than the bandgap energy level. delete delete delete delete delete delete delete

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