WO2016208993A1 - Light-emitting element and display device comprising same - Google Patents

Abstract

An embodiment provides a light-emitting element and a display device comprising the same, the light-emitting element comprising: a conductive base layer; an insulating film, which is arranged on the base layer, and which comprises a plurality of first holes; a plurality of light-emitting structures, each comprising a first semiconductor core, which is electrically connected to the base layer through the first holes, an active layer, which is arranged on the first semiconductor core, and a second semiconductor layer; an insulating particle layer comprising insulating particles that fill the space between the plurality of light-emitting structures; and a first conductive layer arranged on the insulating particle layer, wherein the diameter of the insulating particles is smaller than the width of the first holes.

Description

Light emitting device and display device including same

The embodiment relates to a light emitting device and a display device including the same.

A light emitting device (LED) is a compound semiconductor device that converts electrical energy into light energy, and various colors can be realized by adjusting the composition ratio of the compound semiconductor.

The nitride semiconductor light emitting device has advantages of low power consumption, semi-permanent life, fast response speed, safety and environmental friendliness compared to conventional light sources such as fluorescent lamps and incandescent lamps. Therefore, LED backlights that replace the Cold Cathode Fluorescence Lamps (CCFLs) that make up the backlight of liquid crystal display (LCD) displays, white LED lighting devices that can replace fluorescent or incandescent bulbs, and automotive headlights. And the application is expanding to traffic lights.

Recently, light emitting devices using vertically grown nanostructures have been developed. Since the nanostructures emit light from the front surface, the light emitting area can be widened.

However, there is a problem that leakage current occurs because current is concentrated at the lower end of the nanostructure. In addition, a leakage current occurs in an ungrown region of the nanostructure or a region in which the nanostructure is broken, resulting in a decrease in electrical characteristics.

The embodiment provides a light emitting device capable of reducing leakage current and a display device including the same.

The problem to be solved in the examples is not limited thereto, and the object or effect that can be grasped from the solution means or the embodiment described below will also be included.

In one embodiment, a light emitting device includes: a conductive base layer; An insulating layer disposed on the base layer and including a plurality of first holes; A plurality of light emitting structures including a first semiconductor core electrically connected to the base layer through the first hole, an active layer disposed on the first semiconductor core, and a second semiconductor layer; An insulating particle layer including insulating particles filled between the plurality of light emitting structures; And a first conductive layer disposed on the insulating particle layer, wherein the diameter of the insulating particle is smaller than the width of the first hole.

At least one of the plurality of first holes may be filled with the insulating particles.

The width of the first hole may be 0.5 μm or more and 3 μm or less.

The diameter of the insulating particles may be 150nm or more and 500nm or less.

The insulating particle layer may have a thickness of 400 nm or more and 1000 nm or less.

The material of the insulating film and the material of the insulating particles may be different.

The insulating particles may include first insulating particles having a first diameter and second insulating particles having a second diameter, and the second diameter may be larger than the first diameter.

The insulating particle layer may include a lower insulating particle layer including a first insulating particle, and an upper insulating particle layer including the second insulating particle.

The first insulating particles may be filled in at least one of the plurality of first holes.

In the insulating particle layer, the first insulating particles and the second insulating particles may be randomly dispersed.

It may include a surface treatment layer formed on the second semiconductor layer.

The surface treatment layer may include a silane-based material.

According to one or more exemplary embodiments, a method of manufacturing a light emitting device includes: forming an insulating layer having a plurality of first holes on a conductive base layer; Growing a light emitting structure including a first semiconductor core, an active layer, and a second semiconductor layer on the first hole; Forming an insulating particle layer between the light emitting structures; The method may include forming a conductive layer on the insulating particle layer and the light emitting structure.

In the forming of the insulating particle layer, insulating particles having a diameter smaller than the width of the first hole may be formed between the light emitting structures.

The material of the insulating film and the material of the insulating particles may be different.

The insulating particles may include first insulating particles having a first diameter and second insulating particles having a second diameter, and the second diameter may be larger than the first diameter.

According to the embodiment, the leakage current is reduced to manufacture a light emitting device having excellent electrical characteristics.

Various and advantageous advantages and effects of the present invention are not limited to the above description, and will be more readily understood in the course of describing specific embodiments of the present invention.

1 is a conceptual diagram of a light emitting device according to an embodiment of the present invention;

2 is a view for explaining a path in which leakage current occurs;

3 is a photograph showing a first leakage path occurring at the lower end of the light emitting structure,

4 is a photograph showing a second leakage path occurring in a region in which the light emitting structure is partially unformed,

5 is a photograph showing a third leakage path generated by the pinhole of the insulating film,

6 is a view illustrating a state in which an insulating particle layer is disposed between the light emitting structures of FIG. 1,

7 is a photograph showing a state in which an insulating particle layer is disposed between the light emitting structures of FIG. 1,

8 is a view illustrating a state in which an insulating particle layer is disposed between light emitting structures having various shapes,

9 is a photograph showing a state in which an insulating particle layer is disposed between light emitting structures having various shapes,

10 is a view illustrating a state in which insulating particles having different sizes are disposed between the light emitting structures of FIG. 1,

11 is a photograph showing a state in which insulating particles having different sizes are disposed between the light emitting structures of FIG. 1,

12 is a view illustrating a state in which insulating particles having different sizes are randomly disposed between the light emitting structures of FIG. 1,

FIG. 13 is a view illustrating a state in which insulating particles having different materials are randomly disposed between the light emitting structures of FIG. 1,

14 is a view illustrating a state in which insulating particles having different shapes are randomly disposed between the light emitting structures of FIG. 1,

15 is a view showing a state in which a surface layer is formed on the light emitting structure of FIG. 1,

16 is a view illustrating a state in which an insulating particle layer is formed between the surface-treated light emitting structures of FIG. 15,

17A to 17F are views for explaining a method of manufacturing a light emitting device according to an embodiment of the present invention;

18 is a conceptual diagram of a light emitting device according to another embodiment of the present invention;

19 is a photograph of a conventional light emitting device,

20 is an enlarged view of a portion A of FIG. 18;

FIG. 21 is a photograph of the first semiconductor layer core of FIG. 18;

22 is a photograph of the light emitting structure of FIG. 18,

23 is a conceptual diagram of a light emitting device according to another embodiment of the present invention;

24A to 24E are flowcharts illustrating a method of manufacturing a light emitting device according to another embodiment of the present invention;

25A to 25E are flowcharts illustrating a method of manufacturing a light emitting device according to still another embodiment of the present invention.

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated and described in the drawings. However, this is not intended to limit the embodiments of the present invention to specific embodiments, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the embodiments.

Terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the embodiments, the second component may be referred to as the first component, and similarly, the first component may also be referred to as the second component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of example embodiments. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

In the description of the embodiment, when one element is described as being formed "on or under" of another element, it is on (up) or down (on). or under) includes both two elements being directly contacted with each other or one or more other elements are formed indirectly between the two elements. In addition, when expressed as "on" or "under", it may include the meaning of the downward direction as well as the upward direction based on one element.

Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings, and the same or corresponding components will be given the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted.

1 is a conceptual diagram of a light emitting device according to an embodiment of the present invention.

Referring to FIG. 1, a light emitting device according to an exemplary embodiment may include a conductive base layer 131 on a substrate 110, an insulating layer 120 including a plurality of first holes W1, and a plurality of light emitting devices. The light emitting structure 130, an insulating particle layer 140 disposed between the plurality of light emitting structures 130, and a first conductive layer 150 disposed on the insulating particle layer 140 are included.

The substrate 110 may include a conductive substrate or an insulating substrate. The substrate 110 may be a material or a carrier wafer suitable for growing a semiconductor material. The substrate 110 may be formed of a material selected from sapphire (Al ₂ O ₃ ), SiC, GaAs, GaN, ZnO, Si, GaP, InP, and Ge, but is not limited thereto.

The conductive base layer 131 may be formed on the substrate 110 and provide a growth surface of the light emitting structure 130. In addition, the base layer 131 may be electrically connected to the first electrode 171 and the light emitting structure 130. The conductive base layer 131 may have the same composition as the first semiconductor core 132, but is not limited thereto. The base layer 131 may be doped with n-type dopants such as Si, Ge, Sn, Se, and Te, but is not limited thereto.

The insulating film 120 is disposed on the conductive base layer 131. The insulating layer 120 includes a plurality of first holes W1 through which the base layer 131 and the light emitting structure 130 are electrically connected. The plurality of first holes W1 may be formed by a mask pattern. The insulating layer 120 may include an insulating material such as SiO ₂ or SiNx, but is not limited thereto.

The plurality of light emitting structures 130 may include a first semiconductor core 132 electrically connected to the base layer 131 through a first hole W1, an active layer 134 formed on the first semiconductor core 132, It may include a second semiconductor layer 133 formed on the active layer 134.

The light emitting structure 130 may grow in a substantially vertical direction on the substrate 110 and have a size of nano size. Light emitted from the light emitting structure 130 may be emitted in the substrate direction and / or in the opposite direction.

The first semiconductor core 132 may grow on the surface of the base layer 131 exposed by the first hole W1. The first semiconductor core 132 may be a nanorod, but is not limited thereto.

The first semiconductor core 132 may be a compound semiconductor such as a III-V group or a II-VI group, and a first dopant may be doped into the first semiconductor core 132. The first semiconductor core 132 is a semiconductor material having a composition formula of In _x1 Al _y1 Ga _1-x1-y1 N (0 ≦ x1 ≦ 1, 0 ≦ _y1 ≦ 1, 0 ≦ x1 + _y1 ≦ 1), for example GaN, AlGaN, InGaN, InAlGaN and the like can be selected. The first dopant may be an n-type dopant such as Si, Ge, Sn, Se, or Te. When the first dopant is an n-type dopant, the first semiconductor core 132 doped with the first dopant may be an n-type semiconductor.

The active layer 134 grows on the insulating film 120 and is disposed on the first semiconductor core 132. The active layer 134 is a layer where electrons (or holes) injected through the first semiconductor core 132 meet holes (or electrons) injected through the second semiconductor layer 133. The active layer 134 transitions to a low energy level as electrons and holes recombine, and may generate light having a corresponding wavelength. There is no restriction on the emission wavelength in this embodiment.

The active layer 134 may have any one of a single well structure, a multi well structure, a single quantum well structure, a multi quantum well (MQW) structure, a quantum dot structure, or a quantum line structure, and the active layer 134 The structure of is not limited to this.

The active layer 134 may have a structure in which a plurality of well layers and barrier layers are alternately arranged. The well layer and the barrier layer may have a composition formula of InxAlyGa1-x-yN (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), and the energy bandgap of the barrier layer is the energy of the well layer. It may be larger than the bandgap.

The second semiconductor layer 133 is grown on the insulating film 120 and disposed on the active layer 134. The second semiconductor layer 133 may be formed of a compound semiconductor such as a group III-V group or a group II-VI group, and a second dopant may be doped into the second semiconductor layer 133. The second semiconductor layer 133 may be formed of a semiconductor material having a composition formula of In _x5 Al _y2 Ga _{1 -x5- y2} N (0≤x5≤1, 0≤y2≤1, 0≤x5 + y2≤1), or AlInN, AlGaAs. It may be formed of a material selected from GaP, GaAs, GaAsP, AlGaInP. When the second dopant is a p-type dopant such as Mg, Zn, Ca, Sr, or Ba, the second semiconductor layer 133 doped with the second dopant may be a p-type semiconductor.

An electron blocking layer EBL may be disposed between the active layer 134 and the second semiconductor layer 133. The electron blocking layer is a semiconductor material having a composition formula of In _x1 Al _y1 Ga _{1 -x1- y1} N (0≤x1≤1, 0≤y1≤1, 0≤x1 + y1≤1), for example AlGaN, InGaN, InAlGaN may be selected from, but is not limited thereto.

The conductive layer 150 is disposed on the insulating particle layer 140 and the light emitting structure 130. The conductive layer 150 may electrically connect the second electrode 172 and the second semiconductor layer 133. In addition, the first electrode 171 may be disposed on the partially exposed base layer 131 and electrically connected to the first semiconductor core 132.

The insulating particle layer 140 may be filled between the plurality of light emitting structures 130 to support the light emitting structures 130 and to electrically insulate the same.

2 is a view illustrating a path in which leakage current occurs, FIG. 3 is a photograph showing a first leakage path occurring at a lower end of the light emitting structure, and FIG. 4 is a second view in a region in which the light emitting structure is partially unformed. 5 is a photograph showing a leakage path, and FIG. 5 is a photograph showing a third leakage path generated by the pinhole of the insulating layer.

2 to 5, three types of leakage paths may be formed in the light emitting device including the nano light emitting structure 130. The first leakage path D1 may occur at the lower end of the light emitting structure 130. Current condensation occurs at the lower end of the light emitting structure 130. Therefore, the current leakage path occurs in the current density region. The size of the current density region may be 300 to 500 nm.

The second leakage path D2 may occur in a region where the light emitting structure 130 is not generated and a region where the light emitting structure 130 is broken. Due to various processes, the light emitting structure 130 may not be grown in some of the first holes W1. In addition, the light emitting structure 130 may be broken during growth due to the large aspect ratio.

The third leakage path D3 may be caused by a defect formed on the insulating layer 120. When the film quality of the insulating layer 120 for growing the light emitting structure 130 is reduced, a pinhole d4 may be generated in a nanostructure growth environment of high temperature / high pressure to leak current. The diameter of the pinhole d4 may be 50 nm to 100 nm.

6 is a view illustrating a state in which an insulating particle layer is disposed between the light emitting structures of FIG. 1, and FIG. 7 is a photograph showing a state in which the insulating particle layer is disposed between the light emitting structures of FIG. 1.

6 and 7, the insulating particle layer 140 may insulate between the plurality of light emitting structures 130 to block the first leakage path and the third leakage path. The thickness of the insulating particle layer 140 may be 400 nm or more and 1000 nm or less. When the thickness is less than 400 nm, a dislocation formed during regrowth of the light emitting structure 130 may come into contact with the conductive layer 150 or the base layer 131, thereby causing leakage current. When the thickness exceeds 1000 nm, the light emitting area of the side surface (m-plane) of the light emitting structure 130 may be excessively reduced, thereby reducing the light emitting efficiency.

In addition, the insulating particle layer 140 may be filled in the first hole W1 in which the light emitting structure 130 is not generated to block the leakage path. To this end, the insulating particle layer 140 may be applied after the light emitting structure 130 is formed, the size may be smaller than the width of the first hole (W1). Since the width of the first hole W1 may be controlled to 0.5 μm or more and 3 μm or less, the diameter of the insulating particles P is preferably at least 0.5 μm.

At this time, the diameter of the insulating particles (P) may be 150nm or more and less than 500nm. If the diameter is less than 150nm, the insulating particles (P) is stuck to the upper end of the light emitting structure 130 there is a problem that the luminous efficiency is reduced. That is, when the diameter is less than 150nm, the attraction of the light emitting structure 130 and the insulating particles (P) is stronger than the attraction between the insulating particles (P) it may be difficult to uniformly apply to the lower end of the light emitting structure (130).

When the diameter exceeds 500 nm, the gap between the insulating particles P increases, so that the conductive layer 150 penetrates to the lower end of the light emitting structure 130 when the conductive layer 150 is formed. If the diameter of the insulating particles (P) is 200nm to 400nm can solve the problems listed more effectively.

Since the gap between the insulating particles P is present in the insulating particle layer 140, it may have a light extraction effect as compared with the insulating film 120. That is, the light L1 generated from the side surface of the light emitting structure 130 covering the insulating particle layer 140 may be scattered in the insulating particle layer 140 and emitted to the outside. Therefore, luminous efficiency can be improved. The porosity may be about 0.2 to 0.3, but is not limited thereto.

8 is a view illustrating a state in which an insulating particle layer is disposed between light emitting structures having various shapes, and FIG. 9 is a photo illustrating a state in which the insulating particle layer is disposed between various light emitting structures.

8 and 9, various shapes of the light emitting structure 130 may be applied. Depending on the growth conditions, it may include all of the pyramid shape, nano rod shape, and the flat top shape. In this case, the insulating particle layer 140 may be formed of an insulating film. There is no restriction on the method of forming the insulating film. Exemplary PVDs such as sputtering, E-Beam evaporation, Thermal evaporation, Pulsed Laser Deposition, Laser molecular beam epitaxy Process and CVD processes such as MOCVD, HVPE, ALD, PECVD, LPCVD, APCVD can be applied.

FIG. 10 is a view illustrating a state in which insulating particles having different sizes are disposed between the light emitting structures of FIG. 1, and FIG. 11 is a photo illustrating a state in which insulating particles of different sizes are disposed between the light emitting structures of FIG. 1, and FIG. 12. 1 is a view illustrating a state in which insulating particles having different sizes are randomly disposed between the light emitting structures of FIG. 1.

10 and 11, the insulating particle layer 140 may include first insulating particles P1 having a first diameter and second insulating particles P2 having a second diameter. In this case, the second diameter may be larger than the first diameter. The first insulating particles P1 may constitute a lower insulating particle layer, and the second insulating particles P2 may constitute an upper insulating particle layer.

According to this configuration, the first insulating particles P1 having a small diameter can be densely packed in the first holes W1 to effectively block the second leakage path. In addition, the second insulating particles P2 having a relatively large diameter may emit light emitted from the side surface of the light emitting structure 130 to the outside.

Referring to FIG. 12, the first insulating particles P1 and the second insulating particles P2 may be randomly dispersed. In this case, two kinds of insulating particles P1 and P2 having different sizes may be dispersed to reduce porosity. Therefore, the first to third leakage paths can be effectively blocked.

FIG. 13 is a view illustrating a state in which insulating particles having different materials are randomly disposed between the light emitting structures of FIG. 1, and FIG. 14 is a view illustrating a state in which insulating particles having different shapes are randomly disposed between the light emitting structures of FIG. 1. to be.

Referring to FIG. 13, the plurality of insulating particles P3 and P4 having different materials may be SiO ₂ , Si ₃ N ₄ , Al ₂ O ₃ , ZrSiO ₄ , HfSiO ₄ , ZrO ₂ , HfO ₂ , La ₂ O ₃ , Ta ₂ O ₅ , TiO ₂ may be selected. Therefore, insulating materials having different effects may be mixed. For example, by using SiO ₂ having excellent electrical insulation and Al ₂ O ₃ having excellent reflectance, electrical insulation and light extraction may be simultaneously improved.

Referring to FIG. 14, the shapes of the insulating particles P3, P4, and P5 may be different from each other. The shape of the insulating particles P3, P4, P5 is not particularly limited. The shape of the insulating particles (P3, P4, P5) is spherical, rod-like, polygonal, cube-like (branched), branched, complex, Polygonal shape and the like can be applied in various ways.

FIG. 15 is a view illustrating a surface layer formed on the light emitting structure of FIG. 1, and FIG. 16 is a view illustrating a state in which an insulating particle layer is formed between the surface treated light emitting structures of FIG. 15.

15 and 16, a surface layer 135 may be further formed on the light emitting structure 130. GaN semiconductors are exposed to air and have tens of nm thick Ga ₂ O ₃ layers. Since the Ga ₂ O ₃ layer is hydrophilic (Hydrophillic), the attraction to the insulating particles is stronger. Therefore, when the insulating particle layer is formed, most of the insulating particles are attached to the light emitting structure 130, and thus uniform coating becomes difficult.

When the surface treatment material is applied to the light emitting structure 130, the surface layer 135 has a hydrophobic property. Therefore, the attraction force with the insulating particles P having a hydrophilic surface is weakened to form a uniform insulating particle layer 140. That is, the attraction between the insulating particles (P) is greater than the attraction between the insulating particles (P) and the light emitting structure 130 can be uniformly applied.

The surface treatment material may be selected from various materials that can impart hydrophobicity. For example, it may include a silane-based material or an organic-inorganic silane compound. The surface treatment material may include at least one selected from heptadecafluorodecyltrimethoxysilane (PFAS), octadecyldimethylchlorosilane, octadecyltrichlorosilane (OTS), tris (trimethylsiloxy silylethyl-dimethylchlorosilane, octyl dimethylchlorosilane, dimethyldichlorosilane, butyl dimethyl chlorosilane, and trimethylchlorosilane.

In addition, the cover layer S having the same composition as the surface layer 135 may also be formed in the first hole W1, thereby enabling uniform coating of the insulating particles. However, the present invention is not limited thereto, and the insulating film 120 may maintain a hydrophilic surface to easily insert the insulating particles into the first hole W1. The method in which the insulating film maintains the hydrophilic surface is not particularly limited. For example, it may be selectively coated only on the light emitting structure 130 using a mask.

17A to 17F are views for explaining a method of manufacturing a light emitting device according to an embodiment of the present invention.

Referring to FIG. 17A, a conductive base layer 131 is formed on the substrate 110. The substrate 110 may be formed of a material selected from sapphire (Al 2 O 3), SiC, GaAs, GaN, ZnO, Si, GaP, InP, and Ge, but is not limited thereto.

The base layer 131 may have the same composition as the first semiconductor core, but is not limited thereto. The base layer 131 may be doped with n-type dopants such as Si, Ge, Sn, Se, and Te, but is not limited thereto.

Referring to FIG. 17B, an insulating layer 120 having a plurality of first holes W1 is formed on the base layer 131. The insulating layer 120 may be selected from various insulating materials such as SiO ₂ , Si ₃ N ₄ , Al ₂ O ₃ , ZrSiO ₄ , HfSiO ₄ , ZrO ₂ , HfO ₂ , La ₂ O ₃ , Ta ₂ O ₅ , TiO ₂ . The first hole W1 can be produced in a width of 0.5 µm or more and 3 µm or less.

Referring to FIG. 17C, a plurality of light emitting structures 130 are grown on the insulating film 120. As the growth method of the light emitting structure 130, all conventional semiconductor growth methods may be applied. The first semiconductor core 132 may be grown on the surface of the base layer 131, and an active layer 134 and a second semiconductor layer 133 may be formed thereon. The active layer 134 and the second semiconductor layer 133 may be grown on the insulating layer 120. If necessary, a mask pattern may be used to grow the light emitting structure 130.

Referring to FIGS. 17D and 17E, a solution in which insulating particles P are dispersed may be coated on the light emitting structures 130. The solution is not particularly limited.

Dispersion methods include drop-coating, dip coating, spin coating, electrophoretic deposition, self-assembly at the gas / liquid interface, and transceiver methods. (transfer from the gas / liquid to the gas / solid interface), and spray coating (spray coating) can be used. If a solution is used, the solution may be volatilized after coating.

The diameter of the insulating particles P may be 150 nm or more and less than 500 nm. Therefore, the diameter of the insulating particles may be smaller than the diameter of the first hole (W1). In addition, the material of the insulating particles P may be different from the material of the insulating film 120, and the diameter size may be different. In addition, the insulating particle layer 140 may be formed so that all of the aforementioned characteristics of the insulating particle may be applied.

In this case, the light emitting structure 130 may be subjected to surface treatment in advance. As described above, the surface of the light emitting structure may be hydrophobic to allow uniform coating of the insulating particles P by surface treatment. The silane-based material or the organic-inorganic silane compound may be coated on the light emitting structure 130.

Referring to FIG. 17F, the conductive layer 150 may be formed on the insulating particle layer 140, and the filling layer 160 may be further formed thereon. Fill layer 160 may be an optically transparent layer or an insulating layer. For example, the filling layer 160 may include spin on glass. The height of the filling layer 160 may be lower than the height of the light emitting structure 130.

The second electrode 172 may be formed on the light emitting structure 130 exposed to the outside of the filling layer 160, and the first electrode 171 may be formed on the partially exposed base layer 131.

18 is a conceptual view of a light emitting device according to another embodiment of the present invention, FIG. 19 is a photograph of a conventional light emitting device, FIG. 20 is an enlarged view of a portion A of FIG. 18, and FIG. 21 is a first semiconductor layer core of FIG. 18. 22 is a photograph of the light emitting structure of FIG. 18.

Referring to FIG. 18, the light emitting device according to the embodiment includes a conductive base layer 131 disposed on the substrate 110, and a plurality of first holes W1 disposed on the conductive base layer 131. The first insulating layer 120 and a plurality of light emitting structures 130 are electrically connected to the conductive base layer 131 through the first hole W1.

The substrate 110 may include a conductive substrate or an insulating substrate. The substrate 110 may be a material or a carrier wafer suitable for growing a semiconductor material. The substrate 110 may be formed of a material selected from sapphire (Al ₂ O ₃ ), SiC, GaAs, GaN, ZnO, Si, GaP, InP, and Ge, but is not limited thereto.

The conductive base layer 131 may be formed on the substrate 110 and provide a growth surface of the light emitting structure 130. In addition, the conductive base layer 131 may be electrically connected to the first electrode 171 and the light emitting structure 130.

The conductive base layer 131 may have the same composition as the first semiconductor core 132, but is not limited thereto. The conductive base layer 131 may be doped with n-type dopants such as Si, Ge, Sn, Se, and Te, but is not limited thereto.

The first insulating layer 120 is disposed on the conductive base layer 131. The first insulating layer 120 includes a plurality of first holes W1 through which the conductive base layer 131 and the light emitting structure 130 are electrically connected. The plurality of first holes W1 may be formed by a mask pattern. The first insulating layer 120 may include an insulating material such as SiO ₂ or SiNx, but is not limited thereto.

The plurality of light emitting structures 130 may be formed on the first semiconductor core 132 and the first semiconductor core 132 that are electrically connected to the conductive base layer 131 through the first hole W1. The second semiconductor layer 133 may be formed on the active layer 134.

The light emitting structure 130 may grow in a substantially vertical direction on the substrate 110 and have a size of nano size. Light emitted from the light emitting structure 130 may be emitted in the direction of the substrate 110 and / or in the opposite direction.

The first semiconductor core 132 may grow on the surface of the conductive base layer 131 exposed by the first hole W1. The first semiconductor core 132 may be a nanorod, but is not limited thereto.

The first semiconductor core 132 may be a compound semiconductor such as a III-V group or a II-VI group, and a first dopant may be doped into the first semiconductor core 132.

The first semiconductor core 132 is a semiconductor material having a composition formula of In _x1 Al _y1 Ga _{1 -x1- y1} N (0≤x1≤1, 0≤y1≤1, 0≤x1 + y1≤1), for example GaN, AlGaN, InGaN, InAlGaN and the like can be selected. The first dopant may be an n-type dopant such as Si, Ge, Sn, Se, Te. When the first dopant is an n-type dopant, the first semiconductor core 132 doped with the first dopant may be an n-type semiconductor.

Referring to FIG. 19, the active layer grown on the pointed core may have a problem in which the upper region A is partially collapsed. The collapsed region forms a first leakage current path. In addition, the dislocation present between B and nGaN forms a second leakage current path.

Referring to FIG. 20, the first semiconductor core 132 according to the embodiment may include a first flat surface 132a formed at an upper portion thereof. The method of controlling the top of the first semiconductor core 132 to be flat may vary. For example, it may be grown in a nitrogen atmosphere to control the top flat, or may be controlled by mechanical leveling.

The active layer 134 is disposed on the first semiconductor core 132. Accordingly, the active layer 134 includes a second planar surface 134a formed on the first planar surface 132a of the first semiconductor core 132. Therefore, the problem that the active layer 134 is sufficiently supported by the first semiconductor core 132 may collapse.

The active layer 134 is a layer where electrons (or holes) injected through the first semiconductor core 132 meet holes (or electrons) injected through the second semiconductor layer 133. The active layer 134 transitions to a low energy level as electrons and holes recombine, and may generate light having a corresponding wavelength. There is no restriction on the emission wavelength in this embodiment.

The active layer 134 may have any one of a single well structure, a multi well structure, a single quantum well structure, a multi quantum well (MQW) structure, a quantum dot structure, or a quantum line structure, and the active layer 134 The structure of is not limited to this.

The active layer 134 may have a structure in which a plurality of well layers and barrier layers are alternately arranged. The well layer and the barrier layer may have a composition formula of InxAlyGa1-x-yN (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), and the energy bandgap of the barrier layer is the energy of the well layer. It may be larger than the bandgap.

The second semiconductor layer 133 is disposed on the active layer 134. The second semiconductor layer 133 may be formed of a compound semiconductor such as a group III-V group or a group II-VI group, and a second dopant may be doped into the second semiconductor layer 133.

The second semiconductor layer 133 may be formed of a semiconductor material having a composition formula of In _x5 Al _y2 Ga _{1 -x5- y2} N (0≤x5≤1, 0≤y2≤1, 0≤x5 + y2≤1), or AlInN, AlGaAs. It may be formed of a material selected from GaP, GaAs, GaAsP, AlGaInP. When the second dopant is a p-type dopant such as Mg, Zn, Ca, Sr, or Ba, the second semiconductor layer 133 doped with the second dopant may be a p-type semiconductor.

An electron blocking layer EBL may be disposed between the active layer 134 and the second semiconductor layer 133. The electron blocking layer is a semiconductor material having a composition formula of In _x1 Al _y1 Ga _{1 -x1- y1} N (0≤x1≤1, 0≤y1≤1, 0≤x1 + y1≤1), for example AlGaN, InGaN, InAlGaN may be selected from, but is not limited thereto.

The second insulating layer 141 may be disposed on the second semiconductor layer 133. The second insulating layer 141 may block the first leakage current path and / or the second leakage current path. The height h2 of the second insulating layer 141 may be formed to 1/5 to 1/2 of the height h1 of the second semiconductor layer 133. When the height h2 of the second insulating layer 141 is less than 1/5 of the second semiconductor layer 133, the leakage current path may not be effectively blocked. In addition, when the height h2 of the second insulating layer 141 is greater than 1/2 of the second semiconductor layer 133, the emission area may be excessively reduced.

The conductive layer 160 is disposed on the light emitting structure 130. The conductive layer 160 may electrically connect the second electrode 172 and the second semiconductor layer 133. In addition, the first electrode 171 may be disposed on the partially exposed conductive base layer 131 and electrically connected to the first semiconductor core 132.

The light emitting structure 130 may be applied to all the various shapes. Depending on the growth conditions, it may include all of the pyramid shape, nano rod shape, and the flat top shape. Referring to FIG. 21, even when the first flat surface 132a is formed on the first semiconductor core 132, the final light emitting structure 130 may have a pyramid shape as shown in FIG. 22.

23 is a conceptual view of a light emitting device according to another embodiment of the present invention.

Referring to FIG. 23, the light emitting device according to the embodiment may include a conductive base layer 131, a first insulating layer 120 disposed on the conductive base layer 131 and including a plurality of first holes W1, And a plurality of light emitting structures 130 connected to the conductive base layer 131 through the first hole W1.

The light emitting structure 130 is disposed on the first semiconductor core 132 electrically connected to the conductive base layer 131, the active layer 134 disposed on the first semiconductor core 132, and the active layer 134. The second semiconductor layer 133 is included. In the present embodiment, the above-described configuration may be applied as it is except for the upper portion 132b of the first semiconductor core 132. That is, the general structure of the conductive base layer 131, the first insulating layer 120, the second insulating layer 141, and the light emitting structure may be applied as it is.

The upper portion 132b of the first semiconductor core 132 according to the embodiment may be controlled to have a different doping concentration from the conductive base layer 131. For example, the upper portion 132b of the first semiconductor core 132 may include an undoped u-GaN layer.

According to this configuration, even if the upper portion of the light emitting structure 130 collapses, the conductive portion of the first semiconductor core 132 and the second semiconductor layer 133 may not be electrically connected by the u-GaN layer. That is, the upper portion 132b of the first semiconductor core 132 may block the current leakage path. The height at which the upper portion 132b starts may be 1/5 to 1/2 of the second semiconductor layer 133.

24A to 24E are flowcharts illustrating a method of manufacturing a light emitting device according to another embodiment of the present invention.

The method of manufacturing a light emitting device according to the embodiment may include forming a first insulating layer 120 having a plurality of first holes W1 on the conductive base layer 131, and forming a first insulating layer 120 on the first hole W1. Growing a light emitting structure 130 including a first semiconductor core 132, an active layer 134, and a second semiconductor layer 133.

Referring to FIG. 24A, a conductive conductive base layer 131 is formed on the substrate 110. The substrate 110 may be formed of a material selected from sapphire (Al 2 O 3), SiC, GaAs, GaN, ZnO, Si, GaP, InP, and Ge, but is not limited thereto.

The conductive base layer 131 may have the same composition as the first semiconductor core 132, but is not limited thereto. The conductive base layer 131 may be doped with n-type dopants such as Si, Ge, Sn, Se, and Te, but is not limited thereto.

Referring to FIG. 24B, a first insulating layer 120 having a plurality of first holes W1 is formed on the conductive base layer 131. The first insulating layer 120 may be formed of various insulating materials such as SiO ₂ , Si ₃ N ₄ , Al ₂ O ₃ , ZrSiO ₄ , HfSiO ₄ , ZrO ₂ , HfO ₂ , La ₂ O ₃ , Ta ₂ O ₅ , and TiO ₂ . The first hole W1 may be manufactured to have a width of 0.5 μm or more and 3 μm or less, but is not limited thereto.

Referring to FIG. 24C, a plurality of light emitting structures 130 are grown on the first insulating layer 120. As the growth method of the light emitting structure 130, all conventional semiconductor growth methods may be applied. For example, all CVD processes such as MOCVD, HVPE, ALD, PECVD, LPCVD, and APCVD may be applied.

The first semiconductor core 132 may be grown on the surface of the conductive base layer 131. In this case, the first semiconductor core 132 may be grown in a nitrogen atmosphere so that the upper portion of the first semiconductor core 132 may have the first flat surface 132a. When grown in a hydrogen and nitrogen atmosphere it can be made of a pointed top structure, when grown in a nitrogen atmosphere it can be produced an epitaxial flat structure.

Thereafter, the active layer 134 and the second semiconductor layer 133 may be sequentially grown. The active layer 134 may grow along the outer surface of the first semiconductor core 132. Thus, the active layer has a second planar surface 134. When the second semiconductor layer 133 is grown, the end may be sharply controlled by growing in a hydrogen and nitrogen atmosphere.

Referring to FIG. 24D, a second insulating layer 141 may be formed on the light emitting structure 130 and the first insulating layer 120. The height of the second insulating layer 141 may be formed to 1/5 to 1/2 of the second semiconductor layer 133.

Referring to FIG. 24E, the conductive layer 160 covering the light emitting structure 130 may be formed, and the first electrode 171 and the second electrode 172 may be formed.

25 is a flowchart illustrating a method of manufacturing a light emitting device according to another embodiment of the present invention.

In the light emitting device manufacturing method according to the embodiment, the step of forming a first insulating layer 120 having a plurality of first holes on the conductive base layer 131, and the first semiconductor core 132 on the first hole In this regard, the above-described process may be applied as it is, including growing the light emitting structure 130 including the active layer 134 and the second semiconductor layer 133. Hereinafter, the characteristic part will be described.

Referring to FIG. 25B, the first semiconductor core 132 may be grown on the surface of the conductive base layer 131. In this case, the first semiconductor core 132 may be grown by blocking the doping element supply from the upper portion 132b. Thus, the upper portion 132b of the first semiconductor core 132 may include a u-GaN layer. However, trace amounts of doping elements may be doped depending on the growth conditions.

Thereafter, as shown in FIG. 25C, the active layer 134 and the second semiconductor layer 133 may be sequentially grown. The active layer 134 may grow along the outer surface of the first semiconductor core 132. According to this structure, even when the upper portion of the light emitting structure collapses, the first semiconductor core 132 and the second semiconductor layer 133 may not be electrically connected by the u-GaN layer. That is, the u-GaN layer may block the current leakage path.

The light emitting device according to the embodiment may further include an optical member such as a light guide plate, a prism sheet, and a diffusion sheet to function as a backlight unit. In addition, the light emitting device of the embodiment may be further applied to a display device, a lighting device, and a pointing device.

In this case, the display device may include a bottom cover, a reflector, a light emitting module, a light guide plate, an optical sheet, a display panel, an image signal output circuit, and a color filter. The bottom cover, the reflector, the light emitting module, the light guide plate, and the optical sheet may form a backlight unit.

The reflecting plate is disposed on the bottom cover, and the light emitting module emits light. The light guide plate is disposed in front of the reflective plate to guide light emitted from the light emitting module to the front, and the optical sheet includes a prism sheet or the like and is disposed in front of the light guide plate. The display panel is disposed in front of the optical sheet, the image signal output circuit supplies the image signal to the display panel, and the color filter is disposed in front of the display panel.

The lighting apparatus may include a light source module including a substrate and a light emitting device according to an embodiment, a heat dissipation unit for dissipating heat of the light source module, and a power supply unit for processing or converting an electrical signal provided from the outside and providing the light source module to the light source module. . Furthermore, the lighting device may include a lamp, a head lamp, a street lamp or the like.

The embodiments of the present invention described above are not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes can be made without departing from the technical spirit of the embodiments. It will be apparent to those skilled in the art.

Claims (20)

Conductive base layer; An insulating layer disposed on the base layer and including a plurality of first holes; A plurality of light emitting structures including a first semiconductor core electrically connected to the base layer through the first hole, an active layer disposed on the first semiconductor core, and a second semiconductor layer; An insulating particle layer including insulating particles filled between the plurality of light emitting structures; And A first conductive layer disposed on the insulating particle layer, The diameter of the insulating particles is smaller than the width of the first hole light emitting device. The method of claim 1, A light emitting device in which at least one of the plurality of first holes is filled with the insulating particles. The method of claim 1, The first hole has a width of 0.5㎛ 3㎛ less than. The method of claim 3, The insulating particles have a diameter of 150nm or more and 500nm or less. The method of claim 1, The insulating particle layer has a thickness of 400nm or more and 1000nm or less. The method of claim 1, The light emitting device of which the material of the insulating film and the material of the insulating particle are different. The method of claim 1, The insulating particle includes a first insulating particle having a first diameter and a second insulating particle having a second diameter, wherein the second diameter is larger than the first diameter. The method of claim 7, wherein The insulating particle layer includes a lower insulating particle layer including a first insulating particle, and an upper insulating particle layer including the second insulating particle. The method of claim 8, The first insulating particles are filled in at least one of the plurality of first holes. The method of claim 7, wherein The insulating particle layer is a light emitting device in which the first insulating particles and the second insulating particles are randomly dispersed. The method of claim 1, The light emitting device includes a surface treatment layer formed on the second semiconductor layer. The method of claim 1, The surface treatment layer has a hydrophobic surface. The method of claim 11, The surface treatment layer comprises a silane-based material. The method of claim 1, Light emitting device comprising a gap formed between the plurality of insulating particles. Conductive base layer; A first insulating layer disposed on the conductive base layer and including a plurality of first holes; And A plurality of light emitting structures including a first semiconductor core electrically connected to the conductive base layer through the first hole, an active layer disposed on the first semiconductor core, and a second semiconductor layer disposed on the active layer Including, The upper portion of the first semiconductor core has a first flat surface. The method of claim 15, The active layer includes a second planar surface disposed on the first planar surface. The method of claim 16, The upper portion of the second semiconductor layer is lighter than the upper portion of the first semiconductor core and the active layer. The method of claim 15, A light emitting device comprising a second insulating layer disposed on the side of the second semiconductor layer. The method of claim 18, The second insulating layer is a light emitting device disposed to 1/5 to 1/2 of the height of the second semiconductor layer. A backlight unit including a plurality of light emitting elements; And Including a display panel, The light emitting device, Conductive base layer; An insulating layer disposed on the base layer and including a plurality of first holes; A plurality of light emitting structures including a first semiconductor core electrically connected to the base layer through the first hole, an active layer disposed on the first semiconductor core, and a second semiconductor layer; An insulating particle layer including insulating particles filled between the plurality of light emitting structures; And A first conductive layer disposed on the insulating particle layer, The diameter of the insulating particles is smaller than the width of the first hole.

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