KR20120055332A - Light emitting device and light emitting device package - Google Patents

Abstract

PURPOSE: A light emitting device and a light emitting device package are provided to prevent light loss by forming a lateral reflection layer on one more surfaces among outer lateral surfaces of an electrode layer and a support substrate. CONSTITUTION: An electrode layer(114) is arranged on a support substrate. A light emitting structure is arranged on the electrode layer. The light emitting structure comprises first and second semiconductor layers(151,153) and an active layer(152). The active layer is formed between the first and second semiconductor layers. A lateral reflection layer(180) is formed on one or more surfaces among outer surfaces of the electrode layer and the support substrate.

Description

Light Emitting Device and Light Emitting Device Package

Embodiments relate to a light emitting device and a light emitting device package.

Fluorescent lamps are increasingly being replaced by other light sources because they are against the trend of the future lighting market aiming to be environmentally friendly due to frequent replacement and the use of fluorescent materials.

The most popular light source is LED (Light Emitting Diode), which has the advantages of fast processing speed and low power consumption of semiconductor, and it is considered as next generation light source because it is environmentally friendly and has high energy saving effect. Therefore, the use of LED to replace the existing fluorescent lamp is actively in progress.

Currently, semiconductor light emitting devices such as LEDs are applied to various devices including televisions, monitors, notebooks, mobile phones, and other display devices, and in particular, are widely used as backlight units in place of existing CCFLs.

Recently, high brightness is required to use a light emitting device as an illumination light source, and in order to achieve such high brightness, research is being conducted to manufacture a light emitting device capable of increasing light emission efficiency by uniformly spreading current.

The embodiment can provide a light emitting device capable of improving the stability and reliability of the light emitting device.

The light emitting device according to the embodiment includes a support substrate and an electrode layer disposed on the support substrate; And a light emitting structure disposed on the electrode layer, the light emitting structure including an active layer between the first and second semiconductor layers and the first and second semiconductor layers, wherein at least one surface of the support substrate and the outer surface of the electrode layer has light. It may include a side reflective layer capable of reflecting.

Here, the side reflection layer may be formed on the entire outer surface of the support substrate and the electrode layer.

In addition, the side reflection layer may be formed by stacking a plurality of layers.

The side reflecting layer may be formed by alternately stacking layers having different reflectances from each other.

The side reflection layer may have a thickness of about 10 nm to about 3 μm.

Since the side reflection layer is formed on at least one of the outer surface of the support substrate and the electrode layer, the light extraction efficiency of the light emitting device can be increased by preventing light loss at the side of the support substrate and the electrode layer, which is one of the disadvantages of the vertical light emitting device.

In addition, the side reflecting layer also serves as a protective layer of the support substrate and the electrode layer can protect the light emitting device from moisture, etc., and also has the advantage of improving the stability and reliability of the light emitting device.

1 is a cross-sectional view showing a light emitting device according to an embodiment.
2 is a cross-sectional view showing a light emitting device according to another embodiment.
3 to 7 are flowcharts illustrating a manufacturing process of the light emitting device of FIG.
8 is a cross-sectional view of a light emitting device package including a light emitting device according to the embodiment.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention, and the general knowledge in the art to which the present invention pertains. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims. Thus, in some embodiments, well known process steps, well known device structures, and well-known techniques are not specifically described to avoid an undesirable interpretation of the present invention. Like reference numerals refer to like elements throughout.

The terms spatially relative, "below", "beneath", "lower", "above", "upper" May be used to readily describe a device or a relationship of components to other devices or components. Spatially relative terms should be understood to include, in addition to the orientation shown in the drawings, terms that include different orientations of the device during use or operation. For example, when flipping a device shown in the figure, a device described as "below" or "beneath" of another device may be placed "above" of another device. Thus, the exemplary term "below" can include both downward and upward directions. The device can also be oriented in other directions, so that spatially relative terms can be interpreted according to orientation.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. As used herein, “comprises” and / or “comprising” refers to the presence of one or more other components, steps, operations and / or elements. Or does not exclude additions.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used in a sense that can be commonly understood by those skilled in the art. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size and area of each component does not necessarily reflect the actual size or area.

In addition, the angle and direction mentioned in the process of describing the structure of the light emitting device in the embodiment are based on those described in the drawings. In the description of the structure of the light emitting device in the specification, reference points and positional relationship with respect to angles are not explicitly referred to, refer to the related drawings.

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

Referring to FIG. 1, the light emitting device 100 according to the embodiment may include a support substrate 111, an electrode layer 114, a light emitting structure 150, and a side reflective layer 180.

The support substrate 111 may be formed using a material having excellent thermal conductivity and may be formed of a conductive material, and may be formed using a metal material or a conductive ceramic. The support substrate 111 may be formed of a single layer and may be formed of a dual structure or multiple structures.

In the embodiment, the support substrate 111 is described as having conductivity, but may not have conductivity, but is not limited thereto.

That is, the support substrate 111 may include gold (Au), nickel (Ni), tungsten (W), molybdenum (Mo), copper (Cu), aluminum (Al), tantalum (Ta), silver (Ag), and platinum ( It may be formed of any one selected from Pt) and chromium (Cr) or formed of two or more alloys, and may be formed by stacking two or more different materials. However, it is not limited thereto.

The support substrate 111 may facilitate the emission of heat generated from the light emitting device 100 to improve the thermal stability of the light emitting device 100.

In addition, the interlayer bonding layer 112 may be further included between the support substrate 111 and the electrode layer 114. The interlayer bonding layer 112 may increase the adhesion between the support substrate 111 and the electrode layer 114.

Among the materials having excellent adhesion used as the interlayer bonding layer 112, among indium (In), tin (Sn), silver (Ag), niobium (Nb), nickel (Ni), aluminum (Au), and copper (Cu) At least one is not limited thereto. In addition, the interlayer bonding layer 112 may be formed in a single layer or a multilayer structure.

A capping layer (not shown) may be formed on the interlayer bonding layer 112. The capping layer may serve to prevent a material forming the support substrate 111 and the interlayer bonding layer 112 from penetrating into the light emitting structure 150 through diffusion. The capping layer may be formed of a material having an anti-diffusion effect. For example, nickel (Ni), platinum (Pt), titanium (Ti), tungsten (W), Vanadium (V), Iron (Fe) It may be formed using at least one or two or more alloys of molybdenum (Mo). However, it is not limited thereto. The capping layer may be formed in a single layer or a multilayer structure. The electrode layer 114 is disposed on the support substrate 111.

The electrode layer 114 may include a conductive material. For example, nickel (Ni), platinum (Pt), ruthenium (Ru), iridium (Ir), rhodium (Rh), tantalum (Ta), and molybdenum (Mo) ), Titanium (Ti), silver (Ag), tungsten (W), copper (Cu), chromium (Cr), palladium (Pd), vanadium (V), cobalt (Co), niobium (Nb), zirconium (Zr) ), At least one of indium tin oxide (ITO), aluminum zinc oxide (AZO), and indium zinc oxide (IZO). However, it is not limited thereto.

In addition, the interlayer reflective layer 113 may be further included between the support substrate 111 and the electrode layer 114.

The interlayer reflective layer 113 reflects light toward the upper direction of the light emitting device 100 when a part of the light generated from the active layer 152 of the light emitting structure 150 is directed toward the support substrate 111. The light extraction efficiency of 100 can be improved.

Therefore, the interlayer reflective layer 113 is a material capable of reflecting light, for example, silver (Ag), nickel (Ni), aluminum (Al), rhodium (Rh), palladium (Pd), iridium (Ir). , Ruthenium (Ru), magnesium (Mg), zinc (Zn), platinum (Pt), gold (Au), hafnium (Hf) and may be formed of one or a plurality of layers of a material composed of two or more alloys thereof. In addition, the materials having different refractive indices may be formed in a multilayer structure, and may be formed of other materials in addition to the above materials, but are not limited thereto.

Although the interlayer reflective layer 113 and the electrode layer 114 are described as having the same width and length, at least one of the width and the length may be different and the present invention is not limited thereto.

The light emitting structure 150 may be in contact with the electrode layer 114, and may include a first semiconductor layer 151, an active layer 152, and a second semiconductor layer 153, and may include a first semiconductor layer 151 and a second semiconductor layer 153. The active layer 152 may be interposed between the semiconductor layers 153.

The first semiconductor layer 151 may be implemented as an n-type semiconductor layer, and the n-type semiconductor layer may be formed of any one of GaN-based compound semiconductors such as a GaN layer, an AlGaN layer, an InGAN layer, or the like, and the n-type dopant may be doped. Can be.

Meanwhile, the electrode pad 160 may be formed of nickel (Ni) on the first semiconductor layer 151, and the entire or partial region of the surface of the first semiconductor layer 151 on which the electrode pad 160 is not formed. Concave-convex 158 can be formed in the region to improve light extraction efficiency by a predetermined etching method.

Here, the electrode pad 160 is described as being formed on a flat surface on which the unevenness 158 is not formed, but may be formed on the upper surface on which the unevenness 158 is formed, but is not limited thereto.

An active layer 152 may be formed under the first semiconductor layer 151. The active layer 152 is an area where electrons and holes are recombined. The active layer 152 may transition to a low energy level as the electrons and holes recombine, and may generate light having a corresponding wavelength.

An active layer 152, e.g., including a semiconductor material having a compositional formula of _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1) It may be formed, and may be formed of a single quantum well structure or a multi quantum well structure (MQW).

Therefore, more electrons are collected at the lower energy level of the quantum well layer, and as a result, the probability of recombination of electrons and holes can be increased, thereby improving the light emitting effect. In addition, a quantum wire structure or a quantum dot structure may be included.

The second semiconductor layer 153 may be formed under the active layer 152. The second semiconductor layer 153 may be implemented as a p-type semiconductor layer to inject holes into the active layer 152. For example, the p-type semiconductor layer is a semiconductor material having a composition formula of In _x Al _y Ga _{1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1), for example GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, or the like, and may be doped with p-type dopants such as Mg, Zn, Ca, Sr, and Ba.

In addition, a third semiconductor layer (not shown) may be formed under the second semiconductor layer 153. The third semiconductor layer may be implemented as an n-type semiconductor layer.

The first semiconductor layer 151, the active layer 152, and the second semiconductor layer 153 may be formed of metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), and plasma. Plasma-Enhanced Chemical Vapor Deposition (PECVD), Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), Sputtering But it is not limited thereto.

In addition, unlike the above-described embodiments, the first semiconductor layer 151 may be implemented as a p-type semiconductor layer, and the second semiconductor layer 153 may be implemented as an n-type semiconductor layer.

In addition, the passivation 170 may be formed to protect a portion or the entire region of the outer circumferential surface of the light emitting structure 150 from external impact and to prevent electrical short.

Referring back to FIG. 1, the side reflective layer 180 may be formed on at least one of the outer surfaces of the support substrate 111 and the electrode layer 114. In other words, it may be formed on the outer surface of the support substrate 111 and the electrode layer 114 or the outer surface of the support substrate 111, the electrode layer 114, the interlayer reflective layer 113, and the interlayer bonding layer 112.

Here, the side reflective layer 180 may be formed on the entire outer surface of the support substrate 111 and the electrode layer 114. However, the present invention is not limited thereto, and the side reflective layer 180 may be formed on at least one of the outer surfaces.

Therefore, the light extraction efficiency of the light emitting device can be increased by preventing light loss on the side of the support substrate 111 and the electrode layer 114, which is one of the disadvantages of the vertical light emitting device, and the side reflective layer 180 is a support substrate ( 111 also serves as a protective layer of the electrode layer 114 can protect the light emitting device from moisture, etc., and can improve the stability and reliability of the light emitting device.

In addition, the length of the side reflective layer 180 is not limited, and may be formed in various ways in consideration of electrical short and reflectance with the light emitting structure 150, preferably from the support substrate 111 to the electrode layer 114 It can be formed equal to the length of.

The side reflective layer 180 may be made of any material that reflects light, but is preferably silver (Ag), aluminum (Al), rhodium (Rh), platinum (Pt), gold (Au), and two of them. It may be made of any one of the materials consisting of the above alloy.

The side reflective layer 180 may be formed as a single layer, or a plurality of layers may be stacked. It is not limited to this.

In addition, the thickness of the side reflection layer 180 is not limited, but may be preferably formed in 10nm to 3㎛. If the thickness of the side reflecting layer 180 is smaller than 10 nm, it does not reflect light and transmits light. If the thickness of the side reflecting layer 180 is larger than 3 μm, the efficiency is not good in terms of cost and weight of the light emitting device.

Although the side reflective layer 180 is illustrated in a straight line in FIG. 1, the side reflective layer 180 is not limited thereto, and may have a bending or curvature in consideration of the side shape of the support substrate 111 and the electrode layer 114 or the light efficiency of the light emitting device 100. May have

Meanwhile, the side reflective layer 180 may be formed by alternately stacking layers having different reflectances from each other. In other words, the first layer 181 having the first refractive index and the second layer 182 having the second refractive index may be formed. ) Can be formed by alternating lamination. Therefore, the layers having different refractive indices are stacked to induce total reflection of light to serve as a reflective layer.

Meanwhile, a side bonding layer (not shown) may be further included between the support substrate 111, the electrode layer 114, and the side reflective layer 180 to improve adhesion. The side bonding layer may be formed of a material having excellent adhesion, and may be formed of, for example, Ni (nickel), vanadium (V), Cr (chromium), Ti (titanium), or an oxide-based material. no.

2 is a cross-sectional view showing a light emitting device according to another embodiment. In another embodiment, the channel layer 215 may be further included on both sides of the outer circumference of the electrode layer 214 as compared with the above-described embodiment of FIG. 1. Hereinafter, the description of the same components will be omitted.

The channel layer 215 may be in contact with the outer circumferential side of the electrode layer 214 and disposed on the same line as the electrode layer 214. However, the present invention is not limited to being arranged on the same line.

The channel layer 215 prevents etching to the light emitting structure 150 when dry etching the electrode layer 214 formed by firing.

Here, the channel layer 215 may include at least one of a metal material and an insulating material. In the case of the metal material, the channel layer 215 may be formed of a material having a lower electrical conductivity than the material forming the electrode layer 114. The applied power may be prevented from being applied to the channel layer 215.

The channel layer 215 includes at least one of titanium (Ti), nickel (Ni), platinum (Pt), lead (Pb), rhodium (Rh), iridium (Ir), and tungsten (W), or At least one of aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), and titanium oxide (TiO _x ), or indium tin oxide (ITO), It may include at least one of aluminum zinc oxide (AZO) and indium zinc oxide (IZO).

In this case, the channel layer 215 may include a metal material or an insulating material to form a plurality of layers.

3 to 7 are flowcharts showing a manufacturing process of the light emitting device of the embodiment.

The light emitting device manufacturing method according to the embodiment is as follows.

Referring to FIG. 3, first, a light emitting structure 250 including a first semiconductor layer 251, an active layer 252, and a second semiconductor layer 253 is sequentially formed on a growth substrate 201.

The growth substrate 201 may be selected from the group consisting of sapphire substrate (Al ₂ 0 ₃ ), GaN, SiC, ZnO, Si, GaP, InP, GaAs, and the like. A buffer layer (not shown) may be formed between the light emitting structures 250.

The buffer layer (not shown) may have a form in which Group 3 and Group 5 elements are combined, or may be formed of any one of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN, and dopants may be doped.

An undoped semiconductor layer (not shown) may be formed on the growth substrate 201 or the buffer layer (not shown), and either or both of the buffer layer and the undoped semiconductor layer (not shown) may be formed. It may or may not be formed and is not limited to this structure.

Referring to FIG. 4, an electrode layer 214 may be formed on the second semiconductor layer 253, and a reflective layer 213 may be formed on the electrode layer 214.

Thereafter, a PR (Photo Resist) 290 having a predetermined pattern may be disposed on the electrode layer 214 or the reflective layer 213. In this case, the PR may be arranged in a predetermined pattern corresponding to the electrode shape in consideration of current diffusion and light extraction efficiency.

Thereafter, regions other than the region vertically overlapping with the region where the PR 290 is disposed among the electrode layer 214 and the reflective layer 213 are removed. In this case, the cross section to be removed may form a rectangle, and may have a curvature or a step. It does not limit to this. The removal method may be a wet etching, dry etching, or laser lift off method, but is not limited thereto.

Thereafter, the PR 290 may be removed.

Meanwhile, in the case of the light emitting device without the channel layer 215, the process of forming the PR 290 and the etching process may be omitted.

Referring to FIG. 5, a channel layer 215 may be formed in the etched region.

Thereafter, the support substrate 211 on which the reflective layer 213 and the channel layer 215 and the adhesive layer 212 are disposed is bonded and bonded, and at this time, the growth substrate 201 disposed on the first semiconductor layer 251 is separated. Can be.

In this case, the growth substrate 201 may be removed by physical or / and chemical methods, and the physical method may be removed by, for example, a laser lift off (LLO) method.

Referring to FIG. 6, the outer area of the light emitting structure 250 may be etched to have an inclination.

Referring to FIG. 7, a passivation 270 may be formed on a portion or the entire area of the outer circumferential surface of the light emitting structure 250.

The concave-convex 258 may be formed on a portion or the entire surface of the first semiconductor layer 251 of the light emitting structure 250 by a predetermined etching method, and an electrode pad may be formed on the surface of the first semiconductor layer 251. Form 260.

Here, the concave-convex 258 structure may not be formed, but is not limited to the structure shown in FIG. 7.

Thereafter, the side reflective layer 280 may be formed on at least one of the outer surfaces of the light emitting structure 250. The method of forming the side reflective layer 280 is not limited, but preferably, any one of an E-Beam process, a Sputter process, and an Electroplating process may be used.

In addition, at least one process in the process sequence illustrated in FIGS. 3 to 7 may be changed in order, without being limited thereto.

8 is a cross-sectional view of a light emitting device package including a light emitting device according to the embodiment. Referring to FIG. 8, the light emitting device package 300 is installed on the body 320, the first electrode layer 331 and the second electrode layer 332 installed on the body 320, and the body 320. The light emitting device 100 according to the embodiment electrically connected to the first electrode layer 331 and the second electrode layer 332, and a molding member 340 for sealing the light emitting device 100.

The body 320 may include 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 electrode layer 331 and the second electrode layer 332 are electrically separated from each other, and provide power to the light emitting device 100. In addition, the first electrode layer 331 and the second electrode layer 332 can increase the light efficiency by reflecting the light generated from the light emitting device 100, and discharges heat generated from the light emitting device 100 to the outside It can also play a role.

The light emitting device 100 may be installed on the body 320 or on the first electrode layer 331 or the second electrode layer 332.

The light emitting device 100 may be electrically connected to the first electrode layer 331 and the second electrode layer 332 by any one of a wire method, a flip chip method, or a die bonding method.

The molding member 340 may seal and protect the light emitting device 100. In addition, the molding member 340 may include a phosphor to change the wavelength of the light emitted from the light emitting device 100.

The light emitting device package 300 may be mounted as at least one or a plurality of light emitting devices of the above-described embodiments, but is not limited thereto.

The light emitting device package 300 may be easily manufactured and may prevent peeling and detachment of the electrode layer, the channel layer, and other layers.

In addition, the above description has been made with reference to the embodiment, which is merely an example, and is not intended to limit the present invention. Those skilled in the art to which the present invention pertains will be illustrated as above without departing from the essential characteristics of the present embodiment. It will be appreciated that various modifications and applications are possible. For example, each component specifically shown in the embodiment can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

100: light emitting element 111: support substrate
112: interlayer bonding layer 113: interlayer reflective layer
114: electrode layer 115: channel layer
151: first semiconductor layer 152: active layer
153: second semiconductor layer 160: electrode pad
170: passivation 180: side reflective layer

Claims (15)

A support substrate and an electrode layer disposed on the support substrate; And
A light emitting structure disposed on the electrode layer, the light emitting structure including an active layer between the first and second semiconductor layers and the first and second semiconductor layers;
At least one surface of the support substrate and the outer surface of the electrode layer includes a light emitting element that can reflect light. The method of claim 1,
The side reflective layer is formed on the entire surface of the outer surface of the support substrate and the electrode layer. The method of claim 1,
The side reflection layer is a light emitting device formed by stacking a plurality of layers. The method of claim 1,
The side reflection layer is a light emitting device formed by alternately stacking layers having different reflectances from each other. The method of claim 1,
The thickness of the side reflection layer is a light emitting device of 10nm to 3㎛. The method of claim 1,
The side reflective layer is made of any one of silver (Ag), aluminum (Al), rhodium (Rh), platinum (Pt), gold (Au), and a material composed of two or more alloys thereof. The method of claim 1,
And a side bonding layer further improving adhesion between the support substrate and the electrode layer and the side reflection layer. The method of claim 7, wherein
The side bonding layer is made of any one of materials consisting of Ni (nickel), vanadium (V), Cr (chromium), Ti (titanium) and two or more alloys thereof. The method of claim 1,
The side reflection layer is a light emitting device having a bend or curvature. The method of claim 1,
Light emitting device further comprises an interlayer reflective layer between the support substrate and the electrode layer. The method of claim 1,
The light emitting device further comprises an interlayer bonding layer between the support substrate and the electrode layer. The method of claim 1,
Light emitting device further comprises a channel layer in contact with the electrode layer on both sides of the outer peripheral portion of the electrode layer. The method of claim 1,
The light emitting device further comprises a capping layer between the support substrate and the electrode layer. The method of claim 1,
The light emitting device is formed on the first semiconductor layer irregularities to improve the light extraction efficiency. A light emitting device package comprising the light emitting device of any one of claims 1 to 12.

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