KR20120139198A - Lihgt emitting device and light emitting device package including the same - Google Patents

Abstract

PURPOSE: A light emitting device and a light extracting unit including the same are provided to improve the luminous efficiency of light inputted to a light guide plate by selectively forming an uneven part on the surface of a light emitting structure to widen an emission angle of light emitted from an active layer. CONSTITUTION: A junction layer(150), a reflective layer(140), and an ohmic layer(130) are formed on a support substrate(160). A light emitting structure(120) is formed on the ohmic layer. The light emitting structure includes a first conductive semiconductor layer(122), an active layer(124), and a second conductive semiconductor layer(126). An uneven part is formed on the surface of the light emitting structure. A passivation layer(170) is formed on the side of the light emitting structure.

Description

Light emitting device and light emitting device package including the same {Lihgt emitting device and light emitting device package including the same}

The embodiment provides a light emitting device and a light emitting device package including the same.

Light emitting devices such as light emitting diodes or laser diodes using semiconductors of Group 3-5 or 2-6 compound semiconductor materials of semiconductors have various colors such as red, green, blue, and ultraviolet rays due to the development of thin film growth technology and device materials. It is possible to realize efficient white light by using fluorescent materials or combining colors, and it has low power consumption, semi-permanent life, fast response speed, safety and environmental friendliness compared to conventional light sources such as fluorescent and incandescent lamps. Has an advantage.

Therefore, a transmission module of the optical communication means, a light emitting diode backlight replacing a cold cathode fluorescent lamp (CCFL) constituting a backlight of an LCD (Liquid Crystal Display) display device, a white light emitting element capable of replacing a fluorescent lamp or an incandescent lamp Diode lighting, automotive headlights, and traffic lights.

The embodiment provides a light emitting device and a light emitting device package with improved light efficiency.

An embodiment includes a light emitting structure including a first conductive semiconductor layer, an active layer on the first conductive semiconductor layer, and a second conductive semiconductor layer on the active layer; A first electrode on the first conductive semiconductor layer; And a second electrode on the second conductivity type semiconductor layer, wherein a surface of the light emitting structure includes a first region and an edge second region and a third region between the first region and the second region. And a light extracting portion formed on surfaces of the light emitting structure in the first region and the second region, and the third region provides a light emitting element in which the light block portion is formed.

The third region may form a closed curved surface around the first region.

Surfaces of the light emitting structure in the first region and the second region may form irregularities.

The unevenness may include unevenness having a depth of 0.8 to 1.2 micrometers.

The irregularities may include irregularities having a period of 0.8 to 1.2 micrometers.

The cross section of the first region may be a polygon having a side length of 16 to 20 micrometers.

The width of the second region may be 8 to 12 micrometers.

The width of the third region may be 8 to 12 micrometers.

The first region and the second region may be spaced apart from 8 to 12 micrometers.

Light emitted from the active layer may travel to the first, second, and third regions, and at least some of the light may be totally reflected in the third region.

Momentum of the light transmitted from the active layer in the first and second regions and the light propagated through the total reflection on the surface of the third region may be different.

Another embodiment includes a light emitting structure including a first conductive semiconductor layer, an active layer on the first conductive semiconductor layer, and a second conductive semiconductor layer on the active layer; A first electrode on the first conductive semiconductor layer; And a second electrode on the second conductivity type semiconductor layer, wherein the light emitting structure has a first region in the center and a second region of the edge and a third region between the first region and the second region. And the surface of the light emitting structure is formed in the first region and the second region, and the third region provides a flat light emitting device.

Light emitted from the active layer may travel to the first, second, and third regions, and at least some of the light may be totally reflected in the third region.

Momentum of light transmitted from the first and second regions from the active layer and totally reflected on the surface of the third region may be different.

Yet another embodiment provides a light emitting device package including the light emitting device according to the above embodiments.

The light emitting device and the light emitting device package according to the embodiment improve light efficiency.

1 is a view showing an embodiment of a light emitting device,
2 is a view showing an embodiment of a light emitting device package,
3A and 3B are enlarged views and a plan view of an embodiment of portion 'A' of FIG. 1,
4A and 4B are enlarged views and plan views of another embodiment of portion 'A' of FIG. 1,
4C and 4D are enlarged views and plan views of still another embodiment of portion 'A' of FIG. 1,
4E is an enlarged view of a portion 'U' of FIG. 4D.
4F and 4G are enlarged views and top views of still another embodiment of portion 'A' of FIG. 1,
4H is a view illustrating patterning light emitting structures having different patterns on one wafer;
5a to 5c are diagrams showing the light efficiency of the light emitting device according to the embodiment;
6 is a view schematically showing a light emitting device of Comparative Example 1,
7a to 7c are diagrams showing the light efficiency of the light emitting device of FIG.
8 is a view schematically showing a light emitting device of Comparative Example 2,
9A to 9C are diagrams showing the light efficiency of the light emitting device of FIG.
10 to 17 is a view showing an embodiment of the manufacturing method of the light emitting device of FIG.
18 to 20 are views showing a manufacturing method of another embodiment of the light emitting device package,
21 is an exploded perspective view of an embodiment of a lighting device package a light emitting device,
22 is a diagram illustrating a display device including a light emitting device package.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

In the description of the embodiment according to the present invention, when described as being formed on the "on or under" of each element, the (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. Also, when expressed as "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. In addition, the size of each component does not necessarily reflect the actual size.

1 is a view showing an embodiment of a light emitting device.

The light emitting device 100 according to the embodiment includes a bonding layer 150, a reflective layer 140, an ohmic layer 130, and a light emitting structure 120 on a conductive support substrate (metal support) 160.

Since the conductive support substrate 160 may serve as a second electrode, a metal having excellent electrical conductivity may be used, and a metal having high thermal conductivity may be used because it must be able to sufficiently dissipate heat generated when the light emitting device is operated.

The conductive support substrate 160 may be made of a material selected from the group consisting of molybdenum (Mo), silicon (Si), tungsten (W), copper (Cu), and aluminum (Al) or an alloy thereof. , Gold (Au), copper alloy (Cu Alloy), nickel (Ni), copper-tungsten (Cu-W), carrier wafers (e.g. GaN, Si, Ge, GaAs, ZnO, SiGe, SiC, SiGe, Ga ₂ O _3, etc.) may be optionally included.

In addition, the conductive support substrate 160 may have a mechanical strength enough to be separated into a separate chip through a scribing process and a breaking process without bringing warpage to the entire nitride semiconductor. have.

The bonding layer 150 may combine the reflective layer 140 and the conductive support substrate 160, and the reflective layer 140 may function as an adhesion layer. The bonding layer (150) is composed of gold (Au), tin (Sn), indium (In), aluminum (Al), silicon (Si), silver (Ag), nickel (Ni) and copper (Cu) It may be formed of a material selected from or alloys thereof.

The reflective layer 140 may be about 2500 angstroms thick. The reflective layer 140 may be formed of a metal layer including aluminum (Al), silver (Ag), nickel (Ni), platinum (Pt), rhodium (Rh), or an alloy containing Al, Ag, Pt, or Rh. have. Aluminum or silver may effectively reflect light generated from the active layer 124 to greatly improve the light extraction efficiency of the light emitting device.

Since the light emitting structure 120, in particular, the second conductive semiconductor layer 126 has a low impurity doping concentration and a high contact resistance, and thus may not have good ohmic characteristics, the ohmic layer 130 may be improved. Transparent electrodes and the like can be formed.

The ohmic layer 130 may be about 200 angstroms thick. The ohmic layer 130 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), and indium gallium tin (IGTO). oxide), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IZO (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, Sn, In, Ru, Mg, Zn, Pt At least one of Au, Hf, and the like may be formed, and the material is not limited thereto.

The light emitting structure 120 is formed on the first conductivity type semiconductor layer 122 and the first conductivity type semiconductor layer 122 and the active layer 124 for emitting light and the second layer formed on the active layer 124. And a conductive semiconductor layer 126.

The first conductivity type semiconductor layer 122 may be implemented as a group III-V compound semiconductor doped with a first conductivity type dopant, and when the first conductivity type semiconductor layer 122 is an N-type semiconductor layer, The first conductive dopant may be an N-type dopant and may include Si, Ge, Sn, Se, or Te, but is not limited thereto.

The first conductive semiconductor layer 122 may be formed of a semiconductor material having a composition formula of Al _x In _y Ga _(1-xy) N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1). It may include. The first conductive semiconductor layer 122 may be formed of any one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, InP.

In addition, irregularities may be formed on the surface of the light emitting structure 120, that is, the surface of the first conductivity-type semiconductor layer 122.

3A and 3B are enlarged views and plan views of an embodiment of portion 'A' of FIG. 1. Hereinafter, the shape of the surface of the light emitting structure 120 will be described in detail with reference to FIGS. 3A and 3B.

The surface of the light emitting structure 120 has a first region (a) in the center and a second region (b) at the edge and a third region (c) between the first region (a) and the second region (b). The light extracting portion may be formed on the surface of the light emitting structure 120 in the first region a and the second region b, and the light blocking portion may be formed in the third region c.

That is, in the first region a and the second region b, the surface of the light emitting structure 120 has irregularities, and the third region c may have a flat surface. Can be.

Light emitted from the active layer 124 proceeds to the first region a, the second region b, and the third region c in the direction of the first conductivity type semiconductor layer 122. In addition, the light traveling to the first area a and the second area b may travel to the outside of the light emitting structure 120. At least a part of the light traveling to the third area c is totally reflected. .

That is, when the light proceeds from the optically dense medium to the small medium, the light incident at an incident angle greater than a certain critical angle may be reflected 100 percent (%) without refracting. The flat shape of the surface of the third region (c) Due to this, total reflection may occur.

In this case, total reflection does not occur in the whole of the third region (c), but total reflection may occur in at least a portion of the region. Accordingly, the first region a and the second region b may serve as light extracting portions, and the third region c may act as light blocking portions.

3B, the third region c may form a closed curved surface around the first region a, and the second region b may correspond to the third region c. A closed surface can be achieved at the perimeter.

In addition, although the irregularities are regularly illustrated in FIGS. 3A and 3B, they may be irregular. In FIG. 3A, the unevenness may include unevenness having a depth h of 0.8 to 1.2 micrometers, wherein the depth h is the height of the highest and lowest points of the unevenness of the surface of the light emitting structure 120. Is the difference.

The irregularities may include irregularities having a period of 0.8 to 1.2 micrometers, wherein the period is a distance from the highest point to the next highest point or the lowest point to the next lowest point of the irregularities on the surface of the light emitting structure 120. .

3B, the cross section of the first region a may have a length W _a of 16 to 20 micrometers. In addition, in FIG. 3B, the first region a has a rectangular shape, and may be a polygon or a circle having sides of the size described above.

In addition, in FIG. 3B, the width W _c of the second region b may be 8 to 12 micrometers. The width W _c of the second region b is the shortest distance from the edge of the third region c to the edge of the light emitting structure 120.

The width W _c of the third region c may be 8 to 12 micrometers, and the width W _c of the third region _c may be the first region a and the second region b. ) May be the shortest separation distance.

The active layer 124 has an energy band inherent in the active layer (light emitting layer) material because electrons injected through the first conductive semiconductor layer 122 and holes injected through the second conductive semiconductor layer 126 formed thereafter meet each other. It is a layer that emits light with energy determined by.

The active layer 124 may be formed of at least one of a single quantum well structure, a multi quantum well structure (MQW), a quantum-wire structure, or a quantum dot structure. For example, the active layer 120 may be injected with trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and trimethyl indium gas (TMIn) to form a multi-quantum well structure. It is not limited to this.

The well layer / barrier layer of the active layer 124 is formed of one or more pair structures of InGaN / GaN, InGaN / InGaN, GaN / AlGaN, InAlGaN / GaN, GaAs (InGaAs) / AlGaAs, GaP (InGaP) / AlGaP. But it is not limited thereto. The well layer may be formed of a material having a lower band gap than the band gap of the barrier layer.

A conductive cladding layer (not shown) may be formed on or under the active layer 124. The conductive clad layer may be formed of an AlGaN-based semiconductor, and may have a higher band gap than the band gap of the active layer 124.

The second conductive type semiconductor layer 126 is a second conductive type dopant is doped III-V compound semiconductor, for example _{-5, In x Al y Ga 1 -x-} y N (0≤x≤1, 0≤y≤ And 1, 0 ≦ x + y ≦ 1). When the second conductive semiconductor layer 124 is a P-type semiconductor layer, the second conductive dopant may include Mg, Zn, Ca, Sr, Ba, or the like as a P-type dopant.

Although not shown, a first electrode may be formed on the first conductivity type semiconductor layer 122. The first electrode may be formed in a single layer or a multilayer structure including at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu), and gold (Au).

In addition, a passivation layer 170 may be formed on a side surface of the light emitting structure 120.

The passivation layer 170 may be made of an insulating material, and the insulating material may be made of an oxide or nitride which is non-conductive. As an example, the passivation layer 170 may be formed of a silicon oxide (SiO ₂ ) layer, an oxynitride layer, and an aluminum oxide layer.

In the present exemplary embodiment, the first conductive semiconductor layer 122 may be a P-type semiconductor layer, and the second conductive semiconductor layer 126 may be an N-type semiconductor layer. In addition, an N-type semiconductor layer (not shown) may be formed on the second conductive semiconductor layer 126 when the semiconductor having a polarity opposite to that of the second conductive type, for example, the second conductive semiconductor layer is a P-type semiconductor layer. have. Accordingly, the light emitting structure may be implemented as 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.

2 is a view showing an embodiment of a light emitting device package.

The light emitting device package 200 according to the embodiment may be installed in the package body 210, the first electrode layer 221 and the second electrode layer 222 installed on the package body 210, and the package body 210. The light emitting device 100 according to the embodiment is electrically connected to the first electrode layer 221 and the second electrode layer 222, and a resin layer 230 covering the surface or the side surface of the light emitting device 100. .

The package body 210 may be formed of a silicon material, a synthetic resin material, or a metal material. An inclined surface may be formed around the light emitting device 100 to increase light extraction efficiency.

The first electrode layer 221 and the second electrode layer 222 are electrically separated from each other, and provide power to the light emitting device 100. In addition, the first electrode layer 221 and the second electrode layer 222 may increase the light efficiency by reflecting the light generated from the light emitting device 100, the outside of the heat generated from the light emitting device 100 May also act as a drain.

The light emitting device 100 may be installed on the package body 210 or on the first electrode layer 221 or the second electrode layer 222. The light emitting device 100 may be electrically connected to the first electrode layer 221 and the second electrode layer 222 by any one of a wire method, a flip chip method, or a die bonding method.

The resin layer 230 may surround and protect the light emitting device 100. In addition, the resin layer 230 may include a phosphor 240 to change the wavelength of light emitted from the light emitting device 100.

The light emitting device package may mount at least one of the light emitting devices of the above-described embodiments as one or more, but is not limited thereto.

4A and 4B are enlarged views and plan views of another embodiment of part 'A' of FIG. 1. Hereinafter, the shape of the surface of the light emitting structure 120 will be described in detail with reference to FIGS. 4A and 4B.

In the surface of the light emitting structure 120, the second region b and the third region c are repeated twice. That is, the light extraction portion may be formed on the surface of the light emitting structure 120 in the second region b, and the light block portion may be formed on the third region c.

That is, in the second region b, the surface of the light emitting structure 120 may have irregularities, and the third region c may have a flat surface.

In addition, the light emitted from the active layer 124 proceeds to the second region b and the third region c in the direction of the first conductivity-type semiconductor layer 122. In addition, the light propagated to the second region b may travel to the outside of the light emitting structure 120, and at least a part of the light propagated to the third region c is totally reflected.

That is, when the light proceeds from the optically dense medium to the small medium, the light incident at an incident angle greater than a certain critical angle may be reflected 100 percent (%) without refracting. The flat shape of the surface of the third region (c) Due to this, total reflection may occur.

In this case, total reflection does not occur in the whole of the third region (c), but total reflection may occur in at least a portion of the region. Therefore, the second region (b) may act as a light extraction portion, and the third region (c) may act as an optical block portion.

As shown in FIG. 4B, the surface structure of FIG. 4A is repeated a plurality of times on the surface of the light emitting device. When the surface structure of the light emitting structure shown in FIG. 4A, that is, the structure in which the second region and the third region are repeated twice each in the horizontal and vertical directions, is referred to as the surface pattern unit U, the light emitting element illustrated in FIG. The surface pattern unit U may be repeated on the surface 50 times in the horizontal and vertical directions, respectively.

In FIG. 4A and FIG. 4B, the irregularities are shown regularly, but may be irregular. In FIG. 4A, the unevenness may include unevenness having a depth (h) of 0.8 to 1.2 micrometers, wherein the depth (h) is the height of the highest and lowest points of the unevenness of the surface of the light emitting structure 120. Is the difference.

The irregularities may include irregularities having a period of 0.8 to 1.2 micrometers, wherein the period is a distance from the highest point to the next highest point or the lowest point to the next lowest point of the irregularities on the surface of the light emitting structure 120. .

In addition, in FIG. 4B, the width W _c of the second region b may be 8 to 12 micrometers, and the width W _c of the third region c may be 8 to 12 micrometers. .

4C and 4D are enlarged views and plan views of still another embodiment of portion 'A' of FIG. 1. Hereinafter, the shape of the surface of the light emitting structure 120 will be described in detail with reference to FIGS. 4C and 4D.

In the present exemplary embodiment, the surface of the light emitting structure 120 is repeated with the first region a, the second region b, and the third region c. Specifically, the third region c is repeated twice in the center, and a pair of the first regions a is disposed outside the central third region c, and the respective first regions a are disposed. The third region c and the second region b are disposed outside the perimeter.

The first region a and the second region b have irregularities formed on the surface of the light emitting structure 120 to form a light extracting portion, and the third region c has a flat surface of the light emitting structure 120. The optical block may be formed in the same manner as in the above-described embodiment. In addition, the width of the first region a is 16 to 20 micrometers, and the width of the second region b and the third region c is 8 to 12 micrometers.

The overall structure of the light emitting element surface is shown in FIG. 4D. In the present embodiment, ten surface pattern units U are arranged on the surface of the light emitting element, respectively, horizontally and vertically.

Each surface pattern unit U has a circular structure as a whole. That is, with reference to FIGS. 4C and 4E, a third region c is disposed in the center, a first region a is disposed around the third region c, and the first region a. The third region c and the second region b are arranged in turn around. Therefore, the surface of the surface pattern unit U as a whole has a concentric circle structure.

Although the irregularities are shown regularly in FIG. 4C, they may be irregular. In FIG. 4C, the unevenness may include unevenness having a depth h of 0.8 to 1.2 micrometers, and the unevenness may include unevenness having a period of 0.8 to 1.2 micrometers.

4F and 4G are enlarged views and plan views of still another embodiment of portion 'A' of FIG. 1. Hereinafter, the shape of the surface of the light emitting structure 120 will be described in detail with reference to FIGS. 4F and 4G.

This embodiment is similar to the embodiment shown in FIGS. 3A and 3B, but the widths of the first region a, the second region b, and the third region c are the same.

As shown in FIG. 4G, the third region c may form a closed curved surface around the first region a, and the second region b may correspond to the third region c. At the circumference of the closed surface.

In addition, 100 surface pattern units U are disposed in the horizontal and vertical directions on the surface of the light emitting structure 120, respectively.

4H is a view illustrating patterning light emitting structures having different patterns on one wafer.

As shown, in one quarter, the surface is randomly patterned without using a mask in one quarter, and in the second quarter, light is emitted in the same shape as the surface pattern unit shown in FIGS. 4A and 4B. The surface of the structure is patterned, the surface of the light emitting structure is patterned in the same shape as the surface pattern unit shown in FIGS. 4C to 4E in the 3/4 quadrant, and FIGS. 3A and 3B or 4F in FIG. The surface of the light emitting structure can be patterned using a mask in the same shape as the surface pattern unit according to the embodiment shown in 4g. That is, the surface of the light emitting structure may be patterned differently by using different masks for each region in one wafer.

5A to 5C illustrate light efficiency of the light emitting device according to the embodiment. As shown, it can be seen that light is strongly emitted to the outside of the light emitting structure not only in the region corresponding to the light extraction unit but also in the region corresponding to the light blocking unit.

That is, by forming a random texture on the surface of the first conductive semiconductor layer of the light emitting structure, the light extraction efficiency may be improved by narrowing the total internal reflection (TIR) angle in the light emitting structure made of GaN.

6 is a view schematically showing the light emitting device of Comparative Example 1, and FIGS. 7A to 7C are diagrams showing the light efficiency of the light emitting device of FIG.

Comparative Example 1 shows a structure in which no irregularities are formed on the surface of the light emitting structure. In Comparative Example 1, the total reflection of light emitted from the active layer due to the flat surface of the light emitting structure is increased compared to the embodiment, and thus the amount of light emitted to the outside of the light emitting structure is relatively small as shown.

8 is a view schematically showing the light emitting device of Comparative Example 2, and FIGS. 9A to 9C are diagrams showing the light efficiency of the light emitting device of FIG.

In Comparative Example 2, irregularities are formed on the entire surface of the light emitting structure. This structure has an increased light output efficiency compared to Comparative Example 1, but the light output efficiency is reduced compared to the embodiment.

That is, if the irregularities are formed on the entire surface of the light emitting structure, the total reflection at the surface may be reduced, but the pattern of light passing through the surface of the light emitting structure is changed narrowly while passing through the uneven structure, and thus, the phosphors of the light emitting device package may be changed. The ratio of the part involved in the wavelength conversion of the light passing through the surface of the light emitting structure is relatively reduced, and the individual light conversion efficiency reduction of the phosphor may lead to a decrease in the light efficiency of the entire light emitting device package.

In an exemplary embodiment, irregularities may be selectively formed on the surface of the light emitting structure, and the momentum of the light transmitted through the total reflection on the surface of the third region may be different from the light transmitted from the active layer in the first and second regions where the irregularities are formed. have.

In this case, when the light totally reflected in the third region passes through the first and second regions, the light may receive momentum due to total reflection, and at a larger angle when passing through the uneven structure of the first and second regions. Can spread. In addition, since the amount of light attenuated in the third region without the uneven structure is reduced in the embodiment, the light amount of the entire light emitting device to the light emitting device package is increased.

10 to 17 are diagrams illustrating one embodiment of a method of manufacturing the light emitting device of FIG. 1.

As shown in FIG. 10, a light emitting structure including a buffer layer (not shown), a first conductivity type semiconductor layer 122, an active layer 124, and a second conductivity type semiconductor layer 126 on the substrate 110. 126).

The light emitting structure 126 may include, for example, a metal organic chemical vapor deposition (MOCVD), a chemical vapor deposition (CVD), a plasma chemical vapor deposition (PECVD), a molecular beam. Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), etc. may be formed using, but is not limited thereto.

The substrate 110 may include a conductive substrate or an insulating substrate. For example, at least one of sapphire (Al ₂ O ₃ ), SiC, GaAs, GaN, ZnO, Si, GaP, InP, Ge, and Ga ₂ 0 ₃ may be used. Can be. An uneven structure may be formed on the substrate 110, but is not limited thereto. Impurities on the surface may be removed by wet cleaning the substrate 110.

A buffer layer (not shown) may be grown between the light emitting structure and the substrate 110 to alleviate the difference in lattice mismatch and thermal expansion coefficient of the material. The material of the buffer layer may be formed of at least one of Group III-V compound semiconductors such as GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN. An undoped semiconductor layer may be formed on the buffer layer, but the present invention is not limited thereto.

The light emitting structure may be grown by vapor deposition such as metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), and hydraulic vapor phase epitaxy (HVPE).

The composition of the first conductive semiconductor layer 122 is the same as described above, and using N, using a chemical vapor deposition method (CVD), molecular beam epitaxy (MBE) or sputtering or hydroxide vapor phase epitaxy (HVPE), etc. A type GaN layer can be formed. In addition, the first conductive semiconductor layer 110 may include a silane including n-type impurities such as trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and silicon (Si) in the chamber. The gas SiH ₄ may be injected and formed.

The active layer 124 has the same composition as described above. For example, the trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and trimethyl indium gas (TMIn) are injected to form A quantum well structure may be formed, but is not limited thereto.

The second conductivity-type semiconductor layer 126 has the same composition as described above, and in the chamber, p such as trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and magnesium (Mg) Bicetyl cyclopentadienyl magnesium (EtCp ₂ Mg) {Mg (C ₂ H ₅ C ₅ H ₄ ) ₂ } containing a type impurity may be implanted to form a p-type GaN layer, but is not limited thereto.

Subsequently, as shown in FIG. 11, an ohmic layer 130 and a reflective layer 140 may be formed on the light emitting structure 120. The composition of the ohmic layer 130 and the reflective layer 140 is as described above, and may be formed by sputtering or electron beam deposition.

12, the bonding layer 150 and the conductive support substrate 160 may be formed on the reflective layer 140. The conductive support substrate 170 may be formed using an electrochemical metal deposition method, a bonding method using an etchant metal, or a separate bonding layer 150.

Then, the substrate 110 is separated as shown in FIG. 13. The substrate 110 may be removed by a laser lift off (LLO) method using an excimer laser or the like, or may be a method of dry and wet etching.

For example, when the laser lift-off method focuses and irradiates excimer laser light having a predetermined wavelength in the direction of the substrate 110, heat energy is applied to the interface between the substrate 110 and the light emitting structure 120. As the interface is concentrated and separated into gallium and nitrogen molecules, separation of the substrate 110 occurs at a portion where the laser light passes.

14 or 15, the surface of the light emitting structure 120, that is, the surface of the first conductive semiconductor layer 122 is selectively etched. In this case, the mask 300 may be etched on the surface of the light emitting structure 120, and the wet etching may be performed using the dry etching as shown in FIG. 14 or the etching solution 350 as shown in FIG. 15.

In FIG. 16, an optional concave-convex shape is formed on the surface of the light emitting structure after the etching process is completed.

17, a passivation layer 100 is deposited on a side surface of the light emitting structure 120, and a first electrode (not shown) is formed on the surface of the light emitting structure 120. 100 is completed.

18 to 20 illustrate a method of manufacturing another embodiment of a light emitting device package.

First, as shown in FIG. 18, the cavity and the first and second electrode layers 221 and 222 are formed in the package body 210. The cavity may be formed by selectively etching the package body 210 using a mask (not shown) or by an anisotropic wet etching method using a bulk micro machining process.

In addition, copper (Cu) may be used to form the first electrode layer 221 and the second electrode layer 222 electrically separated from each other on the surface of the package body 210. In this case, although not shown, an insulating film may be first formed on the surface of the package body 210 to insulate the first and second electrode layers 221.

19, the light emitting device 100 is mounted on the package body 210, and the light emitting device 100 is connected to at least one of the first and second electrode layers 221 and 222 and the wire 180. Bonding is possible.

As shown in FIG. 20, the resin layer 230 including the phosphor 240 is filled in the cavity to surround the light emitting device 100. In addition, the light emission angle may be adjusted by forming the lens 250 on the resin layer 230.

A plurality of light emitting device packages may be arranged on a substrate, and a light guide plate, a prism sheet, a diffusion sheet, or the like, which is an optical member, may be disposed on an optical path of the light emitting device package. Such a light emitting device package, a substrate, and an optical member can function as a light unit. Another embodiment may be implemented as a display device, an indicator device, or a lighting system including the semiconductor light emitting device or the light emitting device package described in the above embodiments, and for example, the lighting system may include a lamp or a street lamp. Hereinafter, an illumination device and a backlight unit will be described as an embodiment of a lighting system in which the above-described light emitting device package is disposed.

21 is an exploded perspective view of an embodiment of a lighting device including a light emitting device package.

The lighting apparatus according to the embodiment includes a light source 600 for projecting light, a housing 400 in which the light source 600 is embedded, a heat dissipation part 500 for dissipating heat from the light source 600, and the light source 600. And a holder 700 for coupling the heat dissipation part 500 to the housing 400.

The housing 400 includes a socket coupling part 410 coupled to an electric socket and a body part 420 connected to the socket coupling part 410 and having a light source 600 embedded therein. One air flow port 430 may be formed in the body portion 420.

A plurality of air flow port 430 is provided on the body portion 420 of the housing 400, wherein the air flow port 430 is composed of one air flow port, or a plurality of flow ports as shown in the radial arrangement Various other arrangements are also possible.

The light source 600 includes a plurality of light emitting device packages 650 on the circuit board 610. Here, the circuit board 610 may be inserted into the opening of the housing 400, and may be made of a material having a high thermal conductivity to transmit heat to the heat dissipating unit 500, as described later.

A holder 700 is provided below the light source, and the holder 700 may include a frame and another air flow port. In addition, although not shown, an optical member may be provided under the light source 100 to diffuse, scatter, or converge light projected from the light emitting device package 150 of the light source 100.

In the above-described lighting device, irregularities are selectively formed on the surface of the light emitting structure in the light emitting device package, thereby increasing light emission angle of the light emitted from the active layer and reducing the amount of light reduction, thereby increasing light efficiency.

22 illustrates a backlight including a light emitting device package.

As shown, the display device 800 according to the present exemplary embodiment is disposed in front of the light source modules 830 and 835, the reflector 820 on the bottom cover 820, and the reflector 820. The light guide plate 840 for guiding light emitted from the front of the display device, the first prism sheet 850 and the second prism sheet 860 disposed in front of the light guide plate 840, and the second prism sheet ( And a color filter 880 disposed in front of the panel 870 disposed in front of the panel 870.

The light source module includes a light emitting device package 835 on the circuit board 830. Here, the PCB 830 may be used as the circuit board 830, and the light emitting device package 835 is as described with reference to FIG. 13.

The bottom cover 810 may accommodate components in the display device 800. The reflective plate 820 may be provided as a separate component as shown in the drawing, or may be disposed on the rear surface of the light guide plate 840, or The bottom cover 810 may be provided in the form of a coating with a highly reflective material.

Here, the reflection plate 820 can be made of a material having a high reflectance and can be used in an ultra-thin shape, and polyethylene terephthalate (PET) can be used.

The light guide plate 830 scatters the light emitted from the light emitting device package module so that the light is uniformly distributed over the entire area of the screen of the liquid crystal display. Accordingly, the light guide plate 830 is made of a material having a good refractive index and transmittance. The light guide plate 830 may be formed of polymethyl methacrylate (PMMA), polycarbonate (PC), or polyethylene (PE).

The first prism sheet 850 is formed of a translucent and elastic polymer material on one surface of the support film, and the polymer may have a prism layer in which a plurality of three-dimensional structures are repeatedly formed. Here, the plurality of patterns may be provided in the stripe type and the valley repeatedly as shown.

In the second prism sheet 860, the direction of the floor and the valley of one surface of the support film may be perpendicular to the direction of the floor and the valley of one surface of the support film in the first prism sheet 850. This is to evenly distribute the light transmitted from the light source module and the reflective sheet in all directions of the panel 870.

In the present embodiment, the first prism sheet 850 and the second prism sheet 860 form an optical sheet, which is composed of another combination, for example, a micro lens array or a diffusion sheet and a micro lens array. Or a combination of one prism sheet and a micro lens array.

The liquid crystal display panel (Liquid Crystal Display) may be disposed on the panel 870, in addition to the liquid crystal display panel 860 may be provided with other types of display devices that require a light source.

The panel 870 is a state in which the liquid crystal is located between the glass body and the polarizing plate is placed on both glass bodies in order to use the polarization of light. Here, the liquid crystal has an intermediate property between a liquid and a solid, and liquid crystals, which are organic molecules having fluidity like a liquid, are regularly arranged like crystals. The liquid crystal has a structure in which the molecular arrangement is changed by an external electric field And displays an image.

A liquid crystal display panel used in a display device is an active matrix type, and a transistor is used as a switch for controlling a voltage supplied to each pixel.

The front surface of the panel 870 is provided with a color filter 880 to transmit the light projected from the panel 870, only the red, green and blue light for each pixel can represent an image.

The above-mentioned backlight is selectively formed with irregularities on the surface of the light emitting structure in the light emitting device package, thereby widening the emission angle of the light emitted from the active layer and reducing the amount of light reduction, thereby improving the light efficiency of the light incident on the light guide plate. .

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

100 light emitting element 110 substrate
120: light emitting structure 122: first conductive semiconductor layer
124: active layer 126: second conductive semiconductor layer
130: ohmic layer 140: reflective layer
150: bonding layer 160: conductive support substrate
170: passivation layer 180: wire
200: light emitting device package 210: body
221, 222: first and second lead frames 230: resin layer
240: phosphor 250: lens
300: mask 350: etching solution
400 housing 500 heat dissipation unit
600: light source 700: holder
800: display device 810: bottom cover
820: reflector 830: circuit board module
840: Light guide plate 850, 860: First and second prism sheet
870 panel 880 color filter

Claims (12)

A light emitting structure comprising a first conductive semiconductor layer, an active layer on the first conductive semiconductor layer, and a second conductive semiconductor layer on the active layer;
A first electrode on the first conductive semiconductor layer; And
A second electrode on the second conductivity type semiconductor layer,
The surface of the light emitting structure includes a central first region and an edge second region and a third region between the first region and the second region, the surface of the light emitting structure in the first region and the second region. A light extraction unit is formed, and the third region is formed with a light block unit and forms a closed curved surface around the first region. The method of claim 1,
The third region is a flat light emitting device. The method of claim 1,
A light emitting device in which the surface of the light emitting structure in the first region and the second region is irregular. The method of claim 3, wherein the unevenness,
A light emitting device comprising irregularities having a depth of 0.8 to 1.2 micrometers. The method of claim 3, wherein the unevenness,
A light emitting device comprising irregularities having a period of 0.8 to 1.2 micrometers. The cross section of the first region,
A light emitting device having a polygonal length of one side of 16 to 20 micrometers. The method of claim 1, wherein the width of the second region,
8 to 12 micrometers light emitting device. The method of claim 1, wherein the width of the third region,
8 to 12 micrometers light emitting device. The method of claim 1,
The first region and the second region of the light emitting device spaced apart from 8 to 12 micrometers. The method of claim 1,
The light emitted from the active layer proceeds to the first, second, and third regions, and at least a portion of the light is totally reflected in the third region. 11. The method of claim 10,
The light emitting device of claim 1, wherein the momentum of the light transmitted from the active layer in the first and second regions and the light propagated through the surface of the third region is different. A light emitting device package comprising the light emitting device of any one of claims 1 to 11.

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