KR20150035211A - Light emitting device having wide beam angle and uniform intensity of illumination, and method of fabricating the same - Google Patents

Light emitting device having wide beam angle and uniform intensity of illumination, and method of fabricating the same Download PDF

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Publication number
KR20150035211A
KR20150035211A KR20130115500A KR20130115500A KR20150035211A KR 20150035211 A KR20150035211 A KR 20150035211A KR 20130115500 A KR20130115500 A KR 20130115500A KR 20130115500 A KR20130115500 A KR 20130115500A KR 20150035211 A KR20150035211 A KR 20150035211A
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South Korea
Prior art keywords
region
transparent substrate
pattern
light emitting
layer
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KR20130115500A
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Korean (ko)
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장종민
이준섭
서대웅
노원영
김현아
채종현
배선민
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서울바이오시스 주식회사
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Priority to KR20130115500A priority Critical patent/KR20150035211A/en
Priority claimed from US14/481,351 external-priority patent/US20150069444A1/en
Publication of KR20150035211A publication Critical patent/KR20150035211A/en

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    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L27/00Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/15Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components with at least one potential-jump barrier or surface barrier specially adapted for light emission
    • H01L27/153Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components with at least one potential-jump barrier or surface barrier specially adapted for light emission in a repetitive configuration, e.g. LED bars
    • H01L27/156Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components with at least one potential-jump barrier or surface barrier specially adapted for light emission in a repetitive configuration, e.g. LED bars two-dimensional arrays
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L33/00Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/20Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a particular shape, e.g. curved or truncated substrate
    • H01L33/22Roughened surfaces, e.g. at the interface between epitaxial layers
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L33/00Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/36Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the electrodes
    • H01L33/40Materials therefor
    • H01L33/405Reflective materials
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L33/00Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/44Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the coatings, e.g. passivation layer or anti-reflective coating
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L2933/00Details relating to devices covered by the group H01L33/00 but not provided for in its subgroups
    • H01L2933/0008Processes

Abstract

A light emitting device having a wide directivity angle and a uniform illuminance and a method of manufacturing the same are disclosed. The light emitting device includes a light emitting structure, and a transparent substrate disposed on the light emitting structure, wherein the transparent substrate is disposed on the upper surface thereof and includes at least two or more different Wherein the projection of the first concave-convex pattern has a larger size than the projection of the second concave-convex pattern, the first concave-convex pattern is located in a central region of the upper surface of the transparent substrate, And is located in the outer region of the upper surface of the transparent substrate. Accordingly, the light emitting device may have a wide directivity angle and a uniform illuminance depending on the light emission angle.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device having a wide directivity angle and a uniform illuminance,

The present invention relates to a light emitting device and a method of manufacturing the same, and more particularly to a light emitting device having a wide directivity angle and a uniform illuminance by including a pattern formed on the light emitting surface, and a manufacturing method thereof.

BACKGROUND ART [0002] Light emitting devices are inorganic semiconductor devices that emit light generated by recombination of electrons and holes, and have recently been used in various fields such as displays, automobile lamps, and general lighting. Particularly, nitride semiconductors such as gallium nitride and aluminum nitride have direct transition characteristics and can be fabricated to have energy band gaps in various bands, so that light emitting devices having various wavelength ranges can be manufactured as needed.

For example, it is advantageous for a UV light emitting element used for a backlight of a display, a sterilizing apparatus, etc. to have a wide directivity angle. Therefore, in order to widen the directivity angle of the light emitting element, a technique such as application of a further configuration such as a lens or surface treatment of the light emitting element is applied.

On the other hand, a wafer-level package or a chip-on-board type light emitting device which does not use a separate package body needs to adjust the directivity angle without a separate additional structure such as a lens. However, the conventional surface processing technique and the like can increase the light extraction efficiency of the light emitting device, but it is difficult to increase the directivity angle. Particularly, in the case of a UV light emitting device, there is a limitation in applying a technique of increasing the directivity angle because a molding part or a lens using a material that can be deformed or deteriorated by UV light can not be applied. In addition, when the technique of increasing the amount of light emitted to the side and increasing the directional angle is applied, the illuminance can not be maintained uniformly depending on the angle at which the light is emitted. In particular, the amount of light emitted in the direction perpendicular to the emitting surface of the light emitting element is significantly higher than the amount of light emitted in the lateral direction.

Accordingly, there is a demand for a technique capable of uniformizing the illuminance irrespective of the emission angle while widening the directivity angle of the light emitting element itself. Particularly, in a light emitting device not using a package body or a lens, A technique capable of maintaining uniformity is required.

A problem to be solved by the present invention is to provide a light emitting device having a wide directivity angle and a uniform illuminance.

A further object of the present invention is to provide a method of manufacturing a light emitting device capable of controlling the uniformity of the orientation angle and the illuminance according to the light emitting property of the light emitting device.

A light emitting device according to an embodiment of the present invention includes: a light emitting structure; And a transparent substrate disposed on the light emitting structure, wherein the transparent substrate includes at least two or more different concavo-convex patterns located on an upper surface thereof and including a first concavo-convex pattern and a second concavo-convex pattern, Wherein the protrusions of the first concavo-convex pattern have a larger size than the protrusions of the second concavo-convex pattern, the first concavo-convex pattern is located in a central region of the upper surface of the transparent substrate, do.

The upper surface of the transparent substrate may include a first region and a second region, the first region is located at a central region of the upper surface of the transparent substrate, and the second region is located at a region surrounding the first region The first irregular pattern may be disposed in the first area, and the second irregular pattern may be disposed in the second area.

In addition, the first irregular pattern and / or the second irregular pattern may include at least two or more differently shaped protrusions.

Alternatively, the first irregular pattern and the second irregular pattern may have projections having the same shape.

Furthermore, the protrusions of the first irregular pattern and / or the second irregular pattern may have at least one of a hemispherical shape, a cone shape, a truncated cone shape, and a convex heart shape.

The two or more different concavo-convex patterns may further include a third concavo-convex pattern, and the protrusions of the third concavo-convex pattern may have a smaller size than the protrusions of the second concavo-convex pattern.

Further, the upper surface of the transparent substrate may include a first region, a second region, and a third region, the first region being located in a central region of the upper surface of the transparent substrate, And the third area is located in an area surrounding the second area, wherein the first irregular pattern, the second irregular pattern, and the third irregular pattern are located in a region surrounding the first area, the second area, And may be disposed in the third region.

In some embodiments, the transparent substrate may be a sapphire substrate.

The light emitting device may further include a first electrode and a second electrode positioned below the light emitting structure.

The light emitting device according to other embodiments may further include an antireflection layer that covers a side surface of the transparent substrate.

In addition, the light emitting structure may emit light having a peak wavelength in the ultraviolet region.

In some embodiments, the light emitting structure includes a first conductive semiconductor layer; A plurality of mesas spaced apart from each other below the first conductive semiconductor layer and each including an active layer and a second conductive semiconductor layer; Reflective electrodes positioned under each of the plurality of mesas to make ohmic contact with the second conductive semiconductor layer; And an ohmic contact layer covering the plurality of mesas and the first conductivity type semiconductor layer, the ohmic contact layer being located in a region below each of the mesas and having openings exposing the reflective electrodes, Lt; RTI ID = 0.0 > of < / RTI > mesas.

The plurality of mesas may have an elongated shape extending parallel and extending in one direction, and openings of the current dispersion layer may be biased toward the same end side of the plurality of mesas.

The light emitting device includes: an upper insulating layer covering at least a part of the current spreading layer, the upper insulating layer having openings for exposing the reflective electrodes; And a second electrode pad located on the upper insulating layer and connected to the reflective electrodes exposed through the openings of the upper insulating layer.

Furthermore, the light emitting device may further include a first electrode pad connected to the current dispersion layer.

According to another embodiment of the present invention, there is provided a method of manufacturing a light emitting device, comprising: preparing a light emitting structure having a transparent substrate on a top thereof; Disposing an etch mask pattern on the transparent substrate; And forming at least two or more different concavo-convex patterns on the transparent substrate by partially removing the transparent substrate using the etching mask pattern as a mask, wherein the etching mask pattern includes a first mask pattern and a second mask pattern Wherein the first mask pattern is disposed on a central region of the transparent substrate and the second mask pattern is disposed on an outer peripheral region of the transparent substrate, The size of the concavo-convex pattern formed on the second mask pattern may be larger than the size of the concavo-convex pattern formed below the second mask pattern.

According to the present invention, since at least two or more different concavo-convex patterns are formed on the upper surface of the transparent substrate, a light emitting device having a wide directivity angle and uniform illuminance can be provided. In particular, the amount of light emitted in the lateral direction of the light emitting element can be increased.

In addition, according to the method of manufacturing a light emitting device of the present invention, it is possible to easily adjust the directivity and uniformity of light intensity of a light emitting device manufactured through a simple process deformation.

1 is a plan view and a cross-sectional view illustrating a light emitting device according to an embodiment of the present invention.
2 is a plan view and a cross-sectional view illustrating a light emitting device according to another embodiment of the present invention.
3 is a plan view and a cross-sectional view illustrating a light emitting device according to another embodiment of the present invention.
FIGS. 4 to 6 are cross-sectional views for explaining the method of manufacturing the upper pattern of the light emitting device according to FIGS. 1 to 3, respectively.
7 to 11 are sectional views and plan views illustrating a light emitting diode according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided by way of example so that those skilled in the art can sufficiently convey the spirit of the present invention. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the width, length, thickness, etc. of components may be exaggerated for convenience. It is also to be understood that when an element is referred to as being "above" or "above" another element, But also includes the case where there are other components in between. Like reference numerals designate like elements throughout the specification.

1 is a plan view and a cross-sectional view illustrating a light emitting device according to an embodiment of the present invention. 1 is a sectional view taken along the line A-A 'in the plan view of FIG.

Referring to FIG. 1, a light emitting device according to an embodiment of the present invention includes a light emitting diode 100 including a transparent substrate 21 and a light emitting structure 110.

The light emitting structure 110 is not limited as long as it includes a semiconductor layer and can emit light. For example, the light emitting structure 110 may have a flip chip structure or a vertical structure including an n-type semiconductor layer and a p-type semiconductor layer. Furthermore, the light emitting device may further include a first electrode and a second electrode (not shown) formed under the light emitting structure 110, and thus may be used as a wafer level package without a packaging process. In particular, the light emitting structure 110 can emit light having a peak wavelength in the ultraviolet region.

Hereinafter, an example of the light emitting diode 100 will be described with reference to Figs. 7 to 11. Fig. However, the present invention is not limited thereto, and the structure of the light emitting diode 100 described below is for facilitating understanding of the present invention.

7 to 11 are views for explaining a light emitting diode 100 and a method of manufacturing the same according to an embodiment of the present invention. In each drawing, (a) is a plan view, (b) is a sectional view taken along a perforation line AA to be.

7, a first conductivity type semiconductor layer 23 is formed on a transparent substrate 21 and a plurality of mesas M spaced apart from each other on the first conductivity type semiconductor layer 23, . The plurality of mesas M each include an active layer 25 and a second conductivity type semiconductor layer 27. The active layer 25 is located between the first conductivity type semiconductor layer 23 and the second conductivity type semiconductor layer 27. On the other hand, the reflective electrodes 30 are positioned on the plurality of mesas M, respectively.

The plurality of mesas M are formed on the transparent substrate 21 by depositing an epi layer including a first conductive type semiconductor layer 23, an active layer 25 and a second conductive type semiconductor layer 27 on a metal organic chemical vapor deposition (MOCVD) method, and then patterning the second conductivity type semiconductor layer 27 and the active layer 25 so that the first conductivity type semiconductor layer 23 is exposed. The sides of the plurality of mesas M may be formed obliquely by using a technique such as photoresist reflow. The inclined profile of the mesa (M) side improves the extraction efficiency of the light generated in the active layer 25.

The plurality of mesas M may have an elongated shape extending parallel to each other in one direction as shown. This shape simplifies the formation of a plurality of mesas M of the same shape in a plurality of chip areas on the transparent substrate 21. [

The reflective electrodes 30 may be formed on each of the mesas M after the plurality of mesas M are formed. However, the present invention is not limited thereto, and the second conductivity type semiconductor layer 27 may be grown It may be formed on the second conductive type semiconductor layer 27 before forming the mesas M. [ The reflective electrode 30 covers most of the upper surface of the mesa M and has substantially the same shape as the planar shape of the mesa M. [

The reflective electrodes 30 may include a reflective layer 28 and may further include a barrier layer 29 and the barrier layer 29 may cover the top and sides of the reflective layer 28. For example, the barrier layer 29 may be formed to cover the upper surface and the side surface of the reflective layer 28 by forming a pattern of the reflective layer 28 and forming a barrier layer 29 thereon. For example, the reflective layer 28 may be formed by depositing and patterning Ag, Ag alloy, Ni / Ag, NiZn / Ag, TiO / Ag layer, and Pt / Ag layer. Meanwhile, the barrier layer 29 may be formed of Ni, Cr, Ti, Pt, W, Mo, or a composite layer thereof to prevent diffusion or contamination of the metal material of the reflection layer.

After the plurality of mesas M are formed, the edges of the first conductive type semiconductor layer 23 may also be etched. Thus, the upper surface of the transparent substrate 21 can be exposed. The side surfaces of the first conductivity type semiconductor layer 23 may also be inclined.

The plurality of mesas M may be formed to be confined within the upper region of the first conductivity type semiconductor layer 23 as shown in FIG. That is, a plurality of mesas M may be located on the upper region of the first conductivity type semiconductor layer 23 in an island shape.

Referring to FIG. 8, a lower insulating layer 31 covering the plurality of mesas M and the first conductivity type semiconductor layer 23 is formed. The lower insulating layer 31 has openings 31a and 31b for allowing electrical connection to the first conductivity type semiconductor layer 23 and the second conductivity type semiconductor layer 27 in a specific region. For example, the lower insulating layer 31 may have openings 31a for exposing the first conductivity type semiconductor layer 23 and openings 31b for exposing the reflective electrodes 30.

The openings 31a may be located near the edge between the mesa M and the transparent substrate 21 and may have an elongated shape extending along the mesa M. [ On the other hand, the openings 31b are located on the upper portion of the mesa M and are biased to the same end side of the mesa.

The lower insulating layer 31 may be formed of an oxide film such as SiO 2 , a nitride film such as SiN x, or an insulating film of MgF 2 using a technique such as chemical vapor deposition (CVD) or electron beam evaporation. The lower insulating layer 31 may be formed of a single layer, but is not limited thereto and may be formed of multiple layers. Further, the lower insulating layer 31 may be formed of a distributed Bragg reflector (DBR) in which a low refractive index material layer and a high refractive index material layer are alternately laminated. For example, an insulating reflection layer having a high reflectance can be formed by laminating SiO 2 / TiO 2 or SiO 2 / Nb 2 O 5 layers.

Referring to FIG. 9, a current spreading layer 33 is formed on the lower insulating layer 31. The current spreading layer 33 covers the plurality of mesas M and the first conductivity type semiconductor layer 23. In addition, the current spreading layer 33 has openings 33a located in the respective upper portions of the mesa M and exposing the reflective electrodes. The current spreading layer 33 may be in ohmic contact with the first conductive semiconductor layer 23 through the openings 31a of the lower insulating layer 31. [ The current spreading layer 33 is insulated from the plurality of mesas M and the reflective electrodes 30 by the lower insulating layer 31.

The openings 33a of the current spreading layer 33 are formed to have a larger area than the openings 31b of the lower insulating layer 31 so as to prevent the current spreading layer 33 from being connected to the reflective electrodes 30. [ Respectively. Therefore, the side walls of the openings 33a are located on the lower insulating layer 31. [

The current spreading layer 33 is formed on almost the entire region of the substrate 31 except for the openings 33a. Therefore, the current can be easily dispersed through the current dispersion layer 33. The current spreading layer 33 may include a highly reflective metal layer such as an Al layer and the highly reflective metal layer may be formed on an adhesive layer such as Ti, Cr, or Ni. Further, a protective layer of a single layer or a multiple layer structure such as Ni, Cr, Au or the like may be formed on the highly reflective metal layer. The current spreading layer 33 may have a multilayer structure of Ti / Al / Ti / Ni / Au, for example.

Referring to FIG. 10, an upper insulating layer 35 is formed on the current spreading layer 33. The upper insulating layer 35 has openings 35b for exposing the reflective electrodes 30 together with openings 35a for exposing the current spreading layer 33. [ The opening 35a may have an elongated shape in a direction perpendicular to the longitudinal direction of the mesa M and has a relatively large area as compared with the openings 35b. The openings 35b expose the exposed reflective electrodes 30 through the openings 33a of the current spreading layer 33 and the openings 31b of the lower insulating layer 31. [ The openings 35b may have a smaller area than the openings 33a of the current spreading layer 33 and may have a larger area than the openings 31b of the lower insulating layer 31. [ Accordingly, the sidewalls of the openings 33a of the current-spreading layer 33 may be covered with the upper insulating layer 35.

The upper insulating layer 35 may be formed using an oxide insulating layer, a nitride insulating layer, or a polymer such as polyimide, Teflon, or parylene.

Referring to FIG. 11, a first pad 37a and a second pad 37b are formed on the upper insulating layer 35. Referring to FIG. The first pad 37a is connected to the current spreading layer 33 through the opening 35a of the upper insulating layer 35 and the second pad 37b is connected to the openings 35b of the upper insulating layer 35 To the reflective electrodes 30. The first pad 37a and the second pad 37b may be used as a pad for connecting the bump or a pad for SMT in order to mount the light emitting diode on a submount, a package, a printed circuit board or the like.

The first and second pads 37a and 37b may be formed together in the same process and may be formed using, for example, a photo and etch technique or a lift-off technique. The first and second pads 37a and 37b may include, for example, an adhesive layer of Ti, Cr, Ni, or the like and a high-conductivity layer of metal such as Al, Cu, Ag, or Au.

Thereafter, the light-emitting diode 100 is completed by dividing the transparent substrate 21 into individual light-emitting diode chip units. At this time, the transparent substrate 21 may be divided using a scribing process, for example, a laser scribing process may be used.

Hereinafter, a structure of a light emitting diode 100 according to an embodiment of the present invention will be described in detail with reference to FIG.

The light emitting diode includes a transparent substrate 21, a lower insulating layer 31, a first conductive semiconductor layer 23, a mesa M, reflective electrodes 30, and a current dispersion layer 33. An upper insulating layer 35, and a first pad 37a and a second pad 37b.

The transparent substrate 21 may be a growth substrate for growing gallium nitride epilayers, for example, sapphire, silicon carbide, silicon, or a gallium nitride substrate. In this embodiment, the transparent substrate 21 may be a sapphire substrate have.

The first conductivity type semiconductor layer 23 is continuous and a plurality of mesas M are disposed on the first conductivity type semiconductor layer 23 so as to be spaced apart from each other. The mesas M include the active layer 25 and the second conductivity type semiconductor layer 27 as described with reference to FIG. 1 and have an elongated shape extending toward one side. Here, the mesas M are stacked layers of gallium nitride compound semiconductors. The mesa M may be located within the upper region of the first conductivity type semiconductor layer 23 as shown in FIG.

The first conductive semiconductor layer 23, the active layer 25, and the second conductive semiconductor layer 27 may include a nitride semiconductor. The first conductive semiconductor layer 23 may be an n-type semiconductor layer, the second conductive semiconductor layer 27 may be a p-type semiconductor layer, or vice versa. Meanwhile, the active layer 25 may include a nitride semiconductor, and the peak wavelength of light emitted from the active layer 25 may be determined by adjusting the composition ratio of the nitride semiconductor. In particular, in the present embodiment, the active layer 25 may include AlGaN and emit light having a peak wavelength in the ultraviolet region.

Each of the reflective electrodes 30 is located on the plurality of mesas M and ohmically contacts the second conductive type semiconductor layer 27. The reflective electrodes 300 may include a reflective layer 28 and a barrier layer 29 as described with reference to Figure 1 and a barrier layer 29 may cover the top and sides of the reflective layer 28.

The current spreading layer 33 covers the plurality of mesas M and the first conductivity type semiconductor layer 23. The current spreading layer 33 has openings 33a that are located in the respective upper portions of the mesa M and expose the reflective electrodes 30. [ The current spreading layer 33 is also in ohmic contact with the first conductivity type semiconductor layer 23 and is insulated from the plurality of mesas M. [ The current spreading layer 33 may include a reflective metal such as Al.

The current spreading layer 33 may be insulated from the plurality of mesas M by a lower insulating layer 31. For example, the lower insulating layer 31 may be positioned between the plurality of mesas M and the current spreading layer 33 to isolate the current spreading layer 33 from the plurality of mesas M . The lower insulating layer 31 may have openings 31b that are located in the respective upper portions of the mesa M and expose the reflective electrodes 30. The lower insulating layer 31 may have openings 31b, (Not shown). The current spreading layer 33 may be connected to the first conductivity type semiconductor layer 23 through the openings 31a. The openings 31b of the lower insulating layer 31 have a smaller area than the openings 33a of the current spreading layer 33 and are all exposed by the openings 33a.

The upper insulating layer 35 covers at least a part of the current-spreading layer 33. The upper insulating layer 35 has openings 35b for exposing the reflective electrodes 30. Furthermore, the upper insulating layer 35 may have an opening 35a for exposing the current-spreading layer 33. [ The upper insulating layer 35 may cover the sidewalls of the openings 33a of the current spreading layer 33.

The first pad 37a may be located on the current spreading layer 33 and may be connected to the current spreading layer 33 through the opening 35a of the upper insulating layer 35, for example. The second pad 37b is connected to the reflective electrodes 30 exposed through the openings 35b.

According to the present invention, the current-spreading layer 33 covers almost the entire region of the first conductivity type semiconductor layer 23 between the mesas M and the mesas M. [ Therefore, the current can be easily dispersed through the current dispersion layer 33. [

The current dispersion layer 23 includes a reflective metal layer such as Al or the lower insulating layer is formed of an insulating reflection layer so that the light that is not reflected by the reflective electrodes 30 is separated from the current dispersion layer 23 or the lower insulating layer 23. [ Layer 31, so that the light extraction efficiency can be improved.

In the present invention, the light emitting diode 100 described above can be used, but the present invention is not limited thereto.

Referring again to FIG. 1, the transparent substrate 21 includes at least two or more different concave-convex patterns 120 and 130. At this time, the concave-convex patterns 120 and 130 may include the first concave-convex pattern 120 and the second concave-convex pattern 130.

The first irregular pattern 120 and the second irregular pattern 130 may be formed on the upper surface of the transparent substrate 21. The first concave-convex pattern 120 may include a protrusion 121 and a concave portion 123 and the second concave-convex pattern 130 may also include a protrusion 131 and a concave portion 133.

1, the first irregular pattern 120 may be located at a central region of the upper surface of the transparent substrate 21, and the second irregular pattern 130 may be located at a peripheral region of the upper surface of the transparent substrate 21, Lt; / RTI > Specifically, the upper surface of the transparent substrate 21 may include a first region and a second region. In this embodiment, the first region may be defined as being located in a central region of the upper surface of the transparent substrate 21 , And the second area may be defined as an area surrounding the first area. Accordingly, the first irregular pattern 120 may be disposed in the first area, and the second irregular pattern 130 may be disposed in the second area.

The protrusions 121 of the first concave-convex pattern 120 may be larger than the protrusions 131 of the second concave-convex pattern 130. For example, as shown in FIG. 1, the protrusions 121 and 131 of the first and second protrusive patterns 120 and 130 may be hemispherical, and the protrusions 121 of the first protrusions / The radius may be larger than the radius of the protrusion 131 of the second concavo-convex pattern 130.

As the uneven patterns 120 and 130 are formed on the upper surface of the transparent substrate 21, the ratio of total reflection when the light emitted from the light emitting structure 110 is emitted to the upper surface of the light emitting device 110 can be reduced. The concavo-convex patterns 120 and 130 may be formed on the upper surface of the transparent substrate 21 so that light emitted to the upper surface of the transparent substrate 21 may be scattered, It can have a uniform illuminance.

Also, depending on the size of the uneven patterns 120 and 130, the ratio of the total reflection of light passing through the first area and the second area may be different. More specifically, since the first irregular pattern 120 includes a relatively large concavo-convex structure as compared with the second irregular pattern 130, the light passing through the second region is larger than the ratio of the light passing through the first region, The rate of total reflection may be relatively low. Therefore, the amount of light emitted through the outer area of the upper surface of the transparent substrate 21 can be increased, and the amount of light directed in the lateral direction can be increased. Accordingly, compared with the conventional light emitting device in which the amount of light emitted in the direction perpendicular to the light emitting surface is significantly higher than the amount of light emitted in the lateral direction, the light emitting device of the present invention can emit more light in the lateral direction, It is possible to have uniform illuminance over the entire emission angle.

Meanwhile, the first and second concavo-convex patterns 120 and 130 may be formed through photolithography and etching processes. For example, as shown in FIG. 4, etching mask patterns 220 and 230 are formed on a transparent substrate 21, and the transparent substrate 21 is partially removed by wet etching or dry etching, Patterns 120 and 130 can be formed. At this time, the etch mask patterns may include a first mask pattern 220 and a second mask pattern 230, and the first and second mask patterns 220 and 230 may have different pattern shapes. When the upper surface of the transparent substrate 21 is partially etched by using the etching mask patterns 220 and 230 as a mask, the upper surface of the transparent substrate 21 may be partially etched according to the shape of the etching mask patterns 220 and 230 120, and 130 may be formed.

Thus, by adjusting the shape of the etching mask patterns 220 and 230, the interval, size, shape, etc. of the concave-convex patterns 120 and 130 can be determined. Accordingly, it is possible to easily adjust the orientation angle of the light emitting device by adjusting only the shape of the etching mask patterns 220 and 230, and also to adjust the illuminance according to the light emission angle. For example, irregular patterns may be densely formed in a portion where the illuminance is relatively low, and a roughness pattern may be formed in a portion where the illuminance is relatively high, so that the illuminance of the light emitting element can be uniform.

The light emitting device may further include an anti-reflection layer (not shown) at least partially covering an upper surface and / or a side surface of the transparent substrate 21. An anti-reflection layer may include SiO 2. The antireflection layer can prevent total reflection of light emitted through the transparent substrate 21, and therefore, it is possible to control the region where the antireflection layer is formed to determine the directivity angle of the light emitting device and the uniformity of the illuminance. For example, if the antireflection layer is formed to cover only the side surface of the transparent substrate 21, the amount of light emitted to the side of the light emitting device can be increased.

2 is a plan view and a cross-sectional view illustrating a light emitting device according to another embodiment of the present invention. 2 is a cross-sectional view taken along the line B-B 'in the plan view of FIG.

The light emitting device described with reference to FIG. 2 is generally similar to the light emitting device described with reference to FIG. 1, but differs in the shape of the concave and convex patterns 140 and 150. Hereinafter, differences will be mainly described.

The concave and convex patterns 140 and 150 may include a third concave and convex pattern 140 and a fourth concave and convex pattern 150 and the third and fourth concave and convex patterns 140 and 150 may have a convex heart shape. At this time, the size of the third irregular pattern 140 may be larger than that of the fourth irregular pattern 150.

According to the light emitting device of this embodiment, the concave and convex patterns 140 and 150 have a convex heart shape, so that they can have higher light output than the light emitting device having the hemispherical concave and convex patterns 120 and 130.

The irregular patterns 140 and 150 of FIG. 2 may be formed by a method similar to the irregular patterns 120 and 130 of FIG. 5, only the shapes of the etching mask patterns 240 and 250 are different from those of FIG. 4, so that the concave-convex patterns 140 and 150 shown in FIG. 2 can be provided. More specifically, the masking portions of the etching mask patterns 240 and 250 in FIG. 4 are formed in a convex heart shape, and the upper portion of the transparent substrate 210 is partially etched using dry etching such as RIE, Concave and convex patterns 140 and 150 may be provided.

3 is a plan view and a cross-sectional view illustrating a light emitting device according to another embodiment of the present invention. 3 is a cross-sectional view taken along the line C-C 'in the plan view of FIG.

The light emitting device described with reference to FIG. 3 is substantially similar to the light emitting device described with reference to FIG. 1, but differs in that it includes three different types of concave and convex patterns 160, 170, and 180. Hereinafter, differences will be mainly described.

The transparent substrate 21 includes at least three or more different concavo-convex patterns 160, 170, and 180. The concavo-convex patterns 160, 170, and 180 may include a fifth concavo-convex pattern 160, a sixth concavo-convex pattern 170, and a seventh concavo-convex pattern 180.

The fifth to seventh irregular patterns 160, 170 and 180 may be formed on the upper surface of the transparent substrate 21. The fifth concave-convex pattern 160 may include a protrusion 161 and a concave portion 163. The sixth concave-convex pattern 170 may include a protrusion 171 and a concave portion 173, The concavo-convex pattern 180 may also include a protrusion 181 and a concave portion 183.

3, the fifth concavo-convex pattern 160 may be located in the central region of the upper surface of the transparent substrate 21, and the seventh concavo-convex pattern 180 may be located in the outer circumferential region of the upper surface of the transparent substrate 21, And the sixth concavo-convex pattern 170 may be located between the areas where the fifth and seventh concavo-convex patterns 160 and 180 are located. Specifically, the upper surface of the transparent substrate 21 may include a first region, a second region, and a third region. In this embodiment, the first region is located in the central region of the upper surface of the transparent substrate 21 A second area may be defined as an area surrounding the first area, and a third area may be defined as an area surrounding the second area. Accordingly, the fifth concavo-convex pattern 160, the sixth concavo-convex pattern 170, and the seventh concavo-convex pattern 180 may be disposed in the first region, the second region, and the third region, respectively.

The protrusion 161 of the fifth concavo-convex pattern 160 may have a larger size than the protrusion 161 of the sixth concavo-convex pattern 170, and the protrusion 171 of the sixth concavo- The protrusion 181 of the protrusion pattern 180 may have a larger size than the protrusion 181 of the protrusion pattern 180. That is, in the light emitting device of the present embodiment, the concavo-convex patterns 160, 170, and 180 may be formed so that their sizes gradually decrease from the central area of the upper surface of the transparent substrate 21 along the outer area. Accordingly, the amount of light emitted from the side surface of the light emitting element can be increased more effectively. Further, by forming the irregular patterns 160, 170, and 180 more variously than the light emitting device of FIG. 1, it is possible to more easily control the directivity angle and the illuminance.

The fifth to seventh concave-convex patterns 160, 170, and 180 may be formed using the etching mask patterns 260, 270, and 280 shown in FIG. 6, And therefore, a detailed description thereof will be omitted.

In the above embodiments, the transparent substrate 21 has two or three kinds of different concavo-convex patterns, but the present invention is not limited thereto. Alternatively, the light emitting device having four or more kinds of different concavo-convex patterns is also included in the scope of the present invention. In addition, although the concavo-convex patterns are described as being formed continuously on a certain area, they may be formed of a group of concavo-convex patterns spaced apart from each other in a plurality of areas.

Further, in the embodiments described with reference to Figs. 1 to 6, the concavo-convex patterns are described as having a hemispherical or convex heart shape, but may have other various shapes. For example, the concavo-convex patterns may have at least one of a hemispherical shape, a cone shape, a truncated cone shape, and a convex heart shape.

In addition, in the above-described embodiments, one light emitting device is described as having concave and convex patterns having different sizes and shapes, but different types of concave and convex patterns may be formed in one light emitting device have.

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, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims (16)

  1. A light emitting structure; And
    And a transparent substrate disposed on the light emitting structure,
    Wherein the transparent substrate includes at least two or more different concavo-convex patterns located on the upper surface thereof and including a first concavo-convex pattern and a second concavo-convex pattern,
    The projection of the first concave-convex pattern has a larger size than the projection of the second concave-
    Wherein the first concavo-convex pattern is located in a central region of the upper surface of the transparent substrate, and the second concavo-convex pattern is located in an outer region of the upper surface of the transparent substrate.
  2. The method according to claim 1,
    Wherein the upper surface of the transparent substrate includes a first region and a second region, the first region is located in a central region of the upper surface of the transparent substrate, the second region is located in an area surrounding the first region,
    The first irregular pattern is disposed in the first region, and the second irregular pattern is disposed in the second region.
  3. The method according to claim 1,
    Wherein the first concavo-convex pattern and / or the second concavo-convex pattern includes protrusions of at least two or more different shapes.
  4. The method according to claim 1,
    Wherein the first concavo-convex pattern and the second concavo-convex pattern have projections having the same shape.
  5. The method according to claim 3 or 4,
    Wherein the protrusions of the first irregular pattern and / or the second irregular pattern have at least one of hemispherical shape, cone shape, truncated cone shape, and convex heart shape.
  6. The method according to claim 1,
    Wherein the at least two different concave-convex patterns further comprise a third concave-convex pattern,
    And the protruding portion of the third irregular pattern has a smaller size than the protruding portion of the second irregular pattern.
  7. The method of claim 6,
    Wherein the upper surface of the transparent substrate includes a first region, a second region and a third region, the first region is located in a central region of the upper surface of the transparent substrate, the second region is a region surrounding the first region, Wherein the third region is located in an area surrounding the second region,
    Wherein the first irregular pattern, the second irregular pattern, and the third irregular pattern are disposed in the first area, the second area, and the third area, respectively.
  8. The method according to claim 1,
    Wherein the transparent substrate is a sapphire substrate.
  9. The method according to claim 1,
    And a first electrode and a second electrode located below the light emitting structure.
  10. The method according to claim 1,
    And an antireflection layer covering a side surface of the transparent substrate.
  11. The method according to claim 1,
    Wherein the light emitting structure emits light having a peak wavelength in an ultraviolet region.
  12. The method according to claim 1,
    The light-
    A first conductive semiconductor layer;
    A plurality of mesas spaced apart from each other below the first conductive semiconductor layer and each including an active layer and a second conductive semiconductor layer;
    Reflective electrodes positioned under each of the plurality of mesas to make ohmic contact with the second conductive semiconductor layer; And
    And a second conductive semiconductor layer formed on the first conductive semiconductor layer, wherein the first conductive semiconductor layer and the second conductive semiconductor layer are formed on the first conductive semiconductor layer, And a current spreading layer insulated from the mesas.
  13. The method of claim 12,
    Wherein the plurality of mesas have an elongated shape extending parallel and extending in one direction, and the openings of the current dispersion layer are biased toward the same end side of the plurality of mesas.
  14. The method of claim 12,
    An upper insulating layer covering at least a part of the current spreading layer, the upper insulating layer having openings for exposing the reflective electrodes; And
    And a second electrode pad located on the upper insulating layer and connected to the reflective electrodes exposed through the openings of the upper insulating layer.
  15. 15. The method of claim 14,
    And a first electrode pad connected to the current dispersion layer.
  16. Preparing a light emitting structure on which a transparent substrate is formed;
    Disposing an etch mask pattern on the transparent substrate;
    And partially removing the transparent substrate using the etching mask pattern as a mask to form at least two or more different concavo-convex patterns on the transparent substrate,
    Wherein the etch mask pattern includes at least two different mask patterns including a first mask pattern and a second mask pattern,
    Wherein the first mask pattern is disposed on a central region of the transparent substrate, the second mask pattern is disposed on an outer peripheral region of the transparent substrate,
    Wherein the size of the concavo-convex pattern formed under the first mask pattern is larger than the size of the concavo-convex pattern formed under the second mask pattern.
KR20130115500A 2013-09-27 2013-09-27 Light emitting device having wide beam angle and uniform intensity of illumination, and method of fabricating the same KR20150035211A (en)

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KR20130115500A KR20150035211A (en) 2013-09-27 2013-09-27 Light emitting device having wide beam angle and uniform intensity of illumination, and method of fabricating the same
US14/481,351 US20150069444A1 (en) 2013-09-10 2014-09-09 Light emitting diode
CN201420565607.XU CN204243076U (en) 2013-09-27 2014-09-28 There is the luminescent device of angle pencil of ray angle and uniform illumination intensity

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