Light emitting device having an electro-static discharge protection part

Provided are a light emitting device and a light emitting device package. According to the light emitting device, a light emitting part and an electro-static discharge (ESD) protection part are disposed on a conductive support member. A connection layer electrically connects a first conducitve type semiconductor layer of the light emitting part to a second conductive type semiconductor layer of the ESD protection part. A ptrtection member is disposed on the connection layer and the ESD protection layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. § 119(a) of Korean Patent Application No. 10-2010-0072805 filed on Jul. 28, 2010, which is hereby incorporated by reference in its entirety.

BACKGROUND

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

A light emitting diode (LED) is a kind of semiconductor device for converting electrical energy into light. The LED has advantages such as low power consumption, a semi-permanent life cycle, a fast response time, safety, and environment friendly compared to the related art light source such as a fluorescent lamp and an incandescent bulb. Many studies are being in progress in order to replace the related art light source with an LED. Also, the LED is being increasingly used according to the trend as light sources of a lighting device such as a variety of lamps and streetlights, a lighting unit of a liquid crystal display device, and a scoreboard in indoor and outdoor places.

SUMMARY

Embodiments provide a light emitting device having a new structure and a light emitting device package.

Embodiments also provide a light emitting device which is protected against static electricity and a light emitting device package.

In one embodiment, a light emitting device includes: a conductive support member; a light emitting part including a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer on the conductive support member, wherein the second conductive type semiconductor layer is electrically connected to the conductive support member; an electro-static discharge (ESD) protection part including a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer on the conductive support member; a first connection layer electrically connecting the first conductive type semiconductor layer of the light emitting part to the second conductive type semiconductor layer of the ESD protection part; and a protection member on the ESD protection part and the first connection layer.

In another embodiment, a light emitting device includes: a conductive support member; a light emitting part including a first structure layer; an electro-static discharge (ESD) protection part including a second structure layer, wherein the first and second structure layers include a first conductive type semiconductor layer on the conductive support member, an active layer on the first conductive type semiconductor layer, and a second conductive type semiconductor layer on the active layer; first and second recesses passing through the first conductive type semiconductor layer and the active layer to expose a Ga-face region of the second conductive type semiconductor layer; first and second protection layers around side surfaces of the first and second recesses, respectively; a first connection layer connecting the Ga-face region of the second conductive type semiconductor layer to the first conductive type semiconductor layer of the ESD protection part through the first protection layer; and a protection member on the first connection layer and the first conductive type semiconductor layer of the ESD protection part.

In further another embodiment, a light emitting device package includes: a body; a light emitting device on the body; and a molding member surrounding the light emitting device, wherein the light emitting device includes: a conductive support member; a light emitting part including a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer on the conductive support member, wherein the second conductive type semiconductor layer is electrically connected to the conductive support member; an electro-static discharge (ESD) protection part including a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer on the conductive support member; a first connection layer electrically connecting the first conductive type semiconductor layer of the light emitting part to the second conductive type semiconductor layer of the ESD protection part; a second connection layer electrically connecting the second conductive type semiconductor layer of the light emitting part to the first conductive type semiconductor layer of the ESD protection part; and a protection member on the ESD protection part and the first connection layer.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the descriptions of embodiments, it will be understood that when a layer (or film), a region, a pattern, or a structure is referred to as being ‘on’ a substrate, a layer (or film), a region, a pad, or patterns, it can be directly on another layer or substrate, or intervening layers may also be present. Further, it will be understood that when a layer is referred to as being ‘under’ another layer, it can be directly under another layer, and one or more intervening layers may also be present. Further, the reference about ‘on’ and ‘under’ each layer will be made on the basis of drawings.

Hereinafter, embodiments will be described with reference to the accompanying drawings. In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience in description and clarity. Also, the size of each element does not entirely reflect an actual size.

FIG. 1is a side-sectional view of a light emitting device according to an embodiment.

Referring toFIG. 1, a light emitting device100includes a light emitting part101, an electro-static discharge (ESD) protection part103, an adhesion layer190supporting the light emitting device101and the ESD protection part103, and a conductive support member195.

The light emitting part101includes a first conductive type semiconductor layer110, an active layer120, a second conductive type semiconductor layer130, a first ohmic contact layer150, and an electrode198. The ESD protection part103includes a first conductive type semiconductor layer112, an active layer122, a second conductive type semiconductor layer132, and a second ohmic contact layer152.

A first protection layer140is disposed on an inner surface of a light emitting structure layer135to electrically separate the light emitting part101from the ESD protection part103. The first protection layer140may be formed of at least one of SiO2, Si3N4, Al2O3, and TiO2.

The first ohmic contact layer150is disposed in an inner region above the second conductive type semiconductor layer130, and the second ohmic contact layer152is disposed in an inner region above the second conductive type semiconductor layer132.

A reflective layer160may be disposed on the first ohmic contact layer150. The reflective layer160may reflect light incident from the light emitting structure layer135to improve light emitting efficiency of the light emitting device100.

A first connection layer170is disposed in an inner region. A first end of the first connection layer170is connected to the first conductive type semiconductor layer110and a second end of the first connection layer170is connected to the second ohmic contact layer152. The first end of the first connection layer170may be connected to a Ga-face region of the first conductive type semiconductor layer110.

The Ga-face region and an N-face region will be described below.

Referring toFIG. 2, a Ga material and an N material may be mixed with each other and then grown in an upward direction to form a GaN layer200. Here, an In material or an Al material may be further added.

A bottom or top surface of the grown GaN layer200may be etched.

That is, the GaN layer200may be etched upwardly from the bottom surface thereof. A surface of the GaN layer200exposed by the above-described etching process may become an N-face region202.

Also, the GaN layer200may be etched downwardly from the top surface thereof. A surface of the GaN layer200exposed by the above-described etching process may become a Ga-face region204.

Thermal stability and operation voltage characteristic in the N-face region202and the Ga-face region204are different from each other.

Typically, a crystalization in the Ga-face region204is superior to that in the N-face region202. Thus, the thermal stability in the Ga-face region204is superior to that in the N-face region202.

Furthermore, the operation voltage characteristic in the Ga-face region204is superior to that in the N-face region202.

Referring toFIG. 3, when the light emitting device is operated for a long time, e.g., ten hours, the operation voltage characteristic in the Ga-face region204keep unchanged. However, the operation voltage characteristic in the N-face region202is reduced.

Thus, when an electrical contact occurs in the Ga-face region204, a light emitting device having superior operation voltage characteristics may be obtained.

According to an embodiment, since the first end of the first connection layer170is connected to the Ga-face region of the first conductive type semiconductor layer110of the light emitting part101, a light emitting device having superior operation voltage characteristics may be obtained.

A protection member180may be disposed in outer regions of the second conductive type semiconductor layers130and132and on the first protection layer140, the first connection layer170, and the second ohmic contact layer152. The first protection layer140surrounds each of the first and second connection layers170and185to prevent the first conductive type semiconductor layers110and112and the second conductive type semiconductor layers130and132from being be shorted.

The protection member180may prevent moisture from being permeated into a gap between the light emitting structure layer135and the conductive support member195and also may electrically insulate the light emitting part101from the ESD protection part103. In addition, the protection member180completely covers the first connection layer170to prevent the electrical connection of the first connection layer to any other elements. Furthermore, the protection member180is disposed on the first connection layer170and the ESD protection part103.

A second connection layer185is disposed on top surfaces of the protection member180and the reflective layer160and top and side surfaces of the first protection layer140.

The second connection layer185electrically connects the second conductive type semiconductor layer130of the light emitting part101to the first conductive type semiconductor layer112of the ESD protection part103.

The light emitting part101and the ESD protection part103are connected to each other in parallel by the first and second connection layers170and185.

The adhesion layer190may serve as a bonding layer. The adhesion layer190may be disposed on the second connection layer185to enhance an adhesion force with the conductive support member195.

The conductive support member195may be disposed on the adhesion layer190. The conductive support member195may support the light emitting structure layer135to provide a power into the light emitting structure layer135together with the electrode198. For example, the conductive support member195may be formed of at least one of copper (Cu), gold (An), nickel (Ni), molybdenum (Mo), copper-tungsten (Cu—W), and carrier wafers (e.g., Si, Ge, GaAs, ZnO, Sic, etc). The conductive support member195may have a thickness varied according to a design of the light emitting device100. For example, the conductive support member195may have a thickness of about 30 μm to about 500 μm.

As described above, when a forward bias is supplied through the electrode198and the conductive support member195, the semiconductor light emitting device100is operated in an LED region. Also, when a voltage such as an ESD is applied, the ESD protection part103may protect the light emitting part101. Here, the ESD protection part103may have a size less than about 50% of that of the light emitting part101to secure an area of the active layer120. That is, the ESD protection part103may have a size of about 10% to about 20% of that of the light emitting part101.

As described above, since the crystalization and the thermal stability in the Ga-face region of the second conductive type semiconductor layer130of the light emitting part101is relatively superior to those in the N-face region of the first conductive type semiconductor layer110, the Ga-face region of the second conductive type semiconductor layer130may be electrically connected to the second conductive type semiconductor layer122of the ESD protection part103through the first connection layer170. Also, the second semiconductor layer130of the light emitting part101may be electrically connected to the first conductive type semiconductor layer112of the ESD protection part103through the second connection layer185. Thus, since the ESD surely passes through the ESD protection part103, it may prevent the light emitting part101from being damaged by the ESD to improve reliability of the light emitting device100.

FIGS. 4 to 16are views illustrating a process of manufacturing the light emitting device according to an embodiment.

Referring toFIG. 4, a light emitting structure layer135may be formed on a growth substrate105.

For example, the growth substrate105may be formed of at least one selected from the group consisting of sapphire (Al2O), SiC, GaAs, GaN, ZnO, Si, GaP, InP, and Ge, but is not limited thereto.

The light emitting structure layer135may be formed by successively growing a first conductive type semiconductor layer110, an active layer120, and a second conductive type semiconductor layer130on the growth substrate105.

For example, the light emitting structure layer135may be formed using one of a metal organic chemical vapor deposition (MOCVD) process, a chemical vapor deposition (CVD) process, a plasma-enhanced chemical vapor deposition (PECVD) process, a molecular beam epitaxy (MBE) process, and a hydride vapor phase epitaxy (HVPE) process, but is not limited thereto.

A buffer layer (not shown) for reducing a lattice constant between the light emitting structure layer135and the growth substrate105may be formed therebetween.

The first conductive type semiconductor layer110may be formed of a group III-V compound semiconductor in which a first conductive type dopant is doped, i.e., a semiconductor material having a compositional formula of InxAlyGa1-x-yN (0≦x≦1, 0≦y≦1, 0≦x+y≦1). For example, the first conductive type semiconductor layer110may be formed of at least one selected from the group consisting of GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP. When the first conductive type semiconductor layer110is an N-type semiconductor layer, the first conductive type dopant may include N-type dopants such as Si, Ge, Sn, Se, and Te. The second conductive type semiconductor layer110may be formed as a single layer or a multi layer, but is not limited thereto.

The first conductive type semiconductor layer110may be formed by an organic metal chemical deposition process. Here, a Ga material and an N material may be injected onto the growth substrate105heated within a chamber to grow the Ga and N materials upward from the growth substrate105. In this case, an N-face region in which the N material has a relatively high concentration may be defined in a region adjacent to the growth substrate105within the first conductive type semiconductor layer110. Also, a Ga-face region in which the Ga material has a relatively high concentration may be defined in a region adjacent to the active layer120. Since a crystalization in the Ga-face region is superior to that in the N-face region, thermal stability in the Ga-face region is superior to that in the N-face region.

The active layer120may be formed on the first conductive type semiconductor layer110. In addition, the active layer120may have one of a single quantum well structure, a multi quantum well (MQW) structure, a quantum dot structure, and a quantum wire structure. The active layer120may have a cycle of a well layer and a barrier layer, e.g., an InGaN well layer/GaN barrier layer or an InGaN well layer/AlGaN barrier layer using the group III-V compound semiconductor material.

A conductive type clad layer (not shown) may be formed above or/and under the active layer120. The conductive type clad layer may be formed of an AlGaN-based semiconductor.

The second conductive type semiconductor layer130may be formed on the active layer120. The second conductive type semiconductor layer130may be formed of a group III-V compound semiconductor in which a second conductive type dopant is doped, i.e., a semiconductor material having a compositional formula of InxAlyGa1-x-yN (0≦x≦120, 0≦y≦2, 0≦x+y≦1). For example, the first conductive type semiconductor layer110may be formed of at least one selected from the group consisting of GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP. When the second conductive type semiconductor layer130is a P-type semiconductor layer, the second conductive type dopant may include P-type dopants such as Mg, Be, and Zn.

A third conductive type semiconductor layer (not shown) may be formed on the second conductive type semiconductor layer130. Also, the first conductive type semiconductor layer110may be realized as the P-type semiconductor layer, and the second conductive type semiconductor layer130may be realizes as the N-type semiconductor layer. Here, when the second conductive type semiconductor layer is the N-type semiconductor layer, the third conductive type semiconductor layer may be realized as the P-type semiconductor layer. On the other hand, when the second conductive type semiconductor layer is the P-type semiconductor layer, the third conductive type semiconductor layer may be realized as the N-type semiconductor layer. The light emitting part101may have at least one of an n-p junction structure, a pn junction structure, an n-p-n junction structure, and a p-n-p junction structure.

Referring toFIG. 5, a portion of the light emitting structure layer135may be etched to form a recess107in a plurality of regions so that the Ga-face region of the first conductive type semiconductor layer110is exposed. That is, an etched surface of the first conductive type semiconductor layer110exposed by the recess107may be defined as the Ga-face region. The light emitting part101and the ESD protection part103are separated from each other by the recess107. That is, the light emitting structure layer135may be divided into the light emitting part101including the first conductive type semiconductor layer110, the active layer120, and the second conductive type semiconductor layer130and the ESD protection part103including the first conductive type semiconductor layer112, the active layer122, and the second conductive type semiconductor layer132.

Although a side surface of the light emitting structure layer125having the recess107is vertically formed with respect to a top surface of the light emitting structure layer125inFIG. 5, the recess107may have a width gradually increasing or decreasing from the second conductive type semiconductor layer130toward the first conductive type semiconductor layer110, i.e., a width having a trapezoid shape. For example, the recess107may be formed so that a portion at which the first conductive type semiconductor layer110is disposed has a width less than that of a portion at which the second conductive type semiconductor layer130is disposed.

The recess107may be formed by an etching process including a wet etching process and a dry etching process or a laser process, but is not limited thereto. Also, the light emitting structure layer135having the recess107through the etching process or the laser process may have a side surface perpendicular or inclined with respect to a bottom surface of the recess107. Also, the side surface of the light emitting structure layer135may be perpendicular or inclined with respect to a top surface of the light emitting structure layer135.

Referring toFIG. 6, a first protection layer140is formed on an inner surface of the light emitting structure layer135having the recess107. The first protection layer140may be formed of at least one of insulation materials such as SiO2, Si3N4, Al2O3, and TiO2to prevent the light emitting structure layer135from being electrically short-circuited.

Referring toFIG. 5, first and second ohmic contact layers150and152are formed on the second conductive type semiconductor layer130of the light emitting part101and the second conductive type semiconductor layer132of the ESD protection part103, respectively.

The first and second ohmic contact layer150and152may respectively ohmic-contact the second conductive type semiconductor layers130and132to smoothly supply a power into the light emitting structure layer135. For example, a light-transmitting conductive layer and a metal may be selectively used as the ohmic contact layers150and152. That is, each of the ohmic contact layers150and152may be realized as a single or multi layer by using at least one selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), indium gallium tin oxide (IGTO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IrOx, RuOx, RuOx/ITO, Ni, Ag, Pt, Ni/IrOx/Au, and Ni/IrOx/Au/ITO.

A current blocking layer (CBL) (not shown) may be formed within the first ohmic contact layer150of the light emitting part101to contact the second conductive type semiconductor layer130. The CBL may partially overlap the electrode198in a vertical direction. Thus, a phenomenon in which a current is concentrated into the shortest distance between the electrode198and a conductive support member196that will be described later may be reduced to improve light emitting efficiency of the light emitting device100.

For example, the CBL may be formed of at least one of an insulating material, a material having conductivity less than that of the reflective layer160or the adhesion layer190, and a material schottky-contacting the second conductive type semiconductor layer130. For example, the CBL may be formed of at least one selected from the group consisting of ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, ZnO, SiO2, SiOx, SiOxNy, Si3N4, Al2O3, TiOx, Ti, Al, and Cr.

The CBL may be formed between the first ohmic contact layer150and the second conductive type semiconductor layer130or between the reflective layer160and the first ohmic contact layer150, but is not limited thereto.

Next, the reflective layer160may be formed on the first ohmic contact layer150to reflect light incident from the light emitting structure layer135. For example, the reflective layer160may be formed of a metal or alloy including at least one selected from the group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au and Hf. Alternatively, the reflective layer160may be formed as a multi layer using the metal or alloy and a light-transmitting conductive material such as IZO, IZTO, IAZO, IGZO, IGTO, AZO, or ATO. For example, the reflective layer160may be formed in a stacked structure such as IZO/Ni, AZO/Ag, IZO/Ag/Ni, AZO/Ag/Ni.

Referring toFIG. 8, a first connection layer170electrically connecting the first conductive type semiconductor layer110of the light emitting part101to the second conductive type semiconductor layer130of the ESD protection part103may be formed. An end of the first connection layer170may be connected to the Ga-face region of the first conductive type semiconductor layer110of the light emitting part101exposed by the recess107.

For example, the first connection layer170may be formed of a conductive metal material having superior conductivity, e.g., at least one selected from the group consisting of Ti, Ni, Cr, Au, and Cu, but is not limited thereto.

For example, the first connection layer170may be formed using one of an E-beam deposition process, a sputtering process, and a plasma enhanced chemical vapor deposition (PECVD) process. Here, since the first connection layer170is formed before the growth substrate105is removed by a laser lift off process, the process of forming the first connection layer170may be easily and stably performed.

Referring toFIG. 9, a protection member180may be formed in outer regions of the second conductive type semiconductor layer130of the light emitting part101and the second conductive type semiconductor layer132of the ESD protection layer103and on the first protection layer140and the first connection layer170. The protection member180may protect the light emitting device100against the outside and electrically insulate the light emitting part101from the ESD protection part103.

For example, the protection member180may be formed of at least one of an insulating material, a material having conductivity less than that of the reflective layer160or the adhesion layer190, and a material schottky-contacting the second conductive type semiconductor layer130. For example, the protection member180may be formed of at least one selected from the group consisting of ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, ZnO, SiO2, SiOx, SiOxNy, Si3N4, Al2O3, TiOx, Ti, Al, and Cr.

Referring toFIG. 10, a second connection layer185electrically connecting the second conductive type semiconductor layer130of the light emitting part101to the first conductive type semiconductor layer112of the ESD protection part103may be formed. Although the second connection layer185is formed on the reflective layer160and the protection member180formed within the light emitting device100to fill the recess107formed in a side of the ESD protection part103in the current embodiment, the present disclosure is not limited thereto. For example, the recess107formed in a side of the ESD protection part103is filled using a mask to form the second connection layer185having a pillar shape, thereby connecting the first conductive type semiconductor layer112of the ESD protection part103to an adhesion layer190.

For example, the second connection layer185may be formed of at least one selected from the group consisting of Ti, Ni, W, WTi, Mo, and Pt.

The light emitting part101and the ESD protection part103are connected to each other in parallel by the first and second connection layers170and185.

Next, the adhesion layer190may be formed on the second connection layer185. The adhesion layer190may enhance an adhesion force with a conductive support member195that will be described later. For example, the adhesion layer190may be formed of a barrier metal or bonding metal, e.g., at least one selected from the group consisting of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, and Ta.

Next, the conductive support member195may be formed on the adhesion layer190. The conductive support member195may support the light emitting structure layer135to provide a power into the light emitting structure layer135together with an electrode198that will be described later. For example, the conductive support member195may be formed of at least one selected from the group consisting of copper (Cu), gold (Au), nickel (Ni), molybdenum (Mo), copper-tungsten (Cu—W), AlSi, and carrier wafers (e.g., Si, Ge, GaAs, ZnO, Sic, etc).

Referring toFIG. 11, the growth substrate105may be removed after the light emitting device ofFIG. 8turns over by about 180 degrees.

Here, the growth substrate105may be removed using at least one of a laser lift off process and an etching process.

The growth substrate105may be removed to expose a surface of the first conductive type semiconductor layer110.

Referring toFIG. 12, a first mask148may be formed on a portion of the exposed first conductive type semiconductor layer110.

For example, the first mask148may be formed of one of a photo resist or a metal material, but is not limited thereto.

Referring toFIG. 13, a light extraction pattern117is formed on a top surface of the first conductive type semiconductor layer110. Here, the light extraction pattern117may be formed on the top surface of the first conductive type semiconductor layer110of the light emitting part101except a region of the top surface of the first conductive type semiconductor layer110covered by the first mask148.

The light extraction pattern117may have a random shape and arrangement or a desired shape and arrangement.

A wet etching process may be performed on the top surface of the light emitting structure layer135or a physical process such as a polishing process may be performed to form the light extraction pattern117having the random shape.

A pattern mask including a pattern having a shape corresponding to that of the light extraction pattern117may be formed on the top surface of the first conductive type semiconductor layer110to perform an etching process along the pattern mask, thereby forming the light extraction pattern117having the desired shape and arrangement.

After the light extraction pattern117is formed, the first mask148may be removed.

Referring toFIG. 14, a second mask149may be formed on the light extraction pattern117and the first conductive type semiconductor layer112of the ESD protection part103. The second mask149may be formed to perform an isolation etching process for separating the first conductive type semiconductor layer110of the light emitting part101from the first conductive type semiconductor layer112of the first conductive type semiconductor layer112of the ESD protection part103as well as for dividing a plurality of light emitting devices into device units.

For example, the second mask149may be formed of one of a photo resist or a metal material, but is not limited thereto.

Referring toFIG. 15, the isolation etching process may be performed in a chip boundary region105of the light emitting structure layer135using the second mask149to separate the first conductive type semiconductor layer110of the light emitting part101from the first conductive type semiconductor layer112of the first conductive type semiconductor layer112of the ESD protection part103and divide a plurality of light emitting devices into device units.

For example, the isolation etching process may be performed through a dry etching process such as an inductively coupled plasma (ICP) process or a wet etching using an etchant such as KOH, H2SO4, H3PO4, but is not limited thereto.

Referring toFIG. 16, a second protection layer197may be formed on a top surface of the light emitting structure layer135and inner and outer surfaces of the light emitting structure layer135etched by the isolation etching process. The second protection layer197may prevent the light emitting structure layer135from being electrically short-circuited with an external electrode. Also, the second protection layer197may prevent the first conductive type semiconductor layer110of the light emitting part101from being electrically short-circuited with the first conductive type semiconductor layer112of the ESD protection part103. For example, the second protection layer197may be formed of an insulating and light-transmitting material, e.g., at least one of SiO2, SiOx, SiOxNy, Si3N4, and Al2O3.

Next, an electrode198may be formed on the first conductive type semiconductor layer110of the light emitting part101. The electrode198may supply a current into the first conductive type semiconductor layer110. The electrode198may be formed as a single or multi layer using at least one material selected from the group consisting of Ti, Al, In, Ta, Pd, Co, Ni, Si, Ge, Ag, Au, Hf, Pt, Ru, and Au.

As shown inFIG. 16, the light emitting part101is formed in one region of the vertical type light emitting device100, and the ESD protection part103is formed in the other region of the vertical type light emitting device100. Since the crystalline is relatively superior in a region of the first conductive type semiconductor layer110of the light emitting part101by the first connection layer170, the Ga-face region having more thermal stability may be electrically connected to the second conductive type semiconductor layer132of the ESD protection part103and also the second conducive type semiconductor layer130of the light emitting part103may be electrically connected to the first conductive type semiconductor layer112of the ESD protection part103. Thus, since the ESD passes through the ESD protection part103, the light emitting part101may be protected to improve the reliability of the light emitting device100.

FIG. 17is a sectional view of a light emitting device package including the light emitting device according to an embodiment.

Referring toFIG. 17, a light emitting device package according to an embodiment includes a package body20, first and second electrode layers31and32disposed on the package body20, a light emitting device100disposed on the package body20and electrically connected to the first and second electrode layers31and32, and a molding member40surrounding the light emitting device100.

The package body20may be formed of a silicon material, a synthetic region material, or a metal material. Also, the package body20may have a cavity in which a side surface thereof is inclined.

The first electrode layer31and the second electrode layer32are electrically separated from each other and supply a power to the light emitting device100. Also, the first electrode layer31and the second electrode layer32may reflect light generated in the light emitting device100to improve light efficiency and may release heat generated in the light emitting device100to the outside.

The light emitting device100may be disposed on the package body20or on the first or second electrode layer31or32.

The light emitting device100may be electrically connected to the first and second electrode layers31and32through one of a wiring process, a flip-chip process, and a die bonding process. According to the current embodiment, the light emitting device100may be electrically connected to the first conductive layer31through a wire50and may directly contact the second conductive layer32and be electrically connected to the second conductive layer32.

The molding member40may surround the light emitting device100to protect the light emitting device100. The molding member40may include a phosphor to change a wavelength of light emitted form the light emitting device100.

The light emitting device package may be provided in plurality on a board, and optical members such as a light guide plate, a prism sheet, a diffusion sheet, and a fluorescent sheet may be disposed in a path of light emitted from the light emitting device package. The light emitting device package, the board, and the optical member may function as a backlight unit or a lighting unit. For example, a lighting system may include backlight units, lighting units, indicating devices, lamps, and street lamps.

FIG. 18is a view of a backlight unit including the light emitting device or the light emitting device package according to the embodiment. However, a backlight unit1100ofFIG. 18is described as an example of the lighting system. Thus, the present disclosure is not limited thereto.

Referring toFIG. 18, the backlight unit1100may include a bottom frame1140, a light guide member1120disposed within the bottom frame1140, and a light emitting module1110disposed on at least one side or an under surface of the light guide member1120. Also, a reflective sheet1130may be disposed under the light guide member1120.

The bottom frame1140may have a box shape with an opened upper side to receive the light guide member1120, the light emitting module1110, and the reflective sheet1130. The bottom frame1140may be formed of a metal material or a resin material, but is not limited thereto.

The light emitting module1110may include a board300and a plurality of light emitting device packages200mounted on the board300. The plurality of light emitting device packages200may provide light to the light guide member1120.

As shown inFIG. 18, the light emitting module1110may be disposed on at least one of inner surfaces of the bottom frame1140. Thus, the light emitting module1110may provide light toward at least one side surface of the light guide member1120.

However, the light emitting module1110may be disposed under the bottom frame1140to provide light toward the under surface of the light guide member1120. Since this structure is variously varied according to a design of the backlight unit1100, the present disclosure is not limited thereto.

The light guide member1120may be disposed within the bottom frame1140. The light guide member1120may receive the light provided from the light emitting module1110to produce planar light, thereby guiding the planar light to a display panel (not shown).

For example, the light guide member1120may be a light guide panel (LGP). The LGP may be formed of one of a resin-based material such as polymethyl methacrylate (PMMA), a polyethylene terephthalate (PET) resin, a poly carbonate (PC) resin, a cyclic olefin copolymer (COC) resin, and a polyethylene naphthalate (PEN) resin.

An optical sheet1150may be disposed above the light guide member1120.

For example, the optical sheet1150may include at least one of a diffusion sheet, a light collection sheet, a brightness enhancement sheet, and a fluorescence sheet. For example, the diffusion sheet, the light collection sheet, the brightness enhancement sheet, and the fluorescence sheet may be stacked to form the optical sheet1150. In this case, the diffusion sheet1150may uniformly diffuse light emitted from the light emitting module1110, and the diffused light may be collected into the display panel (not shown) by the light collection sheet. Here, the light emitted from the light collection sheet is randomly polarized light. The bright enhancement sheet may enhance a degree of polarization of the light emitted from the light collection sheet. For example, the light collection sheet may be a horizontal and/or vertical prism sheet. Also, the bright enhancement sheet may be a dual brightness enhancement film. Also, the fluorescence sheet may be a light transmitting plate or film including a phosphor.

The reflective sheet1130may be disposed under the light guide member1120. The reflective sheet1130reflects the light emitted through the bottom surface of the light guide member1120toward a light emission surface of the light guide member1120.

The reflective sheet1130may be formed of a material having superior reflectance, e.g., a PET resin, a PC resin, or a PVC resin, but is not limited thereto.

FIG. 19is a perspective view of a lighting unit including the light emitting device or the light emitting device package according to the embodiments. However, a lighting unit1200ofFIG. 19is described as an example of the lighting system. Thus, the present disclosure is not limited thereto.

Referring toFIG. 19, the lighting unit1200may include a case body1210, a light emitting module1230disposed on the case body1210, and a connection terminal1220disposed on the case body1210to receive a power from an external power source.

The case body1210may be formed of a material having good thermal dissipation properties, e.g., a metal material or a resin material.

The light emitting module1230may include a board300and at least one light emitting device package200mounted on the board300.

A circuit pattern may be printed on a dielectric to manufacture the board300. For example, the board300may include a printed circuit board (PCB), a metal core PCB, a flexible PCB, and a ceramic PCB.

Also, the board300may be formed of a material which may effectively reflect light or have a color by which light is effectively reflected, e.g., a white color or a silver color.

The at least one light emitting device package200may be mounted on the board300. The light emitting device package200may include at least one light emitting diode (LED). The LED may include colored LEDs, which respectively emit light having a red color, a green color, a blue color, and a white color and an ultraviolet (UV) LED emitting UV rays.

The light emitting module1230may have various combinations of the LEDs to obtain color impression and brightness. For example, the white LED, the red LED, and the green LED may be combined with each other to secure a high color rendering index. Also, a fluorescence sheet may be further disposed on a path of light emitted from the light emitting module1230. The fluorescence sheet may change a wavelength of light emitted from the light emitting module1230. For example, when the light emitted from the light emitting module1230has a blue wavelength band, the fluorescence sheet may include a yellow phosphor. Thus, the light emitted from the light emitting module1230passes through the fluorescence sheet to finally emit white light.

The connection terminal1220may be electrically connected to the light emitting module1230to provide a power to the light emitting module1230. Referring toFIG. 17, the connected terminal1220is screw-coupled to an external power source in a socket manner, but is not limited thereto. For example, the connection terminal1220may have a pin shape, and thus, be inserted into the external power source. Alternatively, the connection terminal1220may be connected to the external power source by a wire.

As described above, in the lighting system, at least one of the light guide member, the diffusion sheet, the light collection sheet, the brightness enhancement sheet, and the fluorescence sheet may be disposed on the path of the light emitted from the light emitting module to obtain desired optical effects.

As described above, the lighting system according to the embodiments includes the light emitting device or the light emitting device package according to the embodiment to improve the light efficiency.