KR20150050164A - Light emitting device - Google Patents

Abstract

A light emitting device according to an embodiment comprises a light emitting structure including a first semiconductor doped with a first dopant, an active layer located on the first semiconductor layer, and a second semiconductor layer located on the active layer, and doped with a second dopant having polarity opposite to the first dopant; a first electrode located under the first semiconductor layer, and electrically connected with the first semiconductor layer; a second electrode located on the second semiconductor layer, and electrically connected with the second semiconductor layer; and a current limiting part located between the active layer and the first electrode, wherein the current limiting part is characterized by having a part of the area located to be perpendicularly overlapped with at least the second electrode, and having a part of the area of the first semiconductor layer exposed in a gas discharge state.

Description

[0001]

An embodiment relates to a light emitting element.

As a typical example of a light emitting device, a light emitting diode (LED) is a device for converting an electric signal into an infrared ray, a visible ray, or a light using the characteristics of a compound semiconductor, and is used for various devices such as household appliances, remote controllers, Automation equipment, and the like, and the use area of LEDs is gradually widening.

In general, miniaturized LEDs are made of a surface mounting device for mounting directly on a PCB (Printed Circuit Board) substrate, and an LED lamp used as a display device is also being developed as a surface mounting device type . Such a surface mount device can replace a conventional simple lighting lamp, which is used for a lighting indicator for various colors, a character indicator, an image indicator, and the like.

As the use area of the LED is widened as described above, it is important to increase the luminance of the LED as the brightness required for a lamp used in daily life and a lamp for a structural signal is increased.

A current limiting portion is generally used to prevent electrons injected from the second semiconductor layer from being injected into the first semiconductor without being recombined in the active layer.

However, in general, the lower aluminum oxide conductivity (Al ₂ O _3), silicon oxide (SiO _2), silicon nitride (Si ₃ N _4), titanium (TiO _x), indium tin oxide to form the current-limiting Indium tin oxide (ITO), aluminum zinc oxide (AZO), and indium zinc oxide (IZO).

However, in order to form the current confined part with the above-described material, there is a problem that it is troublesome to perform the step of opening the chamber and depositing the current confined part in the manufacturing process of the light emitting device.

In addition, when the above-described insulating material is formed on the first semiconductor layer, there is a problem that damage occurs in the first semiconductor layer.

The embodiment provides a light emitting device which improves the luminous efficiency and is easy to manufacture.

A light emitting device according to an embodiment includes a first semiconductor layer doped with a first dopant, an active layer located on the first semiconductor layer, and a second dopant, which is located on the active layer and has a polarity opposite to the first dopant, A first electrode located under the first semiconductor layer and electrically connected to the first semiconductor layer; a second electrode located in the second semiconductor layer and electrically connected to the second semiconductor layer; And a current confinement portion disposed between the active layer and the first electrode, wherein the current confinement portion is positioned such that at least a portion of the second electrode is vertically overlapped with the first electrode, Is formed by exposing a part of the gas to a gas discharge state.

Here, the current limiter may include a defect caused by the second dopant.

In addition, the current limiting portion may be positioned such that one surface thereof is in contact with the first electrode.

The horizontal cross-sectional area of the current limiting portion may be equal to or greater than the horizontal cross-sectional area of the second electrode.

The first dopant may include a p-type dopant, and the second dopant may include an n-type dopant.

The active layer may include at least one well layer and a barrier layer having a band gap energy greater than that of the well layer.

In addition, the current limiting portion may have a lower electrical conductivity than the first semiconductor layer.

The surface of the first semiconductor layer, which is in contact with the first electrode, may include a doping region doped with a higher concentration than the first semiconductor layer.

The current limiting portion may be formed in the excessive region.

According to the embodiment, since the current limiting portion is formed by being exposed to the gas discharge (plasma) state, there is no need to stop the manufacturing process of the light emitting element to take out the light emitting element in the chamber to form the current limiting portion There is an advantage.

In addition, since the gas discharge can be performed by supplying power to the gas in the chamber, there is an advantage that the gas discharge can be performed in a chamber of a light emitting device manufacturing process without a separate process or equipment.

Further, since the current limiting portion is used, it is possible to prevent the electrons injected from the second semiconductor layer from being injected into the first semiconductor layer without being recombined in the active layer. As a result, the probability of recombination of electrons and holes in the active layer can be increased and leakage current can be prevented.

In addition, when the insulating material is formed on the first semiconductor layer, the problem of damage to the first semiconductor layer can be solved.

1 is a plan view showing a light emitting device according to an embodiment of the present invention,
FIG. 2 is a cross-sectional view taken along a line I-I of the light emitting device of FIG. 1,
3 is an enlarged cross-sectional view of part A of the light emitting device of Fig. 2,
4 is a plan view showing a light emitting device according to another embodiment of the present invention,
5 is a cross-sectional view taken along a line II-II of the light emitting device of FIG. 4,
6 is a cross-sectional view illustrating a light emitting device according to another embodiment of the present invention,
7A is a photograph of a light emission distribution according to a comparative example,
FIG. 7B is a photograph of the emission distribution according to the embodiment,
8 is a sectional view of a light emitting device package including the light emitting device according to the embodiment,
9 is an exploded perspective view of a display device including a light emitting device according to an embodiment.
10 is a cross-sectional view of the display device of Fig.
11 is an exploded perspective view of a lighting device including a light emitting device according to an embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

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

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size and area of each component do not entirely reflect actual size or area.

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

FIG. 1 is a plan view of a light emitting device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along a line I-I of FIG. 1, and FIG.

1 and 2, the light emitting device 200 according to the embodiment includes a support member 210, a first electrode 245 disposed on the support member 210, a first electrode 245 disposed on the first electrode 245, A second semiconductor layer 250 on the active layer 230 and a second electrode electrically connected to the second semiconductor layer 250. The second semiconductor layer 250 is formed on the first semiconductor layer 220, And a current restricting portion 295 positioned between the first electrode 245 and the active layer 230. [

The support member 210 may be formed using a material having a high thermal conductivity, or may be formed of a conductive material. The support member 210 may be formed using a metal material or a conductive ceramic. The support member 210 may be formed as a single layer, and may be formed as a double structure or a multiple structure.

That is, the support member 210 may be formed of any one selected from a metal, for example, Au, Ni, W, Mo, Cu, Al, Ta, Ag, Pt, and Cr, or may be formed of two or more alloys. The above materials can be laminated. In addition, the support member 210 may be implemented with a carrier wafer such as Si, Ge, GaAs, ZnO, SiC, SiGe, GaN, Ga 2 O 3.

Such a support member 210 facilitates the release of heat generated in the light emitting device 200, thereby improving the thermal stability of the light emitting device 200.

In addition, a metal layer (not shown) may be further formed on the lower surface of the support member 210 to prevent the light emitting device 200 from being bent.

A first electrode 245 may be formed on the support member 210. The first electrode 245 may include an ohmic layer (not shown), a reflective layer (not shown), a bonding layer and a bonding layer (not shown).

For example, the first electrode 245 may be a structure of an ohmic layer / reflection layer / bonding layer, a laminate structure of an ohmic layer / reflection layer, or a structure of a reflection layer (including ohmic) / bonding layer. For example, the first electrode 245 may be formed by sequentially stacking a reflective layer and an ohmic layer on an insulating layer.

The reflective layer (not shown) may be disposed between an ohmic layer (not shown) and an insulating layer (not shown), and may be formed of a material having excellent reflection characteristics, such as Ag, Ni, Al, Rh, Pd, , Zn, Pt, Au, Hf and combinations thereof, or may be formed using a metal material and a light-transmitting conductive material such as IZO, IZTO, IAZO, IGZO, IGTO, AZO or ATO have.

Further, the reflective layer (not shown) can be laminated with IZO / Ni, AZO / Ag, IZO / Ag / Ni, AZO / Ag / Ni and the like. In addition, when a reflective layer (not shown) is formed of a material in ohmic contact with the light emitting structure 260 (e.g., the first semiconductor layer 220), an ohmic layer (not shown) may not be formed separately, I do not.

The ohmic layer (not shown) is in ohmic contact with the lower surface of the light emitting structure 260, and may be formed in a layer or a plurality of patterns. The ohmic layer (not shown) may be formed of a transparent electrode layer and a metal. For example, ITO (indium tin oxide), IZO (indium zinc oxide), IZTO (indium zinc tin oxide) ), IGZO (indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IrO _x , RuO _x , RuO _x / Ni, Ag, Ni / IrO _x / Au, and Ni / IrO _x / Au / ITO. The ohmic layer (not shown) is for facilitating the injection of carriers into the first semiconductor layer 220, and is not necessarily formed.

In addition, the first electrode 245 may include a bonding layer (not shown), wherein the bonding layer (not shown) may include a barrier metal or a bonding metal such as Ti, Au, Sn, Ni , Cr, Ga, In, Bi, Cu, Ag, or Ta.

The light emitting structure 260 may be positioned on the first electrode 245.

The light emitting structure 260 may include at least a first semiconductor layer 220, an active layer 230 and a second semiconductor layer 250 and may be formed between the first semiconductor layer 220 and the second semiconductor layer 250 And the active layer 230 may be disposed.

Specifically, a first semiconductor layer 220 doped with a first dopant may be formed on the first electrode 245. The first semiconductor layer 220 may be a p-type semiconductor layer doped with a p-type dopant. The p-type semiconductor layer is a semiconductor material having a composition formula of In _x Al _y Ga _1-xy N (0? x? 1, 0? y? 1, 0? x + y? 1), for example, GaN, AlN, AlGaN InGaN, InN, InAlGaN, AlInN and the like, and a p-type dopant such as Mg, Zn, Ca, Sr, and Ba can be doped.

 The active layer 230 may be formed on the first semiconductor layer 220. The active layer 230 may be formed of a single or multiple quantum well structure, a quantum-wire structure, a quantum dot structure, or the like using a compound semiconductor material of Group 3-V group elements.

When the active layer 230 is formed of a quantum well structure, for example, a well layer having a composition formula of In _x Al _y Ga _1-xy N (0? X? 1, 0? Y? 1, 0? X + y? 1) And a barrier layer having a composition formula of In _a Al _b Ga _1-ab N (0? A? ₁ , 0? B? ₁ , 0? A + b? 1). The well layer may be formed of a material having a band gap smaller than the band gap of the barrier layer.

A conductive clad layer (not shown) may be formed on and / or below the active layer 230. The conductive clad layer (not shown) may be formed of an AlGaN-based semiconductor and may have a band gap larger than that of the active layer 230.

Referring to FIG. 3, in detail, the active layer 230 may have a multiple quantum well structure. For example, the active layer 230 includes at least one well layer Q1, Q2, Q3 and barrier layers B1, B2, B3 having bandgap energies greater than the well layers Q1, Q2, Q3 can do.

More specifically, the active layer 230 may include first through third well layers Q1, Q2, Q3 and first through third barrier layers B1, B2, and B3.

Here, the well layer closest to the first semiconductor layer 220, and the barrier layer are defined as a first well layer Q1 and a first barrier layer B1.

The first through third well layers Q1, Q2, and Q3 and the first through third barrier layers B1, B2, and B3 may have a structure in which they are alternately stacked as shown in FIG.

3, the first through third well layers Q1, Q2 and Q3 and the first through third barrier layers B1, B2 and B3 are formed and the first through third barrier layers B1 and B2 Q2 and Q3 and the barrier layers B1, B2 and Q3 and the first through third well layers Q1, Q2 and Q3 are alternately stacked, B3 may be formed to have any number, and the arrangement may also have any arrangement. In addition, as described above, the composition ratio, band gap, and thickness of the material forming each of the well layers Q1, Q2, and Q3 and the barrier layers B1, B2, and B3 may be different from each other, As shown in Fig.

On the active layer 230, a second semiconductor layer 250 doped with a second dopant having a polarity opposite to that of the first dopant may be formed. The second semiconductor layer 250 may be formed of an n-type semiconductor layer, and the n-type semiconductor layer may include, for example, In _x Al _y Ga _1-xy N (0? X? 1, 0? Y? for example, Si, Ge, Sn, Se, Te, or the like can be selected from a semiconductor material having a composition formula of Si, Ge, Sn, Type dopant can be doped.

An electron blocking layer (not shown) may be formed between the active layer 230 and the second semiconductor layer 250, and the electron blocking layer may be formed from the second semiconductor layer 250 to the active layer 230 It is possible to prevent the injected electrons from flowing to the first semiconductor layer 220 without being recombined in the active layer 230.

The electron blocking layer has a band gap relatively larger than that of the active layer 230 so that electrons injected from the second semiconductor layer 250 are injected into the first semiconductor layer 220 without being recombined in the active layer 230 . Accordingly, it is possible to increase the probability of recombination of electrons and holes in the active layer 230 and to prevent a leakage current.

Meanwhile, the electron blocking layer may have a band gap larger than the band gap of the barrier layer included in the active layer 230, and may be formed of a semiconductor layer containing Al, such as p-type AlGaN, but is not limited thereto.

A second electrode 282 electrically connected to the second semiconductor layer 250 may be formed on the second semiconductor layer 250. The second electrode 282 may include at least one pad or / . ≪ / RTI > The second electrode 282 may be disposed in the center region, the outer region, or the edge region of the upper surface of the second semiconductor layer 250, but the present invention is not limited thereto. The second electrode 282 may be disposed in a region other than the upper portion of the second semiconductor layer 250, but the present invention is not limited thereto.

The second electrode 282 may be formed of a conductive material such as In, Co, Si, Ge, Au, Pd, Pt, Ru, Re, Mg, Zn, Hf, Ta, Rh, Ir, W, , Mo, Nb, Al, Ni, Cu, and WTi.

Although not shown in the figure, a light-transmitting electrode layer (not shown) may be disposed between the second electrode 282 and the second semiconductor layer 250.

The transparent electrode layer ITO, IZO (In-ZnO) , GZO (Ga-ZnO), AZO (Al-ZnO), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), IrO x, RuO x, RuO x / ITO, Ni / IrO _x / Au, and Ni / IrO _x / Au / ITO, and is formed on the entire upper surface of the second semiconductor layer 250, have.

A light extracting structure 284 may be formed on the upper portion of the light emitting structure 260.

The light extracting structure 284 may be formed on the upper surface of the second semiconductor layer 250 or may be formed on a transparent electrode layer (not shown) after forming a light transmitting electrode layer (not shown) on the light emitting structure 260 But not limited to,

The light extracting structure 284 may be formed in a light transmitting electrode layer (not shown), or in some or all of the upper surface of the second semiconductor layer 250.

The light extracting structure 284 may be formed by performing etching on at least one region of the light transmitting electrode layer (not shown), or the upper surface of the second semiconductor layer 250, but is not limited thereto. The upper surface of the light-transmitting electrode layer (not shown) or the upper surface of the second semiconductor layer 250 may be a rough surface (not shown) forming the light extracting structure 284, ≪ / RTI >

The roughness may be irregularly formed in a random size, but is not limited thereto. The roughness may be at least one of a texture pattern, a concave-convex pattern, and an uneven pattern, which is an uneven surface.

The roughness may be formed to have various shapes such as a cylinder, a polygonal column, a cone, a polygonal pyramid, a truncated cone, a polygonal pyramid, and the like, preferably including a horn shape.

Meanwhile, the light extracting structure 284 may be formed by a method such as PEC (photoelectrochemical), but is not limited thereto. Light generated from the active layer 230 may be transmitted through the light-transmitting electrode layer (not shown) or the second semiconductor layer 250 (not shown) as the light extracting structure 284 is formed on the upper surface of the light- Can be prevented from being totally reflected from the upper surface of the light emitting device 250 and reabsorbed or scattered, thereby contributing to improvement of light extraction efficiency of the light emitting device 200.

A passivation 290 may be formed on the side and upper regions of the light emitting structure 260.

Specifically, the passivation 290 is disposed to cover the upper surface of the light emitting structure 260 and the side surface of the light emitting structure 260, thereby protecting the light emitting device 200 from external shocks and static electricity.

The passivation 290 may be formed of an insulating material.

For example, the passivation 290 may include at least one of silicon dioxide (SiO ₂ ), silicon dioxide (SiO ₂ ), and aluminum oxide (Al ₂ O ₃ ).

Although not shown in the drawing, a stress relaxation layer (not shown) may be further included between the first semiconductor layer 220 and the active layer 230.

The stress relieving layer includes a plurality of first layers (not shown) having compressive stress including AlGaN and a plurality of second layers (not shown) having tensile stress including GaN, They can be alternately repeatedly laminated.

Specifically, the stress relieving layer may have a structure in which 4 to 16 first layers and 4 to 16 second layers are repeatedly laminated. However, the number of the first layer and the second layer is not limited thereto and may have various numbers.

Si substrate has a disadvantage that it is difficult to grow an epitaxial layer due to cracks due to a large lattice constant and thermal expansion coefficient difference with the second semiconductor layer 250 (gallium nitride (GaN)). In addition, if the thickness of the second semiconductor layer 250 is increased, the tensile stress in the thin film gradually increases, and if it exceeds the critical thickness, defects are generated and adversely affect the reverse current characteristics in particular. In particular, when a defect is generated in a portion of the second semiconductor layer 250 adjacent to the active layer 230, the active layer 230 is connected to the light emitting active layer 230, and the micro defect in the active layer also causes a bad reverse current characteristic.

Therefore, the embodiment can prevent defects of the active layer 230 through the first layer having compressive stress and the second layer having tensile stress, and has an effect of improving the reverse current (Vr) characteristic.

Referring again to FIGS. 1 and 2, a current limiting portion 295 is located between the active layer 230 and the first electrode 245. The current limiting portion 295 may be formed in the first semiconductor layer 220 and may have a lower electrical conductivity than the first semiconductor layer 220 and the first electrode 245.

The current limiting unit 295 prevents electrons injected from the second semiconductor layer 250 to the active layer 230 from flowing to the first electrode 245 without being recombined in the active layer 230 when a high current is applied.

The current limiting part 295 can prevent electrons injected from the second semiconductor layer 250 from being injected into the first semiconductor layer 220 without being recombined in the active layer 230. [ Accordingly, it is possible to increase the probability of recombination of electrons and holes in the active layer 230 and to prevent a leakage current.

In order to form the current limiting portion 295, aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), titanium oxide (TiO _x ) Indium tin oxide (ITO), aluminum zinc oxide (AZO), and indium zinc oxide (IZO).

That is, in order to form the current limiting portion 295 with the above-described material, there is a problem that the step of opening the chamber and depositing the current limiting portion 295 in the light emitting device manufacturing process is troublesome.

In order to solve this problem, the current limiting part 295 of the embodiment is characterized in that a part of the first semiconductor layer 220 is formed by being exposed to a gas discharge state.

Here, the gas discharge state means a phenomenon in which a gas molecule which is neutral is ionized and discharged in a specific situation. Also, the gas discharge state may include a corona discharge, a glow discharge, an arc discharge, and a spark discharge.

Specifically, the current limiting portion 295 may be formed by being exposed to a gas discharge state (atmosphere) of various kinds of gases formed in a vacuum chamber (not shown).

There is no limitation on the gas used for gas discharge, but it may preferably include chlorine (Cl ₂ ).

More specifically, when a RF power of 50 W is applied using a Cl ₂ (40 sccm) gas using a Dual-ICP equipment, a gas discharge state is formed, and a current limiting part of the first semiconductor layer 220 And the region where the first electrode 295 is to be formed is exposed for about 12 seconds.

When a part of the first semiconductor layer 220 is exposed to a gas discharge state, a current restricting portion 295 is formed and the current restricting portion 295 is formed of a defect (defect) caused by the second dopant (n-type dopant) (Defect). When the current limiting portion 295 doped with the p-type dopant includes defects due to the n-type dopant, the current limiting portion 295 is formed in the non-conductive or low conductive region. When the current limiting portion 295 is formed in the non-conductive or low conductive region, the probability of recombination of electrons and holes in the active layer 230 can be increased and the leakage current can be prevented.

Therefore, according to the embodiment, since the current limiting portion 295 is formed by being exposed to the gas discharge (plasma) state, the current limiting portion 295 is formed by exposing the light emitting element in the chamber, There is an advantage that there is no need to stop the manufacturing process of the semiconductor device.

In addition, since the gas discharge can be performed by supplying power to the gas in the chamber, there is an advantage that the gas discharge can be performed in a chamber of a light emitting device manufacturing process without a separate process or equipment.

The current limiting portion 295 may be positioned between the active layer 230 and the first electrode 245 so that at least a portion of the second electrode 282 overlaps vertically. Here, the vertical means a direction based on FIG. 2, and does not mean a complete vertical in a mathematical sense.

The current supplied from the second electrode 282 tends to be transmitted to the lower portion perpendicular to the second electrode 282. The current limiting portion 295 is formed between the active layer 230 and the first electrode 245 And the horizontal cross-sectional area (reference in FIG. 2) of the current restricting portion 295 may be equal to or greater than the horizontal cross-sectional area of the second electrode 282.

More specifically, the horizontal cross-sectional area of the current limiting portion 295 may be 80% to 120% of the horizontal cross-sectional area of the second electrode 282. If the horizontal cross-sectional area of the current restricting part 295 is smaller than 80% of the horizontal cross-sectional area of the second electrode 282, the leakage current from the second semiconductor layer 250 toward the first electrode 245 can not be effectively blocked, If the horizontal cross-sectional area of the current restricting part 295 is larger than 120% of the horizontal cross-sectional area of the second electrode 282, the resistance of the light emitting device is increased and the efficiency of the light emitting device is reduced.

The current limiting portion 295 may be freely positioned in the first semiconductor layer 220 but may be located on the lower surface of the first semiconductor layer 220 (in FIG. 2), considering the efficiency of the operation. That is, the current limiting portion 295 may be positioned so that one surface thereof is in contact with the first electrode.

The thickness of the current limiting portion 295 is not limited, but is preferably 4 nm to 10 nm. If the thickness of the current confining portion 295 is thinner than 4 nm, the current is tunneled through the current confining portion 295 to effectively block the current leaking from the second semiconductor layer 250 toward the first electrode 245 If the thickness of the current limiting portion 295 is larger than 10 nm, the resistance of the light emitting element is increased and the efficiency of the light emitting element is reduced.

FIG. 4 is a plan view of a light emitting device according to another embodiment of the present invention, and FIG. 5 is a cross-sectional view taken along a line II-II of the light emitting device of FIG.

4 and 5, the light emitting device 200A of the embodiment has a difference in shape and arrangement of the second electrode 282A and the current limiting portion 295A as compared with the embodiment of FIGS. 1 and 2 do. Hereinafter, differences from FIGS. 1 and 2 will be mainly described, and description of the same components will be omitted.

The second electrode 282A includes at least one electrode pad 282-1 disposed on one side of the second semiconductor layer 250 to effectively diffuse the current, And at least one electrode wing 282-1 extending therefrom.

4, the second electrode 282A is disposed such that two electrode pads 282-1 to which the wires are bonded are disposed on one side of the upper surface (reference in FIG. 5) of the second semiconductor layer 250 And the electrode wing 282-1 connecting the two electrode pads 282-1 may be arranged in a lattice shape on the upper surface of the second semiconductor layer 250. [ Of course, the shape and the number of the electrode pads 282-1 and the electrode wing 282-1 can have various shapes and numbers.

The current limiting portion 295A may be positioned so as to vertically overlap the electrode pad 282-1 and the electrode wing in the first semiconductor layer 220. [ The current limiting portion 295A may have a position and a size corresponding to the electrode pad 282-1 and the electrode wing 282-1.

6 is a cross-sectional view illustrating a light emitting device according to another embodiment of the present invention.

Referring to FIG. 6, the light emitting device 200B of the embodiment has a structure in which the first semiconductor layer 220 further includes an excessive region 251B, and the current limiting portion 295 There are differences in location.

The surface of the first semiconductor layer 220 in contact with the first electrode 245 may be doped with the p-type dopant at a higher concentration than the first semiconductor layer 220 in the doped region 251B.

When the first doped region 251B is formed in the first semiconductor layer 220, the ability to form an ohmic contact with the first electrode 245 is improved.

At this time, the current limiter 295 may be formed at a position vertically overlapping the second electrode 282 in the over-doped region 251B.

FIG. 7A is a photograph of the light emission distribution according to the comparative example, and FIG. 7B is a photograph of the light emission distribution according to the embodiment.

The comparative example of FIG. 7A differs from that of FIG. 7B in that the configuration of the current limiter 295 is omitted.

In the comparative example, since the current limiting portion 295 is not present, it can be seen that the light emitting region is strongly formed around the electrode pad 282-1 to which the wire is bonded and the current is supplied. Therefore, electrons injected from the second semiconductor layer 250 are injected into the first semiconductor layer 220 without being recombined in the active layer 230.

Since the current limiting portion 295 is present in the embodiment, not only the electrode pad 282-1 to which the wire is bonded and the current is supplied, but also the entire second semiconductor layer 250 emits light uniformly have.

As shown in FIGS. 7A and 7B, it can be seen that the difference in luminous efficiency between the comparative example and the embodiment is very large.

8 is a cross-sectional view illustrating a light emitting device package including the light emitting device according to the embodiment.

8, the light emitting device package 300 according to the embodiment includes a body 310 having a cavity, a light source 320 mounted on the cavity of the body 310, and an encapsulant 350 filled in the cavity 310 can do.

The body 310 may be made of a resin material such as polyphthalamide (PPA), silicon (Si), aluminum (Al), aluminum nitride (AlN), photo sensitive glass (PSG), polyamide 9T (SPS), a metal material, sapphire (Al2O3), beryllium oxide (BeO), a printed circuit board (PCB), and ceramics. The body 310 may be formed by injection molding, etching, or the like, but is not limited thereto.

The light source unit 320 may be mounted on the bottom surface of the body 310. For example, the light source unit 320 may be any one of the light emitting devices illustrated in FIGS. The light emitting device may be, for example, a colored light emitting device that emits light such as red, green, blue, or white, or a UV (Ultra Violet) light emitting device that emits ultraviolet light. In addition, one or more light emitting elements can be mounted.

The body 310 may include a first electrode 330 and a second electrode 340. The first electrode 330 and the second electrode 340 may be electrically connected to the light source 320 to supply power to the light source 320.

In addition, the first electrode 330 and the second electrode 340 are electrically separated from each other. The first electrode 330 and the second electrode 340 can reflect the light generated from the light source unit 320 to increase the light efficiency. Further, To the outside.

8 illustrates that both the first electrode 330 and the second electrode 340 are bonded to the light source 320 by the wire 360. However, the present invention is not limited thereto, Any one of the electrode 330 and the second electrode 340 may be bonded to the light source 320 by the wire 360 and may be electrically connected to the light source 320 without the wire 360 by the flip- have.

The first electrode 330 and the second electrode 340 may be formed of a metal material such as titanium (Ti), copper (Cu), nickel (Ni), gold (Au), chromium (Cr), tantalum Ta, Pt, Sn, Ag, P, Al, Pd, Co, Si, Ge, Ge), hafnium (Hf), ruthenium (Ru), and iron (Fe). The first electrode 330 and the second electrode 340 may have a single-layer structure or a multi-layer structure, but the present invention is not limited thereto.

The encapsulant 350 may be filled in the cavity and may include a phosphor (not shown). The encapsulant 350 may be formed of a transparent silicone, epoxy, or other resin material, and may be formed in such a manner that the encapsulant 350 is filled in the cavity and then cured by UV or thermal curing.

The phosphor (not shown) may be selected according to the wavelength of the light emitted from the light source unit 320 so that the light emitting device package 300 may emit white light.

The fluorescent material (not shown) included in the encapsulant 350 may be a blue light emitting phosphor, a blue light emitting fluorescent material, a green light emitting fluorescent material, a yellow green light emitting fluorescent material, a yellow light emitting fluorescent material, , An orange light-emitting fluorescent substance, and a red light-emitting fluorescent substance may be applied.

That is, the phosphor (not shown) may be excited by the light having the first light emitted from the light source 320 to generate the second light. For example, when the light source 320 is a blue light emitting diode and the phosphor (not shown) is a yellow phosphor, the yellow phosphor may be excited by blue light to emit yellow light, and blue light emitted from the blue light emitting diode and blue The light emitting device package 300 can provide white light as yellow light generated by excitation by light is mixed.

The light emitting device according to the embodiment can be applied to a lighting device. The lighting system includes a structure in which a plurality of light emitting elements are arrayed and includes a display device shown in Figs. 9 and 10, a lighting device shown in Fig. 11, and may include a lighting lamp, a traffic light, a vehicle headlight, have.

9 is an exploded perspective view of a display device having a light emitting device according to an embodiment.

9, a display device 1000 according to an exemplary embodiment of the present invention includes a light guide plate 1041, a light source module 1031 for providing light to the light guide plate 1041, and a reflection member 1022 An optical sheet 1051 on the light guide plate 1041 and a display panel 1061 on the optical sheet 1051 and the light guide plate 1041 and the light source module 1031 and the reflection member 1022 But is not limited to, a bottom cover 1011.

The bottom cover 1011, the reflective sheet 1022, the light guide plate 1041, and the optical sheet 1051 can be defined as a light unit 1050.

The light guide plate 1041 serves to diffuse light into a surface light source. The light guide plate 1041 may be made of a transparent material, for example, acrylic resin such as polymethylmethacrylate (PET), polyethylene terephthalate (PET), polycarbonate (PC), cycloolefin copolymer (COC), and polyethylene naphtha late Resin. ≪ / RTI >

The light source module 1031 provides light to at least one side of the light guide plate 1041, and ultimately acts as a light source of the display device.

The light source module 1031 includes at least one light source module 1031 and may directly or indirectly provide light from one side of the light guide plate 1041. The light source module 1031 includes a substrate 1033 and a light emitting device 1035 according to the embodiment described above and the light emitting devices 1035 may be arrayed at a predetermined interval on the substrate 1033 .

The substrate 1033 may be a printed circuit board (PCB) including a circuit pattern (not shown). However, the substrate 1033 may include not only a general PCB, but also a metal core PCB (MCPCB), a flexible PCB (FPCB), and the like. When the light emitting element 1035 is mounted on the side surface of the bottom cover 1011 or on the heat radiation plate, the substrate 1033 can be removed. Here, a part of the heat radiating plate may be in contact with the upper surface of the bottom cover 1011.

The plurality of light emitting devices 1035 may be mounted on the substrate 1033 such that the light emitting surface is spaced apart from the light guiding plate 1041 by a predetermined distance. However, the present invention is not limited thereto. The light emitting device 1035 may directly or indirectly provide light to the light-incident portion, which is one surface of the light guide plate 1041, but the present invention is not limited thereto.

The reflective member 1022 may be disposed under the light guide plate 1041. The reflection member 1022 reflects the light incident on the lower surface of the light guide plate 1041 so as to face upward, thereby improving the brightness of the light unit 1050. The reflective member 1022 may be formed of, for example, PET, PC, or PVC resin, but is not limited thereto. The reflective member 1022 may be an upper surface of the bottom cover 1011, but is not limited thereto.

The bottom cover 1011 may house the light guide plate 1041, the light source module 1031, the reflective member 1022, and the like. To this end, the bottom cover 1011 may be provided with a housing portion 1012 having a box-like shape with an opened upper surface, but the present invention is not limited thereto. The bottom cover 1011 may be coupled to the top cover, but is not limited thereto.

The bottom cover 1011 may be formed of a metal material or a resin material, and may be manufactured using a process such as press molding or extrusion molding. In addition, the bottom cover 1011 may include a metal or a non-metal material having good thermal conductivity, but the present invention is not limited thereto.

The display panel 1061 is, for example, an LCD panel, including first and second transparent substrates facing each other, and a liquid crystal layer interposed between the first and second substrates. A polarizing plate may be attached to at least one surface of the display panel 1061, but the present invention is not limited thereto. The display panel 1061 displays information by light passing through the optical sheet 1051. Such a display device 1000 can be applied to various types of portable terminals, monitors of notebook computers, monitors of laptop computers, televisions, and the like.

The optical sheet 1051 is disposed between the display panel 1061 and the light guide plate 1041 and includes at least one light-transmitting sheet. The optical sheet 1051 may include at least one of a sheet such as a diffusion sheet, a horizontal and vertical prism sheet, and a brightness enhancement sheet. The diffusion sheet diffuses incident light, and the horizontal and / or vertical prism sheet condenses incident light into a display area. The brightness enhancing sheet improves the brightness by reusing the lost light. A protective sheet may be disposed on the display panel 1061, but the present invention is not limited thereto.

Here, the optical path of the light source module 1031 may include the light guide plate 1041 and the optical sheet 1051 as an optical member, but the invention is not limited thereto.

10 is a view showing a display device having a light emitting element according to an embodiment.

10, the display device 1100 includes a bottom cover 1152, a substrate 1120 on which the above-described light emitting device 1124 is arrayed, an optical member 1154, and a display panel 1155.

The substrate 1120 and the light emitting device 1124 may be defined as a light source module 1160. The bottom cover 1152, the at least one light source module 1160, and the optical member 1154 may be defined as a light unit 1150. The bottom cover 1152 may include a receiving portion 1153, but the present invention is not limited thereto. The light source module 1160 includes a substrate 1120 and a plurality of light emitting devices 1124 arranged on the substrate 1120.

Here, the optical member 1154 may include at least one of a lens, a light guide plate, a diffusion sheet, a horizontal and vertical prism sheet, and a brightness enhancement sheet. The light guide plate may be made of a PC material or a polymethyl methacrylate (PMMA) material, and the light guide plate may be removed. The diffusion sheet diffuses incident light, and the horizontal and vertical prism sheets condense incident light into a display area. The brightness enhancing sheet enhances brightness by reusing the lost light.

The optical member 1154 is disposed on the light source module 1160 and performs surface light source, diffusion, and light condensation of light emitted from the light source module 1160.

11 is an exploded perspective view of a lighting device having a light emitting device according to an embodiment.

11, the lighting apparatus according to the embodiment includes a cover 2100, a light source module 2200, a heat discharger 2400, a power supply unit 2600, an inner case 2700, and a socket 2800 . Further, the illumination device according to the embodiment may further include at least one of the member 2300 and the holder 2500. The light source module 2200 may include a light emitting device according to an embodiment of the present invention.

For example, the cover 2100 may have a shape of a bulb or a hemisphere, and may be provided in a shape in which the hollow is hollow and a part is opened. The cover 2100 may be optically coupled to the light source module 2200. For example, the cover 2100 may diffuse, scatter, or excite light provided from the light source module 2200. The cover 2100 may be a kind of optical member. The cover 2100 may be coupled to the heat discharging body 2400. The cover 2100 may have an engaging portion that engages with the heat discharging body 2400.

The inner surface of the cover 2100 may be coated with a milky white paint. Milky white paints may contain a diffusing agent to diffuse light. The surface roughness of the inner surface of the cover 2100 may be larger than the surface roughness of the outer surface of the cover 2100. This is for sufficiently diffusing and diffusing the light from the light source module 2200 and emitting it to the outside.

The cover 2100 may be made of glass, plastic, polypropylene (PP), polyethylene (PE), polycarbonate (PC), or the like. Here, polycarbonate is excellent in light resistance, heat resistance and strength. The cover 2100 may be transparent so that the light source module 2200 is visible from the outside, and may be opaque. The cover 2100 may be formed by blow molding.

The light source module 2200 may be disposed on one side of the heat discharging body 2400. Accordingly, heat from the light source module 2200 is conducted to the heat discharger 2400. The light source module 2200 may include a light emitting device 2210, a connection plate 2230, and a connector 2250.

The member 2300 is disposed on the upper surface of the heat discharging body 2400 and has guide grooves 2310 into which the plurality of light emitting elements 2210 and the connector 2250 are inserted. The guide groove 2310 corresponds to the substrate of the light emitting device 2210 and the connector 2250.

The surface of the member 2300 may be coated or coated with a light reflecting material. For example, the surface of the member 2300 may be coated or coated with a white paint. The member 2300 reflects the light reflected by the inner surface of the cover 2100 toward the cover 2100 in the direction toward the light source module 2200. Therefore, the light efficiency of the illumination device according to the embodiment can be improved.

The member 2300 may be made of an insulating material, for example. The connection plate 2230 of the light source module 2200 may include an electrically conductive material. Therefore, electrical contact can be made between the heat discharging body 2400 and the connecting plate 2230. The member 2300 may be formed of an insulating material to prevent an electrical short circuit between the connection plate 2230 and the heat discharging body 2400. The heat discharger 2400 receives heat from the light source module 2200 and heat from the power supply unit 2600 to dissipate heat.

The holder 2500 blocks the receiving groove 2719 of the insulating portion 2710 of the inner case 2700. Therefore, the power supply unit 2600 housed in the insulating portion 2710 of the inner case 2700 is sealed. The holder 2500 has a guide protrusion 2510. The guide protrusion 2510 may have a hole through which the protrusion 2610 of the power supply unit 2600 passes.

The power supply unit 2600 processes or converts an electrical signal provided from the outside and provides the electrical signal to the light source module 2200. The power supply unit 2600 is housed in the receiving groove 2719 of the inner case 2700 and is sealed inside the inner case 2700 by the holder 2500.

The power supply unit 2600 may include a protrusion 2610, a guide unit 2630, a base 2650, and a protrusion 2670.

The guide portion 2630 has a shape protruding outward from one side of the base 2650. The guide portion 2630 may be inserted into the holder 2500. A plurality of components may be disposed on one side of the base 2650. The plurality of components include, for example, a DC converter for converting AC power supplied from an external power source into DC power, a driving chip for controlling driving of the light source module 2200, an ESD (ElectroStatic discharge) protective device, and the like, but the present invention is not limited thereto.

The protrusion 2670 has a shape protruding outward from the other side of the base 2650. The protrusion 2670 is inserted into the connection portion 2750 of the inner case 2700 and receives an external electrical signal. For example, the protrusion 2670 may be equal to or smaller than the width of the connection portion 2750 of the inner case 2700. One end of each of the positive wire and the negative wire is electrically connected to the protrusion 2670 and the other end of the positive wire and the negative wire are electrically connected to the socket 2800.

The inner case 2700 may include a molding part together with the power supply part 2600. The molding part is a hardened portion of the molding liquid so that the power supply unit 2600 can be fixed inside the inner case 2700.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of illustration, It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims (17)

A first semiconductor layer doped with a first dopant, an active layer located on the first semiconductor layer, and a second semiconductor layer located on the active layer and doped with a second dopant having a polarity opposite to the first dopant, A light emitting structure comprising;
A first electrode located under the first semiconductor layer and electrically connected to the first semiconductor layer;
A second electrode located in the second semiconductor layer and electrically connected to the second semiconductor layer; And
And a current restricting portion located between the active layer and the first electrode,
Wherein the current-
And at least a part of the second electrode and the second electrode are vertically overlapped,
Wherein a portion of the first semiconductor layer is exposed to a gas discharge state.
The method according to claim 1,
Wherein the current limiting portion includes a defect caused by the second dopant. The method according to claim 1,
Wherein the current limiting portion is disposed such that one surface thereof is in contact with the first electrode. 3. The method of claim 2,
Wherein a horizontal cross-sectional area of the current limiting portion is greater than or equal to a horizontal cross-sectional area of the second electrode. 3. The method of claim 2,
Wherein the first dopant comprises a p-type dopant and the second dopant comprises an n-type dopant. 3. The method of claim 2,
Wherein,
At least one well layer,
And a barrier layer having a band gap energy greater than that of the well layer. 3. The method of claim 2,
Wherein the current limiting portion has a lower electrical conductivity than the first semiconductor layer. 3. The method of claim 2,
Wherein the gas used for the gas discharge comprises chlorine (Cl ₂ ). 3. The method of claim 2,
And the thickness of the current limiting portion is 4 nm to 10 nm. The method according to claim 1,
Wherein a surface of the first semiconductor layer in contact with the first electrode includes a doped region doped with a higher concentration than the first semiconductor layer. 11. The method of claim 10,
Wherein the current limiting portion is formed in the over-doped region. 3. The method of claim 2,
Wherein the second electrode comprises:
At least one electrode pad disposed on one side of the second semiconductor layer,
And at least one electrode wing extending in the other direction from the electrode pad,
Wherein the current limiting portion is vertically overlapped with the electrode pad and the electrode wing. 3. The method of claim 2,
And a light extracting structure for improving light extraction efficiency is formed on an upper surface of the second semiconductor layer. 3. The method of claim 2,
And a supporting member on the lower surface of the first electrode. A light emitting device package comprising the light emitting device according to any one of claims 1 to 14. A lighting device comprising the light-emitting element according to any one of claims 1 to 14. A display device comprising the light-emitting element according to any one of claims 1 to 14.

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