KR20130029657A - Light emitting device - Google Patents

Abstract

PURPOSE: A light emitting device is provided to reduce the deformity of GaN by forming SixAlyN1-x-y in a first conductive semiconductor layer. CONSTITUTION: A light emitting structure includes a first conductive semiconductor layer(142a), a second conductive semiconductor layer, and an active layer. The active layer is arranged between the first conductive semiconductor layer and the second conductive semiconductor layer. The light emitting structure includes GaN. A protrusion part is arranged in an interlayer.

Description

[0001]

An embodiment relates to a light emitting element.

BACKGROUND ART Light emitting devices such as a light emitting diode (LD) or a laser diode using semiconductor materials of Group 3-5 or 2-6 group semiconductors are widely used for various colors such as red, green, blue, and ultraviolet And it is possible to realize white light rays with high efficiency by using fluorescent materials or colors, and it is possible to realize low energy consumption, semi-permanent life time, quick response speed, safety and environment friendliness compared to conventional light sources such as fluorescent lamps and incandescent lamps .

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

In the nitride semiconductor light emitting device, a substrate having a crystal structure identical to that of a nitride semiconductor material such as GaN or the like and having no lattice match is used, and a sapphire substrate which is an insulating substrate is used. Differences in lattice constants and coefficients of thermal expansion occur between the GaN layer grown on the sapphire substrate and the sapphire substrate, resulting in lattice mismatch and many crystal defects in the GaN layer.

Crystal defects increase the leakage current of the device and when an external static electricity enters, the active layer of the light emitting device having many crystal defects is destroyed by a strong field.

Generally, GaN thin films are known to have crystal defects (penetration defects) of the order of 10 ¹⁰ to 10 ¹² / cm ² . The nitride semiconductor light emitting device containing many of these crystal defects is very vulnerable to electric shock, and the light emitting device may be damaged by static electricity or lightning.

The embodiment seeks to reduce crystal defects in GaN of the light emitting device.

The embodiment includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer and includes GaN grown to a surface. Light emitting structure; An interlayer disposed adjacent to the light emitting structure and formed of the first conductive semiconductor layer or the undoped semiconductor layer; And a plurality of protrusions disposed in the interlayer.

The protrusion may comprise an inclined surface having at least one curvature.

The protrusions in the interlayer are solid state Si _x Al _y N ₁ formed by nitriding a liquid state Si _x Al _{1 -x} or Si _x Au _{1 - x} dropped on a plane GaN forming the light emitting structure. _-xy or Si _x Au _y N _{1 -xy} .

Si _x Al _{1- x} or Si _x Au _{1- x} in the liquid state may be dropped above the eutectic temperature.

Nitriding of Si _x Al _{1- x} or Si _x Au _{1- x in} a liquid state or growth of the light emitting structure may be performed at 1100 ° C. or less.

The protrusions can be on the nanometer scale to the micrometer scale.

The light emitting device may further include a substrate and a buffer layer disposed between the substrate and the first conductive semiconductor layer, wherein crystal defects may be formed between the protrusions and the boundary surface of the first conductive semiconductor layer from an interface with the buffer layer. have.

The substrate may be an R-plane sapphire substrate.

In the first conductivity type semiconductor layer, crystal defects may be formed between the protrusions and the interface with the undoped semiconductor layer.

The protrusion may be spaced apart from the surface of the first conductivity type semiconductor layer.

The protrusion may be spaced apart from the surface of the undoped semiconductor layer.

The light emitting device and the method of manufacturing the same according to the embodiment selectively arrange Si _x Al _y N _{1 -xy} on an R-plane having a high density of defects in a sapphire substrate, and Si _x Al _y N _{1 -xy} represents a defect. By acting as a growth barrier layer or an absorption layer, it is possible to reduce the growth of crystal defects, particularly in A-plane GaN.

1 to 4 are views showing the first to fourth embodiments of the light emitting device,
5 is a diagram showing a structure of sapphire crystal,
6A to 6F are views illustrating an embodiment of a method of manufacturing the light emitting device of FIG.
7A to 7E are views illustrating one embodiment of a method of manufacturing the light emitting device of FIG.
8A to 8F are views illustrating an embodiment of a method of manufacturing the light emitting device of FIG.
9A to 9I illustrate an embodiment of a method of manufacturing the light emitting device of FIG. 4.
10 is a view showing an embodiment of a light emitting device package in which a light emitting device is disposed;
11 is a view showing an embodiment of a head lamp in which a light emitting device is disposed;
12 is a diagram illustrating an embodiment of a backlight unit in which a light emitting device is disposed.

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

In the description of the embodiment according to the present invention, when described as being formed on the "on or under" of each element, the (up) or down (on) or under) includes both two elements being directly contacted with each other or one or more other elements are formed indirectly between the two elements. Also, when expressed as "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

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

1 to 4 show the first to fourth embodiments of the light emitting device, and FIG. 5 shows the structure of the sapphire crystal.

The light emitting device 100 of FIG. 1 includes a substrate 110, a buffer layer 120, a light emitting structure 140, a first electrode 160, and a second electrode 170. The light emitting structure 140 includes a first conductive semiconductor layer 142, an active layer 144, and a second conductive semiconductor layer 146. Si _x Al _y N _{1 -xy} 150 is disposed in the first conductive semiconductor layer 142.

The substrate 110 may be formed of a carrier wafer, a material suitable for semiconductor material growth. It may be formed of a material having excellent thermal conductivity, and may be a conductive substrate or an insulating substrate. For example, at least one of sapphire (SiO ₂ ), SiC, Si, GaAs, GaN, ZnO, Si, GaP, InP, Ge, and Ga ₂ O ₃ may be used.

The crystal surface of the substrate 110 in the case of using a sapphire substrate as the substrate 110 will be described with reference to FIG. 5.

As A-plane GaN is grown on an R-plane (1-102) sapphire substrate having a high defect density, the transition of the defect in the vertical direction may be particularly problematic, so that the first conductivity will be described later. Si _x Al _y N _{1 -xy} may be disposed in the type semiconductor layer 142 to act as a growth preventing layer or an absorbing layer of defects, thereby reducing non-polar A-plane GaN defects.

The buffer layer 120 is intended to mitigate the difference in lattice mismatch and thermal expansion coefficient of the material between the substrate 110 and the light emitting structure 140. The material of the buffer layer 120 may be formed of at least one of Group III-V compound semiconductors, for example, GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN.

The first conductivity type semiconductor layer 142 may be formed of a semiconductor compound. The first conductive semiconductor layer 142 may be implemented with compound semiconductors such as Groups 3-5 and 2-6, and may be doped with the first conductive dopant. When the first conductive semiconductor layer 142 is an N-type semiconductor layer, the first conductive dopant is an N-type dopant and may include Si, Ge, Sn, Se, Te, but is not limited thereto.

The first conductive semiconductor layer 142 includes a semiconductor material having a composition formula of Al _x In _y Ga _(1-xy) N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1). can do. The first conductive semiconductor layer 142 may be formed of any one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, InP.

Unevenness may be formed on the surface of the light emitting structure 140, that is, the surface of the second conductivity-type semiconductor layer 146 to increase the light extraction effect.

The active layer 144 has energy inherent to the material in which the electrons injected through the first conductive semiconductor layer 142 and the holes injected through the second conductive semiconductor layer 146 formed thereafter meet each other to form the active layer 144. It is a layer that emits light with energy determined by the band.

The active layer 144 may be formed of a double junction structure, a single quantum well structure, a multi quantum well structure (MQW), a quantum-wire structure, or a quantum dot structure. It may be formed of at least one. For example, the active layer 120 may be injected with trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and trimethyl indium gas (TMIn) to form a multi-quantum well structure. It is not limited to this.

The well layer / barrier layer of the active layer 144 is, for example, any one of InGaN / GaN, InGaN / InGaN, GaN / AlGaN, InAlGaN / GaN, InAlGaN / InAlGaN, GaAs (InGaAs) / AlGaAs, GaP (InGaP) / AlGaP. It may be formed of one or more pair structure, but is not limited thereto. The well layer may be formed of a material having a band gap narrower than the band gap of the barrier layer.

A conductive clad layer (not shown) may be formed on or under the active layer 144. The conductive clad layer may be formed of a semiconductor having a band gap wider than the band gap of the barrier layer of the active layer. For example, the conductive clad layer may include GaN, AlGaN, InAlGaN, superlattice structure, or the like. In addition, the conductive clad layer may be doped with n-type or p-type.

The second conductive semiconductor layer 146 may be formed of a semiconductor compound. The second conductive semiconductor layer 146 may be implemented with compound semiconductors such as Groups 3-5 and 2-6, and may be doped with the second conductive dopant. For example, it may include a semiconductor material having a compositional formula of _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1). When the second conductive semiconductor layer 144 is a P-type semiconductor layer, the second conductive dopant may be a P-type dopant and may include Mg, Zn, Ca, Sr, and Ba.

In the present exemplary embodiment and other embodiments to be described later, the first conductivity-type semiconductor layer 142 may be a P-type semiconductor layer, and the second conductivity-type semiconductor layer 146 may be an N-type semiconductor layer. In addition, an N-type semiconductor layer (not shown) may be formed on the second conductive semiconductor layer 146 when a semiconductor having a polarity opposite to that of the second conductive type, for example, the second conductive semiconductor layer is a P-type semiconductor layer. Accordingly, the light emitting structure may be implemented as any one of an N-P junction structure, a P-N junction structure, an N-P-N junction structure, and a P-N-P junction structure.

The light emitting structure 140 includes the first conductivity type semiconductor layer 142, the active layer 144, and the second conductivity type semiconductor layer 146 as described above. A portion of the first conductivity type semiconductor layer 142 is mesa-etched, but since the electrode cannot be formed under the insulating substrate like the sapphire substrate, the first electrode 160 may be disposed in the above-described etched region. Can be.

In the present embodiment, when the light emitting structure 140 is formed of non-polar A-plane GaN, Si _x Al _y N _{1 -xy} 150 is disposed in the first conductivity type semiconductor layer 142, and a plurality of Si _{The x} Al _y N _1-xy 150 may be disposed in a droplet shape. The droplet may include an inclined surface having at least one curvature.

A layer including a plurality of Si _x Al _y N _{1 -xy} 150 may be referred to as an interlayer, and a plurality of Si _x Al _y N _{1 -xy} 150 arranged in a droplet shape may form a protrusion. The same may be said in the following embodiments.

In FIG. 1, the droplet-shaped Si _x Al _y N _{1 -xy} 150 is shown to have the same size and shape, but the shape and size of each Si _x Al _y N _{1 -xy} 150 may be different. have. Si _x Al _y N _{1 -xy} (150) is formed by subjecting SiAl in a liquid state to nitrogen, a specific process will be described later.

_{Si x Al y N 1 -xy (} 150) of the first conductivity type are disposed spaced apart a predetermined distance from the interface of the semiconductor layer 142 and the buffer layer _{(120), Si x Al y} N 1 -xy (150 , as described below Is formed during the growth of the first conductivity-type semiconductor layer 142.

Each Si _x Al _y N _{1 -xy} 150 may be on the nanometer scale to the micrometer scale, ie from 1 nanometer to the tens of micrometers.

In FIG. 1, crystal defects may be grown from an interface between the buffer layer 120 and the first conductivity-type semiconductor layer 142. Some of the crystal defects (a) grow at the interface between the buffer layer 120 and the first conductivity-type semiconductor layer 142 and are blocked at Si _x Al _y N _{1 -xy} 150, and part (b) is Si _x It may not continue to correspond to Al _y N _1-xy 150 and may continue to grow, and crystal defects may not occur in the region c corresponding to some Si _x Al _y N _{1 -xy} 150.

2 is similar to the light emitting device of FIG. 1, but an undoped semiconductor layer 130 is disposed between the buffer layer 120 and the first conductivity-type semiconductor layer 142. Then, the same as described in the size and shape of Figure 1 of the _{Si x Al y N 1-xy} (150) is an undoped semiconductor layer, each of the _{Si x Al y N 1 -xy (} 150) is disposed, in a 130 Do.

In this embodiment, a layer including a plurality of Si _x Al _y N _{1 -xy} 150 may be referred to as an _interlayer , and the same may be applied to the following embodiments. In addition, Si _x Au _y N _{1 -xy} in the solid state may be disposed instead of the solid state Si _x Al _y N _{1 -xy} 150 to form a protrusion, the embodiment shown in FIG. 1 and FIGS. 3 and FIG. The same is true in the embodiments of 4.

Since Si _x Al _y N _{1 -xy} 150 is formed during the growth of the undoped semiconductor layer 130, the Si _x Al _y N _{1 -xy} 150 is spaced apart from the interface between the undoped semiconductor layer 130 and the buffer layer 120 by a predetermined interval.

In FIG. 2, crystal defects may be grown from an interface between the buffer layer 120 and the undoped semiconductor layer 130. Some of the crystal defects (e) grow at the interface between the buffer layer 120 and the undoped semiconductor layer 130 and are blocked at Si _x Al _y N _{1 -xy} 150, and some (d) are Si _x Al _y. did not correspond to the N _1-xy (150) may continue to grow, in the region (c) corresponding to the part of _{Si x Al y N 1 -xy (} 150) may be a crystal defect occurs. In addition, some crystal defects b may occur at the interface between the undoped semiconductor layer 130 and the first conductivity-type semiconductor layer 142.

The light emitting device 100 shown in FIG. 3 is similar to the light emitting device according to the embodiment shown in FIG. 2, but Si _x Al _y N _{1 -xy} 150 is disposed in the first conductivity-type semiconductor layer 142. The point is different. The size and shape of each Si _x Al _y N _{1 -xy} 150 is the same as described in FIGS. 1 and 2.

Since Si _x Al _y N _{1 -xy} 150 is formed during the growth of the first conductivity type semiconductor layer 142, a predetermined distance from the interface between the undoped semiconductor layer 130 and the first conductivity type semiconductor layer 142 is provided. Spaced apart.

3, crystal defects may be grown from an interface between the undoped semiconductor layer 130 and the first conductivity-type semiconductor layer 142. Some of the crystal defects (a) are grown at the interface between the undoped semiconductor layer 130 and the first conductivity type semiconductor layer 142 and are blocked at the Si _x Al _y N _{1 -xy} 150. Part (d) may grow at the interface between the undoped semiconductor layer 130 and the buffer layer 120 to be blocked at the Si _x Al _y N _{1 -xy} 150, and may be partially Si _x Al _y N _1-xy (150 The crystal defect may not occur in the region (c) corresponding to).

In addition, some of the crystal defects (b) may grow at the interface between the undoped semiconductor layer 130 and the first conductivity-type semiconductor layer 142 and may be grown without blocking at the Si _x Al _y N _{1 -xy} 150. In addition, another portion d of the crystal defect may occur at the interface between the undoped semiconductor layer 130 and the buffer layer 120 and may grow without being blocked at the Si _x Al _y N _{1 -xy} 150.

1 to 3 illustrate a lateral type light emitting device, while FIG. 4 illustrates a vertical light emitting device.

The light emitting device 100 illustrated in FIG. 4 includes a bonding layer 186, a reflective layer 184, an ohmic layer 182, and a light emitting structure 140 on a conductive support substrate 188. The light emitting structure 140 includes a first conductive semiconductor layer 142, an active layer 144, and a second conductive semiconductor layer 146, and includes Si _x Al in the first conductive semiconductor layer 142. _y N _{1 -xy} 150 is disposed.

Since the conductive support substrate 188 may serve as a second electrode, a metal having excellent electrical conductivity may be used, and a metal having high thermal conductivity may be used because it must be able to sufficiently dissipate heat generated when the light emitting device is operated.

The conductive support substrate 188 may be formed of a metal or a semiconductor material. And may be formed of a material having high electrical conductivity and high thermal conductivity. For example, a material selected from the group consisting of molybdenum (Mo), silicon (Si), tungsten (W), copper (Cu) and aluminum (Al) (Cu-W), a carrier wafer (e.g., GaN, Si, Ge, GaAs, ZnO, SiGe, SiC, SiGe, Ga ₂ O _3, etc.) And the like.

In addition, the conductive support substrate 188 may have a mechanical strength enough to be separated into a separate chip through a scribing process and a breaking process without causing warping of the entire nitride semiconductor. have.

The bonding layer 186 couples the reflective layer 184 and the conductive support substrate 188, and the reflective layer 184 may serve as an adhesion layer. The bonding layer is (186) from the group consisting of gold (Au), tin (Sn), indium (In), aluminum (Al), silicon (Si), silver (Ag), nickel (Ni) and copper (Cu) It may be formed of the material selected or alloys thereof.

The reflective layer 184 may be about 2500 angs thick. The reflective layer 184 may be formed of a metal layer including aluminum (Al), silver (Ag), nickel (Ni), platinum (Pt), rhodium (Rh), or an alloy containing Al, Ag, Pt, or Rh. . Aluminum or silver may effectively reflect light generated from the active layer 124 to greatly improve the light extraction efficiency of the light emitting device.

Since the light emitting structure 150, in particular, the second conductivity type semiconductor layer 146 has a low impurity doping concentration and high contact resistance, and thus may not have good ohmic characteristics, the light emitting structure 150 may be transferred to the ohmic layer 182 to improve such ohmic characteristics. A transparent electrode or the like can be formed.

The ohmic layer 182 may be about 200 angstroms thick. The ohmic layer 182 may include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IZAZO), indium gallium zinc oxide (IGZO), and indium gallium tin oxide (IGTO). ), Aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IZON (IZO Nitride), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), ZnO, IrOx, RuOx , NiO, RuOx / ITO, Ni / IrOx / Au, and Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Sn, In, Ru, Mg, Zn, Pt, It may be formed including at least one of Au and Hf, but is not limited to these materials.

The configuration of the light emitting structure 140 may be the same as the above-described embodiments.

Si _x Al _y N _{1 -xy} 150 is disposed in the first conductive semiconductor layer 142, and a plurality of Si _x Al _y N _{1 -xy} 150 has a shape in which droplets are disposed upside down. Can be. The size and shape of the droplet-shaped Si _x Al _y N _{1 -xy} 150 is the same as the light emitting device according to the above-described embodiment.

The Si _x Al _y N _{1 -xy} 150 is disposed spaced apart from the surface of the first conductive semiconductor layer by a predetermined interval, and as described later, the Si _x Al _y N _{1 -xy} 150 is formed of the first conductive semiconductor layer. This is because it forms during the growth of 142.

In FIG. 4, crystal defects may be grown from the surface of the first conductivity-type semiconductor layer 142. Some of the crystal defects (a) are grown at the interface of the first conductivity-type semiconductor layer 142 and are blocked by the Si _x Al _y N _1-xy (150), and some (b) are Si _x Al _y N _{1 − It} may not grow to correspond to _xy 150 and may continue to grow, and crystal defects may not occur in the region c corresponding to some Si _x Al _y N _{1 -xy} 150.

Although not shown, irregularities may be formed on the surface of the light emitting structure 140, that is, the surface of the first conductivity-type semiconductor layer 142 to increase the light extraction effect.

The first electrode 160 may be formed on the first conductive semiconductor layer 142. The first electrode 160 may be formed in a single layer or a multilayer structure including at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu), and gold (Au). have.

In addition, a passivation layer 190 may be formed on a side surface of the light emitting structure 140. The passivation layer 190 may be made of an insulating material. The insulating material may be made of a nonconductive oxide or nitride, and may be formed of, for example, a silicon oxide (SiO ₂ ) layer, an oxynitride layer, or an aluminum oxide layer. .

6A to 6F illustrate an embodiment of a method of manufacturing the light emitting device of FIG. 1.

As shown in FIG. 6A, the buffer layer 120 and the first conductivity-type semiconductor layer 142a are grown on the substrate 110.

A conductive or non-conductive substrate 110 may be used as the substrate 110. In particular, when sapphire is used as the substrate 110, a semiconductor layer such as a light emitting structure 140 may be formed on the R-plane (1-102) having a high defect density. Can grow.

The buffer layer 120 may be grown between the first conductive semiconductor layer 142a and the substrate 110 to mitigate the difference in lattice mismatch and thermal expansion coefficient of the material. The material of the buffer layer 120 may be formed of at least one of Group III-V compound semiconductors, for example, GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN.

The composition of the first conductive semiconductor layer 142a is the same as described above, and is N-type using a method such as chemical vapor deposition (CVD) or molecular beam epitaxy (MBE) or sputtering or hydroxide vapor phase epitaxy (HVPE). A GaN layer can be formed. In addition, the first conductive semiconductor layer 142a may include a silane including n-type impurities such as trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and silicon (Si) in the chamber. The gas SiH ₄ may be injected and formed.

In particular, the first conductivity-type semiconductor layer 142a may be grown on the A-plane of GaN, and when the A-plane GaN is grown on the R-plane (1-102) having a high defect density in the sapphire substrate 110. Crystal defect (a) may transition in the vertical direction.

As shown in FIG. 6B, SiAl 155 is disposed in the first conductivity-type semiconductor layer 142a. SiAl 155 may be disposed, for example, Si _{87 .4} Al _{12 .6} , in which trimethyl gallium gas and silane gas are injected to the SiAl 155 in a liquid state to the first conductive semiconductor layer 142a. ) May be formed by being dropped.

The melting point of silicon (Si) is 1400 ^o C but if it contains an appropriate amount of gold (Au) or aluminum (Al), the melting point of silicon is significantly lowered, if it contains gold can be 359 ^o C, as described above Likewise, containing aluminum can be 577 ^o C.

In the above-described embodiment, SiAl (155) is Si _{87 .4} Al _{12 .} Dropped to ₆ , can be dropped to Si _x Al _{1- x} . In addition to SiAl 155, a liquid Si _x Au _{1 -x} may be dropped, but the same may be applied to other embodiments.

The above-mentioned drop of liquid Si _x Al _{1 -x} or Si _x Au _{1 -x} is made at the eutectic temperature or higher, and Si _x Al _{1 -x} is 577 ^o C or more and Si _x Au _{1 -x} is 577 ^o Can drop above C Then, the above-described drop process or growth of the light emitting structure is 1100. ^o can be at temperatures below C.

In the present embodiment, when SiAl 155 is formed by containing aluminum in silicon, the melting temperature is formed at around 577 ^° C., so that SiAl 155 in a liquid state can be obtained.

In addition, as shown in FIG. 6c, nitrogen (N ₂ ) treatment is performed on SiAl to form Si _x Al _y N _{1 -xy} 150, which may be treated at room temperature, and each Si _x Al _y N _{1 -xy.} The light emitting structure 140 may be disposed in the first conductive semiconductor layer 142a including the non-polar A-plane GaN, and may be disposed in the shape of a droplet in a solid state. Thus, without patterning each Si _x Al _y N _{1 -xy} 150 by lithography or the like, the Si _x Al _y N _{1 -xy} 150 forms the first conductive semiconductor layer 142a. It can be formed in part of.

Each Si _x Al _y N _{1 -xy} 150 is shown in the same size and shape, but the shape and size may be different. Each Si _x Al _y N _{1 -xy} 150 formed by subjecting NiAl to nitrogen may be on a nanometer scale to a micrometer scale.

Here, the size of Si _x Al _y N _{1 -xy} (150) may be represented by the height (h) and the width (w), the width (w) may be a nanometer scale to a micrometer scale, the height (h) May be one half of the width w.

The Si _x Al _{1 -x} instead of Si _x Au ₁ when the nitrogen was treated drop the _-x and is in a solid state Si _x Au _y N _1-xy can be formed in the same applies to other embodiments described below.

In FIG. 6C, Si _x Al _y N _{1 -xy} 150 is formed corresponding to the crystal defect a grown from the interface between the buffer layer 120 and the first conductivity-type semiconductor layer 142a. In FIG. 6D, the first conductivity type semiconductor layer 142b is further grown on the first conductivity type semiconductor layer 142a and the Si _x Al _y N _{1 -xy} 150.

The first conductive semiconductor layer 142a grown in FIG. 6A and the first conductive semiconductor layer 142b grown in FIG. 6D may form one first conductive semiconductor layer 142. The crystal defect (a) whose growth is blocked by the Si _x Al _y N _{1 -xy} 150 is not grown in the first conductivity type semiconductor layer 142b.

As shown in FIG. 6E, the active layer 144 and the second conductive semiconductor layer 146 are grown on the first conductive semiconductor layer 142.

The composition of the active layer 144 is the same as described above, for example, the trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and trimethyl indium gas (TMIn) is injected to multi-quantum A well structure may be formed, but is not limited thereto.

The composition of the second conductivity type semiconductor layer 146 is the same as that described above. The composition of the second conductivity type semiconductor layer 146 is the same as that described above, and the p-type conductivity of the chamber, such as trimethyl gallium gas TMGa, ammonia gas NH ₃ , nitrogen gas N ₂ , Bisei including impurities butyl cyclopentadienyl magnesium _{(EtCp 2 Mg) {Mg (} C 2 H 5 C 5 H 4) 2} is injected may be a p-type GaN layer formed, but the embodiment is not limited thereto.

As shown in FIG. 6F, a portion of the active layer 144 and the first conductive semiconductor layer 142 are mesa-etched from the second conductive semiconductor layer 146 to partially remove the portion of the first conductive semiconductor layer 142. Expose

The first electrode 160 and the second electrode 170 are formed on a portion of the first conductive semiconductor layer 142 and the second conductive semiconductor layer 146, respectively. Each electrode 160 and 170 may be formed in a single layer or a multilayer structure including at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu), and gold (Au). Can be

7A to 7E are views illustrating one embodiment of a method of manufacturing the light emitting device of FIG. 2.

This embodiment is similar to the embodiment shown in FIGS. 6A-6F, but differs in that the formation of SiAl and the nitrogen treatment are performed during growth of the undoped semiconductor layer 130. That is, as shown in FIG. 6A, during the growth of the undoped semiconductor layer 130a, crystal defects e may be generated and grow from the interface between the buffer layer 120 and the undoped semiconductor layer 130a, and the undoped semiconductor layer may be grown. SiAl 155 is selectively formed during the growth of 130a. The formation method of SiAl 155 is the same as in the above-described embodiment.

As shown in FIG. 7B, the Si _x Al _y N _{1 -xy} 150 is formed by nitrogen treatment, and the undoped semiconductor layer 130b is disposed on the undoped semiconductor layer 130a as shown in FIG. 7C. Grow additionally.

As shown in FIG. 7D, the light emitting structure 140 is grown, and as shown in FIG. 7E, the mesa etching of the light emitting structure 140 and the process of forming the first and second electrodes 160 and 170 are performed.

In the light emitting structure manufactured according to the present embodiment, crystal defects (e) are generated at the interface between the buffer layer 120 and the undoped semiconductor layer 130 and grow, but growth stops at Si _x Al _y N _{1 -xy} 150. As a result, the occurrence of crystal defects may be eliminated or reduced in the light emitting structure 140 made of GaN, particularly in the first conductive semiconductor layer 142.

8A to 8F illustrate an embodiment of a method of manufacturing the light emitting device of FIG. 3.

The method according to the present embodiment is similar to the embodiment shown in FIG. 2, but crystal defects (a) are generated at the interface between the undoped semiconductor layer 130 and the first conductivity-type semiconductor layer 142. The growth of crystal defects is blocked in the Si _x Al _y N _{1 -xy} 150 formed by nitrogen treatment in FIG. 8C after the formation of SiAl (155).

9A to 9I illustrate an embodiment of a method of manufacturing the light emitting device of FIG. 4.

This embodiment shows a method of manufacturing a vertical light emitting device, and after the growth of crystal defects (a) in the first conductivity type semiconductor layer 142a in FIG. 9A and the formation of SiAl 155 shown in FIG. 9B. Blocking growth of crystal defects by Si _x Al _y N _{1 -xy} 150 formed by nitrogen treatment in FIG. 9C is the same as the embodiment shown in FIGS. 6A to 6F.

In FIG. 9F, an ohmic layer 182, a reflective layer 184, a bonding layer 186, and a conductive support substrate 188 may be formed on the light emitting structure 140. The composition of the ohmic layer 182 and the reflective layer 184 is as described above, and may be formed by sputtering or electron beam deposition.

The bonding layer 186 and the conductive support substrate 188 may be formed on the reflective layer 184. The conductive support substrate 188 may be formed using an electrochemical metal deposition method or an eutectic metal. A bonding method or the like may be used, or a separate bonding layer 186 may be formed.

Then, the substrate 110 is separated as shown in FIG. 9G. The substrate 110 may be removed by a laser lift off (LLO) method using an excimer laser or the like, or may be a method of dry and wet etching.

For example, when the laser lift-off method focuses and irradiates excimer laser light having a predetermined wavelength in the direction of the substrate 110, heat energy is concentrated on the interface between the substrate 110 and the light emitting structure 140. As the interface is separated into gallium and nitrogen molecules, the substrate 110 may be momentarily separated from the portion where the laser light passes, and the buffer layer 120 may be separated together.

As illustrated in FIG. 9H, each of the light emitting structures 140 may be diced in units of devices.

As shown in FIG. 9I, the first electrode 160 may be disposed on the surface of the first conductivity-type semiconductor layer 142, and the passivation layer 190 may be formed around the light emitting structure 140. The composition of the electrode 160 and the passivation layer 190 is the same as described above.

In the present embodiment, the Si _x Al _y N _{1 -xy} 150 disposed in the first conductivity-type semiconductor layer 142 is a shape in which a plurality of droplets are disposed upside down, and the size and shape of the droplet shape are described above. It is the same as the light emitting device according to one embodiment.

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

The light emitting device package 300 according to the embodiment includes a package body 310, a first lead frame 221 and a second lead frame 222 installed on the package body 310, and the package body 310. A light emitting device 360 installed and electrically connected to the first lead frame 221 and the second lead frame 222, and a molding part 350 covering the surface or the side surface of the light emitting device 360. do.

The package body 310 may include a silicon material, a synthetic resin material, or a metal material. An inclined surface may be formed around the light emitting device 360 to increase light extraction efficiency.

The first lead frame 221 and the second lead frame 222 are electrically separated from each other, and provide power to the light emitting device 360. In addition, the first lead frame 221 and the second lead frame 222 may increase the light efficiency by reflecting the light generated from the light emitting device 360, the heat generated by the light emitting device 360 It may also play a role in discharging it to the outside.

The light emitting device 360 may be installed on the package body 310 or on the first lead frame 321 or the second lead frame 322. The light emitting device 360 may be electrically connected to the first lead frame 321 and the second lead frame 322 by any one of a wire method, a flip chip method, or a die bonding method. In the present exemplary embodiment, the light emitting device 360 is connected to the first lead frame 321 and the conductive adhesive layer 330 and is bonded to the second lead frame 322 and the wire 340.

The molding part 350 may surround and protect the light emitting device 360. In addition, the maldium 350 may include a phosphor 355 to change the wavelength of the light emitted from the light emitting device 100.

In the light emitting device package 300 according to the embodiment, the light emitting device 360 is the same as the light emitting device 100 described above, and Si _x Al _y N _{1 -xy} is selectively disposed in the light emitting structure or the undoped semiconductor layer. The growth of defects may be reduced, and thus the characteristics of the entire light emitting device package 300 may be improved.

The light emitting device package 300 may be mounted on one or a plurality of light emitting devices according to the embodiments described above, but the present invention is not limited thereto.

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

11 is a diagram illustrating an embodiment of a head lamp including a light emitting device package.

The light emitted from the light emitting device module 401 in which the light emitting device package is disposed is reflected by the reflector 402 and the shade 403 and then transmitted through the lens 404 to the front of the vehicle body You can head.

As described above, crystal defects of the light emitting device used in the light emitting device module 401 may be reduced, thereby improving electrical characteristics of the entire head lamp.

The light emitting device package included in the light emitting device module 401 may include a plurality of light emitting devices, but is not limited thereto.

12 illustrates an embodiment of a display device including a light emitting device package.

As shown, the display device 500 according to the present exemplary embodiment includes a light source module, a reflector 520 on the bottom cover 510, and a light disposed in front of the reflector 520 and emitting light emitted from the light source module. In front of the light guide plate 540, the first prism sheet 550 and the second prism sheet 560 disposed in front of the light guide plate 540, and in front of the second prism sheet 560. And a color filter 580 disposed throughout the panel 570.

The light source module comprises a light emitting device package 535 on a circuit board 530. Here, a circuit board (PCB) may be used as the circuit board 530, and the light emitting device package 535 is as described with reference to FIG. 13.

The bottom cover 510 may accommodate components in the display device 500. The reflective plate 520 may be formed as a separate component as shown in the drawing, or may be provided on the rear surface of the light guide plate 540 or on the front surface of the bottom cover 510 with a highly reflective material.

The reflector 520 can be made of a material having a high reflectance and can be used in an ultra-thin shape, and a polyethylene terephthalate (PET) can be used.

The light guide plate 540 scatters the light emitted from the light emitting device package module so that the light is uniformly distributed over the entire screen area of the LCD. Accordingly, the light guide plate 530 is made of a material having a good refractive index and transmittance. The light guide plate 530 may be formed of poly methylmethacrylate (PMMA), polycarbonate (PC), or polyethylene (PE). Also, if the light guide plate 540 is omitted, an air guide display device can be realized.

The first prism sheet 550 is formed on one side of the support film with a translucent and elastic polymer material. The polymer may have a prism layer in which a plurality of steric structures are repeatedly formed. Here, the plurality of patterns may be provided in the stripe type and the valley repeatedly as shown.

In the second prism sheet 560, a direction of a floor and a valley of one side of the supporting film may be perpendicular to a direction of a floor and a valley of one side of the supporting film in the first prism sheet 550. This is for evenly distributing the light transmitted from the light source module and the reflective sheet in all directions of the panel 570.

In this embodiment, the first prism sheet 550 and the second prism sheet 560 constitute an optical sheet, which may be made of other combinations, for example, a microlens array or a combination of a diffusion sheet and a microlens array Or a combination of one prism sheet and a microlens array, or the like.

A liquid crystal display (LCD) panel may be disposed on the panel 570. In addition to the liquid crystal display panel 560, other types of display devices requiring a light source may be provided.

In the panel 570, a liquid crystal is positioned between glass bodies, and a polarizing plate is placed on both glass bodies to utilize the polarization of light. Here, the liquid crystal has an intermediate property between a liquid and a solid, and liquid crystals, which are organic molecules having fluidity like a liquid, are regularly arranged like crystals. The liquid crystal has a structure in which the molecular arrangement is changed by an external electric field And displays an image.

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

A color filter 580 is provided on the front surface of the panel 570 so that only the red, green, and blue light is transmitted through the panel 570 for each pixel.

In the display device 500 according to the exemplary embodiment, crystal defects of light emitting devices used may be reduced, thereby improving electrical characteristics of the entire display device.

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

100, 360: light emitting element 110: substrate
120: buffer layer
130, 130a, 130b: undoped semiconductor layer
140: light emitting structure
142, 142a, and 142b: first conductive semiconductor layer
144: active layer 146: second conductive semiconductor layer
150: Si _x Al _y N _1-xy 160: first electrode
170: second electrode 182: ohmic layer
184: reflective layer 186: bonding layer
188: conductive support substrate
300: light emitting device package 310: package body
321: first lead frame 322: second lead frame
330: conductive adhesive layer 340: wire
350 molding unit 355 phosphor
400: head lamp 410: light emitting element module
420: reflector 430: shade
440 lens
800: display device 810: bottom cover
820: reflector 830: circuit board module
840: Light guide plate 850, 860: First and second prism sheet
870 panel 880 color filter

Claims (11)

A light emitting structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, and including GaN grown to a surface;
An interlayer disposed adjacent to the light emitting structure and formed of the first conductive semiconductor layer or the undoped semiconductor layer; And
And a plurality of protrusions disposed in the interlayer. The method of claim 1,
The protrusion includes a sloped surface having at least one curvature. The method of claim 1,
The protrusions in the interlayer are solid state Si _x Al _y N formed by nitriding a liquid state Si _x Al _{1- x} or Si _x Au _{1 - x} dropped on a plane GaN forming the light emitting structure. A light emitting device comprising _1-xy or Si _x Au _y N _{1 -xy} . The method of claim 3,
Si _x Al _{1- x} or Si _x Au _{1- x} in the liquid state is a light emitting device that is dropped above the eutectic temperature. The method of claim 3,
The nitride of the Si _x Al _{1- x} or Si _x Au _{1- x} of the liquid state or the growth of the light emitting structure is carried out at 1100 ° C or less. The method of claim 1,
The protrusion is a light emitting device of the nanometer scale (micrometer scale) to micrometer scale. The method of claim 1,
And a buffer layer disposed between the substrate and the first conductive semiconductor layer.
And a crystal defect formed between the protrusions and the interface with the buffer layer in the first conductivity type semiconductor layer. The method of claim 1,
The substrate is a light emitting device R-plane sapphire substrate. The method of claim 1,
And a crystal defect formed between the protrusions in the first conductive semiconductor layer from an interface with the undoped semiconductor layer. The method of claim 1,
The protrusion part is spaced apart from the surface of the first conductivity type semiconductor layer. The method of claim 1,
The protrusion is disposed apart from the surface of the undoped semiconductor layer.

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