KR101633814B1 - light emitting device - Google Patents

Abstract

A light emitting structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; A non-conductive layer provided on a first region of the second conductivity type semiconductor layer in a first direction; And a reflective layer provided on the non-conductive layer in a first direction.

Description

[0001]

The embodiments relate to a light emitting device and a manufacturing method thereof.

Light emitting devices such as light emitting diodes and laser diodes using semiconductor materials of Group 3-5 or Group 2-6 compound semiconductors can realize various colors such as red, green, blue and ultraviolet rays through the development of thin film growth techniques and device materials, By using fluorescent materials or by combining colors, it is possible to realize a white light beam having high efficiency.

With the development of such technology, not only display devices but also transmission modules of optical communication means, light-emitting diode backlights replacing CCFL (Cold Cathode Fluorescence Lamp) constituting the backlight of LCD (Liquid Crystal Display) White light emitting diodes (LED) lighting devices, automotive headlights, and traffic lights.

Here, the structure of the LED is such that the P electrode, the active layer, and the N electrode are sequentially laminated on the substrate, and the substrate and the N electrode are wire-bonded, so that currents can be mutually energized.

At this time, when current is applied to the substrate, a current is supplied to the P electrode and the N electrode, so that positive (+) is emitted from the P electrode to the active layer, and electrons (-) are emitted from the N electrode to the active layer. Therefore, the energy level is lowered as the holes and electrons are combined in the active layer, and the energy level is lowered, and the emitted energy is emitted in the form of light.

The embodiment attempts to simplify the manufacturing process of the light emitting device package and secure the process stability.

A light emitting structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; A non-conductive layer provided on a first region of the second conductivity type semiconductor layer in a first direction; And a reflective layer provided on the non-conductive layer in a first direction.

Here, the non-conductive layer may form a closed curved surface.

The non-conductive layer may be formed of any one of Al ₂ O ₃ , SiO ₂ , TiO _x (an integer of _{x? 2} ), Si ₃ N _4, and AlN.

The reflective layer may be made of at least one material selected from the group consisting of Ag, Al, Cu, Ni, and Pt.

The reflective layer may be wider than the light emitting structure, and a part of the light emitting structure may be etched to the reflective layer.

The non-conductive layer may further include an ohmic layer provided on a first direction of the non-conductive layer, and the reflective layer may be provided on the first direction of the ohmic layer.

The ohmic layer may be made of at least one material selected from the group consisting of Ag, Ni, Pt, Sn, In, and Zn.

The ohmic layer may be wider than the light emitting structure, and a part of the light emitting structure may be etched to the ohmic layer.

The light emitting structure may be etched from the first conductivity type semiconductor layer to the active layer and the second conductivity type semiconductor layer in a region corresponding to the non-conductive layer.

The light emitting device may further include a first electrode in a second direction of the first conductivity type semiconductor layer, and the first electrode may correspond to the first electrode in the first direction of the second conductivity type semiconductor layer, And a current blocking layer made of the same material.

The manufacturing process of the light emitting device package according to the embodiment is simple and the process stability is secured.

1A to 1F are views illustrating a method of manufacturing an LED according to an embodiment of the present invention,
2A to 2F are views illustrating a method of manufacturing a light emitting device according to an embodiment,
3 is a cross-sectional view of a light emitting device package according to an embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

In describing the above embodiments, it is to be understood that each layer (film), area, pattern or structure may be referred to as being "on" or "under" the substrate, each layer Quot; on "and " under" include both being formed "directly" or "indirectly" In addition, the criteria for above or below each layer will be described with reference to the drawings.

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 of each component does not entirely reflect the actual size.

1A to 1F are views showing a method of manufacturing an embodiment of a light emitting device according to an embodiment.

First, a substrate 110 is prepared as shown in FIG. 1A. The substrate 110 may include at least one of a sapphire (Al ₂ O ₃ ), SiC, Si, GaAs, GaN, ZnO, Si, GaP, InP, Ge, and Ga ₂ O ₃ Can be used. The concavo-convex structure may be formed on the substrate 110, but the present invention is not limited thereto. The substrate 110 may be wet-cleaned to remove impurities on the surface.

The light emitting structure 120 including the first conductive semiconductor layer 122, the active layer 124, and the second conductive semiconductor layer 126 may be formed on the substrate 110.

Herein, " formed on "may mean all that is formed in contact with or through one layer, and so on. The light emitting structure and the light emitting device are reversed between the processes of FIG. 1D and FIG. 1E and the processes of FIGS. 2D and 2E. In the following embodiments, the lower direction of the drawing will be referred to as a first direction and the upper direction will be referred to as a second direction with reference to Figs. 1E and 2F.

At this time, a buffer layer (not shown) may be grown between the light emitting structure 120 and the substrate 110 to mitigate the difference in lattice mismatch and thermal expansion coefficient of the material. The material of the buffer layer may be at least one of Group III-V compound semiconductor such as GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN. An undoped semiconductor layer may be formed on the buffer layer, but the present invention is not limited thereto.

The light emitting structure 120 may be grown by a vapor deposition method such as MOCVD (Metal Organic Chemical Vapor Deposition), MBE (Molecular Beam Epitaxy), or HVPE (Hydride Vapor Phase Epitaxy).

The first conductive semiconductor layer 122 may be formed of a Group III-V compound semiconductor doped with a first conductive dopant. When the first conductive semiconductor layer 112 is an N-type semiconductor layer , The first conductive dopant may include Si, Ge, Sn, Se, and Te as an N-type dopant, but the present invention is not limited thereto.

The first conductive semiconductor layer 122 may include a semiconductor material having a composition formula of Al _x In _y Ga _(1-xy) N (0? X? 1, 0? _Y? 1, 0? _X + . The first conductive semiconductor layer 112 may be formed of any one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, have.

The N-type GaN layer may be formed on the first conductive semiconductor layer 122 by a chemical vapor deposition (CVD) method, a molecular beam epitaxy (MBE) method, a sputtering method, or a vapor phase epitaxy (HVPE) . The first conductive semiconductor layer 122 may be formed by depositing a silane containing an n-type impurity such as trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ) Gas (SiH ₄ ) may be implanted and formed.

Electrons injected through the first conductive type semiconductor layer 122 and holes injected through the second conductive type semiconductor layer 126 formed later are brought into contact with each other to form an energy band unique to the active layer Which emits light having an energy determined by < RTI ID = 0.0 >

The active layer 124 may be formed of at least one of a single quantum well structure, a multi quantum well (MQW) structure, a quantum-wire structure, or a quantum dot structure. For example, the active layer 114 may be formed with a multiple quantum well structure by injecting trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and trimethyl indium gas (TMIn) But is not limited thereto.

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

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

The second conductive type semiconductor layer 126 is a second conductive type dopant is doped III-V compound semiconductor, for example _{-5, In x Al y Ga 1 -x-} y N (0≤x≤1, 0≤y≤ 1, 0? X + y? 1). When the second conductive semiconductor layer 116 is a P-type semiconductor layer, the second conductive dopant may include Mg, Zn, Ca, Sr, and Ba as a P-type dopant.

The second conductive type semiconductor layer 126 is Bisei that the chamber comprises a p-type impurity such as trimethyl gallium gas (TMGa), ammonia gas (NH _3), nitrogen gas (N _2), and magnesium (Mg) butyl bicyclo The p-type GaN layer may be formed by implanting pentadienyl magnesium (EtCp ₂ Mg) {Mg (C ₂ H ₅ C ₅ H ₄ ) ₂ }, but the present invention is not limited thereto.

In an exemplary embodiment, the first conductive semiconductor layer 122 may be a P-type semiconductor layer, and the second conductive semiconductor layer 126 may be an N-type semiconductor layer. An N-type semiconductor layer (not shown) may be formed on the second conductive semiconductor layer 126 if the semiconductor having the opposite polarity to the second conductive type, for example, the second conductive semiconductor layer is a P- have. Accordingly, the light emitting structure 110 may have 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.

1B, the mask 200 is selectively placed on the second conductive type semiconductor layer 126 to form a non-conductive layer 130 and a current blocking layer.

Here, the non-conductive layer 130 may be formed of any one of Al ₂ O ₃ , SiO ₂ , TiO _x (an integer of _{x? 2} ), Si ₃ N _4, and AlN. The current blocking layer 135 may be formed of the same material as the non-conductive layer 130. The non-conductive layer 130 may function as an etching stop layer when a device of a light emitting structure is separated in a process to be described later, and the current blocking layer 135 may serve only as a middle portion of the light emitting structure But it can be formed by a single step with the same material in the manufacturing process.

1C, the reflective layer 160 and the conductive supporting substrate 170 are formed on the second conductive type semiconductor layer 126, the non-conductive layer 130, and the current blocking layer 135, respectively.

The reflective layer 150 may be formed of one selected from the group consisting of Al, Ag, Ni, Pt, Cu, Rh, or an alloy containing Al, Ag, Pt, As shown in FIG. Aluminum, silver, or the like effectively reflects the light generated in the active layer 124, thereby greatly improving the light extraction efficiency of the light emitting device.

The conductive supporting substrate 170 may be formed. The conductive support substrate 170 may be made of a material selected from the group consisting of molybdenum (Mo), silicon (Si), tungsten (W), copper (Cu), and aluminum (Au), a copper alloy (Cu Alloy), a nickel-nickel, a copper-tungsten (Cu-W), a carrier wafer (e.g., GaN, Si, Ge, GaAs, ZnO, SiGe, SiC, SiGe, Ga ₂ O _3, etc.), and the like. The conductive support substrate 170 may be formed using an electrochemical metal deposition method, a bonding method using a yttetic metal, or the like.

The reflective layer 150 may function as a coupling layer or may be formed of gold (Au), tin (Sn), indium (In), indium (In) The bonding layer 160 may be formed of a material selected from the group consisting of aluminum (Al), silicon (Si), silver (Ag), nickel (Ni), and copper (Cu)

Then, as shown in FIG. 1D, the substrate 110 is separated.

The removal of the substrate 110 may be performed by a laser lift off (LLO) method using an excimer laser or the like, or a dry and wet etching method.

When excimer laser light having a wavelength in a certain region in the direction of the substrate 110 is focused and irradiated using the laser lift-off method, heat energy is applied to the interface between the substrate 110 and the light emitting structure 120 The interface is separated into gallium and nitrogen molecules, and the substrate 110 is instantaneously separated from the laser light passing portion.

1E, a mask 200 is deposited and a part of the light emitting structure 120 is etched. At this time, the non-conductive layer 130 provided under the first region A of the first conductive type semiconductor layer 122 prevents the etching, thereby preventing the reflective layer 150 from being etched.

In the etching process, a part of the non-conductive layer 130 may be damaged. In addition, the A region must be etched so as to surround the light emitting structure 120 to form a closed curved surface, thereby preventing a short circuit of the light emitting device. The reflective layer 150 may be exposed to the second region C outside the light emitting structure 120. In the second region, a part of the reflective layer 150 may be etched to reach the light emitting structure 120 in the etching process. However, since no current is supplied to the external light emitting structure separated by the A region of the closed curved surface, ).

In the region B of FIG. 1E, the reflection layer 150 and the light emitting structure 120 are provided in contact with each other. Since the current does not flow in the B-region light emitting structure separated from the internal light emitting structure connected to the electrode, The holes may not bond and may not emit light.

Then, as shown in FIG. 1F, irregularities are formed on the surface of the first conductive type semiconductor layer 122. The concavo-convex shape of the surface of the first conductivity type semiconductor layer 122 can be formed by a PEC method or etching after forming a mask. Here, by controlling the amount of etchant (for example, KOH), the intensity and exposure time of UV (ultraviolet), the difference in etch rate between Gallium-polar and nitropan- The shape can be adjusted.

In the etching process using a mask, a photoresist is coated on the first conductive type semiconductor layer 122, and then an exposure process is performed using a mask. Then, when the exposure process is performed, it is developed to form an etching pattern. An etching pattern is formed on the first conductive type semiconductor layer 122 according to the above-described process, and an etching process is performed to form a concave-convex structure on the first conductive type semiconductor layer 122. Since the concavo-convex structure is for increasing the surface area of the first conductivity type semiconductor layer 122, the larger the number of the floor and the valley is, the better.

The first electrode 180 is formed on the first conductive semiconductor layer 122. The first electrode 180 may be formed of one selected from the group consisting of molybdenum, chromium (Cr), nickel (Ni), gold (Au), aluminum (Al), titanium (Ti), platinum (Pt), vanadium (V), tungsten (W), lead (Pd), copper (Cu), rhodium (Rh) and iridium And an alloy of these metals.

2A to 2F are views showing a manufacturing method of an embodiment of a light emitting device according to an embodiment

2A and 2B are the same as those in FIGS. 1A and 1B, and thus will not be described.

The ohmic layer 145, the reflective layer 160, and the conductive supporting substrate 170 are formed on the second conductive type semiconductor layer 126, the non-conductive layer 130, and the current blocking layer 135 in FIG. 2C. That is, the ohmic layer 145 is formed on the second conductive semiconductor layer 126, the non-conductive layer 130, and the current blocking layer 135.

The ohmic layer 145 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide ZnO, ZnO, IrOx, ZnO, AlGaO, AZO, ATO, GZO, IZO, RuOx, NiO, RuOx / ITO, Ni / IrOx / Au, and Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Sn, In, Ru, , Au, and Hf, and is not limited to such a material. The ohmic layer 1450 may be formed by a sputtering method or an electron beam evaporation method.

The composition of the reflective layer 150, the bonding layer 160 and the conductive supporting substrate 170 and the separation of the conductive supporting substrate 170 are the same as those described above. In FIG. 2D, the process of separating the substrate 1100 is the same as described above.

2E, a mask 200 is deposited and a part of the light emitting structure 120 is etched. At this time, the non-conductive layer 130 provided under the first region A of the first conductive type semiconductor layer 122 prevents the etching to prevent the ohmic layer 145 and the like from being etched. That is, a part of the ohmic layer 145, which is a conductive material, may be etched away from the light emitting structure 120. However, in the embodiment, the non-conductive layer 130 prevents the ohmic layer 150 from being etched .

In the etching process, a part of the non-conductive layer 130 may be damaged. In addition, the A region must be etched so as to surround the light emitting structure 120 to form a closed curved surface, thereby preventing a short circuit of the light emitting device. The ohmic layer 145 may be exposed to the second region C outside the light emitting structure 120.

2F, irregularities are formed on the surface of the first conductivity type semiconductor layer 122 to form the first electrode 180. The detailed processes and the like are the same as those described with reference to FIG. 1F.

3 is a cross-sectional view of one embodiment of a light emitting device package. Hereinafter, an embodiment of the light emitting device package will be described with reference to FIG.

The light emitting device package according to the embodiment includes a package body 320, a first electrode layer 311 and a second electrode layer 312 provided on the package body 320, The light emitting device 300 includes a first electrode layer 311 and a second electrode layer 312 electrically connected to the first electrode layer 311 and the second electrode layer 312 and a filler 340 surrounding the light emitting device 300.

The package body 320 may be formed of a silicon material, a synthetic resin material, or a metal material. An inclined surface may be formed around the light emitting device 300 to enhance light extraction efficiency.

The first electrode layer 311 and the second electrode layer 312 are electrically isolated from each other and provide power to the light emitting device 300. The first electrode layer 311 and the second electrode layer 312 may reflect the light generated from the light emitting device 300 to increase the light efficiency. As shown in FIG.

The light emitting device 300 may be mounted on the package body 320 or on the first electrode layer 311 or the second electrode layer 312.

The light emitting device 300 may be electrically connected to the first electrode layer 311 and the second electrode layer 312 by wire, flip chip, or die bonding.

The filler material 340 may surround and protect the light emitting device 300. The filler 340 may include a phosphor to change the wavelength of the light emitted from the light emitting device 300.

The light emitting device package may include at least one of the light emitting devices of the above-described embodiments, or one or more light emitting devices. However, the present invention is not limited thereto.

A light guide plate, a prism sheet, a diffusion sheet, and the like, which are optical members, may be disposed on the light 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. Still another embodiment may be implemented as a display device, an indicating device, a lighting system including the semiconductor light emitting device or the light emitting device package described in the above embodiments, for example, the lighting system may include a lamp, a streetlight .

The features, structures, effects and the like described in the embodiments are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects and the like illustrated in the embodiments can be combined and modified by other persons skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

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.

110: substrate 120: light emitting structure
122: first conductivity type semiconductor layer 124: active layer
126: second conductivity type semiconductor layer 130: non-conductive layer
135: current blocking layer 145: ohmic layer
150: reflective layer 160: bonding layer
170: conductive supporting substrate 180: first electrode
200: mask 300: light emitting element
311: first electrode layer 312: second electrode layer
320: package body 340: filler

Claims (10)

A light emitting structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer;
A non-conductive layer provided on a first region of the second conductivity type semiconductor layer in a first direction;
A first electrode in a second direction of the first conductivity type semiconductor layer; And
And a reflective layer provided on the non-conductive layer in a first direction,
Wherein the light emitting structure includes a first region provided inside the non-conductive layer and a second region provided outside the non-conductive layer, wherein the first region and the second region have the same structure and are separated from each other And the light emitting structure of the second region is electrically separated from the first electrode. The method according to claim 1,
Wherein the non-conductive layer is a closed curved surface. The non-conductive layer according to claim 1,
Al ₂ O ₃ , SiO ₂ , TiO _x (an integer of _{x? 2} ), Si ₃ N _4, and AlN. The optical information recording medium according to claim 1,
And at least one material selected from the group consisting of Ag, Al, Cu, Ni and Pt. The method according to claim 1,
Wherein the reflective layer is wider than the light emitting structure, and a part of the light emitting structure is etched to the reflective layer. The method according to claim 1,
Further comprising an ohmic layer provided on a first direction of the non-conductive layer, wherein the reflective layer is provided on a first direction of the ohmic layer. 7. The organic electroluminescent device according to claim 6,
And at least one material selected from the group consisting of Ag, Ni, Pt, Sn, In and Zn. The method according to claim 6,
Wherein the ohmic layer is wider than the light emitting structure, and a part of the light emitting structure is etched to the ohmic layer. The light emitting device according to claim 1,
Wherein the first conductivity type semiconductor layer is etched from the first conductivity type semiconductor layer to the active layer and the second conductivity type semiconductor layer in a region corresponding to the non-conductive layer. The method according to claim 1,
And a current blocking layer corresponding to the first electrode on the first direction of the second conductivity type semiconductor layer and made of the same material and manufactured in the same process as the non-conductive layer.

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