US20090291518A1

Movatterモバイル変換

Info

Publication number: US20090291518A1
Application number: US12/464,451
Authority: US
Inventors: Yu-Sik Kim; Sang-Joon Park
Original assignee: Individual
Current assignee: Samsung Electronics Co Ltd
Priority date: 2008-05-22
Filing date: 2009-05-12
Publication date: 2009-11-26
Also published as: JP2009283942A; US8338204B2; JP5461887B2; TWI443860B; TW201006015A; KR20090121599A; KR101428719B1; US20120040479A1

Abstract

The present invention provides a light-emitting element, a method of manufacturing the light-emitting element, a light-emitting device, and a method of manufacturing the light-emitting device. A method of manufacturing a light-emitting element includes: forming a first conductive layer of a first conductive type, a light-emitting layer, and a second conductive layer of a second conductive type on at least one first substrate, forming an ohmic layer on the second conductive layer and bonding the at least one first substrate to a second substrate. The second substrate being larger than the first substrate. The method further includes etching portions of the ohmic layer, the second conductive layer, and the light-emitting layer to expose a portion of the first conductive layer.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No. 10-2008-0047575 filed on May 22, 2008, the disclosure of which is hereby incorporated herein in its entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to a light-emitting element, a method of manufacturing the light-emitting element, a light-emitting device, and to a method of manufacturing the light-emitting device.

2. Description of the Related Art

For example, a small substrate with a size of less than about 6 inches is typically used to manufacture light-emitting elements, such as an LED (light emitting diode) and an LD (laser diode). This is because it may be difficult to fabricate a substrate with a size of about 6 inches or more that is used to manufacture the light-emitting elements.

The use of the small substrate may lower throughput, which in turn may make it difficult to reduce the manufacturing costs of the light-emitting element. In addition, manufacturing equipment suitable for a small substrate such as a substrate with a size of about 6 inches or less should be used to manufacture a light-emitting element. As a result, it may be necessary to develop manufacturing equipment suitable for a small substrate.

SUMMARY OF THE INVENTION

Exemplary embodiments of the present invention may provide a method of manufacturing a light-emitting element with high throughput.

Exemplary embodiments of the present invention may provide a method of manufacturing a light-emitting device using the method of manufacturing a light-emitting element.

Exemplary embodiments of the present invention may provide a light-emitting element fabricated by using the method of manufacturing a light-emitting element.

Exemplary embodiments of the present invention may provide a light-emitting device manufactured by using the light-emitting element.

In accordance with an exemplary embodiment of the present invention, a method of manufacturing a light-emitting element is provided. The method includes forming a first conductive layer of a first conductive type, a light-emitting layer, and a second conductive layer of a second conductive type on at least one first substrate, forming an ohmic layer on the second conductive layer, and bonding the at least one first substrate to a second substrate. The second substrate being larger than the first substrate. The method further includes etching portions of the ohmic layer, the second conductive layer, and the light-emitting layer to expose a portion of the first conductive layer.

In accordance with another exemplary embodiment of the present invention, a method of manufacturing a light-emitting element is provided. The method includes performing a first annealing on at least one insulating substrate at a first temperature, and bonding the at least one insulating substrate to a conductive substrate. The conductive substrate being larger than the insulating substrate. The method further includes performing a second annealing on the insulating substrate and the conductive substrate bonded to each other at a second temperature that is lower than the first temperature.

In accordance with still another exemplary embodiment of the present invention, a method of manufacturing a light-emitting element is provided. The method includes forming a first GaN layer of an n type, a light-emitting layer, a second GaN layer of a p type on at least one sapphire substrate, performing a first annealing on the at least one sapphire substrate, forming an ohmic layer on the second GaN layer, performing a second annealing on the at least one sapphire substrate, and bonding the at least one sapphire substrate to a silicon substrate. The silicon substrate being larger than the sapphire substrate. The method further includes etching portions of the ohmic layer, the second GaN layer, and the light-emitting layer to expose a portion of the first GaN layer, forming a first electrode on the exposed first GaN layer and forming a second electrode on the ohmic layer.

In accordance with yet another exemplary embodiment of the present invention, a method of manufacturing a light-emitting device using the method of manufacturing a light-emitting element according to the above-mentioned aspects is provided.

In accordance with still yet another exemplary embodiment of the present invention, a light-emitting element is provided. The light element includes a substrate, a first conductive pattern of a first conductive type formed on the substrate, a light-emitting pattern formed on the first conductive pattern, a second conductive pattern of a second conductive type formed on the light-emitting pattern and an ohmic pattern formed on the second conductive pattern, wherein the width of the first conductive pattern is larger than that of the light-emitting pattern, and the edge of the second conductive pattern is aligned with the edge of the ohmic pattern.

In accordance with yet still another exemplary embodiment of the present invention, a light-emitting device includes the light-emitting element according to the above-mentioned aspect is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the present invention can be understood in more detail from the following description taken in conjunction with the attached drawings, in which:

FIGS. 1 to 7 are diagrams illustrating intermediate steps of a method of manufacturing a light-emitting element according to a first exemplary embodiment of the present invention;

FIGS. 8A and 8B are diagrams illustrating a light-emitting element according to the first exemplary embodiment of the present invention;

FIG. 9 is a diagram illustrating a method of manufacturing a light-emitting element according to a second exemplary embodiment of the present invention;

FIG. 10 is a diagram illustrating a method of manufacturing a light-emitting element according to a third exemplary embodiment of the present invention;

FIGS. 11 and 12 are diagrams illustrating intermediate steps of a method of manufacturing a light-emitting package according to the first exemplary embodiment of the present invention;

FIGS. 13 and 14A to14C are diagrams specifically illustrating connection between a package body and a light-emitting element;

FIGS. 15 to 17 are diagrams illustrating light-emitting packages according to second to fourth exemplary embodiments of the present invention;

FIG. 18 is a diagram illustrating a light-emitting system according to the first exemplary embodiment of the present invention;

FIG. 19 is a diagram illustrating a light-emitting system according to the second exemplary embodiment of the present invention;

FIGS. 20 to 21B are diagrams illustrating a light-emitting system according to the third exemplary embodiment of the present invention;

FIG. 22 is a diagram illustrating a light-emitting system according to the fourth exemplary embodiment of the present invention; and

FIGS. 23 to 26 are diagrams illustrating light-emitting systems according to fifth to eighth exemplary embodiments of the present invention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS OF THE INVENTION

The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity.

It will be understood that when an element or layer is referred to as being “on”, “connected to” or “coupled to” another element or layer, it can be directly on, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on”, “directly connected to” or “directly coupled to” another element or layer, there are no intervening elements or layers present. Like numbers refer to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

Spatially relative terms, such as “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. In the specification, the same components are denoted by the same reference numerals.

Exemplary embodiments of the present invention are described herein with reference to cross section illustrations that are schematic illustrations of idealized embodiments of the present invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, exemplary embodiments of the present invention should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, a region illustrated or described as flat may, typically, have rough and/or nonlinear features. Moreover, sharp angles that are illustrated may be rounded. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings for clarity of the description of the prevent invention.

FIGS. 1 to 7 are diagrams illustrating intermediate steps of a method of manufacturing a light-emitting element according to a first exemplary embodiment of the invention.FIGS. 8A and 8B are diagrams illustrating a light-emitting element according to the first exemplary embodiment of the invention.

First, referring toFIG. 1, a firstconductive layer112a, a light-emittinglayer114a, and a secondconductive layer116aare sequentially formed on afirst substrate100.

The firstconductive layer112a, the light-emittinglayer114a, and the secondconductive layer116amay include, for example, In_xAl_yGa_(1-x-y)N (0≦x≦1, and 0≦y≦1) (that is, various materials including GaN). That is, the firstconductive layer112a, the light-emittinglayer114a, and the secondconductive layer116amay be formed of, for example, AlGaN or InGaN.

The firstconductive layer112a, the light-emittinglayer114a, and the secondconductive layer116amay be sequentially formed on thefirst substrate100 by, for example, MOCVD (metal organic chemical vapor deposition), liquid phase epitaxy, hydride vapor phase epitaxy, molecular beam epitaxy, or MOVPE (metal organic vapor phase epitaxy).

Next, the layers will be described in detail. The firstconductive layer112amay be a first conductive type (for example, an n type), and the secondconductive layer116amay be a second conductive type (for example, a p type). However, the firstconductive layer112amay be the second conductive type (p type), and the secondconductive layer116amay be the first conductive type (n type) according to the design.

The light-emittinglayer114ais a region in which carriers (for example, electrons) of the firstconductive layer112aare coupled to carriers (for example, holes) of the secondconductive layer116ato emit light. In addition, the light-emittinglayer114amay include a well layer and a barrier layer. As the well layer has a band gap that is narrower than that of the barrier layer, the carriers (the electrons and the holes) are collected and coupled in the well layer. The light-emittinglayer114amay be classified into, for example, a single quantum well (SQW) structure and a multiple quantum well (MQW) structure according to the number of well layers. The single quantum well structure includes one well layer, and the multiple quantum well structure includes multiple well layers. To adjust emission characteristics, at least one of the well layer and the barrier layer may be doped with, for example, at least one of B, P, Si, Mg, Zn, and Se.

Thefirst substrate100 may be formed of any material as long as it can grow the firstconductive layer112a, the light-emittinglayer114a, and the secondconductive layer116a. For example, thefirst substrate100 may be an insulating substrate that is formed of sapphire (Al₂O₃) or zinc oxide (ZnO), or a conductive substrate that is formed of silicon (Si) or silicon carbide (SiC). In the following description, thefirst substrate100 is composed of a sapphire substrate.

Also, a buffer layer may be formed between thefirst substrate100 and the firstconductive layer112a. The buffer layer may be formed of, for example, In_xAl_yGa_(1-x-y)N (0≦x≦1, and 0≦y≦1). The buffer layer is formed to improve the crystallinity of the firstconductive layer112a, the light-emittinglayer114a, and the secondconductive layer116a.

A base substrate having the firstconductive layer112a, the light-emittinglayer114a, and the secondconductive layer116aformed on thesubstrate100 may be used.

Referring toFIG. 2, to activate the secondconductive layer116a, thefirst substrate100 having the firstconductive layer112a, the light-emittinglayer114a, and the secondconductive layer116aformed thereon may be subjected to afirst annealing process181. For example, thefirst annealing process181 may be performed at a temperature of about 400° C. Specifically, for example, when the secondconductive layer116ais formed of In_xAl_yGa_(1-x-y)N doped with Mg, thefirst annealing process181 can reduce the amount of H coupled to Mg. In this way, it is possible to improve the p-type characteristics of the secondconductive layer116a.

Referring toFIG. 3, anohmic layer130ais formed on the secondconductive layer116a. For example, theohmic layer130amay include at least one of ITO (indium tin oxide), zinc (Zn), zinc oxide (ZnO), silver (Ag), tin (Ti), aluminum (Al), silver (Au), nickel (Ni), indium oxide (In₂O₃), tin oxide (SnO₂), copper (Cu), tungsten (W), and platinum (Pt).

To activate theohmic layer130a, asecond annealing process182 may be performed on thefirst substrate100 having theohmic layer130aformed thereon. For example, the second annealing process may be performed at a temperature of about 400° C.

ReferringFIGS. 4A and 4B, at least onefirst substrate100 is bonded to thesecond substrate190.

Thesecond substrate190 may be a conductive substrate or an insulating substrate. For example, thesecond substrate190 may be a conductive substrate that is formed of at least one of silicon, strained silicon (Si), silicon alloy, SOI (silicon-on-insulator), silicon carbide (SiC), silicon germanium (SiGe), silicon germanium carbide (SiGeC), germanium, germanium alloy, gallium arsenide (GaAs), indium arsenide (InAs), a III-V semiconductor, a II-VI semiconductor, compositions thereof, and laminates thereof. In addition, thesecond substrate190 may be, for example, an insulating substrate that is formed of at least one of aluminum nitride, boron nitride, silicon oxide, silicon nitride, beryllium nitride, quartz, compositions thereof, and laminates thereof. In the following description, thesecond substrate190 is the silicon substrate.

Various bonding methods may be used to bond thefirst substrate100 to thesecond substrate190. In the first exemplary embodiment of the invention, direct bonding is used.

First, to directly bond thefirst substrate100 to thesecond substrate190, thefirst substrate100 and thesecond substrate190 may satisfy the following conditions.

The bonding surfaces of thefirst substrate100 and thesecond substrate190 should be substantially flat and smooth. When the bonding surfaces of thefirst substrate100 and thesecond substrate190 are curved or rough, it may be difficult to bond the two substrates.

That is, a total thickness variation may need to be adjusted so as to be equal to or smaller than a predetermined value. For example, in the case of an 8-inch wafer, the total thickness variation may be equal to or less than about 6 μm. In the case of a 2-inch wafer, the total thickness variation may be equal to or less than about 1.5 μm.

Therefore, if necessary, a semiconductor polishing technique may be used to polish at least one of the bonding surface of thefirst substrate100 and the bonding surface of thesecond substrate190. For example, CMP (chemical mechanical polishing) may be used to adjust the surface roughness in the unit of A. It is preferable that the surface roughnesses of the bonding surface of thefirst substrate100 and the bonding surface of thesecond substrate190 be equal to or less than about 1 nm when they are measured by an AFM (atomic force microscope). The bonding surfaces of the first and

second substrates

100 and190 may be mirror-polished.

In addition, the bonding surfaces of the first and

second substrates

100 and190 should be well cleaned.

Therefore, if necessary, it is preferable that at least one of thefirst substrate100 and thesecond substrate190 be well cleaned. The reason is that various impurities adhered to the surfaces of the first and

second substrates

100 and190, such as particles and dust, may be a contamination source. That is, if there are impurities in an interface between thefirst substrate100 and thesecond substrate190 during the bonding process therebetween, the bonding energy may be weakened. When the bonding energy is weakened, thefirst substrate100 may be readily detached from thesecond substrate190.

To directly bond thefirst substrate100 and thesecond substrate190, first, pre-treatment is performed on at least one of the bonding surface of thesecond substrate190 and the bonding surface of thefirst substrate100.

The pre-treatment may be, for example, plasma treatment and/or wet treatment.

For example, the plasma treatment may use at least one of O₂, NH₃, SF₆, Ar, Cl₂, CHF₃, and H₂O, but is not limited thereto. As the plasma treatment can be performed at a low temperature, it is possible to reduce stress applied to the first and

second substrates

100 and190.

The wet treatment may, for example, use at least one of H₂SO₄, HNO₃, HCl, H₂O₂, H₅IO₆, SC-1 (standard clean-1), and SC-2 (standard clean-2), but is not limited thereto. An SC-1 solution may be, for example, NH₄OH/H₂O₂, and an SC-2 solution may be, for example, HCl/H₂O₂.

The pre-treatment can activate the bonding surfaces of the first and

second substrates

100 and190. That is, the pre-treatment can change the states of the bonding surfaces of the first and

second substrates

100 and190 to be suitable for bonding.

A dangling bond may be generated on the bonding surface of the substrate subjected to the pre-treatment. The dangling bond may be a hydrophilic dangling bond or a hydrophobic dangling bond. For example, when thesecond substrate190 is a silicon wafer and thefirst substrate100 is a sapphire wafer, “—OH”, which is a hydrophilic dangling bond, may be formed on the bonding surface of thefirst substrate100 and the bonding surface of thesecond substrate190 by the pre-treatment.

Then, thesecond substrate190 and at least onefirst substrate100 are arranged such that their bonding surfaces face each other. At that time, “—OH” formed on the bonding surface of thefirst substrate100 and “—OH” formed on the bonding surface of thesecond substrate190 are spontaneously bonded to each other by the Van der Waals' force. As shown in the plan view ofFIG. 4B, 9first substrates100 having a diameter of about 2 inches may be arranged on onesecond substrate190 having a diameter of about 8 inches. The number offirst substrates100 arranged on thesecond substrate190 depends on a difference in size between thesecond substrate190 and thefirst substrate100.

Then, thesecond substrate190 and the at least onefirst substrate100 that are spontaneously bonded to each other are subjected to, for example, heat treatment or physical compression. Then, as shown inFIG. 4A, thesecond substrate190 and the at least onefirst substrate100 are connected to each other by a covalent bond. Specifically, when thesecond substrate190 is a silicon wafer and thefirst substrate100 is a sapphire wafer, thesecond substrate190 is coupled to a plurality offirst substrates100 by an oxygen-oxygen covalent bond, as represented by the following chemical formula:

Si—OH+HO—Al₂O₃≡
Si—O—Al₂O₃+H₂O.
The heat treatment may be performed at a temperature in the range of about 25° C. (room temperature) to about 400° C. When the heat treatment is performed at a high temperature for a long time, it is possible to increase the bonding energy between thesecond substrate190 and thefirst substrate100. However, when the heat treatment is performed at an excessively high temperature, thesecond substrate190 and thefirst substrate100 are likely to be curved or cracked. Therefore, it may be necessary to perform the heat treatment in a proper temperature range. As the heat treatment time increases, the bonding energy may increase. However, even when the heat treatment time increases, the bonding energy may not increase after a specific time (for example, several hours) has elapsed. The reason is that, after a specific time has elapsed, “—OH” formed on the bonding surfaces of thesecond substrate190 and the plurality offirst substrates100 may all be consumed (that is, this is because “—OH” may all be changed to the oxygen covalent bond). The heat treatment time may be adjusted, if necessary.
Referring toFIG. 5, theohmic layer130a, the secondconductive layer116, the light-emittinglayer114, and the firstconductive layer112 are partially etched in this order to expose a portion of the firstconductive layer112. As a result of the etching, anohmic pattern130, a secondconductive pattern116, a light-emittingpattern114, and a firstconductive pattern112 are formed, as shown inFIG. 5.
Referring toFIG. 6, anohmic pattern131 is formed on the exposed first conductive pattern112 (that is, a first electrode forming region) and then afirst electrode140 and asecond electrode150 are formed. For example, theohmic pattern131 on the firstconductive pattern112 may include at least one of ITO (indium tin oxide), zinc (Zn), zinc oxide (ZnO), silver (Ag), tin (Ti), aluminum (Al), gold (Au), nickel (Ni), indium oxide (In₂O₃), tin oxide (SnO₂), copper (Cu), tungsten (W), and platinum (Pt).
Specifically, thefirst electrode140 and thesecond electrode150 may be formed of the same material or different materials. For example, thefirst electrode140 and thesecond electrode150 may include at least one of indium tin oxide (ITO), copper (Cu), nickel (Ni), chrome (Cr), gold (Au), titanium (Ti), platinum (Pt), aluminum (Al), vanadium (V), tungsten (W), molybdenum (Mo), and silver (Ag).
Then, the bonded first andsecond substrates100 and190 are subjected to athird annealing process183. In particular, the temperature of thethird annealing process183 may be lower than that of thefirst annealing process181 and/or thesecond annealing process182. For example, the third annealing process may be performed at a temperature of about 190° C. or less.
For reference, thethird annealing process183 may be performed in the stage in which thefirst electrode140 and thesecond electrode150 are not formed. Specifically, after the ohmic layer is formed on thefirst electrode140, the third annealing process may be performed.
In particular, in the first exemplary embodiment of the invention, it is preferable that processes after the bonding process (seeFIGS. 4A and 4B) be performed at a low temperature. The reason is as follows. When the processes after the bonding process are performed at a high temperature, the interfaces between the bonded first andsecond substrates100 and190 may be stressed. When the amount of stress is large, thefirst substrate100 may be detached from thesecond substrate190. For this reason, it is preferable that high temperature processes be executed before the bonding process. For example, the temperature of thethird annealing process183 may be lower than the temperature of thefirst annealing process181 for activating the secondconductive layer116aand the temperature of thesecond annealing process182 for activating theohmic layer130a.
Before or after thesecond electrode150 is formed, a surface texturing process may be performed to form a texture shape on the surface of the secondconductive pattern116. The texture shape may be formed, for example, by subjecting the surface of the secondconductive pattern116 to wet etching using an etchant, such as KOH. The texture shape may be formed by, for example, dry etching. Light having an angle other than an escape cone angle may be confined in the secondconductive pattern116 due to a difference in refractive index between the secondconductive pattern116 and air. The texture shape makes it possible for many light components to escape from the secondconductive pattern116. As a result, it is possible to improve light emission efficiency.
Referring toFIG. 7, thesecond substrate190 is removed.
For example, a grinding process or a CMP (chemical mechanical polishing) process may be used to remove thesecond substrate190.
Then, the thickness of thefirst substrate100 is reduced. For example, the CMP process may be performed to reduce the thickness of thefirst substrate100 to, for example, about 100 μm.
Then, a sawing process is performed to divide the substrate into chips, thereby completing a light-emittingelement1.
In the manufacturing process according to the first exemplary embodiment of the invention in which a plurality of firstsmall substrates100 are bonded to the secondlarge substrate190, only manufacturing equipment suitable for the size of the secondlarge substrate190 is used, but separate manufacturing equipment for the firstsmall substrates100 is not needed. In addition, as a large number offirst substrates100 are manufactured at once, it is possible to improve throughput. As a result, it is possible to reduce the manufacturing costs of the light-emittingelement1.
The light-emittingelement1 according to the first exemplary embodiment of the invention will be described with reference toFIGS. 7,8A, and8B. The light-emittingelement1 according to the first exemplary embodiment of the invention is manufactured by the manufacturing method described with reference toFIGS. 1 to 7.
Referring toFIGS. 7,8A, and8B, the light-emittingelement1 includes the firstconductive pattern112, the light-emittingpattern114 formed on the firstconductive pattern112, the secondconductive pattern116 formed on the light-emittingpattern114, and theohmic patterns130 and131 formed on the firstconductive pattern112 and the secondconductive pattern116. However, in the first exemplary embodiment of the invention, the edge of the secondconductive pattern116 is aligned with the edge of theohmic pattern130.
As described above, to decrease the temperatures of the processes after the bonding process (seeFIGS. 4A and 4B), theohmic layer130ais formed before the bonding process (seeFIG. 3). Then, after the bonding process, theohmic pattern130, the secondconductive pattern116, the light-emittingpattern114, and the firstconductive pattern112 are etched at the same time (seeFIG. 5). Therefore, the edge of the secondconductive pattern116 is aligned with the edge of theohmic pattern130.
Meanwhile, the light-emittingelement1 may be used for a top view type package and a side view type package. In the top view type package, generally, a rectangular light-emitting element having a size of, for example, about 1 mm×1 mm shown inFIG. 8A is used. The top view type package directly emits light to an object, and is generally used for an illuminating device and a display device. On the other hand, in the side view type package, a rectangular light-emitting element having, for example, a size of about 150 μm×400 μm shown inFIG. 8B is used, but the structure thereof may be changed depending upon the desired purpose. The side view type package is generally used for a mobile device (for example, a mobile phone, an MP3 player, and a navigation system) and a display device. The top view type package and the side view type package may be different from each other in size and shape, but substantially similar to each other in configuration and operation.
Next, the operation of the light-emittingelement1 will be described.
When the firstconductive pattern112 is an n type and the secondconductive pattern116 is a p type, a first bias (V−, I−, or the ground voltage) is applied to the firstconductive pattern112 through thefirst electrode140 and a second bias (V+ or I+) is applied to the secondconductive pattern116 through thesecond electrode150. Therefore, a forward bias is applied to a light-emitting structure110. The forward bias causes the light-emittingpattern114 to emit light.
FIG. 9 is a diagram illustrating a method of manufacturing a light-emitting element according to a second exemplary embodiment of the invention.FIG. 10 is a diagram illustrating a method of manufacturing a light-emitting element according to a third exemplary embodiment of the invention.
Referring toFIGS. 9 and 10, the method of manufacturing the light-emitting element according to the second and third exemplary embodiments differs from that according to the first exemplary embodiment in that thefirst substrate100 is not directly bonded to thesecond substrate190, but rather thefirst substrate100 is bonded to thesecond substrate190 by an adhesive. In the adhesive bonding, intermediate material layers191 and192 are interposed between thefirst substrate100 and thesecond substrate190. When theintermediate material layer191 has a sufficient thickness, theintermediate material layer191 can compensate for the slight curvature of thefirst substrate100 or thesecond substrate190.
The intermediate material layers191 and192 may be formed on the bonding surface of thesecond substrate190 and/or the bonding surface of thefirst substrate100, and thefirst substrate100 and thesecond substrate190 may be bonded to each other by, for example, thermal compression or physical compression. InFIGS. 9 and 10, for the convenience of explanation, theintermediate material layer191 is formed on the bonding surface of thesecond substrate190.
As shown inFIG. 9, theintermediate material layer191 may be, for example, a metal layer that is formed of a conductive material. For example, the metal layer may include at least one of Au, Ag, Pt, Ni, Cu, Sn, Al, Pb, Cr, and Ti. That is, the metal layer may be, for example, a single layer formed of Au, Ag, Pt, Ni, Cu, Sn, Al, Pb, Cr, or Ti, a laminate thereof, or a composition thereof. For example, the metal layer may be an Au layer, an Au—Sn layer, or a multilayer formed by alternately laminating Au and Sn layers.
As shown inFIG. 10, theintermediate material layer192 may be an organic layer. The organic layer may be, for example, BCB (benzocyclobutene). The BCB has been sold as Dow Cyclotene. The BCB is suitable to manufacture a semiconductor device. As the BCB is highly resistant to most of wet etchants, it may be difficult to remove the BCB. In general, the BCB is removed usually only by dry etching. The BCB may generate less stress than a silicon oxide (SiO₂). That is, even when the BCB is formed with a large thickness, thesecond substrate190 may not be curved or cracked.
Next, a method of manufacturing a light-emitting device using the method of manufacturing the light-emitting element according to the first to third exemplary embodiments of the invention will be described. Examples of the light-emitting device include a light-emitting package (seeFIGS. 11 to 17) manufactured using the light-emitting element and a light-emitting system (seeFIGS. 18 to 25) manufactured using the light-emitting element and/or the light-emitting package.
FIGS. 11 and 12 are diagrams illustrating intermediate steps of a method of manufacturing the light-emitting package according to the first exemplary embodiment of the invention. For clarity of the description of the invention,FIGS. 11 and 12 simply show main parts.FIG. 13 andFIGS. 14A to 14C are diagrams illustrating connection between a package body and a light-emitting element in detail.FIGS. 14A to 14C are cross-sectional views taken along the line XIV-XIV ofFIG. 13.
First, referring toFIG. 11, the light-emittingelement1 is arranged on apackage body210.
Specifically, thepackage body210 may include aslot212 therein, and the light-emittingelement1 may be provided in theslot212. In particular, aside wall212aof theslot212 may be inclined. Light emitted from the light-emittingelement1 may be reflected from theside wall212aand then travel forward.
In the drawings, the light-emittingelement1 is connected to asub mount230, and the light-emittingelement1 connected to thesub mount230 is provided in theslot212 of thepackage body210. However, the exemplary embodiments of the present invention are not limited thereto. For example, the light-emittingelement1 may be directly provided on thepackage body210 without using thesub mount230.
Various methods may be used to connect thepackage body210 and the light-emittingelement1. For example, connecting methods shown inFIG. 13 andFIGS. 14A to 14C may be used.
Referring toFIGS. 13 and 14A, the light-emittingelement1 may be mounted to thesub mount230. In the drawings, the light-emittingelement1 is connected in a flip chip manner, but the exemplary embodiments of the present invention are not limited thereto. For example, the light-emittingelement1 may be connected in a lateral manner. In the flip chip connection, the first electrode and the second electrode are connected so as to face the bottom of the package. In a lateral-type LED, the first electrode and the second electrode are connected so as to face the upper surface of the package. InFIG. 13, the light-emittingelement1 has a rectangular shape used for the top view type package, but the exemplary embodiments of the present invention are not limited thereto. For example, the light-emittingelement1 may have a rectangular shape used for the side view type package.
The light-emittingelement1 may be a UV light-emittingelement1 that emits UV light or a blue light-emittingelement1 that emits blue light, that is, light having a blue wavelength.
The light-emittingelement1 is arranged in theslot212 of thepackage body210. Theslot212 is larger than the light-emittingelement1. The size of theslot212 may be determined in consideration of the amount of light which is emitted from the light-emittingelement1 and reflected from theside wall212aof theslot212, the reflection angle thereof, the kind of transparent resin (reference numeral250 inFIG. 12) filling theslot212, and the kind of phosphor layer (reference numeral260 inFIG. 12). It is preferable that the light-emittingelement1 be arranged at the center of theslot212. When the distance between the light-emittingelement1 and theside wall212ais constant, it is easy to prevent color irregularity.
Thepackage body210 may be formed of an organic material having high resistance, such as, for example, silicon resin, epoxy resin, acrylic resin, urea resin, fluororesin, or imide resin, or an inorganic material having high resistance, such as glass or silica gel. In addition, thepackage body210 may be formed of heat-resistant resin such that it is not melted by heat during a manufacturing process. In addition, to reduce the thermal stress of resin, various fillers, such as, for example, aluminum nitride, aluminum oxide, and a compound thereof, may be mixed with the resin. The material forming thepackage body210 is not limited to resin. A portion (for example, theside wall212a) of or theentire package body210 may be formed of, for example, a metal material or a ceramic material. For example, when theentire package body210 is formed of a metal material, it may be relatively easy to dissipate heat generated from the light-emittingelement1.FIG. 3A shows the case in which theentire package body210 is formed of a metal material.
In addition, leads214aand214belectrically connected to the light-emittingelement1 are provided in thepackage body210. The light-emittingelement1 may be electrically connected to thesub mount230, and thesub mount230 and theleads214aand214bmay be connected to each other by, for example,wires216aand216b, respectively. The leads214aand214bmay be formed of a material having high thermal conductivity to directly dissipate heat generated from the light-emittingelement1 to the outside through theleads214aand214b.
The light-emitting package shown inFIG. 14B differs from the light-emitting package shown inFIG. 14ain that thesub mount230 and theleads214aand214bare not connected to each other by the wires (216aand216binFIG. 14A), but they are connected to each other byvias232 that are provided in thesub mount230.
Further, the light-emitting package shown inFIG. 14C differs from the light-emitting package shown inFIG. 14A in that thesub mount230 and theleads214aand214bare not connected to each other by the wires (216aand216binFIG. 14A), but they are connected to each other by awiring line234 that is provided on the upper, side, and rear surfaces of thesub mount230.
The light-emitting package shown inFIG. 14B and the light-emitting package shown inFIG. 14C do not use any wire. Therefore, it is possible to reduce the size of a light-emitting package.
As described with reference toFIGS. 13 to 14C, the invention can be applied to various light-emitting packages. In the specification, the following drawings simply show main parts to prevent the scope of the exemplary embodiments of the invention from being limited.
Referring toFIG. 12 again, thetransparent resin layer250 is formed on the light-emittingelement1. Specifically, thetransparent resin layer250 fills at least a portion of theslot212. For example, as shown inFIG. 12, thetransparent resin layer250 may not completely fill theslot212. The material forming thetransparent resin layer250 may not be particularly limited as long as it can fill up theslot212 of thepackage body210. For example, thetransparent resin layer250 may be formed of an epoxy resin, a silicon resin, a hard silicon resin, a modified silicon resin, a urethane resin, oxetane resin, an acrylic resin, a polycarbonate resin, or a polyimide resin.
Then, thephosphor layer260 is formed on thetransparent resin layer250. Thephosphor layer260 may be formed of a mixture of atransparent resin262 and aphosphor264. Thephosphor264 dispersed in thephosphor layer260 absorbs light emitted from the light-emittingpackage1 and converts it into light with a different wavelength. Therefore, as thephosphor264 is dispersed well, the emission characteristics are improved. As a result, the wavelength conversion efficiency and the color mixture effect of thephosphor264 can be improved.
For example, thephosphor layer260 may be formed in the light-emittingpackage11 to emit white light. When the light-emittingpackage11 emits blue light, thephosphor264 may include a yellow phosphor, and it may also include a red phosphor to improve a color rendering index (CRI) characteristic. When the light-emittingpackage11 emits UV light, thephosphor264 may include all of the red, green, and blue phosphors.
Thetransparent resin262 is not particularly limited as long as it can stably disperse thephosphor264. For example, thetransparent resin262 may be, for example, an epoxy resin, a silicon resin, a hard silicon resin, a modified silicon resin, a urethane resin, an oxetane resin, an acrylic resin, a polycarbonate resin, or a polyimide resin.
Thephosphor264 is not particularly limited as long as it can absorb light from the light-emittingelement1 and convert it into light having a different wavelength. For example, the phosphor is preferably at least one selected from the following materials: a nitride-based phosphor or an oxynitride-based phosphor that is mainly activated by a lanthanoid element, such as Eu or Ce; an alkaline earth element halogen apatite phosphor, an alkaline earth metal element boride halogen phosphor, an alkaline earth metal element aluminate phosphor, alkaline earth element silicate, alkaline earth element sulfide, alkali earth element thiogallate, alkaline earth element silicon nitride, and germanate that are mainly activated by a lanthanoid element, such as Eu, or a transition metal element, such as Mn; rare earth aluminate and rare earth silicate that are mainly activated by a lanthanoid element, such as Ce; and an organic compound and an organic complex that are mainly activated by a lanthanoid element, such as Eu. Specifically, the following phosphors may be used, but the exemplary embodiments of the present invention are not limited to thereto.
The nitride-based phosphors that are mainly activated by a lanthanoid element, such as Eu or Ce include, for example, M2Si₅N₈:Eu (M is at least one element selected from the group consisting of Sr, Ca, Ba, Mg, and Zn). In addition to M₂Si₅N₈:Eu, MSi₇N₁₀:Eu, M_1.8Si₅O_0.2N₈:Eu, M_0.9Si₇O_0.1N₁₀:Eu (M is at least one element selected from the group consisting of Sr, Ca, Ba, Mg, and Zn) may also be included.
The oxynitride-based phosphors mainly activated by a lanthanoid element, such as Eu or Ce, include, for example, MSi₂O₂N₂:Eu (M is at least one element selected from the group consisting of Sr, Ca, Ba, Mg, and Zn).
The alkaline earth element halogen apatite phosphors mainly activated by a lanthanoid element, such as Eu, or a transition metal element, such as Mn, include, for example, M₅(PO₄)₃X:R (M is at least one element selected from the group consisting of Sr, Ca, Ba, Mg, and Zn, X is at least one element selected from the group consisting of F, Cl, Br, and I, and R is at least one element selected from the group consisting of Eu, Mn, and a combination of Eu and Mn).
The alkaline earth metal element boride halogen phosphors include, for example, M₂B₅O₉X:R (M is at least one element selected from the group consisting of Sr, Ca, Ba, Mg, and Zn, X is at least one element selected from the group consisting of F, Cl, Br, and I, and R is at least one element selected from the group consisting of Eu, Mn, and a combination of Eu and Mn).
The alkaline earth metal element aluminate phosphors include, for example, SrAl₂O₄:R, Sr₄Al₁₄O₂₅:R, CaAl₂O₄:R, BaMg₂Al₁₆O₂₇:R, and BaMgAl₁₀O₁₇:R(R is at least one element selected from the group consisting of Eu, Mn, and a combination of Eu and Mn).
The alkaline earth sulfide-based phosphors include, for example, La₂O₂S:Eu, Y₂O₂S:Eu, and Gd₂O₂S:Eu.
The rare earth aluminate phosphors mainly activated by a lanthanoid element, such as Ce, include, for example, YAG phosphors having the compositions of Y₃Al₅O₁₂:Ce, (Y_0.8Gd_0.2)₃Al₅O₁₂:Ce, Y₃(Al_0.8Ga_0.2)₅O₁₂:Ce, and (Y, Gd)₃(Al, Ga)₅O₁₂:Ce. The rare earth aluminate phosphors may also include, for example, Tb₃Al₅O₁₂:Ce and Lu₃Al₅O₁₂:Ce wherein a part or the whole of Y is substituted with, for example, Tb or Lu.
The alkaline earth element silicate phosphor may consist of silicate, and a representative example thereof is, for example, (SrBa)₂SiO₄:Eu.
Other phosphors include, for example, ZnS:Eu, Zn₂GeO₄:Mn, and MGa₂S₄:Eu (M is at least one element selected from the group consisting of Sr, Ca, Ba, Mg, and Zn, and X is at least one element selected from the group consisting of F, Cl, Br and I).
The above-mentioned phosphors may include, for example, at least one element selected from the group consisting of Tb, Cu, Ag, Au, Cr, Nd, Dy, Co, Ni, and Ti, instead of or in addition to Eu, if necessary.
Other phosphors having the same performance and effect as those described above may also be used.
FIGS. 15 to 17 are diagrams illustrating light-emitting packages according to the second to fourth exemplary embodiments of the invention. As those skilled in the art can derive a method of manufacturing the light-emitting packages according to the second to fourth exemplary embodiments of the invention from the method of manufacturing the light-emitting package according to the first exemplary embodiment of the invention, a description thereof will be omitted.
First, referring toFIG. 15, a light-emittingpackage12 according to the second embodiment of the invention differs from that according to the first exemplary embodiment in that afilter280 is formed on thephosphor layer260. Thefilter280 absorbs light having a specific wavelength. For example, thefilter280 may absorb light that is primarily emitted from the light-emittingelement1, and may not absorb light that is secondarily emitted from thephosphor layer260. Thefilter280 may be formed of a material that absorbs light having a specific wavelength and dissipates heat. For example, thefilter280 may be formed of an inorganic dye or an organic dye.
In particular, when the light-emittingelement1 emits UV light, aUV filter280 may be used. This is because an excessively large amount of UV light may be harmful to the human body.
Referring toFIG. 16, a light-emittingpackage13 according to the third exemplary embodiment of the invention differs from that according to the first exemplary embodiment in that thephosphor layer260 is formed in a lens shape. Thephosphor layer260 may have a predetermined curvature to improve the diffusion characteristics and the extraction characteristics of light emitted from the light-emittingelement1. InFIG. 16, the phosphor layer is formed in a convex lens shape, but it may be formed in a concave lens shape, if necessary.
Referring toFIG. 17, a light-emitting package14 according to the fourth exemplary embodiment of the invention differs from that according to the first exemplary embodiment in that thetransparent resin layer250 is formed on only the light-emittingelement1 and thesub mount230. Thephosphor layer260 is formed on thetransparent resin layer250 so as to fill up theslot212.
FIG. 18 is a diagram illustrating a light-emitting system according to the first exemplary embodiment of the invention.
Referring toFIG. 18, a light-emittingsystem21 according to the first exemplary embodiment of the invention includes acircuit board300 and the light-emittingpackage11 arranged on thecircuit board300.
Thecircuit board300 includes a firstconductive region310 and a secondconductive region320 that are electrically isolated from each other. The firstconductive region310 and the secondconductive region320 are provided on one surface of thecircuit board300.
The firstconductive region310 is electrically connected to the lead214aof the light-emittingpackage11, and the secondconductive region320 is electrically connected to thelead214bof the light-emittingpackage11. The first and secondconductive regions310 and320 may be respectively connected to theleads214aand214bby solder.
FIG. 19 is a diagram illustrating a light-emitting system according to the second exemplary embodiment of the invention.
Referring toFIG. 19, a light-emittingsystem22 according to the second exemplary embodiment of the invention differs from that according to the first exemplary embodiment in that thecircuit board300 includes throughvias316 and326.
Specifically, the firstconductive region310 and the secondconductive region320 are formed on one surface of thecircuit board300 so as to be electrically isolated from each other, and a thirdconductive region312 and a fourthconductive region322 are formed on the other surface of thecircuit board300 so as to be electrically isolated from each other. The firstconductive region310 and the thirdconductive region312 are connected to each other through the first through via316, and the secondconductive region320 and the fourthconductive region322 are connected to each other through the second through via326. The firstconductive region310 is electrically connected to the lead214aof the light-emittingpackage11, and the secondconductive region320 is electrically connected to thelead214bof the light-emittingpackage11.
FIGS. 20 to 21B are diagrams illustrating a light-emitting system according to the third exemplary embodiment of the invention. In particular,FIGS. 21A and 21B show an example in which aphosphor layer340 and atransparent resin350 are formed on a light-emitting package array.
FIG. 20 shows a light-emitting package array having a plurality of light-emittingpackages11 arranged on thecircuit board300 in a light-emittingsystem23 according to the third exemplary embodiment of the invention.
The firstconductive regions310 and the secondconductive regions320 extend in parallel to each other in the same direction on thecircuit board300. The light-emittingpackages11 are provided between the firstconductive regions310 and the secondconductive regions320. A plurality of light-emittingpackages11 are arranged in parallel to each other so as to extend in the direction in which the firstconductive region310 and the secondconductive region320 extend. The firstconductive region310 is electrically connected to the lead214aof the light-emittingpackage11, and the secondconductive region320 is electrically connected to thelead214bof the light-emittingpackage11. When a first bias is applied to the firstconductive region310 and a second bias is applied to the secondconductive region320, a forward bias is applied to a light-emitting element in the light-emittingpackage11, which causes the plurality of light-emittingpackages11 to emit light at the same time.
Referring toFIG. 21A, thephosphor layer340 and thetransparent resin350 may be formed in linear shapes. For example, when the light-emittingpackage11 is arranged in the direction in which the first and secondconductive regions310 and320 extend as shown inFIG. 14A, thephosphor layer340 and thetransparent resin350 may also be arranged in the direction in which the first and secondconductive regions310 and320 extend. Thephosphor layer340 and thetransparent resin350 may be formed so as to surround both the firstconductive region310 and the secondconductive region320.
Referring toFIG. 21B, thephosphor layer340 and thetransparent resin350 may be formed in dots. In this case, thephosphor layer340 and thetransparent resin350 may be formed so as to surround only the corresponding light-emittingpackage11.
FIG. 22 is a diagram illustrating a light-emitting system according to the fourth exemplary embodiment of the invention.
FIG. 22 shows an example of an end product to which the light-emitting system described with reference toFIGS. 18 to 21B is applied. The light-emitting system may be applied to various apparatuses, such as, for example, an illuminating device, a display device, and a mobile apparatus (for example, a mobile phone, an MP3 player, and a navigation system). The device shown inFIG. 22 is an edge type backlight unit (BLU) used in a liquid crystal display (LCD). As the liquid crystal display does not have a light source therein, the backlight unit is used as a light source, and the backlight unit illuminates the rear surface of a liquid crystal panel.
Referring toFIG. 22, the backlight unit includes the light-emittingpackage11, alight guide plate410, a reflectingplate412, adiffusion sheet414, and a pair ofprism sheets416.
The light-emittingelement1 emits light. The light-emittingelement1 may be a side view type. As described above, the light-emittingelement1 is arranged in the slot of thepackage body210 of the light-emittingpackage11.
Thelight guide plate410 guides light emitted to theliquid crystal panel450. Thelight guide plate410 is formed of a transparent plastic material, such as, for example, acrylic resin, and guides light emitted from the light-emittingelement1 to theliquid crystal panel450 that is provided above thelight guide plate410. Therefore,various patterns412athat change the traveling direction of light incident on thelight guide plate410 to theliquid crystal panel450 are printed on the rear surface of thelight guide plate410.
The reflectingplate412 is provided on the lower surface of thelight guide plate410 to reflect light emitted from the lower side of thelight guide plate410 to the upper side. The reflectingplate412 reflects light that is not reflected by thepatterns412a, which is provided on the rear surface of thelight guide plate410, to the emission surface of thelight guide plate410. In this way, it is possible to reduce light loss and improve the uniformity of light emitted from the emission surface of thelight guide plate410.
Thediffusion sheet414 diffuses light emitted from thelight guide plate410 to prevent partial light concentration.
Trigonal prisms are formed on the upper surface of theprism sheet416 in a predetermined array. In general, two prism sheets are arranged such that the prisms deviate from each other at a predetermined angle. In this way, the prism sheets make light diffused by thediffusion sheet414 travel in a direction that is vertical to theliquid crystal panel450.
FIGS. 23 to 26 are diagrams illustrating light-emitting systems according to the fifth to eighth exemplary embodiments of the invention.
FIGS. 23 to 26 show end products to which the above-mentioned light-emitting system is applied.FIG. 23 shows a projector,FIG. 24 shows a car headlight,FIG. 25 shows a streetlamp, andFIG. 26 shows a lamp. The light-emittingelements1 used for the lighting devices shown inFIGS. 23 to 26 may be a top view type.
Referring toFIG. 23, light emitted from alight source510 passes through a condensinglens520, acolor filter530, and asharping lens540 and is then reflected from a digital micromirror device (DMD)550. Then, the light reaches ascreen590 through aprojection lens580. The light-emitting element according to the above-described exemplary embodiments of the invention is provided in thelight source510.
Having described the exemplary embodiments of the present invention, it is further noted that it is readily apparent to those of reasonable skill in the art that various modifications may be made without departing from the spirit and scope of the invention which is defined by the metes and bounds of the appended claims.

Claims

1. A method of manufacturing a light-emitting element, the method comprising:

forming a first conductive layer of a first conductive type, a light-emitting layer, and a second conductive layer of a second conductive type on at least one first substrate;

forming an ohmic layer on the second conductive layer;

bonding the at least one first substrate to a second substrate, the second substrate being larger than the first substrate; and

etching portions of the ohmic layer, the second conductive layer, and the light-emitting layer to expose a portion of the first conductive layer.

2. The method ofclaim 1, further comprising:

before the ohmic layer is formed, performing a first annealing on the first substrate having the first conductive layer, the light-emitting layer, and the second conductive layer formed thereon.

3. The method ofclaim 2, further comprising:

forming a first electrode on the exposed first conductive layer, forming a second electrode on the ohmic layer; and

performing an annealing on the first and second substrates bonded to each other after the first and second electrodes are formed,

wherein the process temperature of the annealing performed on the first and second substrate bonded to each other is lower than that of the first annealing.

4. The method ofclaim 2, further comprising:

before the bonding of the first and second substrates to each other, performing second annealing on the first substrate having the ohmic layer formed thereon.

5. The method ofclaim 4, further comprising:

performing a third annealing on the first and second substrates bonded to each other after the first and second electrodes are formed,

wherein the process temperature of the third annealing is lower than that of the second annealing.

6. The method ofclaim 1, further comprising:

forming a first electrode on the exposed first conductive layer, forming a second electrode on the ohmic layer;

removing the second substrate after the first and second electrodes are formed, reducing the thickness of the first substrate; and

dividing the first substrate into chips.

7. The method ofclaim 1, wherein the bonding of the at least one first substrate to the second substrate is performed by at least one of direct bonding and adhesive bonding.

8. The method ofclaim 7, wherein:

the direct bonding includes:

pre-treating a bonding surface of the second substrate or a bonding surface of the at least one first substrate; and

performing a heat treatment on the second substrate and the at least one first substrate, or physically compressing the second substrate and the at least one first substrate.

9. The method ofclaim 8, wherein the pre-treatment includes a plasma treatment or a wet treatment.

10. The method ofclaim 8, further comprising:

before the pre-treatment, polishing at least one of the bonding surface of the first substrate and the bonding surface of the second substrate.

11. The method ofclaim 8, further comprising:

before the pre-treatment, cleaning the first substrate and the second substrate.

12. The method ofclaim 7, wherein:

the adhesive bonding includes:

interposing an intermediate material layer between the bonding surface of the second substrate and the bonding surface of the at least one first substrate; and

13. The method ofclaim 1, wherein the first substrate is an insulating substrate, and the second substrate is a conductive substrate.

14. The method ofclaim 1, wherein the first conductive layer, the light-emitting layer, and the second conductive layer each include In_xAl_yGa_(1-x-y)N (0≦x≦1, and 0≦y≦1).

15. The method ofclaim 1, wherein the first conductive type is an n type, and the second conductive type is a p type.

16. A method of manufacturing a light-emitting element, the method comprising:

performing a first annealing on at least one insulating substrate at a first temperature;

bonding the at least one insulating substrate to a conductive substrate, the conductive substrate being larger than the insulating substrate; and

performing a second annealing on the insulating substrate and the conductive substrate bonded to each other at a second temperature that is lower than the first temperature.

17. The method ofclaim 16, further comprising:

before the first annealing, sequentially forming a first conductive layer of a first conductive type, a light-emitting layer, and a second conductive layer of a second conductive type on the insulating substrate.

18. The method ofclaim 17, further comprising:

before the first annealing, forming an ohmic layer on the second conductive layer.

19. The method ofclaim 18, further comprising:

after the bonding of the at least one insulating substrate to a conductive substrate and prior to the second annealing,

sequentially etching portions of the ohmic layer, the second conductive layer, and the light-emitting layer to expose a portion of the first conductive layer;

forming a first electrode on the exposed first conductive layer; and

forming a second electrode on the ohmic layer.

20. The method ofclaim 16, wherein the bonding of the at least one insulating substrate to the conductive substrate is performed by at least one of direct bonding and adhesive bonding.

21. A method of manufacturing a light-emitting element, the method comprising:

forming a first GaN layer of an n type, a light-emitting layer, a second GaN layer of a p type on at least one sapphire substrate;

performing a first annealing on the at least one sapphire substrate;

forming an ohmic layer on the second GaN layer;

performing a second annealing on the at least one sapphire substrate;

bonding the at least one sapphire substrate to a silicon substrate, the silicon substrate being larger than the sapphire substrate;

etching portions of the ohmic layer, the second GaN layer, and the light-emitting layer to expose a portion of the first GaN layer;

forming a first electrode on the exposed first GaN layer; and

forming a second electrode on the ohmic layer.

22. The method ofclaim 21, further comprising:

before or after the first and second electrodes are formed, performing a third annealing on the sapphire substrate and the silicon substrate bonded to each other,

wherein the process temperature of the third annealing is lower than that of the first annealing or the second annealing.

23. A method of manufacturing a light-emitting device using the method of manufacturing a light-emitting element according toclaim 1.

24-27. (canceled)