KR101349550B1

KR101349550B1 - Method of fabricating light emitting diode

Info

Publication number: KR101349550B1
Application number: KR1020080001807A
Authority: KR
Inventors: 문용태
Original assignee: 엘지이노텍 주식회사
Priority date: 2008-01-07
Filing date: 2008-01-07
Publication date: 2014-01-08
Also published as: KR20090076064A

Abstract

Disclosed is a light emitting diode manufacturing method. The method of manufacturing a light emitting diode includes: forming a first conductive semiconductor layer on a substrate, forming an active layer on the first conductive semiconductor layer, and a second including a plurality of nitrogen polarized reverse phase zones on the active layer. Forming a conductive semiconductor layer, and selectively removing nitrogen polarized reverse phase zones in the second conductive semiconductor layer to implement an uneven shape.

Light Emitting Diode, Surface Unevenness, Internal Quantum Efficiency, Light Extraction Efficiency

Description

Light emitting diode manufacturing method {METHOD OF FABRICATING LIGHT EMITTING DIODE}

The present invention relates to a method of manufacturing a light emitting diode.

Gallium nitride based light emitting diodes (LEDs) are attracting attention in the field of optical devices due to their high thermal stability and wide band gap (energy band gap). They are gallium nitride series light emitting diodes, Various color LEDs such as UV (Ultra Violet) have been developed and commercialized.

In particular, in the case of a high-output light emitting diode such as a high-efficiency white light emitting diode, efficency has been reached to such an extent that it can replace other light emitting devices, and studies for further improving the luminous efficiency have been actively made.

Currently, in order to improve the luminous efficiency, the crystal quality and the epi layer structure are improved to implement a high quality thin film to increase the internal quantum efficiency or the light emitted from the inside can be efficiently emitted to the outside. It is necessary to increase the light extraction efficiency.

Recently, researches for controlling the geometry of light emitting diode devices have been conducted to improve light extraction efficiency, and a method of reducing the internal light loss by roughening the surface of a sapphire substrate has been proposed.

However, when the sapphire substrate of the rough surface is adopted as described above, the light extraction efficiency is increased, but as the crystallinity of the epitaxial layer grown thereon is lowered, the internal quantum efficiency is not improved or rather degraded.

Accordingly, a number of methods for roughening the surface of the P-type gallium nitride layer in order to reduce internal light loss have been proposed. However, even in this case, problems such as deterioration of the crystal quality of the epi layer still appear.

An object of the present invention is to provide a light emitting diode and a method of manufacturing the same that can improve the luminous efficiency.

According to an aspect of the present invention, there is provided a method of fabricating a light emitting diode, including: forming a first conductive semiconductor layer on a substrate; Forming an active layer on the first conductive semiconductor layer; Forming a second conductivity type semiconductor layer on the active layer, the second conductivity type semiconductor layer including a plurality of nitrogen polarized reverse phase zones; And selectively removing the nitrogen polarized reverse phase zones in the second conductivity type semiconductor layer to implement an uneven shape.

Meanwhile, the forming of the second conductive semiconductor layer may include forming a reverse phase zone generation layer including a plurality of nitrogen polarized reverse phase zones between the gallium polarized thin films.

In the forming of the reverse phase zone generation layer, the reverse phase zone generation layer may be formed by doping a large amount of P-type impurities.

In the forming of the reverse phase zone generating layer, magnesium (Mg) may be doped in a large amount as the P-type impurity.

The forming of the second conductivity type semiconductor layer may include forming an uneven layer by growing the nitrogen polarized reverse phase zone into an uneven shape as the gallium polarized thin film layer grows on the reverse phase zone generation layer. It may further include.

The forming of the second conductivity-type semiconductor layer may further include forming a second conductivity-type semiconductor primary-forming layer by growing a gallium polarization thin film layer having minimal crystal defects at a high quality under the reverse phase zone generation layer. can do.

In addition, the forming of the reverse phase zone generation layer may control the formation of the nitrogen polarized reverse phase zones by adjusting the composition of aluminum or indium.

In addition, the step of implementing the concave-convex shape may selectively remove the nitrogen polarized reversed phase zones by a wet etching method.

Accordingly, the luminous efficiency of the light emitting diode can be improved.

According to the present invention, the luminous efficiency of the light emitting diode can be improved.

In addition, as the epitaxial layer of the light emitting diode has an uneven shape, light extraction efficiency is improved.

In addition, according to the present invention, while implementing the uneven shape on the epitaxial layer of the light emitting diode, high-quality crystal growth is possible, thereby improving the internal quantum efficiency.

In addition, according to the present invention, since the uneven shape is realized by a simple process after the epitaxial layer growth, the production process is simple, so that a light emitting diode having easy mass production and excellent price competitiveness can be manufactured.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided as examples in order to ensure that features of the present invention to those skilled in the art will fully convey. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the width, length, thickness, etc. of components may be exaggerated for convenience. Like numbers refer to like elements throughout.

1 is a cross-sectional view illustrating a light emitting diode according to an embodiment of the present invention.

Referring to FIG. 1, a light emitting diode 100 according to an embodiment of the present invention may include a substrate 1, a first conductive semiconductor layer 3, an active layer 5, and a second conductive semiconductor layer 7, 9. , 11).

The substrate 1 may use sapphire of an insulating material, and silicon carbide (SiC), zinc oxide (ZnO), gallium arsenide (GaAs), gallium nitride (GaN), silicon (Si), and lithium aluminum oxide (LiAlO _2). ) Or a semiconductor substrate such as lithium gallium oxide (LiGaO ₂ ) may also be used.

Although not shown, a buffer layer (not shown) may be disposed on the substrate 1 to reduce the lattice mismatch between the substrate 1 and the first conductivity type semiconductor layer 3 to a predetermined thickness. Such a buffer layer can be made of AlN, InGaN, GaN, AlGaN or the like.

The first conductivity type semiconductor layer 3 may be formed by doping an N-type impurity such as Si, Ge, Se, S, or Te.

The active layer 5 can be formed of a quantum well (QW) structure including InGaN, AlGaN, or GaN, or a multi quantum well (MQW) structure.

The second conductivity type semiconductor layers 7, 9, and 11 may include three different second conductivity type semiconductor layers, a primary formation layer 7, a secondary formation layer 9, and a tertiary formation layer 11. have.

The second conductive semiconductor layers 7, 9, and 11 may be formed by doping a P-type impurity such as, for example, magnesium (Mg).

Particularly, the second semiconductor layer 9 formed of the second conductive semiconductor layer is formed by excessively doping the P-type impurities, thereby creating a reverse phase region in which nitrogen polarized reverse phase zones are randomly formed in the P-type gallium nitride series thin film. Layer 9.

Accordingly, in the formation of the third formation layer 11 of the second conductivity type semiconductor layer, the nitrogen polarization reversed phase zones are gradually increased in size so that the tertiary formation layer 11 has a plurality of nitrogen polarization reversed phases. It is formed as an uneven layer 11 comprising zones.

In addition, the nitrogen-polarized reversed phase zones formed in the second conductive semiconductor reversed-phase zone forming layer 9 and the uneven layer 11 are selectively removed by wet etching, so that the second conductive semiconductor layer 7, 9, and 11 is formed. The surface includes a plurality of irregularities.

The plurality of irregularities formed on the surface of the second conductivity-type semiconductor layer 11 may have a hexagonal shape and the arrangement may be irregular as the nitrogen polarized reverse phase zones are selectively removed. have.

Therefore, the light emitted from the active layer 5 and radiated into the semiconductor layers is easily emitted into the air without being totally reflected into the inside as the reflection angle is changed or diffusely reflected by the uneven shape of the second conductivity-type semiconductor layer 11. The luminous efficiency of a light emitting element can be improved.

In addition, the light emitting diode 100 partially etches the second conductive semiconductor layers 7, 9, and 11, the active layer 5, and a part of the first conductive semiconductor layer 3 to form a first conductive semiconductor layer. Part of (3) is exposed to the outside. In this case, the exposed portion of the first conductivity-type semiconductor layer 3 may also be formed into an uneven shape by transferring the uneven shape of the second conductivity-type semiconductor layer 11 as it is by etching.

In addition, electrode pads 13 and 14 are formed on the exposed first conductive semiconductor layer 3 and the second conductive semiconductor layer 11, respectively. On the other hand, although not shown in the drawing on the second conductive semiconductor layer 11 in order to efficiently emit light generated in the ohmic contact and / or the active layer 5 to reduce the contact resistance between the semiconductor and the metal to the outside For example, the transparent electrode (not shown) may be formed to a thin thickness.

2 to 5 are views for explaining a light emitting diode manufacturing method according to an embodiment of the present invention.

Referring to FIG. 2, a first conductive semiconductor layer 1 of Al _x In _y Ga _(1-xy) N (where _0? _X, _Y _{? 1} and 0? X + (3) is formed.

On the other hand, before forming the first conductivity type semiconductor layer 3, a buffer layer (not shown) which is an undoped nitride semiconductor layer may be formed on the substrate 1. In this case, the buffer layer (not shown) may be formed of a material film of Al _x In _y Ga _(1-XY) N (where _0? _X, _Y _{? 1} and 0? X + Y? 1) , GaN, AlGaN, or the like is used.

The semiconductor layers described above and described below may be formed using metalorganic chemical vapor deposition (MOCVD), hydride vapor phase epitaxy (HVPE), molecular beam epitaxy (MBE) Can be formed in the same chamber.

The active layer 5 is formed on the first conductive semiconductor layer 3. The active layer 5 may be formed to have a single quantum well structure or a multiple quantum well structure. The active layer 5 may be formed of an InGaN, AlGaN, or GaN material film, and the composition ratio of each metal element is determined according to the required emission wavelength.

Thereafter, a second conductivity type semiconductor primary forming layer of Al _X In _Y Ga _(1-XY) N (where 0 ≦ _X, _Y ≦ 1 and 0 ≦ X + Y ≦ 1) material film is formed on the active layer 5. (7) is formed and can be formed into a single layer or multiple layers. When the first conductive semiconductor layer 3 is n-type, the second conductive semiconductor primary formation layer 7 is p-type and may be formed by doping with magnesium (Mg). The second conductive semiconductor primary formation layer 7 can improve the internal quantum efficiency of the light emitting device by growing the material at a high quality at a high temperature in addition to adjusting the material composition to minimize crystal defects of a thin film such as a nitrogen polarized reversed phase zone. .

Subsequently, the second conductive semiconductor secondary forming layer 9 of P-type impurity-heavy-doped gallium nitride series is thinly formed, for example, about 1 to 100 nanometers (nm). In this case, the P-type impurity, for example, magnesium (Mg) may be excessively doped with, for example, about 1 × 10 ²⁰ or more atoms per cm ² . In addition, the secondary formation layer 9 may be grown to high quality at a high temperature in the same manner as the primary formation layer 7 to minimize crystal defects due to low temperature growth.

In this case, N-polar inversion domains are spontaneously formed spontaneously in the second conductive semiconductor secondary formation layer 9 formed of an excessively doped P-type gallium nitride based film. These inverse zones are intrinsically a type of crystal growth defect caused by local changes in the chemical properties of gallium-polarized gallium nitride based thin film growth surfaces when excessively doped with magnesium (Mg) impurities. Corresponding. In addition, these nitrogen polarized reverse phase zones have the property of growing in the thin film growth direction in the surrounding gallium polarized thin film. In addition, the growth rate of the nitrogen-polarized reversed phase zone is different from the growth rate of the gallium-polarized thin film to realize an uneven shape on the surface of the thin film.

According to the present embodiment, the formation of such a nitrogen polarized reverse phase zone can be controlled by adjusting the material composition of the second conductivity type semiconductor secondary formation layer 9. That is, by increasing the composition of aluminum (Al) in the second conductivity type semiconductor secondary formation layer 11, it is possible to promote the formation of the nitrogen polarized reverse phase zone, and to increase the composition of indium (In) to form the nitrogen polarized reverse phase zone. Can be suppressed.

Thereafter, as shown in FIG. 3, the second conductivity-type semiconductor tertiary forming layer 11 is formed at high quality at high temperature. Nitrogen polarized reversed phase zones formed in the second conductive semiconductor secondary formation layer 7 penetrate into the second conductive semiconductor tertiary formation layer 11 and grow together as the thin film grows to increase in size, as described above. The nitrogen polarized reverse phase zones differ from the gallium polarized thin film to form irregularities on the surface of the tertiary forming layer 11 as shown in FIG. 3.

Subsequently, wet etching is performed on the surface of the second conductive semiconductor tertiary forming layer 11 to selectively remove the nitrogen arctic reversed phase regions, thereby as shown in FIG. 4. A nitride semiconductor in which a plurality of irregularities are formed on the surface of 11 can be formed.

The nitrogen polarized reverse phase zone and the gallium polarized thin film have essentially different chemical properties as described above. Therefore, the gallium polarized thin film surface is considerably energy stable compared to the nitrogen polarized reversed phase zone, and the reaction rate to the etchant is very slow. However, the nitrogen polarized reverse phase zones are relatively unstable on the surface of energy so that the reaction rate to the etchant is very fast.

Accordingly, the nitrogen polarization type reverse phase zones may be selectively removed from the surface of the second conductive semiconductor tertiary forming layer 11 by adjusting etching conditions such as etching solution, concentration, and time during wet etching. In this case, for example, a potassium hydroxide (KOH) solution can be used as the etching solution.

Thereafter, the second conductive semiconductor layers 7, 9, and 11 and the active layer 5 are patterned so that one region of the first conductive semiconductor layer 3 is exposed. Such patterning may be performed using a photolithographic and etching process. In this case, the exposed portion of the first conductivity-type semiconductor layer 3 may also be formed into an uneven shape by transferring the uneven shape of the second conductivity-type semiconductor layer 11 as it is by an etching process.

Thereafter, an electrode pad 13 is formed on the exposed first conductive semiconductor layer 3, and an electrode pad 14 is formed on the second conductive semiconductor layer 11. Meanwhile, the region where the electrode pad 14 is to be formed on the upper surface of the second conductive semiconductor layer 11 is planarized after planarizing at least a part of the uneven surface of the second conductive semiconductor layer 11. The electrode pad 14 may be formed on the recessed area. At least a part of the exposed portion of the first conductivity type semiconductor layer 3 to be formed with the electrode pad 13 may be planarized and then the electrode pad 14 may be formed on the planarized region.

Although not shown in the drawing, a transparent electrode (not shown) may be formed on the second conductive semiconductor layer 11 to have a thin thickness as described above. The uneven shape of the second conductivity type semiconductor layer 11 may be transferred to the transparent electrode (not shown) so that the transparent electrode (not shown) may have a uneven shape.

The transparent electrode (not shown) may be formed on the second conductive semiconductor layer 11 after exposing a region of the first conductive semiconductor layer 3 and before forming the electrode pad 14. Before exposing the first conductive semiconductor layer 3, the electrode layer may be formed by using an e-beam evaporation technique, and then patterned by using a photo and etching process.

According to the P-type gallium nitride shape control method using a nitrogen polarization type reverse phase zone according to an embodiment of the present invention, the gallium nitride-based thin film is grown at high temperature at high temperature, so that the light emitting device has excellent crystallinity and high internal light emission efficiency and light emission The reliability of the device can be increased. In addition, there is no problem such as an increase in electrical storage because no extra residue is left on the thin film, and as the plurality of high quality irregularities are formed on the surface of the thin film, the electrical storage is rather low.

5 illustrates another example of semiconductor layers formed to fabricate a light emitting diode according to an embodiment of the present invention.

After the formation of the nitrogen-polarized reversed phase zone in the second conductive semiconductor secondary formation layer 9, a plurality of irregularities are formed on the surface of the second conductive semiconductor layer, and as described above, the second conductive By stacking the type semiconductor tertiary forming layer 11 and selectively removing the nitrogen polarized reversed phase zones, as shown in FIG. 5, a gallium nitride based semiconductor layer having a plurality of irregularities on the surface of the second conductive semiconductor layer is formed. Can be formed.

6 is a cross-sectional view for describing a light emitting diode according to another exemplary embodiment of the present invention. In the description of the light emitting diode according to another exemplary embodiment of FIG. 6, the description of the similar or identical parts to the light emitting diode according to the exemplary embodiment described above will be omitted.

Referring to FIG. 6, a light emitting diode according to another exemplary embodiment of the present invention may include second conductive semiconductor layers 11, 9, and 7, an active layer 5, and a first conductive semiconductor on the conductive holder 19. Layer 3 is laminated. On the other hand, a plurality of irregularities are formed on the lower surface of the second conductivity type semiconductor layer 11. The uneven shape may be irregularly arranged in a plurality on the bottom surface of the second conductivity type semiconductor layer 11. In addition, a reflective film 17 and a metal thin film 18 may be interposed between the conductive holder 19 and the second conductive semiconductor layer 11.

The first electrode 20 is laminated on the upper portion of the conductive holder 19 and the second electrode 21 and the electrode pad 22 are sequentially stacked under the exposed first conductivity type semiconductor layer 3 .

Although not shown, an ohmic contact material layer such as a transparent conductive oxide (TCO) may be disposed between the second conductive semiconductor layer 11 and the reflective film 17.

Accordingly, the light emitted from the active layer 5 and radiated into the semiconductor layers is changed in the reflection angle by the uneven shape of the first conductivity type semiconductor layer and is easily emitted into the air without being totally reflected therein, so that the luminous efficiency of the light emitting device is improved. Can increase.

On the other hand, although not shown, if another example of the gallium nitride-based semiconductor layers shown in FIG. 5 is applied to the present embodiment, as shown in FIG. 5, more irregularities are formed on the surface of the second conductivity-type semiconductor layer 11. The light emitting efficiency of the light emitting device can be further improved.

FIG. 7 is a cross-sectional view for describing a light emitting diode according to another exemplary embodiment of the present invention illustrated in FIG. 6. Hereinafter, a method of forming a light emitting diode having the structure as described above will be briefly described with reference to FIGS. 2 to 5 and 7.

As shown in FIG. 2, first, the first conductive semiconductor layer 3, the active layer 5, and the second conductive semiconductor primary formation layer 7 are sequentially formed on the sacrificial substrate 1, and then magnesium ( The second conductive semiconductor secondary forming layer 9 of Mg) is excessively doped to form a thin gallium nitride series. At this time, by adjusting the composition of aluminum (Al) or indium (In) as described above, the degree of formation of the nitrogen polarized reversed phase zone can be adjusted.

As shown in FIG. 3, the second conductivity type semiconductor tertiary layer 11 is formed on the second conductivity type semiconductor secondary layer 9, so that the nitrogen-polarized-type reverse phase region in the gallium- Grow.

Thereafter, wet etching is performed as shown in FIG. 4 to selectively remove the nitrogen-polarized reverse phase region from the surface of the second conductivity type semiconductor tertiary layer 11.

As shown in FIG. 7, the reflective film 17, the metal thin film 18, and the conductive holder 19 are sequentially formed. Thereafter, the sacrificial substrate 1 is separated from the semiconductor layers, and the electrode 20 and the electrode pad 21 are sequentially formed under the first conductive semiconductor layer 3.

As the sacrificial substrate 1, all kinds of substrates as described above can be used, and a substrate in which a gallium nitride (GaN) template is grown on sapphire or other substrate can be used. On the other hand, before forming the first conductivity-type semiconductor layer 3, the metal layer (not shown), such as a nitriding metal, may be formed on the sacrificial substrate 1 using metals such as Ti and W. . In addition, although not shown in the figure, on the metal layer (not shown) or on the sacrificial substrate 1, there are formed a first conductive semiconductor layer 3, A buffer layer (not shown) of Un-doped GaN can be further formed.

Forming the conductive holder 19 is to support the light emitting diode semiconductor layers after removal of the sacrificial substrate (not shown) in a subsequent process, and to facilitate electrode formation. The conductive holder 19 may be formed by electroplating using the metal thin film 18 as a seed metal after depositing a metal thin film 18 on the reflective film 17. However, the conductive holder 19 is not limited to this method and can be formed in various ways.

In addition, although not shown in the drawing, an ohmic contact material (not shown) such as TCO may be formed before the reflective film 17 is formed on the second conductive semiconductor layer 11. .

The sacrificial substrate 1 and the metal layer (not shown) are removed from the lower portion of the first conductive semiconductor layer 3 by a mechanical or chemical method such as laser lift-off or wet etching. Expose the bottom.

7, a first electrode 20 is formed on the conductive holder 19, and a second electrode 21 and an electrode pad 21 are formed under the exposed first conductive semiconductor layer 3, (22) can be sequentially formed. The first electrode 20 and the electrode pad 22 may be made of a metal for ohmic contact.

Although not shown, when the second conductive semiconductor secondary formation layer 9 is formed, for example, the composition of magnesium (Mg) is increased to promote the formation of the nitrogen polarized reverse phase zone, resulting in the formation of the second conductive semiconductor tertiary formation layer ( 11) the nitrogen polarization type reverse phase zone increases, and as a result, as shown in FIG. 5, the surface of the second conductivity type semiconductor tertiary forming layer 11 may have a large number of irregularities.

In the light emitting diode formed in this manner, light extraction efficiency may be greatly improved according to the uneven shape of the second conductivity-type semiconductor layer 11.

8 is a cross-sectional view for describing a light emitting diode according to still another embodiment of the present invention. In the description of the light emitting diode according to another exemplary embodiment of FIG. 8, the description of the similar or identical parts to the light emitting diode according to the exemplary embodiment described above will be omitted.

Referring to FIG. 8, a light emitting diode according to another embodiment of the present invention includes a first conductive semiconductor layer 3, an active layer 5, and a second conductive semiconductor layer 7 and 9 on the conductive holder 19. , 11) are laminated. On the other hand, a plurality of irregularities are formed on the upper surface of the second conductivity type semiconductor layer 11. The uneven shape may be irregularly arranged in a plurality on the upper surface of the second conductivity type semiconductor layer 11. A reflective layer 17 may be disposed between the conductive holder 19 and the first conductivity type semiconductor layer 3.

In addition, a first electrode 20 is stacked on the conductive holder 19, and a second electrode 21 formed of a material such as Ni / Au or ITO is disposed on the second conductive semiconductor layer 11. The electrode pad 22 is positioned on the upper portion thereof.

9 is a cross-sectional view illustrating a method of manufacturing a light emitting diode according to another embodiment of the present invention.

Hereinafter, a method of manufacturing a light emitting diode having the structure as described above will be described with reference to FIGS. 2 to 5 and 9.

In order to facilitate the removal process of the sacrificial substrate 1 before forming the first conductivity type semiconductor layer 3 on the sacrificial substrate 1, a metal such as Ti, W, The same metal layer (not shown) can be formed. In addition, although not shown in the figure, on the metal layer (not shown) or on the sacrificial substrate 1, there are formed a first conductive semiconductor layer 3, A buffer layer (not shown) of Un-doped GaN can be further formed.

As the sacrificial substrate 1, any type of substrate may be used as described above, or a substrate in which a gallium nitride (GaN) template is grown on sapphire or other substrate may be used.

Subsequently, as shown in FIG. 9, an auxiliary substrate 16 is formed on the second conductive semiconductor layer 11 opposite to the sacrificial substrate 1. The auxiliary substrate 16 may be formed by applying an adhesive to the upper surface of the second conductive semiconductor layer 11 and attaching various kinds of substrates such as glass, sapphire, and silicon substrate. It is possible to prevent the semiconductor layers from being damaged during the subsequent process of removing the sacrificial substrate 1 as well as the formation of the electrodes and the reflective film by forming the auxiliary substrate 16 and thereby improving the reliability of the light, .

After the auxiliary substrate 16 is formed, the semiconductor layers may be separated from the sacrificial substrate 1 by using a laser lift off method, or a mechanical process using a vacuum chuck or the like, The metal layer (not shown) may be removed by a chemical method such as wet etching to separate the sacrificial substrate 1 and expose a lower portion of the first conductive type semiconductor layer 3. [ When a buffer layer (not shown) is formed on the sacrificial substrate 1, the metal layer (not shown) and the buffer layer (not shown) are removed to remove the sacrificial substrate 1 ) Can be separated from the semiconductor layers.

9, a reflective film 17 and a conductive holder 19 are sequentially formed on the bottom of the exposed first conductive semiconductor layer 3. Then, as shown in FIG. The reflective layer 17 may be formed after placing an ohmic contact material on the lower portion of the first conductivity type semiconductor layer 3, if necessary. The conductive holder 19 supports the light emitting diode semiconductor layers after the auxiliary substrate 16 is removed in a subsequent process, and can facilitate electrode formation.

The conductive holder 19 may be formed by plating (Plating) after applying an adhesive (not shown), such as solder (Solder) on the reflective film 17, or the metal (Si) formed on both sides, It can be formed by attaching a silicon carbide (SiC) substrate. In addition, the conductive holder 19 may be formed by depositing a metal thin film (not shown) on the reflective film 17 and then using the metal thin film (not shown) as a seed metal by electroplating. It may be.

Thereafter, the auxiliary substrate 16 is separated from the second conductive semiconductor layer 11, and the first electrode 15 and the electrode pad 19, which are transparent electrodes, are sequentially disposed on the second conductive semiconductor layer 11. The second electrode 20 is formed on the lower surface of the conductive holder 19.

The auxiliary substrate 16 may remove the adhesive used to attach the auxiliary substrate 16 to the second conductive semiconductor layer 11 through wet etching, thereby forming the second conductive semiconductor layer 11. ) Can be separated.

Meanwhile, the region where the electrode pad 19 is to be formed in the upper surface of the second conductive semiconductor layer 11 is planarized after planarizing at least a part of the uneven surface of the second conductive semiconductor layer 11. The electrode pad 19 may be formed on the recessed area.

On the other hand, the above-described embodiment is implemented by forming a reflective film and a conductive holder on the second conductive semiconductor layer 11 on the contrary to the above structure, so that the light emitting device and the light emitting direction made through the above-described process are reversed. May be

Although the preferred embodiments of the present invention have been described, the present invention is not limited to the specific embodiments described above. It will be apparent to those skilled in the art that numerous modifications and variations can be made in the present invention without departing from the spirit or scope of the appended claims. And equivalents should also be considered to be within the scope of the present invention.

2 to 5 are cross-sectional views illustrating a method of manufacturing a light emitting diode according to an embodiment of the present invention.

6 and 7 are cross-sectional views illustrating a light emitting diode and a method of manufacturing the same according to another embodiment of the present invention.

8 and 9 are cross-sectional views illustrating a light emitting diode and a method of manufacturing the same according to still another embodiment of the present invention.

Claims

Forming a first conductive type semiconductor layer on a substrate;

Forming an active layer on the first conductive semiconductor layer;

Forming a second conductivity type semiconductor layer on the active layer, the second conductivity type semiconductor layer including a plurality of nitrogen polarized reverse phase zones; And

And selectively removing the nitrogen polarized reversed phase zones in the second conductive semiconductor layer to implement an uneven shape.

The method of claim 1,

The forming of the second conductivity type semiconductor layer may include:

And forming a reverse phase zone generation layer comprising a plurality of nitrogen polarized reverse phase zones between the gallium polarized thin films.

The method of claim 2,

The reverse phase zone generation layer forming step,

And a large amount of P-type impurities to form the reverse phase zone generation layer.

The method of claim 3, wherein

The reverse phase zone generation layer forming step,

Method of manufacturing a light emitting diode, characterized in that doped with a large amount of magnesium (Mg) as the P-type impurities.

The method of claim 2,

The forming of the second conductivity type semiconductor layer may include:

And growing the nitrogen polarized reverse phase zone into an uneven shape as the gallium polarized thin film layer grows on the reverse phase zone generating layer, thereby forming an uneven shape layer.

6. The method according to claim 2 or 5,

The forming of the second conductivity type semiconductor layer may include:

And growing a high-grade gallium polarization thin film layer having minimum crystal defects under the reverse phase zone generation layer to form a second conductivity type semiconductor primary forming layer.

The method of claim 2,

The reverse phase zone generation layer forming step,

Controlling the formation of the nitrogen polarized reversed phase zones by controlling the composition of aluminum or indium.

The method of claim 1,

The irregular shape implementation step,

And selectively removing the nitrogen polarized reversed phase zones by a wet etching method.