Semiconductor template substrate, light-emitting device using a semiconductor template substrate, and manufacturing method therefor

A light-emitting device includes a semiconductor layer, a light-emitting stack structure formed on a first surface of the semiconductor layer, and a plurality of inverted pyramid structures formed on a second surface of the semiconductor layer opposite to the first surface. Each of the inverted pyramid structures has a sectional area increasing as each of the inverted pyramid structures is more extended in a vertical direction from the second surface.

TECHNICAL FIELD

The present invention relates to a semiconductor template substrate, a light-emitting device using the same, and a method of manufacturing the light-emitting device, and more particularly, to a semiconductor template substrate for decreasing defective crystalline and enabling easy separation, a light-emitting device using the same, and a method of manufacturing the light-emitting device.

BACKGROUND ART

Conventional semiconductor light-emitting devices are formed as horizontal devices or vertical devices with an insulating substrate such as sapphire. For example,FIG. 6Aillustrates a conventional horizontal semiconductor light-emitting device, andFIG. 6Billustrates a conventional vertical semiconductor light-emitting device.

The horizontal semiconductor light-emitting device includes a buffer layer2, an n-type nitride semiconductor layer3, an active layer4, and a p-type nitride semiconductor layer5that are sequentially stacked on a sapphire substrate1. A p-type electrode6is formed on the p-type nitride semiconductor layer5, and, by removing a partial region of the p-type nitride semiconductor layer5and active layer4in an etching process, an n-type electrode7is formed on an exposed portion of the n-type nitride semiconductor layer3. However, in the horizontal light-emitting device ofFIG. 6A, a light-emitting area is relatively reduced, and a surface leakage current increases, causing the decrease in the emission performance of the horizontal light-emitting device. In addition, since an area through which a current passes is relatively small, a resistance increases, and thus, an operating voltage increases. For this reason, heat is generated, causing the reduction in the service life of the horizontal light-emitting device.

Moreover, in the vertical light-emitting device ofFIG. 6B, an operation of forming a p-type nitride semiconductor layer5on a substrate is the same as that of the horizontal light-emitting device. An insulating substrate is separated from the light-emitting device before an n-type electrode7is formed, and then, the n-type electrode7is formed at a bottom of an n-type semiconductor layer3. In this case, a laser lift-off process is generally used for separation of the insulating substrate. By irradiating a laser beam, which is a strong energy source, on a backside of a transparent sapphire substrate, the laser beam is strongly absorbed in a interface between a buffer layer and the sapphire substrate, and thus, a temperature of 900° C. or more is momentarily produced, whereby a nitride semiconductor in the interface is thereto-chemically dissolved and the sapphire substrate is separated from the vertical light-emitting device. However the laser lift-off process causes the thermal/mechanical deformation of a light-emitting stack structure including an active layer. For example, a mechanical stress occurs between the nitride semiconductor layer and a thick sapphire substrate due to different lattice constants and heat expansion coefficients, and, the vertical nitride semiconductor light-emitting device suffers a mechanical/thermal damage because the vertical nitride semiconductor light-emitting device cannot endure the mechanical stress.

As described above, when a thin film of a stack light-emitting structure is damaged, a high leakage current is caused, and moreover, the chip yield of light-emitting devices is largely reduced, causing the reduction in the entire performance of the light-emitting devices.

DISCLOSURE

Technical Problem

In view of the above, the present invention provides a semiconductor template substrate for preventing the damage of a semiconductor substrate in performing a separation process.

Further, the present invention provides an excellent semiconductor light-emitting device.

Further, the present invention provides a method of manufacturing an excellent semiconductor light-emitting device.

Technical Solution

The present invention relates to an approach to solve the above described problems. In forming a light-emitting device, a separation layer is used to facilitate ease separation of the light-emitting device from a semiconductor substrate. According to the present invention, the light-emitting device has an inverted pyramid structure due to the separation layer.

In accordance with a first aspect of the present invention, there is provided a light-emitting device. The light-emitting includes a semiconductor layer, a light-emitting stack structure, and a plurality of inverted pyramid structures. The light-emitting stack structure is formed on a first surface of the semiconductor layer and each of the inverted pyramid structures is formed on a second surface of the semiconductor layer opposite to the first surface. Each of the inverted pyramid structures has a sectional area decreasing as each of the inverted pyramid structures is more extended in a vertical direction from the second surface.

In accordance with a second aspect of the present invention, there is provided a method of manufacturing a light-emitting device. A buffer layer is formed on a substrate. A plurality of pyramid structures protruding from the buffer layer. A semiconductor layer separated from the buffer layer is formed. A semiconductor layer separated from the buffer layer is formed by growing a crystal from on each of the pyramid structures. The pyramid structures connect the buffer layer and the semiconductor layer. A light-emitting stack structure is formed on the semiconductor layer. Each of the pyramid structures is severed or a contact surface between each of the pyramid structures and the buffer layer is separated to separate the semiconductor layer from the buffer layer.

In accordance with a third aspect of the present invention, there is provided a method of manufacturing a light-emitting device. A buffer layer is formed on a substrate. The buffer layer is divided into a plurality of separate light-emitting device regions to form divided separate semiconductor layers respectively formed in the separate light-emitting device regions. The separate semiconductor layers respectively farmed in the separate light-emitting device regions are connected to the buffer layer corresponding to the separate light-emitting device regions by a plurality of protrusions. A light-emitting stack structure is formed on each of the separate semiconductor layers. Each of the pyramid structures is severed or a contact surface between each of the pyramid structures and the buffer layer is separated to separate the semiconductor layers from the buffer layer.

In accordance with a fourth aspect of the present invention, there is provided a method of manufacturing a light-emitting device. A buffer layer is formed on a substrate. The buffer layer is divided into a plurality of light-emitting device regions, and a plurality of pyramid structures are respectively formed in the light-emitting device regions. The pyramid structures is grown from respective tops of the pyramid structures to form a semiconductor layer having a cleavage surface that divides the light-emitting device regions. The semiconductor layer and the buffer layer are connected by the pyramid structures, and the semiconductor layer is separated from the buffer lay. A light-emitting stack structure is formed on the semiconductor layer to make a separate auxiliary light-emitting device. Each of the pyramid structures to strip the semiconductor layer is severed from the buffer layer. The separate auxiliary light-emitting device is separated with respect to the cleavage surface.

In accordance with a fifth aspect of the present invention, there is provided a method of manufacturing a light-emitting device. A buffer layer is formed on a substrate. The buffer layer is divided into a plurality of light-emitting device regions to form a plurality of pyramid structures in the light-emitting device regions. The pyramid structures is grown from respective tops of the pyramid structures to form a plurality of semiconductor layers that correspond to the respective light-emitting device regions and are separated from each other are formed. The semiconductor layers and the buffer layer are connected by the pyramid structures, and the semiconductor layers are separated from the buffer layer. The light-emitting stack structures are formed on the semiconductor layers to form separate light-emitting devices. The pyramid structures is severed to form light-emitting devices separated each other.

In accordance with a sixth aspect of the present invention, there is provided a semiconductor substrate template. The semiconductor substrate template includes a buffer layer formed on a substrate, a plurality of pyramid structures formed on the buffer layer, and a semiconductor layer formed on the buffer layer. The semiconductor layer is separated from the buffer layer and connected to the buffer layer by the plurality of pyramid structures.

In accordance with a seventh aspect of the present invention, there is provided a semiconductor substrate template. The semiconductor substrate template includes a buffer layer formed on a substrate, the buffer layer being divided into a plurality of auxiliary light-emitting regions, a plurality of protrusions protruding upward from the respective auxiliary light-emitting regions, and a plurality of separate semiconductor layers formed on the respective protrusions to be separated from the buffer layer, in the respective auxiliary light-emitting regions.

Advantageous Effects

According to embodiments of the present invention, a semiconductor substrate is simply separated from an insulating substrate, and thus, the semiconductor substrate is not damaged, thereby manufacturing a light-emitting device having excellent performance. Also, a concave-convex pattern is formed at a bottom of a semiconductor substrate without a separate additional process, thus simplifying a manufacturing process. Moreover, the semiconductor substrate cannot be damaged even in a process of separating a separate light-emitting device from the semiconductor substrate.

BEST MODE

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that they can be readily implemented by those skilled in the art.

First, a semiconductor crystal manufacturing method in accordance with an embodiment of the present invention will be described with reference toFIGS. 1A and 1B. For example, the present embodiment is an embodiment for growing an n-type GaN crystal with a sapphire substrate. However, materials that are used for a substrate and a buffer layer, a semiconductor layer, and a light-emitting stack structure are not limited thereto.

In operation S110, a buffer layer20is formed on an insulating substrate10, and a mask layer30having a plurality of exposure patterns39is formed on the buffer layer20. InFIG. 1A, the exposure patterns39are illustrated in a circular shape. However, the exposure patterns39may be formed in a polygonal shape such as a tetragonal shape, a triangular shape, or a hexagonal shape, and may be variously arranged.

The substrate10may be a sapphire substrate or a substrate including silicon, GaAs, InP, and SiC, and may be selected from a group consisting of various materials.

In an embodiment of the present invention, the buffer layer20may be formed by growing a GaN crystal. For example, the buffer layer20may be formed by growing an n-type GaN crystal to a thickness of 2 μm to 5 μm with a HVPE crystal growing device. Unlike this, the buffer layer20may include an AlxGa(1−x)N (0<x<1) layer or Al2O3, and AlN or ZnO.

The material of the mask layer30may use SiO2or Si3N4, and metal such as Cr, Au, Ti, or Ni. For example, SiO2or Si3N4is deposited to a thickness of 500 Å to 5000 Å on the buffer layer20in PECVD, and then, by forming the exposure pattern39in a photolithography process, a portion of the buffer layer20is exposed.

Alternatively, the exposure pattern may be formed by depositing SiO2or Si3N4to a thickness of 500 Å to 5000 Å, or metal such as Cr, Au, Ti, or Ni may be deposited in an exposure pattern shape. For example, the mask layer30may be formed by a lift-off process. Photoresist is applied on the buffer layer20, and an exposure process is performed. Subsequently, a photoresist pattern is formed by performing a development process. Therefore, the buffer layer20having a desired pattern shape is exposed, and the other portion is covered by the photoresist pattern. An auxiliary mask layer (not shown) is formed on the photoresist pattern formed on the buffer layer20. Subsequently, the photoresist pattern and the auxiliary mask layer formed on the photoresist pattern are removed. Accordingly, the mask layer30having a desired pattern may be formed on the buffer layer20.

In an embodiment of the present invention, in case where the exposure pattern39is circular in shape, a diameter of each of the exposure patterns39is about 0.5 μm to about 5 μm, and an interval between adjacent exposure patterns39is about 0.5 μm to about 10 μm.

In operation S120, a crystal is grown from the buffer layer20exposed by the exposure pattern39. For example, by selectively growing an n-type GaN crystal with the HVPE crystal growing device, a pyramid structure40is formed from the inside of the exposure pattern39of the mask layer30. This denotes that a sectional area of the pyramid structure40becomes narrower progressively closer to an upper portion of the pyramid structure40. For example, the pyramid structure40may have a conic structure or a hexagonal pyramid (polygonal pyramid) structure. For example, a basic crystalline structure of GaN is a wurtzite structure, and thus, by growing GaN from the buffer layer20(exposed by the exposure pattern39) to have a horned shape, a hexagonal pyramid structure may be formed. In this case, a diameter of a bottom of the pyramid structure40may be approximately equal to or slightly greater than that of the exposure pattern39. When the diameter of the exposure pattern39is about 0.5 μm or 5 μm, a height of the pyramid structure40may be about 0.5 μm to about 7.5 μm greater by about 1 to 5 times than the diameter of the exposure pattern39. The bottom of the pyramid structure40is overgrown, and thus becomes broader than the exposure pattern39. The pyramid structure40protrudes to on the mask layer30. The pyramid structure40may be formed in a hexagonal pyramid structure.

In an embodiment of the present invention, an example of a crystal growth condition of HVPE is as follows. Ga metal is used as a raw material of Ga, NH3is used as a raw material of N, and Te or Si is mixed with Ga solution for forming n-type GaN. The substrate with the exposure pattern39formed therein is disposed in a reaction pipe, and, by growing a GaN crystal at about 1000° C. to 1100° C., a hexagonal pyramid structure of n-type GaN is formed.

According to another embodiment of the present invention, a composition of the pyramid structure40may be AlxGa(1−x)N (0<x<1). By changing a source that is used in growing the pyramid structure40, a composition of the buffer layer30and the composition of the pyramid structure40may be formed identically or differently. For example, to obtain an AlxGa(1−x)N (0<x<1) layer that is the buffer layer20, by adjusting the amount of Al (which is added into Ga solution that is used in forming the buffer layer20) from 0 g to several g to hundreds mg per 1 g Ga, GaN whose a composition x is 0 to AlN whose a composition x is 1 may be obtained. Also, to obtain an AlxGa(1−x)N (0<x<1) layer that is the buffer layer20, by adjusting the amount of Al (which is added into Ga solution that is used in forming the pyramid structure40) from 0 g to several mg to hundreds mg per 1 g Ga, GaN (whose a composition x is 0) to AlN whose a composition x is 1 may be obtained. In this way, the composition of the buffer layer20and the composition of the pyramid structure40are adjusted by changing a source. That is, the composition of the buffer layer30and the composition of the pyramid structure40may be formed identically or differently.

FIG. 5Ais an SEM photograph in a state in which the pyramid structure40has been formed in accordance with an embodiment of the present invention.

The pyramid structure40is formed, and a semiconductor layer50is then formed in operation S130. In an embodiment of the present invention, the semiconductor layer50may be formed with the HYPE crystal growing device. For example, growth layers grown from respective side surfaces of the pyramid structures40may be coupled, thereby forming the semiconductor layer50. That is, in the mask layer30, it is difficult for a crystal to grow from the buffer layer20. A GaN crystal starts to grow to an inclined side surface of the exposed pyramid structure40, and crystal layers grown from the semiconductor layer50adjacent thereto are adhered to each other, thereby forming the semiconductor layer50.

In an embodiment of the present invention, a height of the semiconductor layer50may be a thickness that enables the pyramid structure40to sustain the thickness of the semiconductor layer50. For example, the height of the semiconductor layer50may be about 1 μm to 100 μm.

In an embodiment of the present invention, the composition of the pyramid structure40may be GaN or AlxGa(1−x)N (0<x<1). In a growth method, when a source growing the pyramid structure40differs from a source growing the semiconductor layer50, layers having different compositions may be obtained. For example, Ga source reacts with ammonia for forming the pyramid structure40, and Ga source reacts with Al source and ammonia for forming the semiconductor layer50. Thus, the pyramid structure40is formed of GaN, and the semiconductor layer50is formed of AlGaN. In this case, by adjusting the amount of Al, an Al composition of the AlGaN layer may be adjusted. The composition of the pyramid structure40is merely one example, and, by changing a source used to form the pyramid structure40, the pyramid structure40having another composition may be formed.

In an embodiment of the present invention, a top of the semiconductor layer50may be a flat planarization layer. For example, a crystal may start to grow from approximate half of the height of the pyramid structure40to the inclined side surface of the pyramid structure40, crystals grown from adjacent pyramid structures40may be adhered to each other, and then, while maintaining growth until an entire region is planarized, the semiconductor layer50may be formed. The bottom of the semiconductor layer50may be formed at a position corresponding to one-third of the height of the pyramid structure40. However, the technical spirit and scope of the present invention are not limited to the height.

An empty space surrounded by the semiconductor layer50, pyramid structure40, and mask layer30is formed. Thus, a separation layer90is formed between the bottom of the semiconductor layer50and the mask layer30.

FIG. 5Bis a side SEM photograph in a state in which the pyramid structure40and the semiconductor layer50have been formed in accordance with an embodiment of the present invention, and an empty space next to the pyramid structure can be seen.

In operation S140, a light-emitting stack structure60is formed on the semiconductor layer50. For example, the light-emitting stack structure may be formed by forming an n-type AlGaN cladding layer, an AlGaN active layer, a p-type AlGaN cladding layer, and a p-type GaN cap layer. In an embodiment of the present invention, the light-emitting stack structure60may be formed by a HVPE crystal growing process. For example, a cladding layer including n-type AlxGa(1−x)N (0<x<1), an active layer including AlxGa(1−x)N (0<x<1), a cladding layer including p-type AlxGa(1−x)N (0<x<1), and a p-type GaN cap layer may be sequentially formed. Materials of the respective layers of the light-emitting stack structure60and a stack sequence may be appropriately changed depending on an emission wavelength range, a light output, or the kind of a light-emitting device.

The buffer layer20, the semiconductor layer50, and the light-emitting stack structure60may all be formed by the HVPE process, and thus, the buffer layer20, the semiconductor layer50, and the light-emitting stack structure60may be formed sequentially. For example, the buffer layer20, the semiconductor layer50, and the light-emitting stack structure60may all be formed by an in-situ process.

In operation S150, the substrate10, the buffer layer20, and the mask layer30are separated from the light-emitting stack structure60. Unevenness may be formed on a separated surface. The separation of the substrate10may be performed by applying ultrasonic waves, physical vibration, or an impact. For example, when the substrate10with the light-emitting stack structure60formed therein is put into a solution such as acetone, methanol, or distilled water and is subjected to ultrasonic waves, the pyramid structure40is severed from the separation layer90in which the semiconductor layer50and the buffer layer40are connected to only the pyramid structure40, whereby separation is made. Alternatively, the pyramid structure40may be severed by applying a simple impact. Thus, an inverted pyramid structure is formed at the bottom of the semiconductor layer50. The inverted pyramid structure denotes a structure in which a cross-sectional area increases progressively farther away from the bottom of the semiconductor layer50. That is, the inverted pyramid structure formed at the semiconductor layer50serves as a structure that facilitates separation between the light-emitting device and the substrate10used to form the light-emitting device.

Alternatively, even when separation is performed by irradiating a laser beam, separation is performed by irradiating the laser beam on the pyramid structure40of the separation layer90having relatively weak coupling strength compared to a conventional laser lift-off process, and thus, only a narrow region of a pyramid lower portion is thermally and chemically damaged by the laser beam, whereby the substrate10is separated from the light-emitting device without damaging the light-emitting stack structure60.

Unlike this, stress occurs in the pyramid structure40by applying strain to the substrate10and/or the buffer layer20, thereby severing the pyramid structure40.

Due to the separation layer90, the light-emitting device is easily separated from the substrate10, and thus, a complicated process is not performed. Also, when separating the light-emitting device from the substrate10, the semiconductor layer50of the light-emitting device is not damaged, and thus, a good-quality light-emitting device can be manufactured.

FIG. 5Cis an SEM photograph showing the bottom of the separated light-emitting stack structure, and a concave-convex pattern formed in severing the pyramid structure40can be seen.

In operation S160, a p-type electrode71is formed on the light-emitting stack structure60, and an n-type electrode72is formed at a bottom51of the separated semiconductor layer50, thereby forming the light-emitting device. The n-type electrode72may be formed on the inverted pyramid structure, or formed at the bottom51of the semiconductor layer50. Also, a separate intermediate layer may be formed, and then the electrodes71and72may be completely formed, depending on its design. In this case, in the bottom51of the semiconductor layer50, the inverted pyramid structure may be formed by severing the pyramid structure40. Also, since the bottom of the pyramid structure40is separated from the substrate10, a protrusion pattern may be formed at the bottom51of the semiconductor layer50even without a separate pattern process.

Depending on a design, the p-type electrode71may be formed immediately before separation operation S510after operation S140of forming the light-emitting stack structure60.

Moreover, the substrate10, which has a structure before a process of separating the substrate10and on which the elements from the buffer layer20to the semiconductor layer50are formed through operation S140, may be used as a semiconductor template substrate. As an example of the present invention, various electronic device structures are formed on the semiconductor template substrate, and then, by separating the separation layer90, various vertical semiconductor devices may be manufactured.

Next, a method of manufacturing a light-emitting device in accordance with another embodiment of the present invention will be described with reference toFIGS. 2A and 2B. A second embodiment is substantially similar to a first embodiment, but relates to a method in which a region of the separation layer90is divided into a plurality of regions having different coupling strengths, and a light-emitting device is formed. Therefore, in forming the mask layer30, as illustrated inFIG. 2A, the region of the separation layer90is divided into a first region31having relatively high coupling strength and a second region32having relatively low coupling strength. A diameter of each exposure pattern in the first region31differs from that of each exposure pattern in the second region32, and an interval between the exposure patterns in the first region31differs from an interval between the exposure patterns in the second region32. Specifically, the diameter of each exposure pattern in the first region31having relatively high coupling strength is less than that of each exposure pattern in the second region32having relatively low coupling strength, and the interval between the exposure patterns in the first region31is less than the interval between the exposure patterns in the second region32. For example, the diameter of each exposure pattern and the interval between the exposure patterns in the first region31may be 1 μm, and the diameter of each exposure pattern and the interval between the exposure patterns in the second region32may be 3 μm.

In this case, as illustrated inFIG. 2B, in forming the pyramid structure40, the pyramid structure40formed in the first region31has a gradient higher than the pyramid structure40formed in the second region32. In the pyramid structure40formed in the first region31, hexagonal pyramids are closely adhered to each other, and thus, an empty space is relatively reduced. Therefore, the separation layer90formed between the mask layer30and the semiconductor layer50is divided into a first separation part91having relatively high coupling strength and a second separation part92having relatively low coupling strength.

In forming a plurality of light-emitting devices on the substrate10, even though the second separation part92having relatively low coupling strength is separated by a physical force that is generated in a process after the semiconductor layer50is formed, the light-emitting stack structure60is supported by the first separation part91having relatively high coupling strength. Accordingly, the second embodiment is useful for a case in which the p-type electrode71is first formed before the separation layer90is separated.

Next, a method of manufacturing a light-emitting device in accordance with another embodiment of the present invention will be described with reference toFIGS. 3A to 3D. In the above-described method of manufacturing the light-emitting device, a method of manufacturing one light-emitting device has been described. However, the present embodiment relates a method of manufacturing light-emitting devices in which a plurality of light-emitting devices are formed on one substrate and easily separated from the one substrate, and moreover, the light-emitting devices are easily separated from each other. Therefore, a manufacturing method similar toFIG. 1will not be described.

First, as described above with reference toFIG. 1, a buffer layer20is formed on a substrate10, and a mask layer30that is as illustrated inFIG. 3Ais formed on the buffer layer20. The mask layer30has a plurality of light-emitting chip regions ‘A’. InFIG. 3A, for convenience of a description, each of the light-emitting chip regions ‘A’ is illustrated in a tetragonal shape. However, the light-emitting chip area ‘A’ is not limited to a tetragonal shape, and may be formed in various shapes such as a circular shape and a hexagonal shape depending on its design. The light-emitting chip regions ‘A’ are separated from each other by a certain chip interval ‘d’.

A plurality of exposure patterns39are formed in each light-emitting chip region of the mask layer30.

For example, in an embodiment of the present invention, the mask layer30is formed, and then, as illustrated inFIG. 3B, a plurality of pyramid structures40are formed by selectively growing a crystal from the buffer layer20in the HVPE process, whereupon a semiconductor layer50is formed. In this case, a cleavage surface55that divides the semiconductor layer50into a plurality of separate light-emitting stack structures may be formed. A depth of the cleavage surface55may be adjusted to a depth a user desires, depending on a chip interval ‘d’ and a process condition.

Moreover, in an embodiment of the present invention, when a height of a formed light-emitting stack structure is ‘h’, the depth of the cleavage surface55may be adjusted by adjusting a ratio of the height ‘h’ and the chip interval ‘d’. For example, by adjusting the chip interval ‘d’ to less by about 0.4 to 0.6 times than the height ‘h’, as illustrated inFIG. 3C, a structure may be formed in which only a portion of the semiconductor chip50is connected and the light-emitting stack structures60are separated from each other.

When the semiconductor layer50is completely formed, as illustrated inFIG. 3C, the light-emitting stack structure is formed on the semiconductor layer50. In this case, the light-emitting stack structure60is divided into a plurality of light-emitting chip regions by the cleavage surface51of the semiconductor layer50for the formation thereof.

As illustratedFIG. 3C, after the light-emitting device is formed up to the light-emitting stack structure60, each of the light-emitting devices is separated in vertical and horizontal directions. Such a separation process may be performed in different sequences. For example, as illustrated inFIG. 3D, by applying ultrasonic waves, vibration, or an impact to a separation layer90, the substrate10is first separated in the vertical direction, and each of the light-emitting devices is then be separated in the horizontal direction. Separation in the horizontal direction may be performed by various processes using a physical impact or pressurization. For example, a film is adhered onto the light-emitting devices, and then, by compressing the film with a roller, each of the light-emitting devices may be separated. Alternatively, by applying appropriate vibration or pressure, separation in the horizontal direction and separation in the vertical direction may be performed simultaneously.

Subsequently, a p-type electrode (not shown) is formed on the light-emitting stack structure60, and an n-type electrode (not shown) is formed at a bottom of the separated semiconductor layer50, thereby finishing the light-emitting device. Depending on a design, a separate intermediate layer may be formed and each of the electrodes is then completely formed. Depending on the case, the p-type electrode (not shown) may be formed at an appropriate time before or after a vertical separation operation and after a horizontal separation operation. Also, the n-type electrode (not shown) may be formed before or after the horizontal separation operation.

When the p-type electrode (not shown) and the n-type electrode (not shown) are separated into respective light-emitting chips and formed, as illustrated inFIG. 4, a jig200for forming an electrode may be used. The jig200includes a matrix type of chip mounting parts210having an appropriate size for accommodating a plurality of light-emitting chips. A chip selector selects a chip and adds the selected chip into each of chip mounting parts210included in the jig200, and then, the electrodes are formed.

Referring toFIGS. 3E to 3G, in another embodiment of the present invention, the mask layer30is formed, and then, by selectively growing a crystal from the buffer layer20, the plurality of pyramid structures are formed, whereupon the semiconductor layer50is formed. In this case, as illustratedFIG. 3E, the semiconductor layer50may be separated and formed in units of separate light-emitting device. For example, by adjusting the chip interval d to greater by 0.4 to 0.6 times than the height h, the separately separated semiconductor layers50and the separate light-emitting stack structures60may be formed. Specifically, as illustrated inFIG. 3F, the light-emitting stack structure60may be formed on each of the semiconductor layers50, and, as illustrated inFIG. 3G, the semiconductor layers50may be separated from the buffer layer30, thereby obtaining the separate light-emitting stack structures60. Subsequently, the p-type electrode (not shown) is formed on each of the light-emitting stack structures60, and the n-type electrode (not shown) is formed at a bottom of each of the separated semiconductor layers50, thereby finishing the plurality of light-emitting devices.

In the light-emitting device of the present invention, a semiconductor layer is formed on a pyramid structure, and then, by forming a light-emitting stack structure, a crystalline defective density is reduced, thus minimizing substrate dependency.

Moreover, in the present invention, it is not required to use a high-cost conductive metal substrate in manufacturing a vertical light-emitting device, and moreover, a substrate can be simply separated from a light-emitting device without performing the laser lift-off process necessary for using an insulating substrate, thus enhancing usefulness. Accordingly, a process of manufacturing a vertical light-emitting device can be simplified, and the manufacturing cost can be largely saved.

Furthermore, according to the embodiments of the present invention, a hexagonal pyramid structure in a light-emitting region is formed by adjusting a chip interval and a height of a light-emitting stack structure in the light-emitting region, thereby forming a planarization nitride semiconductor layer. Accordingly, vertical separation and horizontal separation between light-emitting chips can be easily performed, and a manufacturing process can be simplified.

According to the light-emitting device manufacturing methods of the present invention, a concave-convex pattern in which a hexagonal pyramid structure has been partially severed is formed in a bottom of the planarization nitride semiconductor layer, and thus, without an additional process, provided can be a light-emitting device for maximizing light emission efficiency.

While the invention has been shown and described with respect to the embodiments, the present invention is not limited thereto. It will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims.