KR100714626B1 - Nitride based semiconductor light emitting devices and manufacturing methods - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nitride semiconductor light emitting device, comprising: a nitride semiconductor light emitting device comprising a nitride stacked structure comprising a first conductive nitride semiconductor layer, an active layer, and a second conductive nitride semiconductor layer sequentially formed on a substrate, wherein the nitride At least some side surface of the stacked structure has a surface inclined toward the upper side, the inclined side surface provides a nitride semiconductor light emitting device, characterized in that the uneven pattern having a structure according to the nitride single crystal.

Nitride based semiconductor light emitting diodes, light extraction efficiency

Description

Nitride semiconductor light emitting device and manufacturing method {NITRIDE BASED SEMICONDUCTOR LIGHT EMITTING DEVICES AND MANUFACTURING METHODS}

1 is a side cross-sectional view of a conventional nitride semiconductor light emitting device.

2 is a process flowchart for explaining a method of forming side unevenness employed in the present invention.

3A and 3B are SEM photographs showing side states after plasma treatment and after chemical surface treatment, respectively, according to the method of forming side irregularities employed in the present invention.

Figure 4 is a process cross-sectional view showing an example of a method for manufacturing a nitride semiconductor light emitting device according to the present invention.

5 is a side cross-sectional view of a nitride semiconductor light emitting device according to one embodiment of the present invention.

6A and 6B are a top plan view and a partial side cross-sectional view, respectively, of a high output nitride semiconductor light emitting device according to another embodiment of the present invention.

FIG. 7 is an actual light-emitting photograph of a high output nitride semiconductor light emitting device similar to FIG.

<Code Description of Main Parts of Drawing>

11,31,41,61: Sapphire substrate 12,32,42: Buffer layer

14,34,44,64: first conductive cladding layer 15,35,45,65: active layer

16, 36, 46, 66: second conductive cladding layer P, P1, P1 ', P2: uneven pattern

18,38,48,68: first electrode 19,39,49,69: second electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nitride semiconductor light emitting device, and more particularly, to a nitride semiconductor light emitting device having irregularities for improving light extraction efficiency and a method of manufacturing the same.

Recently, a nitride semiconductor light emitting device is a high output optical device capable of generating light in a wide wavelength band including short wavelength light such as blue or green, and has been greatly attracting attention in the related art. The nitride semiconductor light emitting device is composed of a semiconductor single crystal having an Al _x In _y Ga _(1-xy) N composition formula, where 0 ≦ x ≦ 1, 0 ≦ y ≦ 1, and 0 ≦ x + y ≦ 1.

In general, the light efficiency of a nitride semiconductor light emitting device is determined by an internal quantum efficiedncy and a light extraction efficiency (also called an external quantum efficiency). In particular, the light extraction efficiency is determined by optical factors of the light emitting device, that is, the refractive index of each structure and / or the flatness of the interface.

In view of the light extraction efficiency, the nitride semiconductor light emitting device has a fundamental limitation. That is, since the semiconductor layer constituting the semiconductor light emitting device has a larger refractive index than the external atmosphere or the substrate, the critical angle that determines the range of incidence angle of light emission becomes small, and as a result, a large part of the light generated from the active layer is total internal reflection It is propagated in a substantially undesired direction or lost in the total reflection process, so the light extraction efficiency is low.

More specifically, in the nitride semiconductor light emitting device, since the refractive index of GaN is 2.4, the light generated in the active layer proceeds in the lateral direction while losing internal reflection when it is larger than 23.6 ° which is the critical angle at GaN / mechanical surface, or is lost. Since it is not emitted in a desired direction, the light extraction efficiency is only about 6%.

In order to improve the problem of the light extraction efficiency, conventionally, a method of forming irregularities having periodicity or aperiodicity on the light extraction surface of the nitride semiconductor light emitting device has been used. FIG. 1 illustrates a nitride semiconductor light emitting device having irregularities formed on an upper surface of an upper nitride layer as an example of the related art.

In the nitride semiconductor light emitting device 10 shown in FIG. 1, the first conductive nitride semiconductor layer 14, the active layer 15, and the second conductive layer sequentially formed on the sapphire substrate 11 and the sapphire substrate 11 are shown. The type nitride semiconductor layer 16 is included. In addition, a buffer layer 12 is formed on the sapphire substrate to improve crystallinity of the nitride semiconductor layer, and the nitride semiconductor light emitting device 10 includes the first conductivity type nitride semiconductor layer 14 and the second layer. The first and second electrodes 18 and 19 are respectively connected to the conductive nitride semiconductor layer 16. The lower surface of the sapphire substrate 11 is provided with a reflective layer 13 made of a material such as metal.

In the nitride semiconductor light emitting device shown in Fig. 1, irregularities are formed on the upper surface of the second conductive nitride semiconductor layer provided as the main light extraction surface by a process such as an etching process. When the light generated from the active layer 15 is reflected from the lower surface and directed to the upper surface of the second conductivity type nitride semiconductor layer 16 having irregularities, a large critical angle is provided by the minute irregularities to effectively emit light. have.

The uneven structure is obtained by wet or dry etching a pattern having periodicity or aperiodicity using a metal dot mask or a photomask. However, when a metal mask is used, a heat treatment temperature (about 600 ° C.) for forming a dot structure is high, thereby deactivating a p-type impurity such as Mg and increasing a driving voltage. In addition, a dry etching process using a metal dot mask generates a metal chloride residue on the surface to be etched, and the residue is not easily removed by chemical treatment.

In addition, the lithography process using a photomask has the advantage of being relatively simple, but there is a problem that it is difficult to form the pattern size into a microstructure corresponding to the emission wavelength.

In particular, the concave-convex formation method known up to now, as shown in Figure 1, when applied to the p-type nitride layer, increases the leakage current due to chemical mechanical damage caused by the etching process, even in the depth of the pattern p-type nitride layer Since it must be smaller than the thickness (eg, -130 nm), there are many difficulties in mass production.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to provide a nitride semiconductor light emitting device having a high quality light extraction structure which can be obtained through a simplified method on the side of the nitride stacked structure.

Another object of the present invention is to provide a method of manufacturing a nitride semiconductor light emitting device which changes the structure of a nitride side surface and forms an uneven pattern according to crystallinity on the side surface.

In order to achieve the above technical problem, an aspect of the present invention

A nitride semiconductor light emitting device comprising a nitride stacked structure consisting of a first conductive nitride semiconductor layer, an active layer, and a second conductive nitride semiconductor layer sequentially formed on a substrate, wherein at least some side surfaces of the nitride stacked structure face upwards. It provides a nitride semiconductor light-emitting device having a photographic surface, the uneven pattern having a structure according to the nitride single crystal is formed on the inclined side.

Preferably, the side on which the uneven pattern is formed has a structure inclined at 30 to 60 ° based on the growth surface of the substrate.

The present invention may be implemented by applying an existing process of forming side surfaces, such as a mesa etching process and an element isolation process for forming an electrode. That is, the side surface on which the uneven pattern is formed may be a mesa-etched side so that a part of the upper surface of the first conductivity type nitride semiconductor layer is exposed. Alternatively, the side surface on which the uneven pattern is formed may be a side surface obtained through a device separation process. have.

Preferably, the substrate may further include a reflective layer formed on a lower surface of the substrate in order to further improve light extraction efficiency when the substrate is a light transmissive substrate.

In another aspect of the present invention, there is provided a nitride semiconductor light emitting device having at least one light emitting portion formed in the nitride laminated structure intentionally having a side for improving the light extraction effect. The nitride semiconductor light emitting device includes a nitride stacked structure including a first conductive nitride semiconductor layer, an active layer, and a second conductive nitride semiconductor layer sequentially formed on a substrate, and the nitride stacked such that an inner sidewall is inclined upward. And at least one light emitting portion formed in at least one region of the structure. An uneven pattern having a structure according to a nitride single crystal is formed on the inclined inner side surface of the light emitting portion.

Preferably, the at least one light emitting unit may be formed to expose the substrate. In addition, a plurality of light emitting units employed in the present invention may be provided, and each may be arranged at a predetermined interval. This form can be advantageously applied to a light emitting device for lighting having a large area.

In addition, the present invention provides a nitride stacked structure in which a first conductive nitride semiconductor layer, an active layer and a second conductive nitride semiconductor layer are sequentially formed on a substrate, and a side surface inclined toward the upper side using a plasma. It provides a nitride semiconductor light emitting device manufacturing method comprising the step of dry etching the nitride laminated structure to have a chemical surface treatment to form a concave-convex pattern having a structure according to the nitride single crystal on the side obtained in the dry etching step. .

The dry etching step may be performed by reactive ion etching (RIE) using a plasma source gas. The chemical surface treatment step may be performed using at least one etchant selected from the group consisting of KOH, HF, NaOH and H ₃ PO ₄ .

Furthermore, the present invention provides a nitride stacked structure including a first conductive nitride semiconductor layer, an active layer and a second conductive nitride semiconductor layer sequentially formed on a substrate, and at least one region of the nitride stacked structure is plasma Forming at least one light emitting unit having an inner side inclined toward the upper side by applying a dry etching process using a dry etching process, and applying a chemical surface treatment to the inner side of the light emitting unit to form an uneven pattern having a structure according to a nitride single crystal It provides a nitride semiconductor light emitting device manufacturing method comprising the step of forming a.

Hereinafter, with reference to the accompanying drawings will be described the present invention in more detail.

2 is a process flowchart for explaining a method of forming side unevenness employed in the present invention.

As shown in FIG. 2, the side surface unevenness forming method according to the present invention includes a dry etching process S21 and a chemical surface treatment process S25.

The dry etching process (S21) using the plasma according to the present invention is carried out under the conditions for forming a side that is inclined toward the top, unlike the conventional dry etching process. The dry etching process may be a reactive ion etching (RIE) process using a plasma source. Such plasma sources include Electron Cyclotron Resonance (ECR) sources, Helicon-Wave Exited Plasma (HWEP) sources, Capacitively Coupled Plasma (CCP) sources, and Inductively Coupled Plasma (CCP) sources. ICP (Inductively Coupled Plasma) source or the like can be used.

The inclined side required in the present invention can be formed by appropriately controlling the working pressure, feedstock gas flow rate, bias power, and source power. It is preferable that the inclination angle of a side surface is 30-60 degrees with respect to the upper surface of a board | substrate. If the surface area is less than 30 °, the lateral area becomes too large in the overall device area, and thus, the actual light emitting area is reduced. If it exceeds 60 °, it is difficult to expect a sufficient emission effect toward the top. .

As shown in FIG. 3A, the inclined side surface obtained after the dry etching process using the plasma generates a region (100 nm or less in thickness) damaged by the plasma exposure during the etching process.

Subsequently, in step 25, a chemical surface treatment is performed on the damaged area, thereby forming an uneven pattern according to the nitride single crystal on the inclined side surface (S29). The etchant used in the chemical surface treatment process may be KOH, HF, NaOH, H ₃ PO ₄ or a combination thereof. In general, nitride single crystals have a high binding energy (e.g., GaN: 8.9 eV), and thus exhibit very low etching rates even with chemical etching performed at high temperatures, but the area damaged by plasma has a high etching rate even at room temperature (about 80 nm / min) can be surface treated. This chemical surface treatment process may be understood as a surface treatment process that removes damaged areas so that unevenness due to crystallinity appears in terms of aspects, rather than an etching process for removing specific areas.

As described above, as a result of the chemical surface treatment, the uneven pattern formed on the inclined side has a form in which the intrinsic crystal structure of the nitride single crystal is exposed as shown in FIG. 3B. This uneven pattern is very beneficial to the light extraction effect by providing a very fine pattern structure, and can be easily obtained through a dry etching process and a simple chemical surface treatment process without a mask forming / removing process for forming a separate pattern. .

The lateral irregularities forming method can be applied in various forms. In the first embodiment of the present invention, it can be implemented in combination with an existing process in which side surfaces are formed, such as a mesa etching process and an element separation process, and in the second embodiment, the internal side surface having an inclined inner side surface is formed in the upper surface of the nitride layer structure. It can also be implemented in a way to form a deliberate open area (light emitting unit).

According to the first embodiment of the present invention, the conditions of the dry etching process using plasma applied to the nitride layer structure for mesa etching or device isolation can be changed, and additionally, the side unevenness can be provided through a simple chemical surface treatment process. The second embodiment of the present invention can be advantageously applied to a high output nitride light emitting device having a large area, such as for lighting.

4A to 4E are process cross-sectional views showing a method for manufacturing a nitride semiconductor light emitting device according to the first embodiment of the present invention. The manufacturing method illustrated and described herein shows an example of forming side irregularities by applying an existing device isolation process.

As shown in FIG. 4A, the manufacturing method according to the present invention starts with the process of forming nitride stacking structures 34, 35, and 36 for light emitting devices on a substrate 31 on which a buffer layer 32 is formed. The nitride stacked structure includes a first conductivity type nitride semiconductor layer 34, an active layer 35, and a second conductivity type nitride semiconductor layer 37. The substrate 31 may be a sapphire substrate as a substrate usable for nitride growth.

Next, as shown in FIG. 4B, the first and second electrodes 38 and 39 are formed, and a mask M for device isolation is formed. The electrode forming process includes a mesa etching process for exposing a portion of the first conductivity type nitride layer 34 to form the first electrode 38.

Next, as shown in FIG. 4C, a dry etching process using plasma for device isolation is performed so that the side surfaces of the separated nitride stack structures 34, 35, and 36 are inclined upward. This dry etching process may be a reactive ion etching (RIE) process. As described above, the inclined side surface and the angle thereof may be formed by appropriately controlling the working pressure, the feedstock gas flow rate, the bias power, and the source power. It is preferable that the inclination angle of the side surface of the nitride layered structure is 30 to 60 ° based on the upper surface of the substrate 31. The side surface obtained by this dry etching process has the area | region D damaged by exposure of a plasma.

Subsequently, as shown in FIG. 4D, a chemical surface treatment is applied to the damaged side region D to form the uneven pattern P according to the nitride single crystal. As described above, the region D damaged by the plasma can be easily removed as compared with a conventional nitride single crystal. That is, it can be carried out at a high etching rate at room temperature, the choice of etching liquid is also wide. For example, KOH, HF, NaOH, H ₃ PO ₄ or a combination thereof may be used as an etchant for surface treatment. As can be seen in FIG. 3B, the uneven pattern according to the crystal structure has a periodic and fine structure as the uneven structure for improving light extraction.

Finally, as shown in FIG. 4E, the mask M is removed and the substrate 31 is completely separated in units of elements. As a result, the nitride semiconductor light emitting device 30 having the uneven pattern for improving light extraction on the side of the device can be provided.

In this embodiment, a method of forming irregularities on the side of the nitride stacked structure obtained in the device isolation process has been described. However, the present invention can be applied in a similar manner to the side obtained in the mesa etching process for forming the electrode. That is, in the mesa etching process of FIG. 4B, a dry etching process using plasma to obtain the inclined side surface described in FIG. 4C is performed, and chemical surface treatment is applied to the obtained side surface to further form an uneven pattern according to the nitride crystal structure. can do.

Such a nitride semiconductor light emitting device is illustrated in FIG. Fig. 5 is a side sectional view showing another example of the nitride semiconductor light emitting device according to the first embodiment of the present invention.

In the nitride semiconductor light emitting device 40 shown in FIG. 5, the first conductive nitride semiconductor layer 44, the active layer 45, and the second conductive formed sequentially on the sapphire substrate 41 and the sapphire substrate 41 are formed. The type nitride semiconductor layer 46 is included. A buffer layer 42 is included on the top surface of the sapphire substrate 41 to improve the crystallinity of the nitride layer.

In addition, the nitride semiconductor light emitting device 40 includes first and second electrodes 48 and 49 connected to the first conductivity type nitride semiconductor layer 44 and the second conductivity type nitride semiconductor layer 46, respectively. Include. The lower surface of the sapphire substrate 41 is provided with a reflective layer 43 made of a material such as metal. Preferably, the reflective layer 43 has a reflectance of at least 90%. The reflective layer 43 material may be at least one metal layer or alloy layer selected from the group consisting of Ag, Al, Rh, Ru, Pt, Au, Cu, Pd, Cr, Ni, Co, Ti, In, and Mo.

In this embodiment, as described with reference to Figs. 4A to 4E, the side formed at the time of device separation has a side inclined upward. The inclination angle θ of the side surface is preferably 30 to 60 ° based on the upper surface of the substrate 41. If the surface area is less than 30 °, the lateral area becomes too large in the overall device area, and thus, the actual light emitting area is reduced. If it exceeds 60 °, it is difficult to expect a sufficient emission effect toward the top. . In addition, the side surfaces obtained by device isolation have uneven patterns P1 and P'1 according to the nitride single crystal formed.

In addition, the nitride semiconductor light emitting device 40 has a side view inclined side surface obtained from mesa etching performed to expose a partial region of the first conductivity type nitride semiconductor layer 44 for the first electrode 48. It is also surface treated to have an additional uneven pattern P2. In this way, the plasma dry process for providing the inclined surface may be easily applied to the conventional device isolation process and the mesa etching process to obtain desired uneven patterns P1, P'1, and P2.

In addition, the present invention may be provided in the form of deliberately forming an open region having an inclined inner side surface having an uneven pattern in the nitride stack structure to provide a light emitting portion. This form can be very advantageously applied to a high output nitride light emitting device in which a nitride layer structure is provided with a relatively large area.

6A is a top plan view of a high output nitride semiconductor light emitting device according to another embodiment of the present invention, and FIG. 6B is a partial side cross-sectional view taken along the line X-X 'of the nitride semiconductor light emitting device of FIG. 6A.

Referring to FIG. 6A together with FIG. 6B, the high output nitride semiconductor light emitting device according to the present embodiment includes a sapphire substrate 61 and a first conductive nitride semiconductor layer 64 and an active layer sequentially formed on the sapphire substrate 61. 65 and the second conductivity type nitride semiconductor layer 66. In addition, a transparent electrode layer 67 is provided on an upper surface of the second conductivity type nitride semiconductor layer 64, and a reflective layer 63 is provided on a lower surface of the sapphire substrate 61.

In addition, the nitride semiconductor light emitting device 60 may include first and second electrodes 68 and 69 connected to the first conductivity type nitride semiconductor layer 64 and the second conductivity type nitride semiconductor layer 66, respectively. Include. The first and second electrodes 68 and 69 are composed of bonding electrode portions 68a and 69a and electrode fingers 68b and 69b extending therefrom for uniform current distribution in a large area.

In this embodiment, in order to effectively improve the light extraction efficiency in the large-area nitride stacked structure, the light emitting portion L defined as an open area having an inclined inner side wall A is removed by removing a portion of the nitride stacked structure. Form. The light emitting portion M employed in the present invention preferably has an inner side surface having an inclination angle of 30 to 60 °, and is formed to expose the upper surface of the substrate 61. In addition, as in the present embodiment, the light emitting portions L may be provided in plural, and may be uniformly distributed at predetermined intervals in order to improve light extraction efficiency over the entire area. Although the light emitting part L is illustrated as having a cross section having a quadrangular shape, the light emitting part L may be provided in other shapes and sizes as appropriate, such as a circle and a hexagon, depending on the structure of the nitride stack.

As described above, the light emitting part L employed in the present invention may be formed through a dry etching process using a plasma that provides an inclined inner side A, and has a chemical surface on the inner side A thereof. Through the treatment step, the concave-convex pattern P according to the nitride crystal can be formed on the side surface A. FIG. The light emitting part may improve light emission efficiency as a whole by more effectively extracting light through an uneven pattern formed on an inner side surface.

FIG. 7 is an actual light-emitting photograph of a high output nitride semiconductor light emitting device similar to FIG. Referring to FIG. 7, it can be seen that the light emission luminance is greatly improved by emitting light with high luminance through the light emitting unit having the uneven pattern provided on the inclined inner side.

It is intended that the invention not be limited by the foregoing embodiments and the accompanying drawings, but rather by the claims appended hereto. Accordingly, various forms of substitution, modification, and alteration may be made by those skilled in the art without departing from the technical spirit of the present invention described in the claims, which are also within the scope of the present invention. something to do.

As described above, the present invention provides a method of easily forming the uneven pattern, which is a high quality light extraction structure, by applying a simple chemical surface treatment to the side of the nitride laminated structure obtained through the plasma dry etching process. Therefore, the nitride semiconductor light emitting device according to the present invention can significantly improve the light extraction efficiency through the fine concavo-convex pattern according to the crystallinity.

Claims (24)

In a nitride semiconductor light emitting device comprising a nitride stacked structure consisting of a first conductive nitride semiconductor layer, an active layer and a second conductive nitride semiconductor layer sequentially formed on a substrate, At least a part of the side surface of the nitride laminated structure has a surface inclined toward the upper side, the nitride semiconductor light emitting device, characterized in that the concave-convex pattern having a structure according to the nitride single crystal is formed. The method of claim 1, A nitride semiconductor light emitting device, wherein the side on which the uneven pattern is formed is inclined by 30 to 60 ° based on the growth surface of the substrate. The method of claim 1, The nitride semiconductor light emitting device has a mesa-etched side surface to expose a portion of the upper surface of the first conductivity type nitride semiconductor layer, the side surface on which the uneven pattern is formed is a nitride semiconductor light emitting device. The method of claim 1, The side surface formed with the uneven pattern is a nitride semiconductor light emitting device, characterized in that the side obtained through the device separation process. The method of claim 1, The substrate is a light transmissive substrate, and further comprising a reflective layer formed on the lower surface of the substrate. In a nitride semiconductor light emitting device comprising a nitride stacked structure consisting of a first conductive nitride semiconductor layer, an active layer and a second conductive nitride semiconductor layer sequentially formed on a substrate, At least one region of the nitride layered structure is removed and formed, the inner sidewall includes at least one light emitting portion inclined upwards, A nitride semiconductor light emitting device, characterized in that the concave-convex pattern having a structure according to the nitride single crystal is formed on the inclined inner side of the light emitting portion. The method of claim 6, The inner side surface of which the uneven pattern is formed is inclined 30 to 60 ° with respect to the growth surface of the substrate characterized in that the nitride semiconductor light emitting device The method of claim 6, And the at least one light emitting unit is formed such that the substrate is exposed. The method of claim 6, And the at least one light emitting unit is a plurality of light emitting units arranged at regular intervals. The method of claim 6, The substrate is a light transmissive substrate, and further comprising a reflective layer formed on the lower surface of the substrate. Providing a nitride stacked structure in which a first conductive nitride semiconductor layer, an active layer, and a second conductive nitride semiconductor layer are sequentially formed on a substrate; Dry etching the nitride layered structure to have a side inclined upwardly using a plasma; And A method of manufacturing a nitride semiconductor light emitting device comprising chemical surface treatment to form a concave-convex pattern having a structure according to a nitride single crystal on the side surface obtained in the dry etching step. The method of claim 11, The side surface obtained by the dry etching is inclined at 30 to 60 degrees with respect to the growth surface of the substrate, characterized in that the nitride semiconductor light emitting device manufacturing method. The method of claim 11, The dry etching step is a nitride semiconductor light emitting device manufacturing method, characterized in that carried out by reactive ion etching (RIE) using a plasma source gas. The method of claim 11, The dry etching step is a method of manufacturing a nitride semiconductor light emitting device, characterized in that carried out by a mesa etching process for exposing a portion of the upper surface of the first conductivity type nitride semiconductor layer. The method of claim 11, The dry etching step is a nitride semiconductor light emitting device manufacturing method, characterized in that carried out in a device separation process for separating the nitride stacked structure in each device unit. The method of claim 11, The chemical surface treatment step, the nitride semiconductor light emitting device manufacturing method characterized in that is carried out using at least one etching solution selected from the group consisting of KOH, HF, NaOH and H ₃ PO ₄ . The method of claim 11, The substrate is a light transmissive substrate, and further comprising the step of forming a reflective layer on the lower surface of the substrate. Providing a nitride stacked structure including a first conductive nitride semiconductor layer, an active layer, and a second conductive nitride semiconductor layer sequentially formed on a substrate; Applying at least one region of the nitride stacked structure to a dry etching process using plasma to form at least one light emitting unit having an inner side surface inclined toward an upper portion thereof; And And forming a concave-convex pattern having a structure according to a nitride single crystal by applying a chemical surface treatment to the inner side surface of the light emitting unit. The method of claim 18, The inner side surface obtained by the dry etching is inclined at 30 to 60 degrees with respect to the growth surface of the substrate, characterized in that the nitride semiconductor light emitting device manufacturing method. The method of claim 18, The dry etching step is a nitride semiconductor light emitting device manufacturing method characterized in that carried out by a reactive ion etching process using a plasma source gas. The method of claim 18, And the at least one light emitting unit is formed to expose the substrate. The method of claim 18, And at least one light emitting unit is a plurality of light emitting units arranged at regular intervals. The method of claim 18, The chemical surface treatment step, the nitride semiconductor light emitting device manufacturing method characterized in that is carried out using at least one etching solution selected from the group consisting of KOH, HF, NaOH and H ₃ PO ₄ . The method of claim 18, The substrate is a light transmissive substrate, and further comprising the step of forming a reflective layer on the lower surface of the substrate.

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