KR20120063964A - Substrate for growing semiconductor, manufacturing method of the substrate for growing semiconductor, light emitting device using the substrate for growing semiconductor and manufacturing method of the light emitting device - Google Patents

Abstract

PURPOSE: A semiconductor growth substrate, a manufacturing method thereof, and a light emitting device using the same are provided to improve optical extraction efficiency by including an upper side of a uniform embossed shape. CONSTITUTION: A base substrate(112) comprises an upper side which is patterned to a plurality of embossed part shapes. The base substrate is selected as sapphire. A liquid material which contains A plurality of beads(113) is spread on the upper side of the base substrate. The liquid material is hardened. The plurality of beads is inserted into the plurality of embossed part shapes and is fixed. The plurality of beads forms a plurality of air gaps(114). The plurality of beads is selected as a silicon-based substance.

Description

SUBSTRATE FOR GROWING SEMICONDUCTOR, MANUFACTURING METHOD OF THE SUBSTRATE FOR GROWING SEMICONDUCTOR, LIGHT EMITTING DEVICE USING THE SUBSTRATE FOR GROWING SEMICONDUCTOR AND MANUFACTURING METHOD OF THE LIGHT EMITTING DEVICE}

The present invention relates to a semiconductor growth substrate, a method for manufacturing a semiconductor growth substrate, a light emitting device using the semiconductor growth substrate, and a method for manufacturing the light emitting device, and in particular, for semiconductor growth suitable for growing gallium nitride-based semiconductor materials A light emitting device using a substrate, a semiconductor growth substrate, a semiconductor growth substrate, a semiconductor growth substrate, and a method of manufacturing the light emitting device.

A light emitting device (LED) includes a photoelectric layer formed of a plurality of semiconductor layers including a p-type semiconductor layer, an active layer, and an n-type semiconductor layer, a first electrode for injecting electrons into the n-type semiconductor layer; and a second electrode for injecting holes into the p-type semiconductor layer. In the light emitting device, when a forward voltage is applied between the first electrode and the second electrode, electrons and holes injected through the first electrode and the second electrode in the photoelectric layer meet and recombine to generate excitons. The excitons go from the excited state to the ground state and emit light energy generated.

The substrate used in the light emitting device is selected as a material having a lattice constant similar to that of a semiconductor material. In particular, a low-cost sapphire (Al ₂ O ₃ ) substrate is selected even though the strain due to alkali, acid or heat is low to reduce production costs. Is common.

However, since the semiconductor material is a denser medium than the outside (air), the light generated in the active layer must have an angle of incidence lower than a specific critical angle (where "incidence angle" means an angle at which light enters the interface between the device and the outside). It can be released to the outside.

In addition, the light having an incident angle greater than or equal to a specific critical angle is reflected into the device, so that the ratio of light emitted from the device to the outside (hereinafter, referred to as “light extraction efficiency”) is difficult to be improved. In addition, the light bound in the device is converted into heat, there is a problem that leads to a reduction in the lifetime and reliability of the device due to deterioration.

Accordingly, in order to improve the light extraction efficiency, a method of patterning the upper surface of the substrate in a concave-convex shape consisting of a plurality of recesses has been proposed. The patterning of the upper surface of the substrate may include forming a photoresist including a plurality of opening regions corresponding to a plurality of recesses on the upper surface of the substrate, and patterning the upper surface of the substrate by dry etching using the photoresist as a mask. Include.

By the way, while the plurality of recesses should be formed to a depth enough to improve the light extraction efficiency, the etching ratio (nm / min) of sapphire by dry etching is very low. Therefore, in order to pattern the upper surface of the substrate in the form of unevenness, the substrate must be dry-etched for about 40 minutes of processing time.

The photoresist may be deformed or removed by the dry etching that proceeds for a long time of 30 minutes or more. Accordingly, the shape of the mask is deformed during the dry etching process, so that uniformity of the uneven shape of the upper surface of the substrate is difficult to be improved. And since the photoresist must be formed to a thick thickness so that the mask can be maintained as it is until the long dry etching process is completed, there is a problem that the photoresist is wasted.

In addition, if the substrate is subjected to a dry etching process using plasma for a long time of 30 minutes or more, the overall shape of the substrate may be deformed due to the high temperature. Due to the shape deformation of the substrate, the uneven shape of the upper surface of the substrate is deformed, and thus, the uniformity of the uneven shape of the upper surface of the substrate is difficult to be improved.

In addition, a long dry etching process generates reactants such as etching gases and by-products, and these reactants may remain as impurities on the substrate surface. In this case, impurities on the surface of the substrate may affect the etching of the substrate, thereby deforming the uneven shape of the upper surface of the substrate, thereby inhibiting uniformity of the uneven shape of the upper surface of the substrate, and causing crystal defects of semiconductor materials to be grown on the upper surface of the substrate. .

Therefore, there is a need for a substrate for growing a semiconductor material including an uneven top surface having high uniformity so that light extraction efficiency of the device can be improved and crystal defects of the semiconductor material can be reduced.

The present invention may include a top surface of a uniform concavo-convex shape, thereby improving light extraction efficiency of the light emitting device, and reducing the crystal defects of the semiconductor material grown thereon. A manufacturing method and a method of manufacturing a light emitting device and a light emitting device using the substrate for semiconductor growth.

In order to solve the above problems, the present invention includes a base substrate including an upper surface patterned in the form of a plurality of recesses; And a plurality of beads inserted into and fixed on the plurality of recesses to form a plurality of air gaps, respectively.

The present invention comprises the steps of providing a base substrate comprising an upper surface patterned in the form of a plurality of recesses; Applying a liquid material containing a plurality of beads to an upper surface of the base substrate; And curing the liquid material to form a plurality of beads, each of which is inserted and fixed on the plurality of recesses to form a plurality of air gaps.

The present invention includes a base substrate including an upper surface patterned in the form of a plurality of recesses; A plurality of beads each of which is inserted into and fixed to a plurality of recesses on an upper surface of the base substrate to form a plurality of air gaps; A first semiconductor layer, an active layer, and a second semiconductor layer sequentially stacked on an upper surface of the base substrate including the plurality of beads; An ohmic contact layer formed on an entire surface of the second semiconductor layer; A first electrode formed on a portion of the first semiconductor layer exposed by removing portions of the ohmic contact layer, the active layer, and the second semiconductor layer; And it provides a light emitting device comprising a second electrode formed on the ohmic contact layer.

The present invention comprises the steps of providing a base substrate comprising an upper surface patterned in the form of a plurality of recesses; Applying a liquid material containing a plurality of beads to an upper surface of the base substrate; Hardening the liquid material to form a plurality of beads which are fitted onto the plurality of recesses and are fixed to form a plurality of air gaps; And sequentially stacking a first semiconductor layer, an active layer, and a second semiconductor layer on an upper surface of the base substrate including the plurality of beads.

The substrate for semiconductor growth according to the present invention has a plurality of recesses and an upper surface of the concave-convex shape by a plurality of beads that are fitted and fixed on the plurality of recesses. In this case, since the plurality of beads may be easily formed to have a predetermined shape and size, the upper surface of the substrate for semiconductor growth may have a uniform uneven shape. In addition, the light is irregularly refracted and reflected by the empty space formed between the plurality of recesses and the plurality of beads, so that light having an angle of incidence below the critical angle may be increased.

In addition, since the plurality of recesses are formed to have a lower depth than the conventional ones to fix the plurality of beads, the time required for the etching process for patterning the upper surface of the base substrate in the form of the plurality of recesses may be reduced. Accordingly, damage to the base substrate, deformation of the etching mask, and impurities adsorbed on the surface of the base substrate due to a long time etching process can be prevented, and a plurality of recesses can be uniformly formed on the upper surface of the base substrate.

Therefore, since the upper surface of the semiconductor growth substrate may have a uniform concave-convex shape, light extraction efficiency of the light emitting device using the semiconductor growth substrate may be improved, and crystal defects of the semiconductor material grown on the semiconductor growth substrate may be minimized. The yield of the light emitting device using the substrate for semiconductor growth can be improved.

1 is a cross-sectional view showing a light emitting device according to an embodiment of the present invention.
2A to 2C show a semiconductor growth substrate according to the first to third embodiments of the present invention.
3 is a flowchart illustrating a method of manufacturing a light emitting device according to an embodiment of the present invention.
4 is a flowchart illustrating a process of preparing a substrate for semiconductor growth shown in FIG. 3.
FIG. 5 is a flowchart illustrating a step of patterning an upper surface of the base substrate illustrated in FIG. 4 in the form of a plurality of recesses.
6A through 6K are process diagrams illustrating the steps illustrated in FIGS. 3 through 5.

Hereinafter, a method of manufacturing a semiconductor growth substrate and a semiconductor growth substrate, and a method of manufacturing a light emitting device and a light emitting device including the semiconductor growth substrate according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Let's do it.

First, a semiconductor growth substrate and a light emitting device including the same according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2A to 2C.

1 is a cross-sectional view showing a light emitting device according to an embodiment of the present invention. 2A to 2C show a semiconductor growth substrate according to the first to third embodiments of the present invention.

As shown in FIG. 1, the light emitting device 100 according to an exemplary embodiment of the present invention includes a plurality of semiconductor layers 121 to 124 sequentially stacked on the semiconductor growth substrate 110 and the semiconductor growth substrate 110. ) Ohmic contact layer 130 formed of a transparent conductive material on the p-type semiconductor layer 124 of the photoelectric layer 120, the n-type semiconductor layer of the photoelectric layer 120 ( The first electrode 140 and the second electrode 150 are formed on the ohmic contact layer 130. Here, the semiconductor growth substrate 110 according to the embodiment of the present invention will be described in detail below.

The photoelectric layer 120 is formed of a semiconductor material grown on the semiconductor growth substrate 110, and is sequentially stacked on the buffer layer 121, the n-type semiconductor layer 122, the active layer 123, and the p-type semiconductor. Layer 124.

The buffer layer 121 is a buffer layer for reducing crystal defects of the semiconductor material due to the lattice constant difference and the thermal expansion coefficient difference between the semiconductor growth substrate 110 and the semiconductor material. The buffer layer 121 is formed by growing an undoped nitride semiconductor on the upper surface of the semiconductor growth substrate 110 in an atmosphere containing low temperature heat to grow the semiconductor material horizontally on the growth surface, and crystallizing it in a high temperature atmosphere. .

The n-type semiconductor layer 122 is formed on the buffer layer 121 as an n-type nitride semiconductor doped with n-type impurities to increase electron mobility. In this case, the n-type impurity may be Si.

The active layer 123 is formed on the n-type semiconductor layer 122 as a nitride semiconductor having a quantum well structure. The active layer 123 uses light generated by excitation of the exciton generated by the recombination of electrons and holes applied from the outside through the first electrode 140 and the second electrode 150 to the atmospheric state. Release.

For example, when the semiconductor material forming the photoelectric layer 120 is gallium nitride (GaN) -based, the active layer 123 may be formed of a barrier layer of Inx (AlyGa (1-y)) N and Inx (AlyGa (1-y)). It may be formed of a single quantum well structure or multiple quantum well structure (MQW) consisting of a N well layer. At this time, according to the composition ratio of the nitride semiconductors (InGaN, GaN) of the barrier layer and the well layer, the wavelength region of the light emitted from the light emitting device 100 is freely determined from the long wavelength to the short wavelength having the AlN (˜6.4 eV) band gap.

The p-type semiconductor layer 124 is formed on the active layer 123 as a p-type nitride semiconductor which is doped with p-type impurities to increase hole mobility. In this case, the p-type impurity may be Mg.

Meanwhile, the plurality of semiconductor layers 121 ˜ 124 constituting the photoelectric layer 120 may be formed of a semiconductor material grown by using a metal organic chemical vapor deposition (MOCVD) method. In this case, each of the n-type semiconductor layer 122, the active layer 123, and the p-type semiconductor layer 124 is formed in an atmosphere including high temperature heat for growing the semiconductor material in a direction perpendicular to the growth plane. For example, the high temperature may be selected from 700 degrees Celsius to 1200 degrees Celsius.

The ohmic contact layer 130 is formed of a transparent conductive material on the p-type semiconductor layer 124. The holes injected from the second electrode 150 by the ohmic contact layer 130 may be dispersed in a wide area so as to be the p-type semiconductor layer 124. The transparent conductive material forming the ohmic contact layer 130 may be any one of metal oxides of SnO ₂ , ZnO, In ₂ O _3, and TiO ₂ and at least one of F, Sn, Al, Fe, Ga, and Nb. May be selected as the doped material.

The first electrode 140 is formed on a portion of the n-type semiconductor layer 122 exposed by removing a portion of the ohmic contact layer 130, the p-type semiconductor layer 124, and the active layer 123. . Electrons are injected into the n-type semiconductor layer 122 through the first electrode 140.

The second electrode 150 is formed on the ohmic contact layer 130. In this case, although not separately illustrated, the second electrode 150 may be formed in contact with at least a portion of the p-type semiconductor layer 124. Holes are injected into the p-type semiconductor layer 124 through the second electrode 150.

The first electrode 140 and the second electrode 150 may be formed of any one metal of Ni, Au, Pt, Ti, Al, and Cr, or an alloy including two or more thereof.

Meanwhile, the semiconductor growth substrate 110 according to the exemplary embodiment of the present invention is disposed on the base substrate 112 and the plurality of recesses 111, each of which includes an upper surface patterned in the form of a plurality of recesses 111. The plurality of beads 113 fixed in the form of being fitted into each of the plurality of beads 113 and the plurality of recesses 111 are used as an empty space between the upper surface of the base substrate 112 and the plurality of beads 113. It includes a plurality of air gap 114 is formed.

The base substrate 112 may be selected from Al ₂ O ₃ (Sapphire: Sapphire), SiC, and AlN having a crystal structure similar to GaN and GaN based material. In particular, the base substrate 112 may be selected as a sapphire (Al ₂ O ₃ ) substrate suitable for mass production because it has the advantage of low strain rate by alkali or acid, low strain rate by heat and low cost.

The depth d of the plurality of recesses 111 is equal to or larger than the radius bd / 2 of the plurality of beads 113 and equal to or smaller than the diameter bd of the plurality of beads 113. The width w of the plurality of recesses 111 is equal to or larger than the radius bd / 2 of the plurality of beads 113 and equal to or smaller than the diameter bd of the plurality of beads 113. In this way, while the plurality of recesses 111 can be formed with a width w and a depth d suitable for fixing the plurality of beads 113, the basis for forming the plurality of recesses 111 is provided. Process time required for the etching process of the substrate 112 can be minimized. Therefore, by the etching process for a long time, the plurality of recesses 111 can be prevented from being uniform, and damage to the base substrate 112 can be prevented.

In addition, the plurality of recesses 111 are formed to be concave with the pillar shape interposed therebetween on the upper surface of the base substrate 112. In this case, the pillar shape between the plurality of recesses 111 may be formed in a cylindrical shape so that the plurality of beads 113 may be properly fixed on the plurality of recesses 111.

Since the plurality of beads 113 are sandwiched and fixed on the plurality of recesses 111, the plurality of beads 113 may be arranged in a matrix at predetermined intervals by the plurality of recesses 111. Accordingly, since the upper surface of the base substrate 112 includes at least a partial region that is not filled with the plurality of beads 113 and exposed to the outside to form an uneven pattern, it may be appropriately applied as a growth surface of the semiconductor material.

In this case, when the height of the plurality of beads 113 protruding from the upper surface of the base substrate 112 exceeds 3 μm, a problem such as thickening of the nitride semiconductor layer occurs, resulting in the formation of a semiconductor material on the base substrate 112. It cannot grow properly. Therefore, the present invention provides a plurality of recesses such that the height protruding by the plurality of beads 113 from the top surface of the base substrate 112 is 3 μm or less so that the semiconductor material can be properly grown on the top surface of the base substrate 112. The width and depth of each of the 111 and the plurality of beads 113 are adjusted.

The plurality of beads 113 may be selected as a material containing the same type of material as the material of the base substrate 112. For example, the plurality of beads 113 may be selected from SiO ₂ , Al ₂ O ₃ , TiO ₂ , ZrO ₂ , CuO, Fe ₂ O ₃ , and PZT.

In particular, when the base substrate 112 is selected as the sapphire substrate, the plurality of beads 113 may be formed of a silicon-based material including an element (Si) that is the same as the sapphire substrate. In this case, examples of the silicon-based material include silicon oxide (SiOx) and silicon nitride (SiNx).

The plurality of air gaps 114 are formed of empty spaces generated by a plurality of beads 113 fixed in a shape of being fitted over the plurality of recesses 111, in which air is a medium smaller than a semiconductor material. filled with air.

Accordingly, the angle of incidence in which light is refracted or reflected due to the difference in refractive index of each of the base substrate 112, the plurality of beads 113, and the air gap 114 (here, the "incidence angle" is defined as an interface between the element and the outside). Mean light incident angle). Therefore, as the probability that the light may have an angle of incidence below the critical angle is increased, the rate at which light generated in the photoelectric layer 120 is emitted to the outside (hereinafter, referred to as “light extraction efficiency”) may be improved.

As mentioned above, the plurality of recesses 111 have a depth d that is greater than or equal to the radius bd / 2 of the plurality of beads 113 and less than or equal to the diameter bd of the plurality of beads 113, and the plurality of beads. It has a width w that is equal to or larger than the radius of 113 and equal to or smaller than the diameter of the plurality of beads 113.

As shown in FIG. 2A, in the semiconductor growth substrate 110a according to the first embodiment, the plurality of recesses 111a have a first width that is about 3/4 of the diameter bd of the beads 113. (w1) and the first depth d1 of about 2/3 of the diameter bd of the beads 113. At this time, the plurality of beads 113 are fitted on the plurality of recesses 111a and spaced apart from the upper surface of the base substrate 112 at the first interval s1. A plurality of air gaps 114 are formed in empty spaces generated between the plurality of beads 113 spaced apart from the plurality of beads 113 and the plurality of recesses 111a on the upper surface of the base substrate 112. .

Alternatively, as shown in FIG. 2B, in the semiconductor growth substrate 110b according to the second embodiment, the plurality of recesses 111b have a second width w2 equal to the diameter bd of the beads 113. ) And a first depth d1 of about 2/3 of the diameter bd of the beads 113. Here, the plurality of beads 113 are fitted on the plurality of recesses 111b to be spaced apart from the upper surface of the base substrate 112 at a second interval s2. In this case, since the plurality of recesses 111b according to the second example are formed to have a second width w2, about half of the plurality of beads 113 may be inserted into the plurality of recesses 111b, and thus, the second intervals. (s2) becomes smaller than the 1st space | interval s1. A plurality of air gaps 114 are formed in empty spaces generated between the plurality of beads 113 spaced apart from the plurality of beads 113 and the plurality of recesses 111b on the upper surface of the base substrate 112.

Alternatively, as shown in FIG. 2C, in the semiconductor growth substrate 110c according to the third embodiment, the plurality of recesses 111c have a second width w2 equal to the diameter bd of the beads 113. ) And a second depth d2 equal to the radius bd / 2 of the beads 113. Since the plurality of recesses 111c according to the third embodiment are formed to have a second width w2, about half of the plurality of beads 113 may be inserted into the plurality of recesses 111c. The plurality of beads 113 inserted and fixed on the recess 111c may contact the upper surface of the base substrate 112. Since the plurality of recesses 111c do not have a form coincident with the plurality of beads 113, an empty space is generated between the plurality of beads 113 and the plurality of recesses 111a, and the empty space at this time. A plurality of air gaps 114 are formed.

As described above, the semiconductor growth substrate 110 according to the embodiment of the present invention is sandwiched on the plurality of recesses 111; 111a, 111b, and 111c and the plurality of recesses 111; 111a, 111b, and 111c. A plurality of beads 113 are fixed. In this case, since the plurality of beads 113 may be easily formed to have a predetermined shape and size, the upper surface of the semiconductor growth substrate 110 may have a uniform concave-convex shape. In addition, the light is irregularly refracted and reflected by the plurality of air gaps 114, which are formed as empty spaces between the plurality of recesses 111 and the plurality of beads 113, so that light having an angle of incidence below the critical angle may be increased. Can be.

Table 1 below shows the results of simulating the light extraction efficiency of each of the comparison group and the semiconductor growth substrate 110 according to an embodiment of the present invention under the same conditions. Here, the comparison group applied a substrate having an upper surface patterned in the form of a plurality of recesses.

As shown in Table 1, the comparison group exhibits a light extraction efficiency of 74.28%, while the semiconductor growth substrate 110 according to an embodiment of the present invention exhibits a high 76.74% light extraction efficiency than the comparison group. have.

Comparison Embodiment of the present invention Light extraction efficiency (%) 74.28 76.74

In addition, the light emitting device 100 according to the embodiments of the present invention is a plurality of beads 113 by a semiconductor growth substrate 110 including a top surface and a plurality of air gaps 114 having a uniform uniform shape. The light extraction efficiency may be improved and crystal defects of the photoelectric layer 120 may be reduced. As a result, the reliability of the device can be improved and the yield can be improved.

Next, a method of manufacturing a light emitting device according to an embodiment of the present invention will be described with reference to FIGS. 3 to 5 and 6A to 6K.

As shown in FIG. 3, the method of manufacturing a light emitting device according to an embodiment of the present invention includes preparing a semiconductor growth substrate (S100) and stacking a plurality of semiconductor layers on an upper surface of the semiconductor growth substrate. Forming a step (S200). In addition, forming an ohmic contact layer on the p-type semiconductor layer (S300) and forming a first electrode and a second electrode 150 connected to the plurality of semiconductor layers (S400).

As shown in FIG. 4, in the preparing of the semiconductor growth substrate (S100), the upper surface of the base substrate is patterned into a plurality of recesses (S110), and the plurality of upper surfaces of the patterned base substrate 112 are formed. Applying a liquid material containing the beads (S120) and curing the applied liquid material to form a plurality of beads fitted on the plurality of recesses (S130).

As shown in FIG. 5, the step S110 of patterning the top surface of the base substrate in the form of a plurality of recesses corresponds to the step of applying photoresist to the top surface of the base substrate (S111) and the plurality of recesses. Patterning the photoresist in the form of a plurality of openings (S112). In addition, the step of curing the patterned photoresist to form an etching mask (S113) and patterning the upper surface of the base substrate by dry etching using the etching mask (S114).

As shown in FIG. 6A, in the step S111 of applying the photoresist to the top surface of the base substrate 112, the photoresist 200 is applied to the flat top surface of the base substrate 112. In this case, the application of the photoresist 200 may be performed using slit coating or spin coating. Slit coating is a method of coating by spraying the liquid material using a slit-shaped nozzle, spin coating is a method of spreading the coating of the liquid material falling in the form of droplets using the rotational force.

The thickness of the photoresist 200 is determined according to the etching ratio of the base substrate 112 and the depth of the plurality of recesses to be formed in the next process.

For example, when the base substrate 112 is a sapphire substrate, the plurality of recesses may be formed with a depth d of 0.25 μm to 1.5 μm, corresponding to the plurality of beads having a diameter of 0.5 μm to 1.5 μm. In this case, the photoresist 200 may be selected to have a thickness of 3 μm or less. As described above, according to the exemplary embodiment of the present invention, since the plurality of recesses may be formed at a lower depth d than in the related art, an etching mask may be formed of the photoresist 200 having a thickness thinner than that of the conventional art. 200 waste can be minimized.

As shown in FIG. 6B, the step of patterning the photoresist in the form of a plurality of opening regions (S112) includes arranging the exposure mask 300 on the photoresist 200 and exposure using the exposure mask 300. Patterning the photoresist 200 into a plurality of opening regions. Here, the exposure mask 300 includes a plurality of transmissive portions 310 corresponding to the plurality of opening regions. The plurality of opening regions correspond to regions of the plurality of recesses to be formed in a later process.

As shown in FIG. 6C, light LIGHT is irradiated on the exposure mask 300. In this case, a portion of the photoresist 200 is exposed to light LIGHT through the plurality of transmission parts 310 to form a photoresist pattern 210. Thereafter, as illustrated in FIG. 6D, the photoresist pattern 210 may be cured to form an etching mask 220. (S113)

As shown in FIG. 6E, in the step S114 of patterning the upper surface of the base substrate 112 by dry etching using the etching mask 220, the upper surface of the base substrate 112 including the etching mask 220 is formed. Dry etching is performed to pattern the plurality of recesses 111. In this case, the etching gas of the dry etching process may be selected as long as the base substrate 112 may be isotropically etched, and may include at least one of Cl ₂ , BCl ₃ , HCl, CCl ₄ , SiCl _4, and HBr. can do.

In addition, according to the exemplary embodiment of the present invention, since the plurality of recesses 112 have a lower depth d than before, the time required for the dry etching process of the base substrate 112 may be shorter than that of the prior art. For example, the base substrate 112 is a sapphire substrate having an etching ratio of 50 nm / min, and the plurality of concave portions 112 are 0.25 µm to corresponding to the plurality of beads 113 having a diameter of 0.5 µm to 1.5 µm. When formed to a depth (d) of 1.5㎛, the process time required for the dry etching process is a process time of 5 minutes to 30 minutes.

As the dry etching process is performed for a shorter time as described above, the base substrate 112 may be damaged, the photoresist 200 may be damaged or removed due to a long dry etching process, and the adsorption may be performed on the surface of the base substrate 112. The generation of impurities can be minimized. Therefore, the plurality of recesses 111 on the upper surface of the base substrate 112 may be uniformly formed.

As shown in FIG. 6F, the etching mask 220 remaining on the upper surface of the base substrate 112 is removed before the plurality of beads 113 are formed.

Next, as shown in FIG. 6G, the liquid material 400 containing the plurality of beads 113 is coated on the upper surface of the base substrate 112. (S120)

The solvent of the liquid material 400 is selected as a material having a high volatility, so that the amount of solvent remaining on the upper surface of the base substrate 112 is minimized, and only the plurality of beads 113 are present. Allow it to survive. In addition, the plurality of beads 113 may be formed in a spherical shape.

Meanwhile, the applying of the liquid material 400 (S120) may be performed by using slit coating or spin coating.

Subsequently, as shown in FIG. 6H, the liquid material 400 coated on the upper surface of the base substrate 112 is cured to form a plurality of beads 113 fitted on the plurality of recesses 111. A semiconductor growth substrate 110 according to an embodiment of the present invention is manufactured. Here, although not separately shown, the step S130 of forming the plurality of beads 113 may include a plurality of recesses 111 on the upper surface of the base substrate 112 after curing the liquid material 400. It may further comprise a step of shaking off the beads not fitted on the).

As shown in FIG. 6I, a plurality of semiconductor layers 121 ˜ 124 are sequentially stacked on the semiconductor growth substrate 110 to form a photoelectric layer 120. As illustrated in FIG. 6J, an ohmic contact layer 130 is formed by stacking a transparent conductive material on the upper surface of the p-type semiconductor layer 124. (S300)

Subsequently, as shown in FIG. 6K, in the step S400 of forming the first electrode 140 and the second electrode 150 connected to the plurality of semiconductor layers 121 to 124, the ohmic contact layer 130 is formed. After exposing the partial region of the n-type semiconductor layer by removing partial regions of the p-type semiconductor layer 124 and the active layer 123, the first electrode 140 is disposed on the exposed partial region of the n-type semiconductor layer. ) And a second electrode 150 on the ohmic contact layer 130.

As described above, the method of manufacturing a substrate for semiconductor growth and the method of manufacturing a light emitting device according to an exemplary embodiment of the present invention include a dry etching process having a shorter process time than the prior art, and thus, the base substrate 112 due to a long dry etching process. The damage problem, the problem that all the etching mask 220 is removed or deformed, and the problem that impurities are formed on the surface of the base substrate 112 can be prevented. Therefore, the uneven pattern including the plurality of recesses 111 may be uniformly formed on the upper surface of the base substrate 112, and the air gap 114 due to the plurality of beads 113 may be formed. Extraction efficiency may be improved, and crystal defects of the semiconductor material may be reduced, and thus yield may be improved.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, modifications, and changes may be made without departing from the technical spirit of the present invention.

100: light emitting device 110: semiconductor growth substrate
111: a plurality of recesses 112: the base substrate
113: plural beads 114: plural air gaps
120: photoelectric layer 121: buffer layer
122: n-type semiconductor layer 123: light emitting layer
124: p-type semiconductor layer 130: ohmic contact layer
140: first electrode 150: second electrode
200: photoresist 220: etching mask
300: exposure mask 400; Liquid material

Claims (19)

A base substrate including an upper surface patterned in the form of a plurality of recesses; And
And a plurality of beads each of which is inserted onto and fixed to the plurality of recesses to form a plurality of air gaps. The semiconductor of claim 1, wherein the plurality of recesses have a depth that is greater than or equal to the radius of the plurality of beads and less than or equal to the diameter of the plurality of beads, and has a width greater than or equal to the radius of the plurality of beads and less than or equal to the diameter of the plurality of beads. Growth substrate. The semiconductor growth substrate of claim 1, wherein a height of the uneven pattern formed by protruding the plurality of beads from the top surface of the base substrate is 3 μm or less. The semiconductor growth substrate of claim 1, wherein the base substrate is selected of sapphire, and the plurality of beads are selected of a silicon-based material. The substrate of claim 1, wherein the plurality of beads are formed of at least one material selected from SiO ₂ , Al ₂ O ₃ , TiO ₂ , ZrO ₂ , CuO, Fe ₂ O ₃ , and PZT. Providing a base substrate including an upper surface patterned in the form of a plurality of recesses;
Applying a liquid material containing a plurality of beads to an upper surface of the base substrate; And
Hardening the liquid material to form a plurality of beads which are inserted and fixed on the plurality of recesses to form a plurality of air gaps, respectively. The method of claim 6, wherein the providing of the base substrate including upper surfaces patterned in the form of the plurality of recesses comprises:
Applying a photoresist to the flat upper surface of the base substrate;
Exposing the photoresist in a state in which an exposure mask including a plurality of transmission parts corresponding to the plurality of recesses is aligned to form a photoresist pattern to include a plurality of opening regions corresponding to the plurality of recesses;
Hardening the photoresist pattern to form an etching mask on an upper surface of the base substrate; And
Patterning the upper surface of the base substrate by dry etching using the etching mask. The method of claim 6, wherein in the step of providing a base substrate including an upper surface patterned in the form of the plurality of recesses, the plurality of recesses is a depth of more than the radius of the plurality of beads to less than the diameter of the plurality of beads. And a width not less than the radius of the plurality of beads but not more than the diameter of the plurality of beads. The method of claim 6, wherein in the forming of the plurality of beads, the height of the uneven pattern formed by protruding the plurality of beads from the top surface of the base substrate is 3 μm or less. The method of claim 7, wherein in the applying of the photoresist to the flat upper surface of the base substrate, the photoresist has a thickness of 3 μm or less. A base substrate including an upper surface patterned in the form of a plurality of recesses;
A plurality of beads each of which is inserted into and fixed to a plurality of recesses on an upper surface of the base substrate to form a plurality of air gaps;
A first semiconductor layer, an active layer, and a second semiconductor layer sequentially stacked on an upper surface of the base substrate including the plurality of beads;
An ohmic contact layer formed on an entire surface of the second semiconductor layer;
A first electrode formed on a portion of the first semiconductor layer exposed by removing portions of the ohmic contact layer, the active layer, and the second semiconductor layer; And
A light emitting device comprising a second electrode formed on the ohmic contact layer. 12. The method of claim 11, wherein the plurality of recesses have a depth greater than or equal to the radius of the plurality of beads and less than or equal to the diameter of the plurality of beads, and have a width greater than or equal to the radius of the plurality of beads and less than or equal to the diameter of the plurality of beads. Light emitting element. The light emitting device of claim 11, wherein a height of the uneven pattern formed by protruding the plurality of beads from the top surface of the base substrate is 3 μm or less. The light emitting device of claim 11, wherein the base substrate is selected of sapphire, and the plurality of beads are selected of a silicon-based material. The light emitting device of claim 11, wherein the plurality of beads are formed of at least one material selected from SiO ₂ , Al ₂ O ₃ , TiO ₂ , ZrO ₂ , CuO, Fe ₂ O ₃ , and PZT. Providing a base substrate including an upper surface patterned in the form of a plurality of recesses;
Applying a liquid material containing a plurality of beads to an upper surface of the base substrate;
Hardening the liquid material to form a plurality of beads which are fitted onto the plurality of recesses and are fixed to form a plurality of air gaps; And
And sequentially stacking a first semiconductor layer, an active layer, and a second semiconductor layer on an upper surface of the base substrate including the plurality of beads. The method of claim 16, wherein the providing of the base substrate including upper surfaces patterned in the form of the plurality of recesses comprises:
Applying a photoresist to the flat upper surface of the base substrate;
Exposing the photoresist in a state in which an exposure mask including a plurality of transmission parts corresponding to the plurality of recesses is aligned to form a photoresist pattern to include a plurality of opening regions corresponding to the plurality of recesses;
Hardening the photoresist pattern to form an etching mask on an upper surface of the base substrate; And
Patterning an upper surface of the base substrate by dry etching using the etching mask;
The concave portion has a depth greater than or equal to the radius of the plurality of beads and less than or equal to the diameter of the plurality of beads, and has a width greater than or equal to the radius of the plurality of beads and less than or equal to the diameter of the plurality of beads. The method of claim 16, wherein in the forming of the plurality of beads, the height of the uneven pattern formed by protruding the plurality of beads from the upper surface of the base substrate is 3 μm or less. The method of claim 16, wherein in the step of applying a liquid material containing a plurality of beads on the upper surface of the base substrate, the plurality of beads are SiO ₂ , Al ₂ O ₃ , TiO ₂ , ZrO ₂ , CuO, Fe ₂ O ₃ , and PZT.

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