WO2018221752A1 - Three-dimensional long-wavelength light-emitting diode and manufacturing method therefor - Google Patents

Three-dimensional long-wavelength light-emitting diode and manufacturing method therefor Download PDF

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Publication number
WO2018221752A1
WO2018221752A1 PCT/KR2017/005560 KR2017005560W WO2018221752A1 WO 2018221752 A1 WO2018221752 A1 WO 2018221752A1 KR 2017005560 W KR2017005560 W KR 2017005560W WO 2018221752 A1 WO2018221752 A1 WO 2018221752A1
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semiconductor layer
substrate
dimensional
light emitting
emitting diode
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PCT/KR2017/005560
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French (fr)
Korean (ko)
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이석헌
김광희
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이석헌
김광희
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Priority to PCT/KR2017/005560 priority Critical patent/WO2018221752A1/en
Publication of WO2018221752A1 publication Critical patent/WO2018221752A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/20—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a particular shape, e.g. curved or truncated substrate
    • H01L33/22—Roughened surfaces, e.g. at the interface between epitaxial layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/26—Materials of the light emitting region
    • H01L33/30—Materials of the light emitting region containing only elements of Group III and Group V of the Periodic Table
    • H01L33/32—Materials of the light emitting region containing only elements of Group III and Group V of the Periodic Table containing nitrogen
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/36—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the electrodes

Definitions

  • the present invention relates to a light emitting diode manufacturing technology, and more particularly to a three-dimensional long wavelength light emitting diode and a method of manufacturing the same.
  • Typical light emitting diodes include substrates such as sapphire substrates, buffer layers, n-type semiconductor layers, active layers and p-type semiconductor layers.
  • substrates such as sapphire substrates, buffer layers, n-type semiconductor layers, active layers and p-type semiconductor layers.
  • a p-electrode is formed on the p-type semiconductor layer, and an n-electrode is formed on the n-type semiconductor layer exposed by mesa etching.
  • the light emitting diode is classified into an ultraviolet light emitting diode, a blue light emitting diode, a green light emitting diode, a red light emitting diode, and an infrared light emitting diode according to the wavelength of light emitted from the active layer.
  • the light emitting diode that emits light having a wavelength of 600 nm or more may be a long wavelength light emitting diode.
  • Such long wavelength light emitting diodes have been applied to remote controllers, infrared communication, and infrared cameras of electronic products.
  • the reflective infrared light emitting diode of the above document uses a liquid phase epitaxy (LPE) to grow a transparent conductive layer on an n-type GaAs, GaP or InP substrate, and then grows a light emitting structure layer by MOCVD thereon.
  • LPE liquid phase epitaxy
  • the reflective layer and the transparent conductive film and the eutectic mixture layer are sequentially formed, and then the substrate is removed, and then the upper electrode is formed.
  • a C-axis growth substrate is most commonly used.
  • an unwanted electric field is generated in the light emitting structure layer by the internal polarization action of the Group 3 material and the Group 5 material. Due to the electric field, holes and electrons present in the active layer are distributed to be spaced apart from each other, so that the probability of recombination is lowered, thereby reducing light output.
  • One object of the present invention is to provide a three-dimensional long wavelength light emitting diode having excellent crystal quality and excellent light output characteristics.
  • Another object of the present invention is to provide a method suitable for producing the three-dimensional long wavelength light emitting diode.
  • the plurality of three-dimensional structures may include a concave portion or a convex portion, or may include both a concave portion and a convex portion.
  • the substrate may be a GaAs, GaP or InP substrate.
  • the substrate may be formed of one or more semiconductor layers of an undoped semiconductor layer and a first conductivity type semiconductor layer on a GaAs, GaP or InP substrate.
  • the first electrode may be formed under the substrate, and the second electrode may be formed over the second conductive semiconductor layer.
  • the three-dimensional structure may have a circular cross section of the width varies in the longitudinal direction.
  • the active layer may emit red light or infrared light.
  • a three-dimensional long-wavelength light emitting diode comprising: a first conductive semiconductor layer having a surface having a plurality of three-dimensional structures spaced apart from each other; An active layer formed on a surface of the first conductivity type semiconductor layer and emitting light having a wavelength of 600 nm or more, including AlGaInP or AlGaAs; A second conductivity type semiconductor layer formed on the surface of the active layer; A conductive substrate formed on a surface of the second conductive semiconductor layer; And a first electrode electrically connected to the first conductive semiconductor layer, wherein each of the active layer and the second conductive semiconductor layer maintains a surface shape of the first conductive semiconductor layer.
  • the plurality of three-dimensional structures may include a concave portion or a convex portion, or may include both a concave portion and a convex portion.
  • the three-dimensional structure may have a circular cross section that increases in width toward the surface.
  • the active layer may emit red light or infrared light.
  • a method of manufacturing a three-dimensional long wavelength light emitting diode comprising: (a) forming a plurality of three-dimensional structures spaced apart from each other on a substrate surface; (b) forming a light emitting structure on the surface of the substrate, the light emitting structure including a first conductive semiconductor layer, an active layer that emits light having a wavelength of 600 nm or more, including AlGaInP or AlGaAs, and a second conductive semiconductor layer; And (c) forming a first electrode electrically connected to the first conductivity-type semiconductor layer and a second electrode electrically connected to the second conductivity-type semiconductor layer.
  • the substrate may be a GaAs, GaP or InP substrate, and in step (a), a plurality of three-dimensional structures spaced apart from each other may be formed on the surface of the GaAs, GaP or InP substrate.
  • the substrate may include a semiconductor layer including at least one of an undoped semiconductor layer and a first conductivity type semiconductor layer on a GaAs, GaP, or InP substrate, and spaced apart from each other on the surface of the semiconductor layer in step (a). It can form a three-dimensional structure of.
  • the first electrode may be formed below the substrate, and the second electrode may be formed above the second conductive semiconductor layer.
  • the three-dimensional structure may be formed to have a circular cross section of the width varies in the longitudinal direction.
  • a method of manufacturing a three-dimensional long wavelength light emitting diode comprising: (a) forming a plurality of three-dimensional structures spaced apart from each other on a substrate surface; (b) forming a sacrificial layer on a surface of the substrate on which the plurality of three-dimensional structures are formed; (c) forming a light emitting structure including a first conductive semiconductor layer, an active layer that emits light having a wavelength of 600 nm or more, including AlGaInP or AlGaAs, and a second conductive semiconductor layer on a surface of the substrate on which the sacrificial layer is formed; step; (d) attaching a conductive substrate to the surface of the second conductivity type semiconductor layer and removing the sacrificial layer to separate the substrate; And (e) forming a first electrode electrically connected to the first conductivity-type semiconductor layer to which the sacrificial layer is removed and exposed.
  • the substrate may be a GaAs, GaP or InP substrate, and in step (a), a plurality of three-dimensional structures spaced apart from each other may be formed on the surface of the GaAs, GaP or InP substrate.
  • the substrate may include a semiconductor layer including at least one of an undoped semiconductor layer and a first conductivity type semiconductor layer on a GaAs, GaP, or InP substrate, and spaced apart from each other on the surface of the semiconductor layer in step (a). It can form a three-dimensional structure of.
  • the three-dimensional structure may be formed to have a circular cross section of the width varies in the longitudinal direction.
  • the sacrificial layer may be formed of AlAs.
  • attaching the conductive substrate is performed by forming an additional second conductive semiconductor layer on the second conductive semiconductor layer, and then attaching a silicon substrate or a metal substrate with a conductive adhesive.
  • a silicon substrate or a metal substrate with a conductive adhesive.
  • the surface of the three-dimensional structure of the substrate enables efficient lateral growth, which significantly lowers the bow value as compared to the conventional planar substrate structure, thereby enabling the formation of a high-quality light emitting structure. Accordingly, in addition to increasing the effective area of the active layer, it is possible to obtain high luminous efficiency by reducing stress due to rapid lateral growth, and to have a low driving voltage by increasing the effective area of the surface of the second conductivity-type semiconductor layer. In addition, the thickness of the active layer grown on the upper surface of the active layer and the side of the three-dimensional structure can be made uniform, so that light of a single wavelength can be emitted from the active layer.
  • the substrate may be directly etched to form a three-dimensional structure on the surface.
  • the degree of freedom of formation of the three-dimensional light emitting structure may be increased by providing abundant materials of the substrate, and thus optimization may be performed. It is possible to solve the problem of epi thin film contamination caused by the growth interruption.
  • the degree of freedom of processing may increase significantly. That is, when etching the epi thin film, the etching may be stopped immediately after the photoresist mask is completely removed by etching, whereas when etching the substrate, the pattern may be maintained even when overetching.
  • the three-dimensional structure is shaped like a circular cross section that changes in width in the longitudinal direction, such as a recess having a circular cross section that increases in width toward the surface, all parts within the three-dimensional structure It may be formed as an inclined surface. Accordingly, the epitaxial film formed thereon also enables non-polar growth, so that the probability of carrier recombination may increase, thereby increasing the light output.
  • voids may be naturally formed between the epi thin film and the substrate.
  • the pores can be used as a channel through which an etching solution can be more easily supplied when removing the substrate, thereby facilitating substrate removal.
  • the removed substrate may be used as a growth substrate again.
  • the inclined surface of the three-dimensional structure of the active layer and the thickness of the outer surface of the three-dimensional structure to the same the same thickness, the active layer energy bandgap is the same, it is possible to emit the same wavelength.
  • FIG. 1 schematically shows a three-dimensional long wavelength light emitting diode according to an embodiment of the present invention.
  • FIG. 2 schematically shows a three-dimensional long wavelength light emitting diode according to another embodiment of the present invention.
  • FIG 3 shows an example of a substrate applied to the present invention.
  • FIG 4 shows another example of a substrate applied to the present invention.
  • Fig. 5 shows an example in which a recess is formed as a three-dimensional structure on a substrate, where (a) is a plan view and (b) is a sectional view.
  • Figure 6 schematically shows the light emitted from the active layer in the three-dimensional long wavelength light emitting diode according to the present invention.
  • FIG. 7 to 9 schematically illustrate a process of manufacturing the 3D long wavelength light emitting diode shown in FIG. 1.
  • 10 to 14 schematically illustrate a process of manufacturing the 3D long wavelength light emitting diode shown in FIG. 2.
  • FIG. 15 shows another example in which a recess is formed as a three-dimensional structure on a substrate.
  • FIG. 16 schematically illustrates an example of a 3D long wavelength light emitting diode using the substrate of FIG. 15.
  • FIG. 17 schematically illustrates another example of a 3D long wavelength light emitting diode using the substrate of FIG. 15.
  • the term "three-dimensional” is a concept in which the surface of the substrate and the semiconductor layer is flat, and the recess or the convex portion is formed on the surface of the substrate or the semiconductor layer, or both the recess and the convex portion are formed. it means.
  • the three-dimensional structure may include concave portions or convex portions, and may include both concave portions and convex portions. In the following, an example is described mainly including concave portions as a three-dimensional structure, but may include convex portions or include both concave and convex portions as a three-dimensional structure.
  • the long wavelength light emitting diode means a light emitting diode having a wavelength of light emitted from the active layer of 600 nm or more, such as 600 nm, 650 nm, 850 nm, 940 nm, or the like.
  • the long wavelength light emitting diode may correspond to a red light emitting diode and an infrared light emitting diode.
  • FIG. 1 schematically shows a three-dimensional long wavelength light emitting diode according to an embodiment of the present invention.
  • the illustrated three-dimensional long wavelength light emitting diode 100 includes a substrate 110, a first conductive semiconductor layer 120, an active layer 130, a second conductive semiconductor layer 140, and a first electrode. 160 and the second electrode 150.
  • a plurality of three-dimensional structures including a portion having a curved longitudinal section and spaced apart from each other are formed.
  • the outer surfaces of a three-dimensional structure are connected to each other.
  • 1 shows an example in which the three-dimensional structure 115 is formed of concave portions, the three-dimensional structure 115 may be formed of convex portions, or may include convex portions together with the concave portions.
  • the substrate 110 may be a GaAs, GaP or InP substrate 101, as shown in the example shown in FIG. 3.
  • the three-dimensional structure is formed on the GaAs, GaP or InP substrate 101.
  • the substrate 110 may include one or more semiconductor layers 102 of an undoped semiconductor layer and a first conductivity type semiconductor layer formed on a GaAs, GaP, or InP substrate 101.
  • the three-dimensional structure may be formed in the semiconductor layer 102.
  • the first conductivity type semiconductor layer 120 is formed on the surface of the substrate 110.
  • an additional semiconductor layer may be further formed between the substrate 110 and the first conductivity-type semiconductor layer 120 to improve crystallinity, such as a buffer layer and an undoped semiconductor layer.
  • the first conductive semiconductor layer 120 is formed of a III (Ga, Al, In) -V (P, As) semiconductor doped with n-type impurities such as Si
  • the second conductive semiconductor layer ( 140 may be formed of a III-V semiconductor doped with a p-type impurity such as Mg.
  • the opposite is also possible.
  • the active layer 130 is formed on the surface of the first conductive semiconductor layer 120 and emits light having a wavelength of 600 nm or more, including AlGaInP or AlGaAs.
  • the active layer 130 may preferably emit red light or infrared light.
  • the active layer 130 may be formed of a quantum well structure in which a well layer and a barrier layer are alternately stacked.
  • the second conductivity type semiconductor layer 140 is formed on the surface of the active layer 130.
  • the thickness of the first conductivity-type semiconductor layer 120 is greater than that of the second conductivity-type semiconductor layer 140, and the thickness of the second conductivity-type semiconductor layer 140 is greater than that of the active layer 130. It may be larger than the thickness, but is not necessarily limited thereto.
  • the first electrode 160 is electrically connected to the first conductivity type semiconductor layer 120.
  • the second electrode 150 is electrically connected to the second conductive semiconductor layer 140.
  • the second electrode 150 may be formed on the second conductive semiconductor layer 140, and the first electrode 160 may be formed on the back surface of the substrate 110.
  • a substrate such as GaAs, InP, or the like may exhibit conductivity when semi-conductive or doped.
  • the first electrode is formed on the back surface of the substrate 110 as shown in FIG. 1, rather than a conventional horizontal structure in which the area of the first semiconductor layer is exposed by mesa etching to reduce the active layer area. It is more preferable to maintain a sufficient active layer area by forming 160.
  • the first electrode 160 and the second electrode 150 may be formed of a single layer or a multilayer of known Ag, Au, Ni, or the like.
  • the second electrode 150 is in contact with the second conductivity type semiconductor layer 140 maintaining the surface shape of the substrate 110.
  • the coupling area between the semiconductor layer and the electrode is increased, whereby the contact resistance is reduced, thereby reducing the driving voltage.
  • the surface shape of the first conductive semiconductor layer 120, the active layer 130, and the second conductive semiconductor layer 140, the substrate 110 that is, the shape in which the three-dimensional structures spaced apart from each other exist. It is characteristic.
  • a plurality of three-dimensional structures 115 spaced apart from each other are formed on the substrate 110.
  • Fig. 5 shows an example in which a recess is formed as a three-dimensional structure on a substrate, where (a) is a plan view and (b) is a sectional view.
  • a three-dimensional structure in the form of a recess having a side surface 521 and a bottom surface 522 is formed on the substrate surface 510.
  • the bottom surface may be omitted as in the example shown in FIG. 15.
  • the three-dimensional structure includes a portion whose longitudinal section is curved.
  • the recess may have a circular cross section that increases in width toward the surface, as in the example shown in FIG.
  • the convex portion may have a circular cross section that becomes narrower toward the top. That is, the three-dimensional structure may vary in width in the longitudinal direction. In this type of three-dimensional structure, all parts in the three-dimensional structure can be formed as a slope including a curved surface, and thus the epi thin film formed thereon also enables non-polar growth, thereby increasing the probability of carrier recombination. The light output can be increased.
  • the three-dimensional structure (132, 133) of the active layer due to the three-dimensional structure of the substrate has a flat structure
  • the width (W) is three times or more the height (H).
  • the three-dimensional structure according to the present invention may have a flat shape. Through such a flat shape, it may be easier to equalize the thickness of the inclined surface of the three-dimensional structure of the active layer and the outer surface of the three-dimensional structure.
  • a C-axis growth substrate is most commonly used as a growth substrate, and holes and electrons present in the active layer are mutually different due to internal polarization of the Group 3-5 compound grown on the C-axis growth substrate. Distributed apart, there is a problem that the recombination probability is lowered to reduce the light output.
  • the non-polar growth is much included, it is possible to increase the probability of carrier recombination in the active layer compared to the conventional.
  • Such a three-dimensional surface of the substrate 110 enables efficient lateral growth, and significantly lowers bow value compared to a conventional planar substrate structure, thereby enabling the formation of a high quality light emitting structure. Accordingly, in addition to increasing the effective area of the active layer 130, a high luminous efficiency can be obtained by reducing stress due to rapid lateral growth, and low driving by increasing the effective area of the surface of the second conductive semiconductor layer 140 May have a voltage.
  • the epi layer formed in the three-dimensional structure or the like is non-polarly grown, so that the stress in the epi layer ⁇ including the active layer is reduced, thereby increasing the probability of electrons and recombination in the active layer. Significantly increased.
  • the amount of light emission per unit area in the general flat region such as between the three-dimensional structure and the three-dimensional structure may be significantly higher.
  • the thickness of the active layer grown on the upper surface of the active layer 130 is the same.
  • the inclined surface of the three-dimensional structure of the active layer and the thickness of the outer surface of the three-dimensional structure are the same, the active layer energy bandgap is the same due to the same thickness it is possible to emit a single wavelength.
  • the lateral growth is faster than the upper surface, and because of the same thickness, the active layer energy bandgap is the same, so that the same wavelength is possible.
  • the thickness of the well layer of the active layer is thick, the energy band gap is reduced, and thus the long wavelength light emission is achieved.
  • the energy bandgap of a quantum well structure is inversely proportional to the physical thickness of the quantum well structure, regardless of the material, as well as the intrinsic value of the material selected. For example, if the GaN material is selected as the active layer, the bulk (semiconductor layer thicker than the quantum well structure) is given an energy band value of 3.4 (eV) as a material property and emits light corresponding to 3.4 eV. However, the GaN layer employed in the quantum structure may exhibit an energy band gap of as much as 3.4 + x (eV) due to a thin thickness.
  • the thickness of the well layer is different at the top and side of the three-dimensional structure (generally, the top is thicker than the side), the energy band gaps at the top and the side are different from each other to emit different wavelengths. Since the thickness of the well layer on the side is the same, the energy band gap is the same, and light of the same wavelength may be emitted from the top and the side.
  • Figure 6 schematically shows the light emitted from the active layer in the three-dimensional long wavelength light emitting diode according to the present invention.
  • the active layer 130 maintains the surface shape of the substrate, and the active layer 130 also includes a three-dimensional structure. More specifically, the active layer 130 includes a three-dimensional structure and the three-dimensional structure (131), the side surface 132 of the three-dimensional structure and the bottom surface 133 of the three-dimensional structure. The bottom surface 133 of the three-dimensional structure may be omitted as shown in FIG. 15. At this time, the first peak wavelength ⁇ 1 is emitted between the 3D structure and the 3D structure 131 and the bottom surface 133 of the 3D structure, and the second peak wavelength ⁇ 2 at the side surface 132 of the 3D structure. ) Is released.
  • the side surface and other portions of the three-dimensional structure can be uniformly grown, so that the difference between the first peak wavelength lambda 1 and the second peak wavelength lambda 2 is within 10%. Preferably, it may be within 5%, and light having a uniform wavelength may be emitted through the active layer 130.
  • FIG. 2 schematically shows a three-dimensional long wavelength light emitting diode according to another embodiment of the present invention.
  • the three-dimensional long wavelength light emitting diode 100 of the structure shown in FIG. 1 is a structure in which the substrate 110 exists
  • the three-dimensional long wavelength light emitting diode 200 of the structure shown in FIG. 2 has the substrate 110 removed, It corresponds to a so-called vertical structure.
  • the three-dimensional long wavelength light emitting diode illustrated from above includes a first conductive semiconductor layer 120, an active layer 130, and a second conductive semiconductor layer 140.
  • the conductive substrate 210 is attached to the surface of the second conductive semiconductor layer 140.
  • the conductive substrate may serve as a second electrode electrically connected to the second conductive semiconductor layer.
  • the first electrode 220 may be formed on the first conductive semiconductor layer.
  • the light absorption is excellent, so that a large amount of light emitted from the active layer in the downward direction may be lost without being reflected in the upward direction. Therefore, in the case of a structure in which the substrate is removed and a conductive substrate such as a silicon substrate or a metal substrate is attached instead, this problem can be solved.
  • a three-dimensional structure 115 including a portion having a curved longitudinal section is formed on a lower surface of the first conductivity-type semiconductor layer 120 by removing a substrate and reversing up and down in the manufacturing process.
  • Each of the active layer 130 and the second conductive semiconductor layer 140 maintains the surface shape of the first conductive semiconductor layer 120 having a three-dimensional structure formed on the lower surface thereof.
  • the convex portion is formed along with the concave portion in the three-dimensional structure 115 on the substrate surface.
  • voids may be naturally formed between the epi thin film and the substrate. In the process of manufacturing a light emitting diode having a vertical structure with substrate removal as shown in FIG. 13, this void can be used as a channel through which an etching solution can be more easily supplied when removing the substrate, thereby facilitating substrate removal. Do.
  • the removed substrate may be used as a growth substrate again.
  • FIG. 7 to 9 schematically illustrate a process of manufacturing the 3D long wavelength light emitting diode shown in FIG. 1.
  • a plurality of three-dimensional structures 115 including a portion having a curved longitudinal section and spaced apart from each other are formed on a surface of the substrate 110.
  • the plurality of three-dimensional structures it may be formed through an etching process using a photoresist mask.
  • the substrate 110 is directly etched to form a three-dimensional structure on the surface.
  • the degree of freedom of formation of the 3D light emitting structures 120 to 140 may be increased by providing abundant materials of the substrate 110.
  • the growth stop is necessarily accompanied, which causes contamination of the epi thin film.
  • this problem can be prevented.
  • the degree of freedom of processing may increase significantly. That is, when etching the epi thin film, the etching must be stopped immediately after the photoresist mask is completely removed by etching. That is, when the etching is stopped while the photoresist mask is left, the portion except the photoresist mask includes a flat structure because the side surface of the structure is formed as an inclined surface, and the left portion of the photoresist mask cannot be etched.
  • the further growth of epilayers in the poly ramen makes it difficult to solve the polarization problem.
  • the substrate is etched, the pattern may be maintained even during over etching.
  • the three-dimensional structure 115 may be formed to have a circular cross section that varies in width in the longitudinal direction.
  • the three-dimensional structure 115 may be formed to have a circular cross section that increases in width toward the upper direction.
  • the three-dimensional structure 115 is a convex portion, it may be formed to have a circular cross section that decreases in width toward the upper direction.
  • a plurality of three-dimensional structures 115 spaced apart from each other may be formed on the surface of the GaAs, GaP or InP substrate.
  • the growth substrate can be easily processed using, for example, a GaAs semiconductor bulk substrate.
  • the substrate is formed of a semiconductor layer 102 including at least one of an undoped semiconductor layer and a first conductivity type semiconductor layer on the GaAs, GaP or InP substrate 101, as in the example shown in FIG.
  • a plurality of three-dimensional structures 115 spaced apart from each other may be formed on the surface of the semiconductor layer 102.
  • the first conductive semiconductor layer 120, AlGaInP, or AlGaAs having a wavelength of 600 nm or more is formed on the surface of the substrate 110 on which the plurality of three-dimensional structures 115 are spaced apart from each other.
  • a light emitting structure including an active layer 130 that emits light and a second conductive semiconductor layer 140 are formed.
  • the light emitting structure may be formed through so-called epi thin film growth, and may be formed by a MOCVD method or an LPE method. More preferably, the light emitting structure is formed by an LPE method having a high growth rate.
  • the light emitting structure including the active layer 130 maintains the surface shape of the substrate on which the three-dimensional structure is formed.
  • the first electrode 160 and the second conductive semiconductor layer 140 are electrically connected to the first conductive semiconductor layer 120. 2 electrodes 150 are formed.
  • the first electrode 160 may be formed under the substrate 110, and the second electrode 150 may be formed on the second conductive semiconductor layer 140.
  • 10 to 14 schematically illustrate a process of manufacturing the 3D long wavelength light emitting diode shown in FIG. 2.
  • a plurality of three-dimensional structures 115 including a portion having a curved longitudinal section and spaced apart from each other are formed on a surface of the substrate 110.
  • all of the above-described matters in FIG. 7 may be applied, and thus a detailed description thereof will be omitted.
  • a sacrificial layer 201 is formed on a surface of a substrate on which a plurality of three-dimensional structures are formed.
  • the sacrificial layer 201 is for removing the substrate 110, and a material that can be selectively dissolved in a predetermined etching solution is used.
  • a sacrificial layer of AlAs material may be provided.
  • AlAs it can be selectively etched in HF solution, making it suitable for use as a sacrificial layer.
  • a light emitting structure is formed.
  • all of the above-described matters in FIG. 8 may be applied, and thus a detailed description thereof will be omitted.
  • the conductive substrate 210 is attached to the surface of the second conductivity-type semiconductor layer 140, and the sacrificial layer 201, such as an AlAs material, is removed by an etching solution such as an HF solution.
  • the substrate 110 is separated.
  • the conductive substrate 210 may function as a second electrode electrically connected to the second conductive semiconductor layer 140.
  • attaching the conductive substrate 210 forms an additional second conductive semiconductor layer (not shown) such as, for example, p-GaP on the second conductive semiconductor layer, and then a silicon substrate or a metal substrate thereon.
  • an additional second conductive semiconductor layer such as, for example, p-GaP on the second conductive semiconductor layer, and then a silicon substrate or a metal substrate thereon.
  • the sacrificial layer 201 is removed to form a first electrode 220 electrically connected to the first conductive semiconductor layer 120 exposed.
  • FIG. 15 shows another example in which a three-dimensional structure is formed on a substrate.
  • FIG. 16 schematically illustrates an example of a 3D long wavelength light emitting diode using the substrate of FIG. 15, and
  • FIG. 17 schematically illustrates another example of a 3D long wavelength light emitting diode using the substrate of FIG. 15.
  • FIG. 16 is substantially the same as the structure shown in FIG. 1 except for the shape of the three-dimensional structure
  • the structure shown in FIG. 17 is identical to the structure shown in FIG. 2 except for the shape of the three-dimensional structure. Since they are almost the same, detailed description thereof is omitted here.
  • the concave portion is formed, and the bottom surface of the concave portion does not exist, and the entire concave portion may be formed in a curved surface.
  • the upper surface of the convex portion does not exist, and the entire convex portion may be formed as a curved surface.
  • both epitaxial growth in the concave portion or convex portion may be non-polar growth, and thus the probability of recombination of electrons and electrons in the active layer of the long wavelength light emitting diode shown in FIG. 16 or the long wavelength light emitting diode shown in FIG. This can be significantly higher, and thus the light emission efficiency can be higher.

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Abstract

A three-dimensional long-wavelength light-emitting diode and a manufacturing method therefor are disclosed. According to an embodiment of the present invention, the three-dimensional long-wavelength light-emitting diode comprises: a substrate having a surface having a plurality of three-dimensional structures spaced apart from each other; and a first-conductive type semiconductor layer, an active layer, and a second-conductive type semiconductor layer sequentially formed on the substrate. The active layer includes AlGaInP or AlGaAs and emits light having a wavelength of 600 nm or more. Specifically, the active layer maintains a surface shape of the substrate.

Description

3차원 장파장 발광다이오드 및 그 제조 방법3D long wavelength light emitting diode and its manufacturing method
본 발명은 발광다이오드 제조 기술에 관한 것으로, 더욱 상세하게는 3차원 장파장 발광다이오드 및 그 제조 방법에 관한 것이다.The present invention relates to a light emitting diode manufacturing technology, and more particularly to a three-dimensional long wavelength light emitting diode and a method of manufacturing the same.
일반적인 발광다이오드는 사파이어 기판과 같은 기판, 버퍼층, n형 반도체층, 활성층 및 p형 반도체층을 포함한다. 또한, p형 반도체층 상에 p-전극이 형성되고, 메사 식각에 의해 노출되는 n형 반도체층 상에 n-전극이 형성된다. Typical light emitting diodes include substrates such as sapphire substrates, buffer layers, n-type semiconductor layers, active layers and p-type semiconductor layers. In addition, a p-electrode is formed on the p-type semiconductor layer, and an n-electrode is formed on the n-type semiconductor layer exposed by mesa etching.
상기와 같은 구조를 갖는 반도체 발광소자는, n형 반도체층을 통하여 공급되는 전자와 p형 반도체층을 통하여 공급되는 정공이 활성층(140)에서 재결합하면서 광이 발생한다. In the semiconductor light emitting device having the above structure, light is generated while electrons supplied through the n-type semiconductor layer and holes supplied through the p-type semiconductor layer are recombined in the active layer 140.
발광다이오드는 활성층에서 방출되는 광의 파장에 따라, 자외선 발광다이오드, 청색 발광다이오드, 녹색 발광다이오드, 적색 발광다이오드, 적외선 발광다이오드로 구별된다. The light emitting diode is classified into an ultraviolet light emitting diode, a blue light emitting diode, a green light emitting diode, a red light emitting diode, and an infrared light emitting diode according to the wavelength of light emitted from the active layer.
이중 적색 발광다이오드와 적외선 발광다이오드와 같이 600nm 이상의 파장을 갖는 광을 방출하는 발광다이오드를 장파장 발광다이오드라 할 수 있다. 이러한 장파장 발광다이오드는 전자 제품의 리모콘, 적외선 통신용, 적외선 카메라 등에 적용되고 있다. The light emitting diode that emits light having a wavelength of 600 nm or more, such as a red light emitting diode and an infrared light emitting diode, may be a long wavelength light emitting diode. Such long wavelength light emitting diodes have been applied to remote controllers, infrared communication, and infrared cameras of electronic products.
본 발명에 관련된 배경 기술로는 대한민국 공개특허공보 제10-2015-0080790호(2015년 7월 10일 공개)에 개시된 가 있으며, 상기 문헌에는 반사형 적외선 발광다이오드 및 그 제작 방법이 개시되어 있다. Background art related to the present invention is disclosed in Republic of Korea Patent Publication No. 10-2015-0080790 (July 10, 2015 published), which discloses a reflective infrared light emitting diode and a method of manufacturing the same.
상기 문헌의 반사형 적외선 발광다이오드는 n형 GaAs, GaP 또는 InP 기판 위에 액상 에피택시(Liquid Phase Epitaxy, LPE)를 이용하여 투명전도층을 성장하고, 그 상부에 MOCVD에 의해 발광 구조층을 성장한 후, 반사층 및 투명전도막과 공융 혼합물층을 순차적으로 형성하고, 이후 기판을 제거한 후, 상부 전극을 형성하는 과정으로 제조된다. The reflective infrared light emitting diode of the above document uses a liquid phase epitaxy (LPE) to grow a transparent conductive layer on an n-type GaAs, GaP or InP substrate, and then grows a light emitting structure layer by MOCVD thereon. The reflective layer and the transparent conductive film and the eutectic mixture layer are sequentially formed, and then the substrate is removed, and then the upper electrode is formed.
한편, 통상의 적외선 발광다이오드의 경우, C축 성장기판이 가장 일반적으로 이용된다. 그런데, C축 성장기판 위에 성장된 3-5족 화합물은 3족 물질과 5족 물질이 내부 분극(polar) 작용에 의해 발광 구조층 내에 원하지 않은 전계가 발생된다. 이러한 전계에 의해 활성층 내에 존재하는 정공과 전자는 서로 이격되게 분포하여, 재결합 확률이 저하되어 광출력이 감소되는 문제점이 있다.On the other hand, in the case of a conventional infrared light emitting diode, a C-axis growth substrate is most commonly used. However, in the Group 3-5 compound grown on the C-axis growth substrate, an unwanted electric field is generated in the light emitting structure layer by the internal polarization action of the Group 3 material and the Group 5 material. Due to the electric field, holes and electrons present in the active layer are distributed to be spaced apart from each other, so that the probability of recombination is lowered, thereby reducing light output.
본 발명의 하나의 목적은 결정 품질이 우수하고, 우수한 광출력 특성을 갖는 3차원 장파장 발광다이오드를 제공하는 것이다. One object of the present invention is to provide a three-dimensional long wavelength light emitting diode having excellent crystal quality and excellent light output characteristics.
본 발명의 다른 목적은 상기의 3차원 장파장 발광다이오드를 제조하는데 적합한 방법을 제공하는 것이다.Another object of the present invention is to provide a method suitable for producing the three-dimensional long wavelength light emitting diode.
상기 하나의 목적을 달성하기 위한 본 발명의 실시예에 따른 3차원 장파장 발광다이오드는 서로 이격된 복수의 3차원 구조물을 구비하는 표면을 구비하는 기판; 상기 기판의 표면에 형성되는 제1 도전형 반도체층; 상기 제1 도전형 반도체층의 표면에 형성되며, AlGaInP 또는 AlGaAs를 포함하여 600nm 이상의 파장을 갖는 광을 방출하는 활성층; 상기 활성층의 표면에 형성되는 제2 도전형 반도체층; 상기 제1 도전형 반도체층에 전기적으로 연결되는 제1 전극; 및 상기 제2 도전형 반도체층에 전기적으로 연결되는 제2 전극;을 포함하고, 상기 제1 도전형 반도체층, 활성층 및 제2 도전형 반도체층 각각이 상기 기판의 표면 형상을 유지하는 것을 특징으로 한다. 3D long wavelength light emitting diode according to an embodiment of the present invention for achieving the above object comprises a substrate having a surface having a plurality of three-dimensional structure spaced apart from each other; A first conductivity type semiconductor layer formed on the surface of the substrate; An active layer formed on a surface of the first conductivity type semiconductor layer and emitting light having a wavelength of 600 nm or more, including AlGaInP or AlGaAs; A second conductivity type semiconductor layer formed on the surface of the active layer; A first electrode electrically connected to the first conductive semiconductor layer; And a second electrode electrically connected to the second conductive semiconductor layer, wherein each of the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer maintains a surface shape of the substrate. do.
이때, 상기 복수의 3차원 구조물은 오목부 또는 볼록부를 포함하거나, 또는 오목부와 볼록부 모두를 포함할 수 있다.In this case, the plurality of three-dimensional structures may include a concave portion or a convex portion, or may include both a concave portion and a convex portion.
또한, 상기 기판은 GaAs, GaP 또는 InP 기판일 수 있다. 또한, 상기 기판은 GaAs, GaP 또는 InP 기판에 비도핑 반도체층 및 제1 도전형 반도체층 중 하나 이상의 반도체층이 형성된 것일 수 있다. 이들의 예에서, 상기 제1 전극은 상기 기판 하부에 형성되고, 상기 제2 전극은 상기 제2 도전형 반도체층 상부에 형성될 수 있다. In addition, the substrate may be a GaAs, GaP or InP substrate. In addition, the substrate may be formed of one or more semiconductor layers of an undoped semiconductor layer and a first conductivity type semiconductor layer on a GaAs, GaP or InP substrate. In these examples, the first electrode may be formed under the substrate, and the second electrode may be formed over the second conductive semiconductor layer.
또한, 상기 3차원 구조물은 종방향으로 폭이 변화하는 원형의 횡단면을 가질 수 있다. In addition, the three-dimensional structure may have a circular cross section of the width varies in the longitudinal direction.
또한, 상기 활성층은 적색광 또는 적외선을 방출할 수 있다. In addition, the active layer may emit red light or infrared light.
상기 하나의 목적을 달성하기 위한 본 발명의 다른 실시예에 따른 3차원 장파장 발광다이오드는 서로 이격된 복수의 3차원 구조물을 구비하는 표면을 구비하는 제1 도전형 반도체층; 상기 제1 도전형 반도체층의 표면에 형성되며, AlGaInP 또는 AlGaAs를 포함하여 600nm 이상의 파장을 갖는 광을 방출하는 활성층; 상기 활성층의 표면에 형성되는 제2 도전형 반도체층; 상기 제2 도전형 반도체층 표면에 형성되는 도전성 기판; 상기 제1 도전형 반도체층에 전기적으로 연결되는 제1 전극;을 포함하고, 상기 활성층 및 제2 도전형 반도체층 각각이 상기 제1 도전형 반도체층의 표면 형상을 유지하는 것을 특징으로 한다. According to another aspect of the present invention, there is provided a three-dimensional long-wavelength light emitting diode comprising: a first conductive semiconductor layer having a surface having a plurality of three-dimensional structures spaced apart from each other; An active layer formed on a surface of the first conductivity type semiconductor layer and emitting light having a wavelength of 600 nm or more, including AlGaInP or AlGaAs; A second conductivity type semiconductor layer formed on the surface of the active layer; A conductive substrate formed on a surface of the second conductive semiconductor layer; And a first electrode electrically connected to the first conductive semiconductor layer, wherein each of the active layer and the second conductive semiconductor layer maintains a surface shape of the first conductive semiconductor layer.
이때, 상기 복수의 3차원 구조물은 오목부 또는 볼록부를 포함하거나, 또는 오목부와 볼록부 모두를 포함할 수 있다.In this case, the plurality of three-dimensional structures may include a concave portion or a convex portion, or may include both a concave portion and a convex portion.
또한, 상기 3차원 구조물은 표면으로 향할수록 폭이 증가하는 원형의 횡단면을 가질 수 있다.In addition, the three-dimensional structure may have a circular cross section that increases in width toward the surface.
또한, 상기 활성층은 적색광 또는 적외선을 방출할 수 있다. In addition, the active layer may emit red light or infrared light.
상기 다른 목적을 달성하기 위한 본 발명의 실시예에 따른 3차원 장파장 발광다이오드 제조 방법은 (a) 기판 표면에 서로 이격된 복수의 3차원 구조물을 형성하는 단계; (b) 상기 기판 표면에, 제1 도전형 반도체층, AlGaInP 또는 AlGaAs를 포함하여 600nm 이상의 파장을 갖는 광을 방출하는 활성층 및 제2 도전형 반도체층을 포함하는 발광 구조체를 형성하는 단계; 및 (c) 상기 제1 도전형 반도체층에 전기적으로 연결되는 제1 전극 및 상기 제2 도전형 반도체층에 전기적으로 연결되는 제2 전극을 형성하는 단계;를 포함하고, 상기 (b) 단계에서, 활성층을 포함한 발광 구조체 형성시 상기 3차원 구조물이 형성된 기판의 표면 형상을 유지하는 것을 특징으로 한다. According to another aspect of the present invention, there is provided a method of manufacturing a three-dimensional long wavelength light emitting diode, the method comprising: (a) forming a plurality of three-dimensional structures spaced apart from each other on a substrate surface; (b) forming a light emitting structure on the surface of the substrate, the light emitting structure including a first conductive semiconductor layer, an active layer that emits light having a wavelength of 600 nm or more, including AlGaInP or AlGaAs, and a second conductive semiconductor layer; And (c) forming a first electrode electrically connected to the first conductivity-type semiconductor layer and a second electrode electrically connected to the second conductivity-type semiconductor layer. When maintaining the surface shape of the substrate on which the three-dimensional structure is formed when the light emitting structure including the active layer is formed.
이때, 상기 기판은 GaAs, GaP 또는 InP 기판이고, 상기 (a) 단계에서 GaAs, GaP 또는 InP 기판 표면에 서로 이격된 복수의 3차원 구조물을 형성할 수 있다. 또한, 상기 기판은 GaAs, GaP 또는 InP 기판에 비도핑 반도체층 및 제1 도전형 반도체층 중 하나 이상을 포함하는 반도체층이 형성된 것이고, 상기 (a) 단계에서 상기 반도체층 표면에 서로 이격된 복수의 3차원 구조물을 형성할 수 있다. 이들의 예에서, 상기 (c) 단계에서, 상기 제1 전극을 상기 기판 하부에 형성하고, 상기 제2 전극을 상기 제2 도전형 반도체층 상부에 형성할 수 있다. In this case, the substrate may be a GaAs, GaP or InP substrate, and in step (a), a plurality of three-dimensional structures spaced apart from each other may be formed on the surface of the GaAs, GaP or InP substrate. The substrate may include a semiconductor layer including at least one of an undoped semiconductor layer and a first conductivity type semiconductor layer on a GaAs, GaP, or InP substrate, and spaced apart from each other on the surface of the semiconductor layer in step (a). It can form a three-dimensional structure of. In these examples, in the step (c), the first electrode may be formed below the substrate, and the second electrode may be formed above the second conductive semiconductor layer.
또한, 상기 (a) 단계에서, 상기 3차원 구조물을 종방향으로 폭이 변화하는 원형의 횡단면을 갖도록 형성할 수 있다.In addition, in the step (a), the three-dimensional structure may be formed to have a circular cross section of the width varies in the longitudinal direction.
상기 다른 목적을 달성하기 위한 본 발명의 다른 실시예에 따른 3차원 장파장 발광다이오드 제조 방법은 (a) 기판 표면에 서로 이격된 복수의 3차원 구조물을 형성하는 단계; (b) 상기 복수의 3차원 구조물이 형성된 기판 표면에 희생층을 형성하는 단계; (c) 상기 희생층이 형성된 기판 표면에, 제1 도전형 반도체층, AlGaInP 또는 AlGaAs를 포함하여 600nm 이상의 파장을 갖는 광을 방출하는 활성층 및 제2 도전형 반도체층을 포함하는 발광 구조체를 형성하는 단계; (d) 상기 제2 도전형 반도체층 표면에 도전성 기판을 부착하고 상기 희생층을 제거하여 상기 기판을 분리하는 단계; 및 (e) 상기 희생층이 제거되어 노출되는 제1 도전형 반도체층에 전기적으로 연결되는 제1 전극을 형성하는 단계;를 포함하고, 상기 (b) 단계 및 (c) 단계에서, 상기 희생층 및 상기 활성층을 포함한 발광 구조체 형성시에 상기 3차원 구조물이 형성된 기판의 표면 형상을 유지하는 것을 특징으로 한다. According to another aspect of the present invention, there is provided a method of manufacturing a three-dimensional long wavelength light emitting diode, the method comprising: (a) forming a plurality of three-dimensional structures spaced apart from each other on a substrate surface; (b) forming a sacrificial layer on a surface of the substrate on which the plurality of three-dimensional structures are formed; (c) forming a light emitting structure including a first conductive semiconductor layer, an active layer that emits light having a wavelength of 600 nm or more, including AlGaInP or AlGaAs, and a second conductive semiconductor layer on a surface of the substrate on which the sacrificial layer is formed; step; (d) attaching a conductive substrate to the surface of the second conductivity type semiconductor layer and removing the sacrificial layer to separate the substrate; And (e) forming a first electrode electrically connected to the first conductivity-type semiconductor layer to which the sacrificial layer is removed and exposed. In the steps (b) and (c), the sacrificial layer is formed. And maintaining the surface shape of the substrate on which the three-dimensional structure is formed when the light emitting structure including the active layer is formed.
이때, 상기 기판은 GaAs, GaP 또는 InP 기판이고, 상기 (a) 단계에서 GaAs, GaP 또는 InP 기판 표면에 서로 이격된 복수의 3차원 구조물을 형성할 수 있다. 또한, 상기 기판은 GaAs, GaP 또는 InP 기판에 비도핑 반도체층 및 제1 도전형 반도체층 중 하나 이상을 포함하는 반도체층이 형성된 것이고, 상기 (a) 단계에서 상기 반도체층 표면에 서로 이격된 복수의 3차원 구조물을 형성할 수 있다. In this case, the substrate may be a GaAs, GaP or InP substrate, and in step (a), a plurality of three-dimensional structures spaced apart from each other may be formed on the surface of the GaAs, GaP or InP substrate. The substrate may include a semiconductor layer including at least one of an undoped semiconductor layer and a first conductivity type semiconductor layer on a GaAs, GaP, or InP substrate, and spaced apart from each other on the surface of the semiconductor layer in step (a). It can form a three-dimensional structure of.
또한, 상기 (a) 단계에서, 상기 3차원 구조물을 종방향으로 폭이 변화하는 원형의 횡단면을 갖도록 형성할 수 있다.In addition, in the step (a), the three-dimensional structure may be formed to have a circular cross section of the width varies in the longitudinal direction.
또한, 상기 희생층은 AlAs 재질로 형성될 수 있다. In addition, the sacrificial layer may be formed of AlAs.
또한, 상기 (d) 단계에서, 상기 도전성 기판 부착은 상기 제2 도전형 반도체층 상에 추가의 제2 도전형 반도체층을 형성한 후, 실리콘 기판 또는 금속 기판을 도전성 접착제로 부착하는 방법으로 수행될 수 있다.In addition, in the step (d), attaching the conductive substrate is performed by forming an additional second conductive semiconductor layer on the second conductive semiconductor layer, and then attaching a silicon substrate or a metal substrate with a conductive adhesive. Can be.
본 발명에 따른 3차원 장파장 발광다이오드 및 그 제조 방법에 의하면, 다음과 같은 효과를 얻을 수 있다. According to the three-dimensional long wavelength light emitting diode according to the present invention and a manufacturing method thereof, the following effects can be obtained.
우선, 기판의 3차원 구조의 표면에 의해, 효율적으로 횡방향 성장이 가능하여, 종래의 평면 기판 구조에 비해 휨값(bow value)을 현저히 낮출 수 있어 고품질의 발광 구조체 형성이 가능하다. 이에 따라, 활성층의 유효면적 증가와 더불어, 빠른 횡방향 성장에 의한 스트레스 감소를 통한 높은 발광효율을 얻을 수 있고, 제2 도전형 반도체층 표면의 유효면적 증가에 의해서 낮은 구동전압을 가질 수 있다. 또한, 활성층의 상부면과 3차원 구조물의 측면에서 성장되는 활성층의 두께를 균일하게 할 수 있어서, 활성층에서 단일 파장의 광을 방출할 수 있다. First, the surface of the three-dimensional structure of the substrate enables efficient lateral growth, which significantly lowers the bow value as compared to the conventional planar substrate structure, thereby enabling the formation of a high-quality light emitting structure. Accordingly, in addition to increasing the effective area of the active layer, it is possible to obtain high luminous efficiency by reducing stress due to rapid lateral growth, and to have a low driving voltage by increasing the effective area of the surface of the second conductivity-type semiconductor layer. In addition, the thickness of the active layer grown on the upper surface of the active layer and the side of the three-dimensional structure can be made uniform, so that light of a single wavelength can be emitted from the active layer.
또한, 본 발명에서는 기판을 직접 식각하여 표면에 3차원 구조를 형성할 수 있는데, 이 경우 기판의 풍부한 물질제공으로 3차원 발광 구조체의 형성 자유도가 증가하여 최적화가 가능하며, 에피 박막 형성 도중에 식각하는 방식에 수반되는 성장 중단에 따른 에피 박막의 오염문제를 해결할 수 있다. 아울러, 기판 식각시 공정자유도가 대폭 증가할 수 있다. 즉, 에피 박막을 식각할 경우에 포토레지스터 마스크가 식각에 의해 완전히 제거된 직후 식각을 바로 멈춰야만 하는 것에 비해, 기판을 식각할 경우에는 오버 에칭시에도 패턴이 그대로 유지될 수 있다. In addition, in the present invention, the substrate may be directly etched to form a three-dimensional structure on the surface. In this case, the degree of freedom of formation of the three-dimensional light emitting structure may be increased by providing abundant materials of the substrate, and thus optimization may be performed. It is possible to solve the problem of epi thin film contamination caused by the growth interruption. In addition, when the substrate is etched, the degree of freedom of processing may increase significantly. That is, when etching the epi thin film, the etching may be stopped immediately after the photoresist mask is completely removed by etching, whereas when etching the substrate, the pattern may be maintained even when overetching.
또한, 예를 들어 표면으로 향할수록 폭이 증가하는 원형의 횡단면을 갖는 오목부와 같이, 3차원 구조물이 종방향으로 폭이 변화하는 원형의 횡단면을 갖는 형태일 경우, 3차원 구조물 내의 모든 부분이 경사면으로 형성될 수 있다. 이에 따라, 그 위에 형성되는 에피 박막 역시 non-polar 성장이 가능하게 되어, 캐리어 재결합 확률이 증가하여 광출력이 증가될 수 있다.Also, if the three-dimensional structure is shaped like a circular cross section that changes in width in the longitudinal direction, such as a recess having a circular cross section that increases in width toward the surface, all parts within the three-dimensional structure It may be formed as an inclined surface. Accordingly, the epitaxial film formed thereon also enables non-polar growth, so that the probability of carrier recombination may increase, thereby increasing the light output.
또한, 기판의 복수의 3차원 구조물로서, 오목부와 더불어 볼록부가 형성되어 있는 경우, 에피 박막과 기판 사이에 공극이 자연적으로 형성될 수 있다. 기판 제거를 수반하는 수직형 구조의 발광다이오드 제조 과정에 있어, 이 공극이 기판을 제거할 때 식각 용액이 보다 용이하게 공급될 수 있는 채널로 이용될 수 있어, 기판 제거가 용이하다. 아울러, 제거된 기판은 다시 성장 기판으로 이용될 수 있다. In addition, as a plurality of three-dimensional structures of the substrate, when the convex portion is formed along with the concave portion, voids may be naturally formed between the epi thin film and the substrate. In the process of manufacturing a light emitting diode having a vertical structure involving substrate removal, the pores can be used as a channel through which an etching solution can be more easily supplied when removing the substrate, thereby facilitating substrate removal. In addition, the removed substrate may be used as a growth substrate again.
또한, 활성층의 3차원 구조물의 경사면과 3차원 구조물의 외곽면의 두께를 동일하게 하는 경우, 동일 두께로 인해 활성층 에너지 밴드갭이 동일하여 동일 파장의 방출이 가능하다.In addition, when the inclined surface of the three-dimensional structure of the active layer and the thickness of the outer surface of the three-dimensional structure to the same, the same thickness, the active layer energy bandgap is the same, it is possible to emit the same wavelength.
도 1은 본 발명의 실시예에 따른 3차원 장파장 발광다이오드를 개략적으로 나타낸 것이다. 1 schematically shows a three-dimensional long wavelength light emitting diode according to an embodiment of the present invention.
도 2는 본 발명의 다른 실시예에 따른 3차원 장파장 발광다이오드를 개략적으로 나타낸 것이다.2 schematically shows a three-dimensional long wavelength light emitting diode according to another embodiment of the present invention.
도 3은 본 발명에 적용되는 기판의 예를 나타낸 것이다. 3 shows an example of a substrate applied to the present invention.
도 4는 본 발명에 적용되는 기판의 다른 예를 나타낸 것이다.4 shows another example of a substrate applied to the present invention.
도 5는 기판에 3차원 구조물로서 오목부가 형성된 예를 나타내는 것으로, (a)는 평면도를 (b)는 단면도를 나타낸다.Fig. 5 shows an example in which a recess is formed as a three-dimensional structure on a substrate, where (a) is a plan view and (b) is a sectional view.
도 6은 본 발명에 따른 3차원 장파장 발광다이오드에 있어서, 활성층에서 광이 방출되는 것을 개략적으로 나타낸 것이다.Figure 6 schematically shows the light emitted from the active layer in the three-dimensional long wavelength light emitting diode according to the present invention.
도 7 내지 도 9는 도 1에 도시된 3차원 장파장 발광다이오드를 제조하는 과정을 개략적으로 나타낸 것이다.7 to 9 schematically illustrate a process of manufacturing the 3D long wavelength light emitting diode shown in FIG. 1.
도 10 내지 도 14는 도 2에 도시된 3차원 장파장 발광다이오드를 제조하는 과정을 개략적으로 나타낸 것이다.10 to 14 schematically illustrate a process of manufacturing the 3D long wavelength light emitting diode shown in FIG. 2.
도 15는 기판에 3차원 구조물로서 오목부가 형성된 다른 예를 나타낸 것이다.15 shows another example in which a recess is formed as a three-dimensional structure on a substrate.
도 16은 도 15의 기판을 이용한 3차원 장파장 발광다이오드의 예를 개략적으로 나타낸 것이다.FIG. 16 schematically illustrates an example of a 3D long wavelength light emitting diode using the substrate of FIG. 15.
도 17은 도 15의 기판을 이용한 3차원 장파장 발광다이오드의 다른 예를 개략적으로 나타낸 것이다.FIG. 17 schematically illustrates another example of a 3D long wavelength light emitting diode using the substrate of FIG. 15.
이하, 첨부된 도면을 참조하여 본 발명에 따른 3차원 장파장 발광다이오드 및 그 제조 방법에 관하여 설명하기로 한다.Hereinafter, a 3D long wavelength light emitting diode and a method of manufacturing the same according to the present invention will be described with reference to the accompanying drawings.
본 발명에서, 3차원이라 함은 기판 및 반도체층의 표면이 평탄한 것과 대비되는 개념으로, 기판이나 반도체층의 표면에 오목부 또는 볼록부가 형성되어 있거나 또는 오목부와 볼록부 모두가 형성되어 있는 것을 의미한다. 본 발명에서 3차원 구조물은 오목부들 또는 볼록부들을 포함할 수 있으며, 오목부와 볼록부를 모두 포함할 수 있다. 이하에서는, 주로 3차원 구조물로서 오목부들을 포함하는 예를 들어 설명하나, 3차원 구조물로서 볼록부들을 포함하거나 오목부와 볼록부 모두를 포함할 수 있다. In the present invention, the term "three-dimensional" is a concept in which the surface of the substrate and the semiconductor layer is flat, and the recess or the convex portion is formed on the surface of the substrate or the semiconductor layer, or both the recess and the convex portion are formed. it means. In the present invention, the three-dimensional structure may include concave portions or convex portions, and may include both concave portions and convex portions. In the following, an example is described mainly including concave portions as a three-dimensional structure, but may include convex portions or include both concave and convex portions as a three-dimensional structure.
또한, 본 발명에서, 장파장 발광다이오드라 함은, 활성층에서 방출되는 광의 파장이 600nm, 650nm, 850nm, 940nm 등과 같이, 활성층에서 방출되는 광의 파장이 600nm 이상인 발광다이오드를 의미한다. 이러한 장파장 발광다이오드는 적색 발광다이오드, 적외선 발광다이오드가 해당될 수 있다. In addition, in the present invention, the long wavelength light emitting diode means a light emitting diode having a wavelength of light emitted from the active layer of 600 nm or more, such as 600 nm, 650 nm, 850 nm, 940 nm, or the like. The long wavelength light emitting diode may correspond to a red light emitting diode and an infrared light emitting diode.
도 1은 본 발명의 실시예에 따른 3차원 장파장 발광다이오드를 개략적으로 나타낸 것이다. 1 schematically shows a three-dimensional long wavelength light emitting diode according to an embodiment of the present invention.
도 1을 참조하면, 도시된 3차원 장파장 발광다이오드(100)는 기판(110), 제1 도전형 반도체층(120), 활성층(130), 제2 도전형 반도체층(140), 제1 전극(160) 및 제2 전극(150)을 포함한다. Referring to FIG. 1, the illustrated three-dimensional long wavelength light emitting diode 100 includes a substrate 110, a first conductive semiconductor layer 120, an active layer 130, a second conductive semiconductor layer 140, and a first electrode. 160 and the second electrode 150.
기판(110)의 표면에는 종단면이 곡면인 부분을 포함하고 서로 이격된 복수의 3차원 구조물이 형성되어 있다. 3차원 구조물의 외곽면들은 서로 연결된 면이다. 도 1에는 3차원 구조물(115)이 오목부들로 형성된 예가 나타나 있으나, 3차원 구조물(115)은 볼록부들로 형성되거나, 오목부와 함께 볼록부를 포함할 수도 있다. On the surface of the substrate 110, a plurality of three-dimensional structures including a portion having a curved longitudinal section and spaced apart from each other are formed. The outer surfaces of a three-dimensional structure are connected to each other. 1 shows an example in which the three-dimensional structure 115 is formed of concave portions, the three-dimensional structure 115 may be formed of convex portions, or may include convex portions together with the concave portions.
기판(110)은 도 3에 도시된 예와 같이, GaAs, GaP 또는 InP 기판(101)일 수 있다. 이 경우, 3차원 구조물은 GaAs, GaP 또는 InP 기판(101)에 형성된다. The substrate 110 may be a GaAs, GaP or InP substrate 101, as shown in the example shown in FIG. 3. In this case, the three-dimensional structure is formed on the GaAs, GaP or InP substrate 101.
또한, 기판(110)은 도 4에 도시된 예와 같이, GaAs, GaP 또는 InP 기판(101)에 비도핑 반도체층 및 제1 도전형 반도체층 중 하나 이상의 반도체층(102)이 형성된 것일 수 있다. 이 경우, 3차원 구조물은 반도체층(102)에 형성될 수 있다. In addition, as illustrated in FIG. 4, the substrate 110 may include one or more semiconductor layers 102 of an undoped semiconductor layer and a first conductivity type semiconductor layer formed on a GaAs, GaP, or InP substrate 101. . In this case, the three-dimensional structure may be formed in the semiconductor layer 102.
제1 도전형 반도체층(120)은 기판(110)의 표면에 형성된다. 물론 공지된 바와 같이 기판(110)과 제1 도전형 반도체층(120) 사이에는 버퍼층, 비도핑 반도체층 등 결정성 향상을 위한 추가의 반도체층이 더 형성될 수 있다. 예를 들어, 제1 도전형 반도체층(120)은 Si와 같은 n형 불순물이 도핑된 III(Ga, Al, In)-V(P, As) 반도체로 형성되고, 제2 도전형 반도체층(140)은 Mg와 같은 p형 불순물이 도핑된 III-V 반도체로 형성될 수 있다. 물론, 그 반대도 가능하다. The first conductivity type semiconductor layer 120 is formed on the surface of the substrate 110. As is well known, an additional semiconductor layer may be further formed between the substrate 110 and the first conductivity-type semiconductor layer 120 to improve crystallinity, such as a buffer layer and an undoped semiconductor layer. For example, the first conductive semiconductor layer 120 is formed of a III (Ga, Al, In) -V (P, As) semiconductor doped with n-type impurities such as Si, and the second conductive semiconductor layer ( 140 may be formed of a III-V semiconductor doped with a p-type impurity such as Mg. Of course, the opposite is also possible.
활성층(130)은 제1 도전형 반도체층(120)의 표면에 형성되며, AlGaInP 또는 AlGaAs를 포함하여 600nm 이상의 파장을 갖는 광을 방출한다. 활성층(130)은 바람직하게는 적색광 또는 적외선을 방출할 수 있다. 활성층(130)은 우물층과 장벽층이 교대로 적층된 양자우물구조로 형성될 수 있다. The active layer 130 is formed on the surface of the first conductive semiconductor layer 120 and emits light having a wavelength of 600 nm or more, including AlGaInP or AlGaAs. The active layer 130 may preferably emit red light or infrared light. The active layer 130 may be formed of a quantum well structure in which a well layer and a barrier layer are alternately stacked.
제2 도전형 반도체층(140)은 활성층(130)의 표면에 형성된다. The second conductivity type semiconductor layer 140 is formed on the surface of the active layer 130.
도 1을 참조하면, 제1 도전형 반도체층(120)의 두께가 제2 도전형 반도체층(140)의 두께보다 더 크고, 제2 도전형 반도체층(140)의 두께가 활성층(130)의 두께보다 더 클 수 있으나, 반드시 이에 제한되는 것은 아니다. Referring to FIG. 1, the thickness of the first conductivity-type semiconductor layer 120 is greater than that of the second conductivity-type semiconductor layer 140, and the thickness of the second conductivity-type semiconductor layer 140 is greater than that of the active layer 130. It may be larger than the thickness, but is not necessarily limited thereto.
제1 전극(160)은 제1 도전형 반도체층(120)에 전기적으로 연결된다. 그리고, 제2 전극(150)은 제2 도전형 반도체층(140)에 전기적으로 연결된다. 도 1에 도시된 예와 같이, 제2 전극(150)은 제2 도전형 반도체층(140) 상부에 형성될 수 있고, 제1 전극(160)은 기판(110) 이면에 형성될 수 있다. 예를 들어 GaAs, InP 등의 기판의 경우 반도성 혹은 도핑이 되어 있는 경우, 전도성을 나타낼 수 있다. 이에, 메사 식각에 의해 제1 반도체층이 노출되는 부분에 제1 전극을 형성함으로써 활성층 면적을 감소시키는 종래의 수평형 구조보다는, 도 1에 도시된 예와 같이 기판(110) 이면에 제1 전극(160)을 형성함으로써 충분한 활성층 면적을 유지하는 것이 보다 바람직하다. The first electrode 160 is electrically connected to the first conductivity type semiconductor layer 120. The second electrode 150 is electrically connected to the second conductive semiconductor layer 140. As illustrated in FIG. 1, the second electrode 150 may be formed on the second conductive semiconductor layer 140, and the first electrode 160 may be formed on the back surface of the substrate 110. For example, a substrate such as GaAs, InP, or the like may exhibit conductivity when semi-conductive or doped. Accordingly, the first electrode is formed on the back surface of the substrate 110 as shown in FIG. 1, rather than a conventional horizontal structure in which the area of the first semiconductor layer is exposed by mesa etching to reduce the active layer area. It is more preferable to maintain a sufficient active layer area by forming 160.
제1 전극(160)과 제2 전극(150)은 공지된 Ag, Au, Ni 등으로 단층 혹은 다층으로 형성될 수 있다. The first electrode 160 and the second electrode 150 may be formed of a single layer or a multilayer of known Ag, Au, Ni, or the like.
본 발명에 따른 3차원 장파장 발광다이오드에 의하면, 제2 전극(150)이 기판(110)의 표면 형상을 유지하는 제2 도전형 반도체층(140)에 접촉된다. 이를 통하여, 반도체층과 전극 간의 결합면적이 증대되고, 이에 의해 접촉저항이 감소됨으로써 구동전압이 감소될 수 있다. According to the 3D long wavelength light emitting diode according to the present invention, the second electrode 150 is in contact with the second conductivity type semiconductor layer 140 maintaining the surface shape of the substrate 110. As a result, the coupling area between the semiconductor layer and the electrode is increased, whereby the contact resistance is reduced, thereby reducing the driving voltage.
본 발명의 경우, 제1 도전형 반도체층(120), 활성층(130) 및 제2 도전형 반도체층(140) 기판(110)의 표면 형상, 즉 서로 이격된 3차원 구조물이 존재하는 형상을 유지하는 것이 특징이다. In the present invention, the surface shape of the first conductive semiconductor layer 120, the active layer 130, and the second conductive semiconductor layer 140, the substrate 110, that is, the shape in which the three-dimensional structures spaced apart from each other exist. It is characteristic.
이를 위해 기판(110)에는 서로 이격된 복수의 3차원 구조물(115)이 형성된다. To this end, a plurality of three-dimensional structures 115 spaced apart from each other are formed on the substrate 110.
도 5는 기판에 3차원 구조물로서 오목부가 형성된 예를 나타내는 것으로, (a)는 평면도를 (b)는 단면도를 나타낸다.Fig. 5 shows an example in which a recess is formed as a three-dimensional structure on a substrate, where (a) is a plan view and (b) is a sectional view.
도 5의 (a) 및 (b)를 참조하면, 기판 표면(510)에 측면(521)과 바닥면(522)을 갖는 오목부 형태의 3차원 구조물이 형성된다. 바닥면의 경우 도 15에 도시된 예와 같이 생략될 수 있다. 이때, 3차원 구조물은 종단면이 곡면인 부분을 포함한다. Referring to FIGS. 5A and 5B, a three-dimensional structure in the form of a recess having a side surface 521 and a bottom surface 522 is formed on the substrate surface 510. The bottom surface may be omitted as in the example shown in FIG. 15. At this time, the three-dimensional structure includes a portion whose longitudinal section is curved.
또한, 오목부는 도 5의 (b)에 도시된 예와 같이, 표면으로 향할수록 폭이 증가하는 원형의 횡단면을 가질 수 있다. 반면, 볼록부의 경우, 상부로 향할수록 폭이 좁아지는 원형의 횡단면을 가질 수 있다. 즉, 3차원 구조물은 종방향으로 폭이 변화할 수 있다. 이러한 형태의 3차원 구조물의 경우, 3차원 구조물 내의 모든 부분이 곡면을 포함하는 경사면으로 형성될 수 있고 이에 따라, 그 위에 형성되는 에피 박막 역시 non-polar 성장이 가능하게 되어, 캐리어 재결합 확률이 증가하여 광출력이 증가될 수 있다. In addition, the recess may have a circular cross section that increases in width toward the surface, as in the example shown in FIG. On the other hand, the convex portion may have a circular cross section that becomes narrower toward the top. That is, the three-dimensional structure may vary in width in the longitudinal direction. In this type of three-dimensional structure, all parts in the three-dimensional structure can be formed as a slope including a curved surface, and thus the epi thin film formed thereon also enables non-polar growth, thereby increasing the probability of carrier recombination. The light output can be increased.
한편, 도 6에 도시된 예와 같이, 기판의 3차원 구조물에 기인한 활성층의 3차원 구조물(132, 133)은 폭(W)이 높이(H)의 3배 이상인, 납작한 구조를 갖는 것이 바람직하다. 반구형 3차원 구조물의 경우 폭이 높이의 2배인 점을 고려하면, 본 발명에 따른 3차원 구조물은 납작한 형태를 가질 수 있다. 이러한 납작한 형태를 통하여, 활성층의 3차원 구조물의 경사면과 3차원 구조물의 외곽면의 두께를 동일하게 하는 것이 보다 용이해질 수 있다.On the other hand, as shown in Figure 6, it is preferable that the three-dimensional structure (132, 133) of the active layer due to the three-dimensional structure of the substrate has a flat structure, the width (W) is three times or more the height (H). Do. Considering that the width of the hemispherical three-dimensional structure is twice the height, the three-dimensional structure according to the present invention may have a flat shape. Through such a flat shape, it may be easier to equalize the thickness of the inclined surface of the three-dimensional structure of the active layer and the outer surface of the three-dimensional structure.
전술한 바와 같이, 성장 기판으로는 C축 성장기판이 가장 일반적으로 이용되는데, C축 성장기판 위에 성장된 3-5족 화합물의 내부 분극(polar) 작용에 의해 활성층 내에 존재하는 정공과 전자는 서로 이격되게 분포하여, 재결합 확률이 저하되어 광출력이 감소되는 문제점이 있다. 그러나, 본 발명의 경우, non-polar 성장이 많이 포함되는 바, 종래에 비하여 활성층에서의 캐리어 재결합 확률을 높일 수 있다. As described above, a C-axis growth substrate is most commonly used as a growth substrate, and holes and electrons present in the active layer are mutually different due to internal polarization of the Group 3-5 compound grown on the C-axis growth substrate. Distributed apart, there is a problem that the recombination probability is lowered to reduce the light output. However, in the case of the present invention, since the non-polar growth is much included, it is possible to increase the probability of carrier recombination in the active layer compared to the conventional.
이와 같은 기판(110)의 3차원 구조의 표면에 의해, 효율적으로 횡방향 성장이 가능하여, 종래의 평면 기판 구조에 비해 휨값(bow value)을 현저히 낮출 수 있어 고품질의 발광 구조체 형성이 가능하다. 이에 따라, 활성층(130)의 유효면적 증가와 더불어, 빠른 횡방향 성장에 의한 스트레스 감소를 통한 높은 발광효율을 얻을 수 있고, 제2 도전형 반도체층(140) 표면의 유효면적 증가에 의해서 낮은 구동전압을 가질 수 있다. Such a three-dimensional surface of the substrate 110 enables efficient lateral growth, and significantly lowers bow value compared to a conventional planar substrate structure, thereby enabling the formation of a high quality light emitting structure. Accordingly, in addition to increasing the effective area of the active layer 130, a high luminous efficiency can be obtained by reducing stress due to rapid lateral growth, and low driving by increasing the effective area of the surface of the second conductive semiconductor layer 140 May have a voltage.
결국, 본 발명에 따른 3차원 장파장 발광다이오드의 경우, 3차원 구조물 등에서 형성된 에피층이 non-polar 성장되어 활성층을 포함하는 에피층　내에서 스트레스가 감소되며, 이로 인해 활성층에서의 전자와 재결합 확률이 현저히 증가된다.　3차원 구조물 상부 등에서 Non-polar 성장이 적용된 활성층 부분의 단위 면적당 광 방출량의 경우, 3차원 구조물과 3차원 구조물 사이와 같은 일반 평탄 영역에서의 단위 면적당 광 방출량보다 현저히 높아질 수 있다. As a result, in the three-dimensional long wavelength light emitting diode according to the present invention, the epi layer formed in the three-dimensional structure or the like is non-polarly grown, so that the stress in the epi layer 하는 including the active layer is reduced, thereby increasing the probability of electrons and recombination in the active layer. Significantly increased. In the case of the light emission amount per unit area of the active layer portion to which the non-polar growth is applied in the upper part of the three-dimensional structure, the amount of light emission per unit area in the general flat region such as between the three-dimensional structure and the three-dimensional structure may be significantly higher.
또한, 활성층(130)의 상부면, 즉 3차원 구조물(115)의 외곽면과 3차원 구조물(115)의 경사면(도 5의 521)에서 성장되는 활성층의 두께를 동일하게 하는 것이 보다 바람직하다. 활성층의 3차원 구조물의 경사면과 3차원 구조물의 외곽면의 두께를 동일하게 하는 경우, 동일 두께로 인해 활성층 에너지 밴드갭이 동일하여 단일 파장의 방출이 가능하다. 이는 측면성장이 상부면 보다 빠른 것을 의미하는 것이고, 동일 두께로 인해 활성층 에너지 밴드갭이 동일하여 동일 파장이 가능하다. 그리고, 활성층의 우물층 두께가 두꺼우면 에너지 밴드갭이 작아져서 장파장 발광이 이루어진다.In addition, it is more preferable that the thickness of the active layer grown on the upper surface of the active layer 130, that is, the outer surface of the three-dimensional structure 115 and the inclined surface (521 of FIG. 5) of the three-dimensional structure 115 is the same. When the inclined surface of the three-dimensional structure of the active layer and the thickness of the outer surface of the three-dimensional structure are the same, the active layer energy bandgap is the same due to the same thickness it is possible to emit a single wavelength. This means that the lateral growth is faster than the upper surface, and because of the same thickness, the active layer energy bandgap is the same, so that the same wavelength is possible. In addition, when the thickness of the well layer of the active layer is thick, the energy band gap is reduced, and thus the long wavelength light emission is achieved.
양자우물구조의 에너지 밴드갭은 선택되는 물질의 고유값 뿐 아니라, 물질과 상관없이 그 양자우물구조의 물리적 두께에 반비례한다. 예를 들어 GaN 물질을 활성층으로 선택하면 벌크(양자우물구조에 비해 두께가 충분히 두꺼운 반도체층)에서는 3.4(eV)에 해당하는 에너지 밴드값을 물질특성으로 부여 받아, 3.4eV에 해당하는 광을 방출하지만, 양자구조로 채용된 GaN층은 두께를 얇게 형성하여 던 큰 에너지 밴드갭 3.4 + x (eV)만큼의 에너지 밴드갭을 나타낼 수 있다. 따라서 3차원 구조 상부와 측면에서 우물층 두께가 상이하면(일반적으로 상부가 측면에 비해 두꺼움), 상부와 측면에서의 우물층 에너지 밴드갭이 서로 상이하여 서로 다른 파장이 방출되나, 활성층의 상부와 측면의 우물층 두께가 동일하여 에너지 밴드갭이 동일하여 상부와 측면에서 동일한 파장의 광이 방출될 수 있다.The energy bandgap of a quantum well structure is inversely proportional to the physical thickness of the quantum well structure, regardless of the material, as well as the intrinsic value of the material selected. For example, if the GaN material is selected as the active layer, the bulk (semiconductor layer thicker than the quantum well structure) is given an energy band value of 3.4 (eV) as a material property and emits light corresponding to 3.4 eV. However, the GaN layer employed in the quantum structure may exhibit an energy band gap of as much as 3.4 + x (eV) due to a thin thickness. Therefore, if the thickness of the well layer is different at the top and side of the three-dimensional structure (generally, the top is thicker than the side), the energy band gaps at the top and the side are different from each other to emit different wavelengths. Since the thickness of the well layer on the side is the same, the energy band gap is the same, and light of the same wavelength may be emitted from the top and the side.
도 6은 본 발명에 따른 3차원 장파장 발광다이오드에 있어서, 활성층에서 광이 방출되는 것을 개략적으로 나타낸 것이다.Figure 6 schematically shows the light emitted from the active layer in the three-dimensional long wavelength light emitting diode according to the present invention.
도 6을 참조하면, 활성층(130)은 기판의 표면 형상을 유지하는 바, 활성층(130) 역시 3차원 구조물을 포함한다. 보다 구체적으로 활성층(130)은 3차원 구조물과 3차원 구조물 사이(131), 3차원 구조물의 측면(132) 및 3차원 구조물의 바닥면(133)을 포함한다. 3차원 구조물의 바닥면(133)은 도 15에 도시된 예와 같이 생략될 수 있다. 이때, 3차원 구조물과 3차원 구조물 사이(131) 및 3차원 구조물의 바닥면(133)에서는 제1 피크파장(λ1)이 방출되고, 3차원 구조물의 측면(132)에서는 제2 피크파장(λ2)이 방출된다. 본 발명의 경우, 전술한 바와 같이, 3차원 구조물의 측면과 그 외의 부분의 균일한 성장이 가능하여, 제1 피크파장(λ1)과 제2 피크파장(λ2)의 차이가 10% 이내, 보다 바람직하게는 5% 이내가 될 수 있어, 활성층(130)을 통하여 균일한 파장의 광이 방출될 수 있다. Referring to FIG. 6, the active layer 130 maintains the surface shape of the substrate, and the active layer 130 also includes a three-dimensional structure. More specifically, the active layer 130 includes a three-dimensional structure and the three-dimensional structure (131), the side surface 132 of the three-dimensional structure and the bottom surface 133 of the three-dimensional structure. The bottom surface 133 of the three-dimensional structure may be omitted as shown in FIG. 15. At this time, the first peak wavelength λ1 is emitted between the 3D structure and the 3D structure 131 and the bottom surface 133 of the 3D structure, and the second peak wavelength λ2 at the side surface 132 of the 3D structure. ) Is released. In the case of the present invention, as described above, the side surface and other portions of the three-dimensional structure can be uniformly grown, so that the difference between the first peak wavelength lambda 1 and the second peak wavelength lambda 2 is within 10%. Preferably, it may be within 5%, and light having a uniform wavelength may be emitted through the active layer 130.
도 2는 본 발명의 다른 실시예에 따른 3차원 장파장 발광다이오드를 개략적으로 나타낸 것이다.2 schematically shows a three-dimensional long wavelength light emitting diode according to another embodiment of the present invention.
도 1에 도시된 구조의 3차원 장파장 발광다이오드(100)가 기판(110)이 존재하는 구조라면, 도 2에 도시된 구조의 3차원 장파장 발광다이오드(200)는 기판(110)이 제거된, 이른바 수직형 구조에 해당한다. If the three-dimensional long wavelength light emitting diode 100 of the structure shown in FIG. 1 is a structure in which the substrate 110 exists, the three-dimensional long wavelength light emitting diode 200 of the structure shown in FIG. 2 has the substrate 110 removed, It corresponds to a so-called vertical structure.
도 2를 참조하면, 도시된 3차원 장파장 발광다이오드는 위로부터, 제1 도전형 반도체층(120), 활성층(130) 및 제2 도전형 반도체층(140)을 포함한다. 그리고 기판이 제거된 대신에 제2 도전형 반도체층(140)의 표면에는 도전성 기판(210)이 부착되어 있다. 이러한 도전성 기판은 제2 도전형 반도체층과 전기적으로 연결되는 제2 전극의 역할을 할 수 있다. Referring to FIG. 2, the three-dimensional long wavelength light emitting diode illustrated from above includes a first conductive semiconductor layer 120, an active layer 130, and a second conductive semiconductor layer 140. Instead of the substrate being removed, the conductive substrate 210 is attached to the surface of the second conductive semiconductor layer 140. The conductive substrate may serve as a second electrode electrically connected to the second conductive semiconductor layer.
그리고, 제1 도전형 반도체층의 상부에는 제1 전극(220)이 형성될 수 있다. In addition, the first electrode 220 may be formed on the first conductive semiconductor layer.
예를 들어, GaAs 기판의 경우, 광 흡수성이 우수하여 활성층에서 하부 방향으로 방출되는 광의 많은 양이 상부 방향으로 반사되지 못하고 소실될 수 있다. 이에, 기판이 제거되고, 대신에 실리콘 기판 혹은 금속 기판과 같은 도전성 기판이 부착된 구조의 경우, 이러한 문제점을 해결할 수 있다. For example, in the case of GaAs substrates, the light absorption is excellent, so that a large amount of light emitted from the active layer in the downward direction may be lost without being reflected in the upward direction. Therefore, in the case of a structure in which the substrate is removed and a conductive substrate such as a silicon substrate or a metal substrate is attached instead, this problem can be solved.
도 2에 도시된 예의 경우, 제조 과정에서 기판 제거 및 상하 반전에 의하여 제1 도전형 반도체층(120)의 하부면에 종단면이 곡면인 부분을 포함하는 3차원 구조물(115)이 형성되어 있는 구조에 해당한다. 그리고, 활성층(130) 및 제2 도전형 반도체층(140) 각각은 이러한 하부면에 3차원 구조물이 형성되어 있는 제1 도전형 반도체층(120)의 표면 형상을 유지한다. In the example illustrated in FIG. 2, a three-dimensional structure 115 including a portion having a curved longitudinal section is formed on a lower surface of the first conductivity-type semiconductor layer 120 by removing a substrate and reversing up and down in the manufacturing process. Corresponds to Each of the active layer 130 and the second conductive semiconductor layer 140 maintains the surface shape of the first conductive semiconductor layer 120 having a three-dimensional structure formed on the lower surface thereof.
본 실시예의 경우, 기판 표면의 3차원 구조물(115)로, 오목부와 더불어 볼록부가 형성되어 있는 것이 보다 바람직하다. 기판에 오목부와 더불어 볼록부를 포함하는 3차원 구조물이 형성되어 있는 경우, 에피 박막과 기판 사이에 공극이 자연적으로 형성될 수 있다. 도 13에서와 같이 기판 제거를 수반하는 수직형 구조의 발광다이오드 제조 과정에 있어, 이 공극이 기판을 제거할 때 식각 용액이 보다 용이하게 공급될 수 있는 채널로 이용될 수 있어, 기판 제거가 용이하다. In this embodiment, it is more preferable that the convex portion is formed along with the concave portion in the three-dimensional structure 115 on the substrate surface. When the three-dimensional structure including the convex portion and the concave portion is formed in the substrate, voids may be naturally formed between the epi thin film and the substrate. In the process of manufacturing a light emitting diode having a vertical structure with substrate removal as shown in FIG. 13, this void can be used as a channel through which an etching solution can be more easily supplied when removing the substrate, thereby facilitating substrate removal. Do.
아울러, 제거된 기판은 다시 성장 기판으로 이용될 수 있다.In addition, the removed substrate may be used as a growth substrate again.
도 7 내지 도 9는 도 1에 도시된 3차원 장파장 발광다이오드를 제조하는 과정을 개략적으로 나타낸 것이다.7 to 9 schematically illustrate a process of manufacturing the 3D long wavelength light emitting diode shown in FIG. 1.
도 7을 참조하면, 우선, 기판(110) 표면에 종단면이 곡면인 부분을 포함하고 서로 이격된 복수의 3차원 구조물(115)을 형성한다. Referring to FIG. 7, first, a plurality of three-dimensional structures 115 including a portion having a curved longitudinal section and spaced apart from each other are formed on a surface of the substrate 110.
이러한 복수의 3차원 구조물의 경우, 포토레지스터 마스크를 이용한 식각 공정을 통하여 형성될 수 있다. In the case of the plurality of three-dimensional structures, it may be formed through an etching process using a photoresist mask.
본 발명에서는 기판(110)을 직접 식각하여 표면에 3차원 구조를 형성한다. 이 경우 기판(110)의 풍부한 물질 제공으로 3차원 발광 구조체(120~140)의 형성 자유도가 증가하여 최적화가 가능하다. In the present invention, the substrate 110 is directly etched to form a three-dimensional structure on the surface. In this case, the degree of freedom of formation of the 3D light emitting structures 120 to 140 may be increased by providing abundant materials of the substrate 110.
아울러, 볼록부 혹은 오목부의 형성을 위하여 에피 박막 형성 도중에 식각하는 방식의 경우, 성장 중단이 반드시 수반되는데, 이는 에피 박막의 오염문제를 유발한다. 그러나, 기판 자체에 3차원 구조물을 형성하는 경우, 이러한 문제점을 차단할 수 있다. In addition, in the case of the etching method during the formation of the convex portion or the concave portion, the growth stop is necessarily accompanied, which causes contamination of the epi thin film. However, when the three-dimensional structure is formed on the substrate itself, this problem can be prevented.
아울러, 기판 식각시 공정자유도가 대폭 증가할 수 있다. 즉, 에피 박막을 식각할 경우에 포토레지스터 마스크가 식각에 의해 완전히 제거된 직후 식각을 바로 멈춰야만 한다. 즉, 포토레지스터 마스크가 남겨진 상태에서 식각을 중지하게 되면 포토레지스터 마스크를 제외한 부분은 구조물 측면이 경사면으로 형성되는 것에 비해, 남겨진 포토레지스터 마스크 하부 부분을 식각되지 못해 평편한 구조물을 그대로 포함하고 있어서, 폴라면에서 에피층이 추가 성장하는 바 분극 문제를 해결하기 어렵다. 그러나, 기판을 식각할 경우에는 오버 에칭시에도 패턴이 그대로 유지될 수 있다. In addition, when the substrate is etched, the degree of freedom of processing may increase significantly. That is, when etching the epi thin film, the etching must be stopped immediately after the photoresist mask is completely removed by etching. That is, when the etching is stopped while the photoresist mask is left, the portion except the photoresist mask includes a flat structure because the side surface of the structure is formed as an inclined surface, and the left portion of the photoresist mask cannot be etched. The further growth of epilayers in the poly ramen makes it difficult to solve the polarization problem. However, when the substrate is etched, the pattern may be maintained even during over etching.
특히, 3차원 구조물(115)은 종방향으로 폭이 변화하는 원형의 횡단면을 갖도록 형성될 수 있다. 예를 들어 3차원 구조물(115)이 오목부라면, 상부 방향으로 향할수록 폭이 증가하는 원형의 횡단면을 갖도록 형성될 수 있다. 반대로, 3차원 구조물(115)이 볼록부라면, 상부 방향으로 향할수록 폭이 감소하는 원형의 횡단면을 갖도록 형성될 수 있다. In particular, the three-dimensional structure 115 may be formed to have a circular cross section that varies in width in the longitudinal direction. For example, if the three-dimensional structure 115 is a concave portion, it may be formed to have a circular cross section that increases in width toward the upper direction. On the contrary, if the three-dimensional structure 115 is a convex portion, it may be formed to have a circular cross section that decreases in width toward the upper direction.
기판이 도 3에 도시된 예와 같이, GaAs, GaP 또는 InP 기판일 경우, 본 단계에서 GaAs, GaP 또는 InP 기판 표면에 서로 이격된 복수의 3차원 구조물(115)을 형성할 수 있다. When the substrate is a GaAs, GaP or InP substrate, as shown in the example shown in FIG. 3, in this step, a plurality of three-dimensional structures 115 spaced apart from each other may be formed on the surface of the GaAs, GaP or InP substrate.
통상의 발광다이오드 제조시 이용되는 사파이어 기판의 경우, 내구성 및 화학적 안정성이 우수하나, 이러한 장점은 사파이어 기판 가공을 극히 어렵게 하는 바, 종래에는 기판 자체를 식각하여 3차원 표면을 형성할 수 없었던 것에 비해, 본 발명의 경우, 성장기판으로 예를 들어, GaAs 반도체 벌크 기판을 사용하여 손쉽게 가공이 가능하다.In the case of sapphire substrate used in the manufacture of a conventional light emitting diode, the durability and chemical stability is excellent, but this advantage makes the sapphire substrate processing extremely difficult, compared with the conventional substrate was not able to etch the substrate itself to form a three-dimensional surface In the case of the present invention, the growth substrate can be easily processed using, for example, a GaAs semiconductor bulk substrate.
또한, 기판이 도 4에 도시된 예와 같이, GaAs, GaP 또는 InP 기판(101)에 비도핑 반도체층 및 제1 도전형 반도체층 중 하나 이상을 포함하는 반도체층(102)이 형성된 것일 경우, 본 단계에서 반도체층(102) 표면에 서로 이격된 복수의 3차원 구조물(115)을 형성할 수 있다.In addition, when the substrate is formed of a semiconductor layer 102 including at least one of an undoped semiconductor layer and a first conductivity type semiconductor layer on the GaAs, GaP or InP substrate 101, as in the example shown in FIG. In this step, a plurality of three-dimensional structures 115 spaced apart from each other may be formed on the surface of the semiconductor layer 102.
다음으로, 도 8을 참조하면, 서로 이격된 복수의 3차원 구조물(115)이 형성된 기판(110) 표면에, 제1 도전형 반도체층(120), AlGaInP 또는 AlGaAs를 포함하여 600nm 이상의 파장을 갖는 광을 방출하는 활성층(130) 및 제2 도전형 반도체층(140)을 포함하는 발광 구조체를 형성한다. Next, referring to FIG. 8, the first conductive semiconductor layer 120, AlGaInP, or AlGaAs having a wavelength of 600 nm or more is formed on the surface of the substrate 110 on which the plurality of three-dimensional structures 115 are spaced apart from each other. A light emitting structure including an active layer 130 that emits light and a second conductive semiconductor layer 140 are formed.
발광 구조체는 이른 바 에피 박막 성장을 통하여 형성될 수 있고, MOCVD 방법, LPE 방법으로 형성될 수 있다. 보다 바람직하게는 성장 속도가 빠른 LPE 방법으로 발광 구조체가 형성되는 것이다. The light emitting structure may be formed through so-called epi thin film growth, and may be formed by a MOCVD method or an LPE method. More preferably, the light emitting structure is formed by an LPE method having a high growth rate.
이때, 활성층(130)을 포함한 발광 구조체 형성시 3차원 구조물이 형성된 기판의 표면 형상을 유지한다. At this time, when forming the light emitting structure including the active layer 130 maintains the surface shape of the substrate on which the three-dimensional structure is formed.
다음으로, 도 9를 참조하면, 발광 구조체 형성 후에, 제1 도전형 반도체층(120)에 전기적으로 연결되는 제1 전극(160) 및 제2 도전형 반도체층(140)에 전기적으로 연결되는 제2 전극(150)을 형성한다. Next, referring to FIG. 9, after the light emitting structure is formed, the first electrode 160 and the second conductive semiconductor layer 140 are electrically connected to the first conductive semiconductor layer 120. 2 electrodes 150 are formed.
도 9에 도시된 예와 같이, 제1 전극(160)을 기판(110) 하부에 형성하고, 제2 전극(150)을 상기 제2 도전형 반도체층(140) 상부에 형성할 수 있다. As shown in FIG. 9, the first electrode 160 may be formed under the substrate 110, and the second electrode 150 may be formed on the second conductive semiconductor layer 140.
도 10 내지 도 14는 도 2에 도시된 3차원 장파장 발광다이오드를 제조하는 과정을 개략적으로 나타낸 것이다.10 to 14 schematically illustrate a process of manufacturing the 3D long wavelength light emitting diode shown in FIG. 2.
도 10을 참조하면, 우선, 기판(110) 표면에, 종단면이 곡면인 부분을 포함하고 서로 이격된 복수의 3차원 구조물(115)을 형성한다. 본 단계와 관련되어서는 도 7에서 전술한 모든 사항이 적용될 수 있는 바, 그 상세한 설명을 생략한다. Referring to FIG. 10, first, a plurality of three-dimensional structures 115 including a portion having a curved longitudinal section and spaced apart from each other are formed on a surface of the substrate 110. In relation to this step, all of the above-described matters in FIG. 7 may be applied, and thus a detailed description thereof will be omitted.
다음으로 도 11을 참조하면, 복수의 3차원 구조물이 형성된 기판 표면에 희생층(201)을 형성한다. Next, referring to FIG. 11, a sacrificial layer 201 is formed on a surface of a substrate on which a plurality of three-dimensional structures are formed.
희생층(201)은 기판(110) 제거를 위한 것으로, 미리 정해진 식각 용액에 선택적으로 용해될 수 있는 물질이 이용된다. The sacrificial layer 201 is for removing the substrate 110, and a material that can be selectively dissolved in a predetermined etching solution is used.
바람직하게는 AlAs 재질의 희생층을 제시할 수 있다. AlAs의 경우, HF 용액에 선택적으로 식각될 수 있어, 희생층으로 사용하기에 적합하다. Preferably, a sacrificial layer of AlAs material may be provided. In the case of AlAs, it can be selectively etched in HF solution, making it suitable for use as a sacrificial layer.
다음으로, 도 12를 참조하면, 희생층이 형성된 기판 표면에, 제1 도전형 반도체층, AlGaInP 또는 AlGaAs를 포함하여 600nm 이상의 파장을 갖는 광을 방출하는 활성층 및 제2 도전형 반도체층을 포함하는 발광 구조체를 형성한다. 본 단계와 관련되어서는 도 8에서 전술한 모든 사항이 적용될 수 있는 바, 그 상세한 설명을 생략한다.Next, referring to FIG. 12, on the substrate surface on which the sacrificial layer is formed, an active layer and a second conductivity type semiconductor layer including a first conductivity type semiconductor layer, AlGaInP or AlGaAs, which emit light having a wavelength of 600 nm or more, are included. A light emitting structure is formed. In relation to this step, all of the above-described matters in FIG. 8 may be applied, and thus a detailed description thereof will be omitted.
본 단계에서, 활성층(130)을 포함한 발광 구조체 형성시, 그리고 희생층(201)의 형성시, 3차원 구조물(115)이 형성된 기판의 표면 형상을 유지한다.In this step, when the light emitting structure including the active layer 130 and the sacrificial layer 201 is formed, the surface shape of the substrate on which the three-dimensional structure 115 is formed is maintained.
다음으로, 도 13에 도시된 예와 같이, 제2 도전형 반도체층(140) 표면에 도전성 기판(210)을 부착하고, AlAs 재질 등의 희생층(201)을 HF 용액 등의 식각 용액으로 제거하여 기판(110)을 분리한다.Next, as shown in FIG. 13, the conductive substrate 210 is attached to the surface of the second conductivity-type semiconductor layer 140, and the sacrificial layer 201, such as an AlAs material, is removed by an etching solution such as an HF solution. The substrate 110 is separated.
도전성 기판(210)은 제2 도전형 반도체층(140)과 전기적으로 연결되는 제2 전극으로 작용할 수 있다. The conductive substrate 210 may function as a second electrode electrically connected to the second conductive semiconductor layer 140.
이때, 도전성 기판(210) 부착은 제2 도전형 반도체층 상에 예를 들어, p-GaP와 같은 추가의 제2 도전형 반도체층(미도시)을 형성한 후, 그 위에 실리콘 기판 또는 금속 기판을 도전성 접착제로 부착하는 방법으로 수행될 수 있다. At this time, attaching the conductive substrate 210 forms an additional second conductive semiconductor layer (not shown) such as, for example, p-GaP on the second conductive semiconductor layer, and then a silicon substrate or a metal substrate thereon. To a conductive adhesive.
다음으로, 도 14에 도시된 예와 같이, 희생층(201)이 제거되어 노출되는 제1 도전형 반도체층(120)에 전기적으로 연결되는 제1 전극(220)을 형성한다. Next, as shown in the example of FIG. 14, the sacrificial layer 201 is removed to form a first electrode 220 electrically connected to the first conductive semiconductor layer 120 exposed.
도 15는 기판에 3차원 구조물이 형성된 다른 예를 나타낸 것이다. 또한, 도 16은 도 15의 기판을 이용한 3차원 장파장 발광다이오드의 예를 개략적으로 나타낸 것이고, 도 17은 도 15의 기판을 이용한 3차원 장파장 발광다이오드의 다른 예를 개략적으로 나타낸 것이다.15 shows another example in which a three-dimensional structure is formed on a substrate. In addition, FIG. 16 schematically illustrates an example of a 3D long wavelength light emitting diode using the substrate of FIG. 15, and FIG. 17 schematically illustrates another example of a 3D long wavelength light emitting diode using the substrate of FIG. 15.
도 16에 도시된 구조는 3차원 구조물의 형상을 제외하고는 도 1에 도시된 구조와 거의 동일하고, 도 17에 도시된 구조는 3차원 구조물의 형상을 제외하고는 도 2에 도시된 구조와 거의 동일한 바, 여기서는 그 상세한 설명을 생략한다. The structure shown in FIG. 16 is substantially the same as the structure shown in FIG. 1 except for the shape of the three-dimensional structure, and the structure shown in FIG. 17 is identical to the structure shown in FIG. 2 except for the shape of the three-dimensional structure. Since they are almost the same, detailed description thereof is omitted here.
도 15에 도시된 예와 같이, 기판(110) 표면에 형성된 3차원 구조물(115)의 경우, 오목부로 형성되어 있는데, 오목부의 바닥면이 존재하지 않고, 오목부 전체가 곡면으로 형성될 수 있다. 또한, 3차원 구조물(115)이 볼록부로 형성되어 있는 경우에도 볼록부의 상면이 존재하지 않고, 볼록부 전체가 곡면으로 형성될 수 있다. 이 경우, 오목부 또는 볼록부에서의 에피 성장이 모두 non-polar 성장이 될 수 있어, 도 16에 도시된 장파장 발광다이오드 또는 도 17에 도시된 장파장 발광다이오드의 활성층에서의 전자와 전자의 재결합 확률이 현저히 높아질 수 있고, 이에 따라 광 방출 효율이 보다 높아질 수 있다.As shown in FIG. 15, in the case of the three-dimensional structure 115 formed on the surface of the substrate 110, the concave portion is formed, and the bottom surface of the concave portion does not exist, and the entire concave portion may be formed in a curved surface. . In addition, even when the three-dimensional structure 115 is formed as a convex portion, the upper surface of the convex portion does not exist, and the entire convex portion may be formed as a curved surface. In this case, both epitaxial growth in the concave portion or convex portion may be non-polar growth, and thus the probability of recombination of electrons and electrons in the active layer of the long wavelength light emitting diode shown in FIG. 16 or the long wavelength light emitting diode shown in FIG. This can be significantly higher, and thus the light emission efficiency can be higher.

Claims (25)

  1. 서로 이격된 복수의 3차원 구조물이 형성된 표면을 구비하는 제1 도전형 반도체층; A first conductivity type semiconductor layer having a surface on which a plurality of three-dimensional structures are spaced apart from each other;
    상기 제1 도전형 반도체층의 표면에 형성되며, AlGaInP 또는 AlGaAs를 포함하여 600nm 이상의 파장을 갖는 광을 방출하는 활성층;An active layer formed on a surface of the first conductivity type semiconductor layer and emitting light having a wavelength of 600 nm or more, including AlGaInP or AlGaAs;
    상기 활성층의 표면에 형성되는 제2 도전형 반도체층;A second conductivity type semiconductor layer formed on the surface of the active layer;
    상기 제2 도전형 반도체층 표면에 형성되는 도전성 기판;A conductive substrate formed on a surface of the second conductive semiconductor layer;
    상기 제1 도전형 반도체층에 전기적으로 연결되는 제1 전극;을 포함하고,And a first electrode electrically connected to the first conductive semiconductor layer.
    상기 복수의 3차원 구조물은 종단면이 곡면인 부분을 포함하고,The plurality of three-dimensional structure includes a portion of the longitudinal cross-section,
    상기 활성층 및 제2 도전형 반도체층 각각이 상기 제1 도전형 반도체층의 표면 형상을 유지하며,Each of the active layer and the second conductive semiconductor layer maintains the surface shape of the first conductive semiconductor layer,
    상기 활성층은 상기 제1 도전형 반도체층의 표면 형상을 유지하여, 활성층의 3차원 구조물과 3차원 구조물의 사이에서 제1 피크파장을 갖는 광을 방출함과 더불어 활성층의 3차원 구조물의 측면에서 제2 피크파장을 갖는 광을 방출하되, 상기 활성층의 3차원 구조물의 측면에서의 단위면적당 광 방출량이 상기 활성층의 3차원 구조물과 3차원 구조물의 사이에서의 단위면적당 광 방출량보다 더 크며, 상기 제1 피크파장과 제2 피크파장의 차이가 10% 이내인 것을 특징으로 하는 3차원 장파장 발광다이오드.The active layer maintains the surface shape of the first conductivity-type semiconductor layer, and emits light having a first peak wavelength between the three-dimensional structure and the three-dimensional structure of the active layer, and at the side of the three-dimensional structure of the active layer. Emits light having two peak wavelengths, wherein the amount of light emitted per unit area at the side of the three-dimensional structure of the active layer is greater than the amount of light emitted per unit area between the three-dimensional structure and the three-dimensional structure of the active layer; A three-dimensional long wavelength light emitting diode, wherein the difference between the peak wavelength and the second peak wavelength is within 10%.
  2. 제1항에 있어서,The method of claim 1,
    상기 복수의 3차원 구조물은 오목부 또는 볼록부를 포함하거나, 또는 오목부와 볼록부 모두를 포함하는 것을 특징으로 하는 3차원 장파장 발광다이오드.The plurality of three-dimensional structure includes a concave portion or a convex portion, or a three-dimensional long wavelength light emitting diode, characterized in that it comprises both concave portion and convex portion.
  3. 제1항에 있어서, The method of claim 1,
    상기 3차원 구조물은 종방향으로 폭이 변화하는 원형의 횡단면을 갖는 것을 특징으로 하는 3차원 장파장 발광다이오드.The three-dimensional long-wavelength light emitting diode, characterized in that the three-dimensional structure has a circular cross section of the width varies in the longitudinal direction.
  4. 제1항에 있어서, The method of claim 1,
    상기 활성층은 적색광 또는 적외선을 방출하는 것을 특징으로 하는 3차원 장파장 발광다이오드.The active layer is a three-dimensional long wavelength light emitting diode, characterized in that emitting red light or infrared light.
  5. 제1항에 있어서, The method of claim 1,
    상기 제1 전극이, 상기 제1 도전형 반도체층의 표면 형상과 반대되는 상기 제1 도전형 반도체층의 이면에 접촉되어, 반도체층과 전극 간의 결합면적이 증대되고, 이에 의해 접촉저항이 감소됨으로써 구동전압이 감소되는 것을 특징으로 하는 3차원 장파장 발광다이오드.The first electrode is in contact with the rear surface of the first conductive semiconductor layer opposite to the surface shape of the first conductive semiconductor layer, thereby increasing the bonding area between the semiconductor layer and the electrode, thereby reducing the contact resistance. 3D long wavelength light emitting diode, characterized in that the driving voltage is reduced.
  6. 서로 이격된 복수의 3차원 구조물이 형성된 표면을 구비하는 기판;A substrate having a surface on which a plurality of three-dimensional structures are spaced apart from each other;
    상기 기판의 표면에 형성되는 제1 도전형 반도체층; A first conductivity type semiconductor layer formed on the surface of the substrate;
    상기 제1 도전형 반도체층의 표면에 형성되며, AlGaInP 또는 AlGaAs를 포함하여 600nm 이상의 파장을 갖는 광을 방출하는 활성층;An active layer formed on a surface of the first conductivity type semiconductor layer and emitting light having a wavelength of 600 nm or more, including AlGaInP or AlGaAs;
    상기 활성층의 표면에 형성되는 제2 도전형 반도체층;A second conductivity type semiconductor layer formed on the surface of the active layer;
    상기 제1 도전형 반도체층에 전기적으로 연결되는 제1 전극; 및A first electrode electrically connected to the first conductive semiconductor layer; And
    상기 제2 도전형 반도체층에 전기적으로 연결되는 제2 전극;을 포함하고,And a second electrode electrically connected to the second conductive semiconductor layer.
    상기 기판에 형성된 복수의 3차원 구조물은 오목부 또는 볼록부를 포함하거나, 또는 오목부와 볼록부 모두를 포함하며,The plurality of three-dimensional structures formed on the substrate includes recesses or protrusions, or both recesses and protrusions,
    상기 복수의 3차원 구조물은 종단면이 곡면인 부분을 포함하고, The plurality of three-dimensional structure includes a portion of the longitudinal cross-section,
    상기 제1 도전형 반도체층, 활성층 및 제2 도전형 반도체층 각각이 상기 기판의 표면 형상을 유지하며,Each of the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer maintains the surface shape of the substrate,
    상기 활성층은 상기 기판의 표면 형상을 유지하여, 활성층의 3차원 구조물과 3차원 구조물의 사이에서 제1 피크파장을 갖는 광을 방출함과 더불어 활성층의 3차원 구조물의 측면에서 제2 피크파장을 갖는 광을 방출하되, 상기 활성층의 3차원 구조물의 측면에서의 단위면적당 광 방출량이 상기 활성층의 3차원 구조물과 3차원 구조물의 사이에서의 단위면적당 광 방출량보다 더 크며, 상기 제1 피크파장과 제2 피크파장의 차이가 10% 이내인 것을 특징으로 하는 3차원 장파장 발광다이오드.The active layer maintains the surface shape of the substrate, emits light having a first peak wavelength between the three-dimensional structure and the three-dimensional structure of the active layer, and has a second peak wavelength at the side of the three-dimensional structure of the active layer. Emits light, wherein the amount of light emitted per unit area on the side of the three-dimensional structure of the active layer is greater than the amount of light emitted per unit area between the three-dimensional structure and the three-dimensional structure of the active layer, wherein the first peak wavelength and the second 3D long wavelength light emitting diode, characterized in that the difference in peak wavelength is within 10%.
  7. 제6항에 있어서,The method of claim 6,
    상기 기판은 GaAs, GaP 또는 InP 기판인 것을 특징으로 하는 3차원 장파장 발광다이오드. Wherein said substrate is a GaAs, GaP or InP substrate.
  8. 제6항에 있어서,The method of claim 6,
    상기 기판은 GaAs, GaP 또는 InP 기판에 비도핑 반도체층 및 제1 도전형 반도체층 중 하나 이상의 반도체층이 형성된 것을 특징으로 하는 3차원 장파장 발광다이오드.The substrate is a three-dimensional long-wavelength light emitting diode, characterized in that at least one semiconductor layer of the undoped semiconductor layer and the first conductivity type semiconductor layer is formed on a GaAs, GaP or InP substrate.
  9. 제7항 또는 제8항에 있어서,The method according to claim 7 or 8,
    상기 제1 전극은 상기 기판 하부에 형성되고, The first electrode is formed under the substrate,
    상기 제2 전극은 상기 제2 도전형 반도체층 상부에 형성되는 것을 특징으로 하는 3차원 장파장 발광다이오드. The second electrode is a three-dimensional long wavelength light emitting diode, characterized in that formed on the second conductive semiconductor layer.
  10. 제6항에 있어서, The method of claim 6,
    상기 3차원 구조물은 종방향으로 폭이 변화하는 원형의 횡단면을 갖는 것을 특징으로 하는 3차원 장파장 발광다이오드.The three-dimensional long-wavelength light emitting diode, characterized in that the three-dimensional structure has a circular cross section of the width varies in the longitudinal direction.
  11. 제6항에 있어서, The method of claim 6,
    상기 활성층은 적색광 또는 적외선을 방출하는 것을 특징으로 하는 3차원 장파장 발광다이오드.The active layer is a three-dimensional long wavelength light emitting diode, characterized in that emitting red light or infrared light.
  12. 제6항에 있어서, The method of claim 6,
    상기 제2 전극이, 상기 기판의 표면 형상을 유지하는 상기 제2 도전형 반도체층에 접촉되어, 반도체층과 전극 간의 결합면적이 증대되고, 이에 의해 접촉저항이 감소됨으로써 구동전압이 감소되는 것을 특징으로 하는 3차원 장파장 발광다이오드.The second electrode is in contact with the second conductivity-type semiconductor layer that maintains the surface shape of the substrate, thereby increasing the coupling area between the semiconductor layer and the electrode, thereby reducing the driving resistance, thereby reducing the driving voltage. Three-dimensional long wavelength light emitting diode.
  13. (a) 기판 표면에 서로 이격된 복수의 3차원 구조물을 형성하는 단계;(a) forming a plurality of three-dimensional structures spaced apart from each other on a substrate surface;
    (b) 상기 기판 표면에, 제1 도전형 반도체층, AlGaInP 또는 AlGaAs를 포함하여 600nm 이상의 파장을 갖는 광을 방출하는 활성층 및 제2 도전형 반도체층을 포함하는 발광 구조체를 형성하는 단계; 및(b) forming a light emitting structure on the surface of the substrate, the light emitting structure including a first conductive semiconductor layer, an active layer that emits light having a wavelength of 600 nm or more, including AlGaInP or AlGaAs, and a second conductive semiconductor layer; And
    (c) 상기 제1 도전형 반도체층에 전기적으로 연결되는 제1 전극 및 상기 제2 도전형 반도체층에 전기적으로 연결되는 제2 전극을 형성하는 단계;를 포함하고,(c) forming a first electrode electrically connected to the first conductivity type semiconductor layer and a second electrode electrically connected to the second conductivity type semiconductor layer;
    상기 (a) 단계에서, 종단면이 곡면인 측면 부분을 포함하도록 상기 복수의 3차원 구조물을 형성하고,In the step (a), to form the plurality of three-dimensional structure to include a side portion of the longitudinal cross-section,
    상기 (b) 단계에서, 활성층을 포함한 발광 구조체 형성시 종단면이 곡면인 측면 부분을 포함하는 상기 복수의 3차원 구조물이 형성된 기판의 표면 형상을 유지하여, 상기 활성층의 곡면 부분을 포함하는 측면 부분에서의 성장이 non-polar 성장이 되고, 상기 활성층의 측면과 그 외의 부분이 균일한 두께로 성장되는 것을 특징으로 하는 3차원 장파장 발광다이오드 제조 방법.In the step (b), when forming the light emitting structure including the active layer in the side portion including the curved portion of the active layer by maintaining the surface shape of the substrate on which the plurality of three-dimensional structure is formed, including the side portion having a curved longitudinal section The growth of the non-polarized growth, the side and the other portion of the active layer is a three-dimensional long wavelength light emitting diode manufacturing method characterized in that the growth in a uniform thickness.
  14. 제13항에 있어서,The method of claim 13,
    상기 (a) 단계에서, 상기 기판의 표면에 오목부 또는 볼록부를 형성하거나, 또는 오목부 및 볼록부를 형성하는 것을 특징으로 하는 3차원 장파장 발광다이오드 제조 방법. In the step (a), a concave portion or a convex portion is formed on the surface of the substrate, or a three-dimensional long wavelength light emitting diode manufacturing method, characterized in that to form a concave portion and a convex portion.
  15. 제13항에 있어서,The method of claim 13,
    상기 기판은 GaAs, GaP 또는 InP 기판이고, The substrate is a GaAs, GaP or InP substrate,
    상기 (a) 단계에서 GaAs, GaP 또는 InP 기판 표면에 서로 이격된 복수의 3차원 구조물을 형성하는 것을 특징으로 하는 3차원 장파장 발광다이오드 제조 방법. The method of manufacturing a three-dimensional long wavelength light emitting diode, characterized in that to form a plurality of three-dimensional structures spaced apart from each other on the surface of the GaAs, GaP or InP substrate in step (a).
  16. 제13항에 있어서,The method of claim 13,
    상기 기판은 GaAs, GaP 또는 InP 기판에 비도핑 반도체층 및 제1 도전형 반도체층 중 하나 이상을 포함하는 반도체층이 형성된 것이고,The substrate is a semiconductor layer including at least one of the undoped semiconductor layer and the first conductive semiconductor layer is formed on a GaAs, GaP or InP substrate,
    상기 (a) 단계에서 상기 반도체층 표면에 서로 이격된 복수의 3차원 구조물을 형성하는 것을 특징으로 하는 3차원 장파장 발광다이오드 제조 방법. 3. The method of claim 3, wherein a plurality of three-dimensional structures spaced apart from each other are formed on the surface of the semiconductor layer.
  17. 제15항 또는 제16항에 있어서,The method according to claim 15 or 16,
    상기 (c) 단계에서, 상기 제1 전극을 상기 기판 하부에 형성하고, 상기 제2 전극을 상기 제2 도전형 반도체층 상부에 형성하는 것을 특징으로 하는 3차원 장파장 발광다이오드 제조 방법. In the step (c), the first electrode is formed under the substrate, and the second electrode is formed on the second conductive semiconductor layer, characterized in that the three-dimensional long-wavelength light emitting diode manufacturing method.
  18. 제13항에 있어서, The method of claim 13,
    상기 (a) 단계에서, 상기 3차원 구조물을 종방향으로 폭이 변화하는 원형의 횡단면을 갖도록 형성하는 것을 특징으로 하는 3차원 장파장 발광다이오드 제조 방법.In the step (a), the three-dimensional long-wavelength light emitting diode manufacturing method characterized in that the three-dimensional structure is formed to have a circular cross section of the width varies in the longitudinal direction.
  19. (a) 기판 표면에 서로 이격된 복수의 3차원 구조물을 형성하는 단계;(a) forming a plurality of three-dimensional structures spaced apart from each other on a substrate surface;
    (b) 상기 복수의 3차원 구조물이 형성된 기판 표면에 희생층을 형성하는 단계;(b) forming a sacrificial layer on a surface of the substrate on which the plurality of three-dimensional structures are formed;
    (c) 상기 희생층이 형성된 기판 표면에, 제1 도전형 반도체층, AlGaInP 또는 AlGaAs를 포함하여 600nm 이상의 파장을 갖는 광을 방출하는 활성층 및 제2 도전형 반도체층을 포함하는 발광 구조체를 형성하는 단계; (c) forming a light emitting structure including a first conductive semiconductor layer, an active layer that emits light having a wavelength of 600 nm or more, including AlGaInP or AlGaAs, and a second conductive semiconductor layer on a surface of the substrate on which the sacrificial layer is formed; step;
    (d) 상기 제2 도전형 반도체층 표면에 도전성 기판을 부착하고 상기 희생층을 제거하여 상기 기판을 분리하는 단계; 및(d) attaching a conductive substrate to the surface of the second conductivity type semiconductor layer and removing the sacrificial layer to separate the substrate; And
    (e) 상기 희생층이 제거되어 노출되는 제1 도전형 반도체층에 전기적으로 연결되는 제1 전극을 형성하는 단계;를 포함하고,(e) forming a first electrode electrically connected to the first conductivity type semiconductor layer to which the sacrificial layer is removed and exposed;
    상기 (a) 단계에서, 종단면이 곡면인 측면 부분을 포함하도록 상기 복수의 3차원 구조물을 형성하고,In the step (a), to form the plurality of three-dimensional structure to include a side portion of the longitudinal cross-section,
    상기 (b) 단계 및 (c) 단계에서, 상기 희생층 및 상기 활성층을 포함한 발광 구조체 형성시에 종단면이 곡면인 측면 부분을 포함하는 상기 복수의 3차원 구조물이 형성된 기판의 표면 형상을 유지하여, 상기 활성층의 곡면 부분을 포함하는 측면 부분에서의 성장이 non-polar 성장이 되고, 상기 활성층의 측면과 그 외의 부분이 균일한 두께로 성장되는 것을 특징으로 하는 3차원 장파장 발광다이오드 제조 방법.In the steps (b) and (c), maintaining the surface shape of the substrate on which the plurality of three-dimensional structures including the side surface portion having a curved longitudinal section is formed when the light emitting structure including the sacrificial layer and the active layer is formed, The growth in the side portion including the curved portion of the active layer is a non-polar growth, the side and the other portion of the active layer is characterized in that the growth of a uniform long wavelength light emitting diode.
  20. 제19항에 있어서,The method of claim 19,
    상기 (a) 단계에서, 상기 기판의 표면에 오목부 또는 볼록부를 형성하거나, 또는 오목부 및 볼록부를 형성하는 것을 특징으로 하는 3차원 장파장 발광다이오드 제조 방법. In the step (a), a concave portion or a convex portion is formed on the surface of the substrate, or a three-dimensional long wavelength light emitting diode manufacturing method, characterized in that to form a concave portion and a convex portion.
  21. 제19항에 있어서,The method of claim 19,
    상기 기판은 GaAs, GaP 또는 InP 기판이고, The substrate is a GaAs, GaP or InP substrate,
    상기 (a) 단계에서 GaAs, GaP 또는 InP 기판 표면에 서로 이격된 복수의 3차원 구조물을 형성하는 것을 특징으로 하는 3차원 장파장 발광다이오드 제조 방법. The method of manufacturing a three-dimensional long wavelength light emitting diode, characterized in that to form a plurality of three-dimensional structures spaced apart from each other on the surface of the GaAs, GaP or InP substrate in step (a).
  22. 제19항에 있어서,The method of claim 19,
    상기 기판은 GaAs, GaP 또는 InP 기판에 비도핑 반도체층 및 제1 도전형 반도체층 중 하나 이상을 포함하는 반도체층이 형성된 것이고,The substrate is a semiconductor layer including at least one of the undoped semiconductor layer and the first conductive semiconductor layer is formed on a GaAs, GaP or InP substrate,
    상기 (a) 단계에서 상기 반도체층 표면에 서로 이격된 복수의 3차원 구조물을 형성하는 것을 특징으로 하는 3차원 장파장 발광다이오드 제조 방법.3. The method of claim 3, wherein a plurality of three-dimensional structures spaced apart from each other are formed on the surface of the semiconductor layer.
  23. 제19항에 있어서, The method of claim 19,
    상기 (a) 단계에서, 상기 3차원 구조물을 종방향으로 폭이 변화하는 원형의 횡단면을 갖도록 형성하는 것을 특징으로 하는 3차원 장파장 발광다이오드 제조 방법.In the step (a), the three-dimensional long-wavelength light emitting diode manufacturing method characterized in that the three-dimensional structure is formed to have a circular cross section of the width varies in the longitudinal direction.
  24. 제19항에 있어서,The method of claim 19,
    상기 희생층은 AlAs 재질로 형성되는 것을 특징으로 하는 3차원 장파장 발광다이오드 제조 방법.The sacrificial layer is a three-dimensional long wavelength light emitting diode manufacturing method, characterized in that formed of AlAs material.
  25. 제19항에 있어서,The method of claim 19,
    상기 (d) 단계에서, 상기 도전성 기판 부착은 상기 제2 도전형 반도체층 상에 추가의 제2 도전형 반도체층을 형성한 후, 실리콘 기판 또는 금속 기판을 도전성 접착제로 부착하는 방법으로 수행되는 것을 특징으로 하는 3차원 장파장 발광다이오드 제조 방법.In the step (d), attaching the conductive substrate is performed by forming an additional second conductive semiconductor layer on the second conductive semiconductor layer, and then attaching a silicon substrate or a metal substrate with a conductive adhesive. A three-dimensional long wavelength light emitting diode manufacturing method characterized by the above-mentioned.
PCT/KR2017/005560 2017-05-29 2017-05-29 Three-dimensional long-wavelength light-emitting diode and manufacturing method therefor WO2018221752A1 (en)

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