Method for manufacturing light emitting element and display device including light emitting element

Abstract

A method for manufacturing a light-emitting element and a display device including the light-emitting element are provided. The method for manufacturing a light-emitting element comprises the following steps: providing a semiconductor structure formed on a substrate; defining a wavelength region on the semiconductor structure by measuring light with different wavelengths emitted from the semiconductor structure; and forming nano patterns having different diameters and spaced apart from each other on the semiconductor structure according to the wavelength region, and etching the semiconductor structure to form an element rod.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a light-emitting element and a display device including the light-emitting element, and more particularly, to a method for manufacturing a light-emitting element in which a deviation in an emission wavelength formed according to a difference in a composition of a fluorescent material is compensated and a display device including the light-emitting element. Background Art

[0002] The importance of display devices has increased with the development of multimedia. Therefore, various types of display devices such as organic light emitting displays and liquid crystal displays (LCDs) have been used.

[0003] The display device is a device for displaying an image, and includes a display panel such as a light-emitting display panel or a liquid crystal panel. Among them, the light-emitting display panel may include a light-emitting element such as a light-emitting diode (LED). The light-emitting diode (LED) may include an organic light-emitting diode (OLED) using an organic material as a fluorescent material and an inorganic light-emitting diode using an inorganic material as a fluorescent material.

[0004] In the case of an organic light emitting diode (OLED), since the organic light emitting diode uses an organic material as a fluorescent material, there are advantages that the manufacturing process of the organic light emitting diode is simple and the organic light emitting diode has flexible characteristics. However, it is known that the organic material is susceptible to a high temperature driving environment and has a relatively low blue light efficiency.

[0005] On the other hand, in the case of an inorganic light emitting diode, since the inorganic light emitting diode uses an inorganic semiconductor as a fluorescent material, there are advantages that the inorganic light emitting diode has durability even in a high temperature environment and has higher blue light efficiency than the organic light emitting diode. In addition, even in the manufacturing process that has been pointed out as a limitation of conventional inorganic light emitting diodes, a transfer method using dielectrophoresis (DEP) has been developed. Therefore, research on inorganic light emitting diodes having higher durability and efficiency than organic light emitting diodes is continuing. Summary of the invention

[0006] Technical issues

[0007] An inorganic light emitting diode can be manufactured by growing a semiconductor layer doped with an n-type dopant or a p-type dopant and an inorganic fluorescent material layer on a substrate to form rods each having a specific shape, and then separating the rods. However, when the inorganic fluorescent material layer is grown on a substrate (e.g., a wafer substrate), a difference in the composition of the fluorescent material occurs depending on the spatial position on the wafer substrate. Therefore, there is a problem in that a change in emission wavelength occurs between the rods grown on the wafer substrate.

[0008] The subject matter to be achieved by the present invention is to provide a method for manufacturing a light-emitting element and to provide a display device including the light-emitting element. In the method for manufacturing a light-emitting element, the deviation of the emission wavelength of the non-uniformly formed rods is reduced by controlling the diameter of the rods grown on a wafer substrate when manufacturing the light-emitting element.

[0009] Additional advantages, subjects, and features of the invention will be set forth in part in the description which follows, and in part will become apparent to one of ordinary skill in the art upon examination of the following, or may be learned from practice of the invention.

[0010] Technical Solution

[0011] According to an exemplary embodiment of the present disclosure, a method for manufacturing a light-emitting element is provided, the method comprising: providing a semiconductor structure formed on a substrate; measuring light having wavelength bands different from each other emitted from the semiconductor structure to define a wavelength region; and forming nano-patterns having diameters different from each other and spaced apart from each other on the semiconductor structure, and etching the semiconductor structure to form element rods.

[0012] The wavelength regions may include: a first wavelength region, from which first light having a first wavelength band is emitted; a second wavelength region, from which second light having a second wavelength band shorter than the first wavelength band is emitted; and a third wavelength region, from which third light having a third wavelength band shorter than the second wavelength band is emitted.

[0013] In the step of forming the nano-pattern, as the wavelength band of light emitted from the wavelength region decreases, a nano-pattern having an increasing diameter may be formed on the wavelength region.

[0014] The nanopattern may include a first nanopattern, a second nanopattern, and a third nanopattern, the second nanopattern having a diameter larger than that of the first nanopattern, the third nanopattern having a diameter larger than that of the second nanopattern, the first nanopattern may be formed on a first wavelength region, the second nanopattern may be formed on a second wavelength region, and the third nanopattern may be formed on a third wavelength region.

[0015] The element rods may include: a first element rod formed in a region overlapping the first wavelength region; a second element rod formed in a region overlapping the second wavelength region; and a third element rod formed in a region overlapping the third wavelength region.

[0016] The second element rod may be larger in diameter than the first element rod but smaller in diameter than the third element rod, and the first element rod, the second element rod and the third element rod may emit light of substantially the same wavelength band.

[0017] The third wavelength region may be disposed at the center of the semiconductor structure, the second wavelength region may be disposed to surround an outer surface of the third wavelength region, and the first wavelength region may be disposed to surround an outer surface of the second wavelength region.

[0018] The semiconductor structure may include a first axis passing through the center of the semiconductor structure, a diameter of the nano pattern may increase from one end of the first axis toward the center of the semiconductor structure, and a diameter of the nano pattern may decrease from the center of the semiconductor structure toward the other end of the first axis.

[0019] The semiconductor structure may include a second axis passing through the center of the semiconductor structure, the first wavelength region may be set at one end of the second axis, the second wavelength region may partially surround the outer surface of the first wavelength region and extend in the direction of the other end of the second axis, and the third wavelength region may partially surround the outer surface of the second wavelength region and extend to the other end of the second axis.

[0020] A diameter of the nano-pattern disposed along the second axis may increase from one end of the second axis toward the other end of the second axis.

[0021] According to an exemplary embodiment of the present disclosure, a method for manufacturing a light-emitting element is provided, the method comprising: providing a substrate and a semiconductor structure, the semiconductor structure being disposed on the substrate and comprising a first conductive semiconductor layer, an active material layer, and a second conductive semiconductor layer; forming an etching mask layer and an etching pattern layer comprising one or more nanopatterns, the etching mask layer being formed on the semiconductor structure, the one or more nanopatterns being formed on the etching mask layer, having diameters different from each other, and being spaced apart from each other; etching the semiconductor structure in a direction perpendicular to the substrate along an area where the nanopatterns are spaced apart from each other to form an element rod; and separating the element rod from the substrate to form a light-emitting element.

[0022] The nano-pattern may include: a first nano-pattern; a second nano-pattern having a diameter larger than that of the first nano-pattern; and a third nano-pattern having a diameter larger than that of the second nano-pattern.

[0023] The light emitting element may include: a first light emitting element having a diameter equal to that of the first nano-pattern; a second light emitting element having a diameter equal to that of the second nano-pattern; and a third light emitting element having a diameter equal to that of the third nano-pattern.

[0024] A difference in diameter between the first light emitting element and the second light emitting element may be in the range of 2% to 16% of the diameter of the second light emitting element.

[0025] A pitch between the one or more nano-patterns spaced apart from each other may be in a range of 2.5 to 3.5 times a diameter of each of the nano-patterns.

[0026] The nano-pattern may have a circular shape or a polygonal shape.

[0027] A separation layer may be further provided between the substrate and the first conductive semiconductor layer, and the step of forming the light emitting element may include the step of removing the separation layer to separate the element rod from the substrate.

[0028] According to an exemplary embodiment of the present disclosure, a display device includes: a substrate; at least one first electrode and at least one second electrode, extending along a first direction on the substrate and spaced apart from each other along a second direction different from the first direction; at least one light-emitting element, arranged in a space between the first electrode and the second electrode; a first contact electrode, partially covering the first electrode and contacting a first end of the light-emitting element; and a second contact electrode, partially covering the second electrode and contacting a second end of the light-emitting element, the second end of the light-emitting element being positioned opposite to the first end of the light-emitting element, wherein the light-emitting elements include a first light-emitting element and a second light-emitting element, the second light-emitting element having a diameter larger than that of the first light-emitting element, and the first light-emitting element and the second light-emitting element emit light of substantially the same wavelength band.

[0029] A difference in diameter between the first light emitting element and the second light emitting element may be in the range of 2% to 16% of the diameter of the second light emitting element.

[0030] The light emitting element may further include a third light emitting element, which may have a diameter greater than that of the second light emitting element and emit light of substantially the same wavelength band as that of the second light emitting element.

[0031] The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments of the present invention with reference to the attached drawings.

[0032] Beneficial Effects

[0033] According to the method of manufacturing a light emitting element according to an embodiment, the nano patterns formed on the semiconductor structure have different diameters, so that the wavelength band of light emitted from the element rod can be frequency shifted. Therefore, a plurality of light emitting elements can have different diameters but can emit light of substantially the same wavelength band.

[0034] Furthermore, a display device including the above-described light emitting element and minimizing the deviation of the emission wavelength emitted from each pixel can be provided.

[0035] The effects of the present invention are not limited to the above-mentioned effects, and other unmentioned effects will be clearly understood to those skilled in the art through the description of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a plan view of a display device according to an embodiment.

[0037] Figure 2 It is along Figure 1 Cross-sectional views taken along line II', line II-II' and line III-III'.

[0038] Figure 3 is a schematic perspective view of a light emitting element according to an embodiment.

[0039] Figure 4 It is along Figure 1 A cross-sectional view taken along line IV-IV'.

[0040] Figure 5 and Figure 6 is a cross-sectional view schematically illustrating a method of forming a semiconductor structure according to an embodiment.

[0041] Figure 7 1 is a flowchart showing a step of forming an element rod in a method of manufacturing a light emitting element according to an embodiment.

[0042] Figures 8 to 16 is a cross-sectional view schematically illustrating a method of manufacturing a light emitting element according to an embodiment.

[0043] Figures 17 to 19 is a plan view schematically showing a nano pattern according to another embodiment.

[0044] Fig. 20 and Fig.21 are cross-sectional views illustrating some processes of a method of manufacturing a light emitting element according to another embodiment. DETAILED DESCRIPTION

[0045] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. However, the present invention may be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art.

[0046] It will also be understood that when a layer is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. Throughout the specification, the same reference numerals refer to the same components.

[0047] It will be understood that, although the terms "first", "second", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the teachings of the present invention, the first element discussed below may be named as the second element. Similarly, the second element may also be named as the first element.

[0048] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0049] Figure 1 is a plan view of a display device according to an embodiment.

[0050] The display device 10 may include at least one region defined as a pixel PX. A plurality of pixels PX may be arranged in a display unit of the display device 10 to emit light of a specific wavelength band to the outside of the display device 10. Figure 1 Three pixels PX1, PX2, and PX3 are shown, but it is obvious that the display device 10 includes a larger number of pixels. Although the drawings show that the plurality of pixels PX are arranged only in one direction (e.g., in the first direction D1), the plurality of pixels PX may be arranged in a second direction D2 intersecting the first direction D1. In addition, Figure 1 The pixel PX shown in FIG. 1 may be divided into a plurality of pixels to allow each of the plurality of pixels to constitute a pixel PX. The pixels may be arranged in a vertical direction (or second direction D2) or may be arranged in a zigzag form instead of in a straight line. Figure 1 The ones shown in FIG. 1 are arranged in parallel only along the first direction D1 .

[0051] Although not shown in the drawings, the display device 10 may include a light-emitting area and a non-light-emitting area, the light-emitting element 300 is arranged in the light-emitting area to emit light of a specific color, and the non-light-emitting area is defined as an area other than the light-emitting area. The non-light-emitting area may be covered by a specific component and not viewed from the outside. The non-light-emitting area may be provided with various components for driving the light-emitting element 300 arranged in the light-emitting area. For example, the non-light-emitting area may be provided with wiring, a circuit unit, a driving unit, etc. for applying an electrical signal to the light-emitting area. However, the present invention is not limited thereto.

[0052] Each of the plurality of pixels may include at least one light emitting element 300 that emits light of a specific wavelength band to display a color. The light emitted from the light emitting element 300 may be viewed from the outside of the display device 10. In an embodiment, the light emitting element 300 that emits light of different colors from each other may be provided for each of the pixels PX that express different colors from each other. For example, the first pixel PX1 that expresses red may include a light emitting element 300 that emits red light, the second pixel PX2 that expresses green may include a light emitting element 300 that emits green light, and the third pixel PX3 that expresses blue may include a light emitting element 300 that emits blue light. However, the present invention is not limited thereto, and in some cases, the pixels PX that express different colors from each other may include a light emitting element 300 that emits light of the same color (e.g., blue), and the color of the corresponding pixel PX may be expressed by providing a wavelength conversion layer or a color filter on the light emitting path. However, the present invention is not limited thereto, and in some cases, adjacent pixels PX may emit light of the same color.

[0053] Reference Figure 1 , the display device 10 may include a plurality of electrodes 210 and 220 and a plurality of light emitting elements 300. At least a portion of each of the electrodes 210 and 220 may be disposed in each pixel PX, electrically connected to the light emitting element 300, and apply an electrical signal to the light emitting element 300 to allow the light emitting element 300 to emit light of a specific color.

[0054] In addition, at least a portion of each of the electrodes 210 and 220 may be used to form an electric field in the pixel PX to align the light emitting element 300. Specifically, when aligning the light emitting elements 300 that emit light of different colors from each other in a plurality of pixels PX, the light emitting element 300 needs to be accurately aligned for each pixel PX. When aligning the light emitting element 300 using dielectrophoresis, a solution containing the light emitting element 300 is applied to the display device 10, and AC power is applied to the solution to form a capacitance caused by an electric field, so that the light emitting element 300 can be aligned by dielectrophoretic force.

[0055] The plurality of electrodes 210 and 220 may include a first electrode 210 and a second electrode 220. In an exemplary embodiment, the first electrode 210 may be a pixel electrode separated for each pixel PX, and the second electrode 220 may be a common electrode commonly connected along the plurality of pixels PX. Any one of the first electrode 210 and the second electrode 220 may be an anode electrode of the light emitting element 300, and the other of the first electrode 210 and the second electrode 220 may be a cathode electrode of the light emitting element 300. However, the present invention is not limited to this case, and may have the opposite case.

[0056] The first electrode 210 and the second electrode 220 may include electrode trunk portions 210S and 220S extending in a first direction D1 and electrode branch portions 210B and 220B extending in a second direction D2 intersecting the first direction D1 and branching from the electrode trunk portions 210S and 220S, respectively.

[0057] Specifically, the first electrode 210 may include a first electrode trunk portion 210S and at least one first electrode branch portion 210B, the first electrode trunk portion 210S extending in the first direction D1, and at least one first electrode branch portion 210B branching from the first electrode trunk portion 210S and extending in the second direction D2. Although not shown in the drawings, one end of the first electrode trunk portion 210S may be connected to a signal application pad (pad, or referred to as a "pad"), and the other end thereof may extend in the first direction D1, but be electrically separated between pixels PX. The signal application pad may be connected to a display device or an external power source to apply an electrical signal to the first electrode trunk portion 210S or to apply AC power to the first electrode trunk portion 210S when the light emitting element 300 is aligned.

[0058] The first electrode trunk portion 210S of any one pixel is placed on substantially the same line as the first electrode trunk portion 210S of the adjacent pixel belonging to the same row (e.g., adjacent in the first direction D1). In other words, the first electrode trunk portion 210S of one pixel terminates between the pixels PX, and its two ends are spaced apart from each other, while the first electrode trunk portion 210S of the adjacent pixel can be aligned with the extension line of the first electrode trunk portion 210S of the one pixel. Such an arrangement of the first electrode trunk portion 210S can be performed by forming a trunk electrode during the manufacturing process, performing a process of aligning the light-emitting element 300, and then disconnecting the trunk electrode using a laser. Therefore, the first electrode trunk portion 210S set in each pixel PX can apply different electrical signals to the corresponding pixels PX, and the corresponding pixels PX can be driven independently of each other.

[0059] The first electrode branch portion 210B may branch from at least a portion of the first electrode trunk portion 210S and extend in the second direction D2, but may terminate and be spaced apart from the second electrode trunk portion 220S disposed to face the first electrode trunk portion 210S. That is, one end of the first electrode branch portion 210B may be connected to the first electrode trunk portion 210S, and the other end thereof may be disposed in the pixel PX and spaced apart from the second electrode trunk portion 220S. Since the first electrode branch portion 210B is connected to the first electrode trunk portion 210S electrically separated for each pixel PX, the first electrode branch portion 210B may receive different electrical signals from each other for each pixel PX.

[0060] In addition, one or more first electrode branch portions 210B may be provided for each pixel PX. Figure 1 , two first electrode branch portions 210B are provided and a second electrode branch portion 220B is provided between the two first electrode branch portions 210B, but the present invention is not limited thereto, and a greater number of first electrode branch portions 210B may be provided. In this case, the first electrode branch portion 210B may be alternately spaced apart from a plurality of second electrode branch portions 220B, and a plurality of light-emitting elements 300 may be provided between the first electrode branch portion 210B and the plurality of second electrode branch portions 220B. In some embodiments, the second electrode branch portion 220B is provided between the first electrode branch portions 210B, so that each pixel PX may have a symmetrical structure with respect to the second electrode branch portion 220B. However, the present invention is not limited thereto.

[0061] The second electrode 220 may include a second electrode trunk portion 220S and at least one second electrode branch portion 220B, the second electrode trunk portion 220S extending along the first direction D1, spaced apart from the first electrode trunk portion 210S and facing the first electrode trunk portion 210S, and the second electrode branch portion 220B branching from the second electrode trunk portion 220S, extending along the second direction D2, spaced apart from the first electrode branch portion 210B and facing the first electrode branch portion 210B. Similar to the first electrode trunk portion 210S, one end of the second electrode trunk portion 220S may also be connected to the signal application pad. However, the other end of the second electrode trunk portion 220S may extend to a plurality of pixels PX adjacent in the first direction D1. That is, the second electrode trunk portion 220S may be electrically connected between the pixels PX. Therefore, the two ends of the second electrode trunk portion 220S of any one pixel may be connected to one end of the second electrode trunk portion 220S of the adjacent pixel PX between the corresponding pixels PX, so that the same electrical signal may be applied to the corresponding pixel PX.

[0062] The second electrode branch portion 220B may branch from at least a portion of the second electrode trunk portion 220S and extend in the second direction D2, but may terminate and be spaced apart from the first electrode trunk portion 210S. That is, one end of the second electrode branch portion 220B may be connected to the second electrode trunk portion 220S, and the other end thereof may be disposed in the pixel PX and spaced apart from the first electrode trunk portion 210S. Since the second electrode branch portion 220B is connected to the second electrode trunk portion 220S electrically connected for each pixel PX, the second electrode branch portion 220B may receive the same electrical signal for each pixel PX.

[0063] In addition, the second electrode branch portion 220B may be arranged to be spaced apart from the first electrode branch portion 210B and face the first electrode branch portion 210B. Here, since the first electrode trunk portion 210S and the second electrode trunk portion 220S are spaced apart from each other and face each other in opposite directions relative to the center of each pixel PX, the first electrode branch portion 210B and the second electrode branch portion 220B may extend in opposite directions relative to each other. In other words, the first electrode branch portion 210B extends in one direction in the second direction D2, and the second electrode branch portion 220B extends in another direction in the second direction D2, so that one end of the corresponding branch portion may be arranged in opposite directions relative to the center of the pixel PX. However, the present invention is not limited thereto, and the first electrode trunk portion 210S and the second electrode trunk portion 220S may be arranged to be spaced apart from each other in the same direction relative to the center of the pixel PX. In this case, the first electrode branch portion 210B and the second electrode branch portion 220B branched from the first electrode trunk portion 210S and the second electrode trunk portion 220S, respectively, may extend in the same direction.

[0064] Despite Figure 1 2A and 2B illustrate that one second electrode branch portion 220B is provided in each pixel PX, but the present invention is not limited thereto, and a greater number of second electrode branch portions 220B may be provided.

[0065] A plurality of light emitting elements 300 may be disposed between the first electrode branch portion 210B and the second electrode branch portion 220B. At least some of the plurality of light emitting elements 300 may have one end electrically connected to the first electrode branch portion 210B and the other end electrically connected to the second electrode branch portion 220B.

[0066] The plurality of light emitting elements 300 may be spaced apart from each other along the second direction D2, and may be aligned substantially parallel to each other. The spacing between the light emitting elements 300 is not particularly limited. In some cases, the plurality of light emitting elements 300 are arranged adjacent to each other to form a group, the plurality of light emitting elements 300 may form a group in a state where they are spaced apart at a predetermined spacing, and the plurality of light emitting elements 300 may have a non-uniform density and may be oriented and aligned in one direction.

[0067] In addition, the plurality of light emitting elements 300 may include light emitting elements having diameters different from each other, for example, a first light emitting element 301 , a second light emitting element 302 , and a third light emitting element 303 .

[0068] As will be described later, the light emitting element 300 may emit light of different wavelength bands according to the composition and type of active material of the element active layer 330. When the light emitting element 300 is manufactured, the element active layer 330 grown on the same wafer substrate may have composition differences according to spatial positions and may have deviations in the wavelength band of partly emitted light.

[0069] For example, when the second light emitting element 302 having an arbitrary diameter emits the second light L2 having the second wavelength band, other light emitting elements grown on the same wafer substrate may have differences in the components of the element active layer 330 depending on the spatial position of the wafer substrate. Therefore, when another light emitting element has the same diameter as the second light emitting element 302, it may emit light of different wavelength bands, for example, the first light L1 of the first wavelength band longer than the second wavelength band or the third light L3 of the third wavelength band shorter than the second wavelength band, depending on the differences in the components of the element active layer 330. In other words, when the light emitting elements 300 grown on the same wafer substrate have the same diameter, a deviation in the emission wavelength may occur due to differences in the components of the element active layer 330.

[0070] In order to minimize the deviation of the emission wavelength between the light emitting elements 300, in the method of manufacturing the light emitting element 300 according to the embodiment, the etching pattern layer 1700 (shown in FIG. 1 ) having different diameters may be formed. Figure 8 ), thereby forming element rods ROD having different diameters from each other according to the difference in the composition of the element active layer 330 (shown in Fig.13 ), and the display device 10 according to the embodiment may include light emitting elements 300 having diameters different from each other and emitting light of substantially the same wavelength band. The details thereof will be described later.

[0071] The contact electrodes 260 may be disposed on the first electrode branch portions 210B and the second electrode branch portions 220B, respectively.

[0072] A plurality of contact electrodes 260 may be arranged to extend in the second direction D2 and to be spaced apart from each other in the first direction D1. Each of the contact electrodes 260 may contact at least one end of the light emitting element 300 and may contact the first electrode 210 or the second electrode 220 to receive an electrical signal. Thus, the contact electrode 260 may transmit an electrical signal received from the first electrode 210 or the second electrode 220 to the light emitting element 300.

[0073] The contact electrode 260 may be disposed on the electrode branch portions 210B and 220B to partially cover the electrode branch portions 210B and 220B, and may include a first contact electrode 261 and a second contact electrode 262 each contacting one end or the other end of the light emitting element 300 .

[0074] The first contact electrode 261 may be disposed on the first electrode branch portion 210B and may contact one end of the light emitting element 300 electrically connected to the first electrode 210. The second contact electrode 262 may be disposed on the second electrode branch portion 220B and may contact the other end of the light emitting element 300 electrically connected to the second electrode 220.

[0075] In some embodiments, both ends of the light emitting element 300 electrically connected to the first electrode branch portion 210B or the second electrode branch portion 220B may be a conductive semiconductor layer doped with an n-type dopant or a p-type dopant. When one end of the light emitting element 300 electrically connected to the first electrode branch portion 210B is a conductive semiconductor layer doped with a p-type dopant, the other end of the light emitting element 300 electrically connected to the second electrode branch portion 220B may be a conductive semiconductor layer doped with an n-type dopant. However, the present invention is not limited thereto.

[0076] The first contact electrode 261 and the second contact electrode 262 may be disposed on the first electrode branch portion 210B and the second electrode branch portion 220B, respectively, to partially cover the first electrode branch portion 210B and the second electrode branch portion 220B. Figure 1As shown in , the first contact electrode 261 and the second contact electrode 262 may be arranged to extend along the second direction D2, to be spaced apart from each other, and to face each other. However, one end of each of the first contact electrode 261 and the second contact electrode 262 may terminate to partially expose one end of each of the electrode branch portions 210B and 220B. In addition, the other end of each of the first contact electrode 261 and the second contact electrode 262 may terminate in a state where they are spaced apart from each other so as not to overlap with each of the electrode trunk portions 210S and 220S. However, the present invention is not limited thereto, and the other end of each of the first contact electrode 261 and the second contact electrode 262 may cover each of the electrode branch portions 210B and 220B.

[0077] In addition, if Figure 1 As shown in FIG. 1 , the first electrode stem portion 210S and the second electrode stem portion 220S may be electrically connected to a thin film transistor 120 or a power wiring 161 to be described later through contact holes (eg, a first electrode contact hole CNTD and a second electrode contact hole CNTS), respectively. Figure 1 2 shows that the contact holes on the first electrode trunk portion 210S and the second electrode trunk portion 220S are arranged for each pixel PX, but the present invention is not limited thereto. As described above, since the second electrode trunk portion 220S can be extended to be electrically connected to an adjacent pixel PX, in some embodiments, the second electrode trunk portion 220S can be electrically connected to a thin film transistor or a power wiring through one contact hole.

[0078] In the following, reference will be made to Figure 2 A more specific structure of a plurality of components provided on the display device 10 is described.

[0079] Figure 2 It is along Figure 1 The cross-sectional views taken along the lines II-I', II-II' and III-III'. Figure 2 Only one pixel PX is shown, but it can also be applied to other pixels. Figure 2 A cross section across one end and the other end of any one light emitting element 300 is shown.

[0080] Reference Figure 1 and Figure 2, the display device 10 may include a substrate 110, thin film transistors 120 and 140 disposed on the substrate 110, electrodes 210 and 220 disposed on the thin film transistors 120 and 140, and a light emitting element 300. The thin film transistor may include a first thin film transistor 120 and a second thin film transistor 140, and the first thin film transistor 120 and the second thin film transistor 140 may be a driving transistor and a switching transistor, respectively. Each of the thin film transistors 120 and 140 may include an active layer, a gate electrode, a source electrode, and a drain electrode. The first electrode 210 may be electrically connected to the drain electrode of the first thin film transistor 120.

[0081] More specifically, the substrate 110 may be an insulating substrate. The substrate 110 may be made of an insulating material such as glass, quartz or a polymer resin. Examples of polymer resins may include polyethersulfone (PES), polyacrylate (PA), polyarylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyallylate, polyimide (PI), polycarbonate (PC), cellulose triacetate (CAT), cellulose acetate propionate (CAP) and combinations thereof. The substrate 110 may be a rigid substrate or a flexible substrate that can be bent, folded, curled, etc.

[0082] The buffer layer 115 may be disposed on the substrate 110. The buffer layer 115 may prevent diffusion of impurity ions, may prevent penetration of moisture or external air, and may perform a surface planarization function. The buffer layer 115 may include silicon nitride, silicon oxide, or silicon oxynitride.

[0083] The semiconductor layer is disposed on the buffer layer 115. The semiconductor layer may include a first active layer 126 of the first thin film transistor 120, a second active layer 146 of the second thin film transistor 140, and an auxiliary layer 163. The semiconductor layer may include polycrystalline silicon, single crystal silicon, oxide semiconductor, or the like.

[0084] The first gate insulating layer 170 is disposed on the semiconductor layer. The first gate insulating layer 170 covers the semiconductor layer. The first gate insulating layer 170 may be used as a gate insulating film of a thin film transistor. The first gate insulating layer 170 may include silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, tantalum oxide, hafnium oxide, zirconium oxide, titanium oxide, etc. These compounds may be used alone or in combination with each other.

[0085] The first conductive layer is disposed on the first gate insulating layer 170. The first conductive layer may include a first gate electrode disposed on the first active layer 126 of the first thin film transistor 120, a second gate electrode disposed on the second active layer 146 of the second thin film transistor 140, and a power wiring 161 disposed on the auxiliary layer 163, and the first gate insulating layer 170 is located between the first active layer 126 and the first gate electrode, between the second active layer 146 and the second gate electrode, and between the auxiliary layer 163 and the power wiring 161. The first conductive layer may include at least one metal selected from molybdenum (Mo), aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), calcium (Ca), titanium (Ti), tantalum (Ta), tungsten (W), and copper (Cu). The first conductive layer may be a single-layer film or a multi-layer film.

[0086] The second gate insulating layer 180 is disposed on the first conductive layer. The second gate insulating layer 180 may be an interlayer insulating film. The second gate insulating layer 180 may include an inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride, hafnium oxide, aluminum oxide, titanium oxide, tantalum oxide, or zinc oxide.

[0087] The second conductive layer is disposed on the second gate insulating layer 180. The second conductive layer includes a capacitor electrode 128 disposed on the first gate electrode 121 with the second gate insulating layer 180 being located therebetween. The capacitor electrode 128 may constitute a storage capacitor together with the first gate electrode 121.

[0088] Similar to the first conductive layer, the second conductive layer may include at least one metal selected from molybdenum (Mo), aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), calcium (Ca), titanium (Ti), tantalum (Ta), tungsten (W) and copper (Cu).

[0089] The interlayer insulating layer 190 is disposed on the second conductive layer. The interlayer insulating layer 190 may be an interlayer insulating film. In addition, the interlayer insulating layer 190 may perform a surface planarization function. The interlayer insulating layer 190 may include an organic insulating material such as a polyacrylate resin, an epoxy resin, a phenolic resin, a polyamide resin, a polyimide resin, an unsaturated polyester resin, a polyphenylene ether resin, a polyphenylene sulfide resin, or benzocyclobutene (BCB).

[0090] The third conductive layer is disposed on the interlayer insulating layer 190 , and includes the first drain electrode 123 and the first source electrode 124 of the first thin film transistor 120 , the second drain electrode 143 and the second source electrode 144 of the second thin film transistor 140 , and the power electrode 162 disposed on the power wiring 161 .

[0091] Each of the first source electrode 124 and the first drain electrode 123 may be electrically connected to the first active layer 126 through a first contact hole 129 penetrating the interlayer insulating layer 190, the second gate insulating layer 180, and the first gate insulating layer 170. Each of the second source electrode 144 and the second drain electrode 143 may be electrically connected to the second active layer 146 through a second contact hole 149 penetrating the interlayer insulating layer 190, the second gate insulating layer 180, and the first gate insulating layer 170. The power electrode 162 may be electrically connected to the power wiring 161 through a third contact hole 169 penetrating the interlayer insulating layer 190 and the second gate insulating layer 180.

[0092] The third conductive layer may include at least one metal selected from molybdenum (Mo), aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), calcium (Ca), titanium (Ti), tantalum (Ta), tungsten (W) and copper (Cu). The third conductive layer may be a single-layer film or a multi-layer film. For example, the third conductive layer may be formed by a stacked structure of Ti / Al / Ti, Mo / Al / Mo, Mo / AlGe / Mo or Ti / Cu.

[0093] The insulating base layer 200 is disposed on the third conductive layer. The insulating base layer 200 may include an organic insulating material such as polyacrylate resin, epoxy resin, phenolic resin, polyamide resin, polyimide resin, unsaturated polyester resin, polyphenylene oxide resin, polyphenylene sulfide resin or benzocyclobutene (BCB). The surface of the insulating base layer 200 may be flat.

[0094] A plurality of banks 410 and 420 may be disposed on the insulating base layer 200. The plurality of banks 410 and 420 are disposed to be spaced apart from each other and face each other in each of the pixels PX, and the first electrode 210 and the second electrode 220 may be disposed on the banks 410 and 420 (e.g., the first bank 410 and the second bank 420) spaced apart from each other. Figure 2 A case is shown in which three banks 410 and 420 (specifically, two first banks 410 and one second bank 420 ) are provided in one pixel PX, and thus, two first electrodes 210 and one second electrode 220 are provided. Figure 2 Only a cross-sectional view of a first bank 410 and a second bank 420 is shown, and the arrangement structure thereof can be equally applied to Figure 2The other first bank 410 is not shown.

[0095] However, the number of banks 410 and 420 is not limited thereto. For example, a greater number of banks 410 and 420 may be provided in one pixel PX, and therefore, a greater number of first electrodes 210 and second electrodes 220 may be provided. The banks 410 and 420 may include at least one first bank 410 on which the first electrode 210 is provided and at least one second bank 420 on which the second electrode 220 is provided. In this case, the first bank 410 and the second bank 420 may be provided to be spaced apart from each other and face each other, and a plurality of banks may be arranged alternately in one direction. In some embodiments, two first banks 410 may be provided to be spaced apart from each other, and one second bank 420 may be provided between the spaced first banks 410.

[0096] In addition, despite the Figure 2 Although not shown in the figure, as described above, the first electrode 210 and the second electrode 220 may include electrode trunk portions 210S and 220S and electrode branch portions 210B and 220B, respectively. It is understood that the first electrode branch portion 210B and the second electrode branch portion 220B are disposed on the first bank 410 and the second bank 420, respectively.

[0097] The plurality of banks 410 and 420 may be made of substantially the same material and thus may be formed in one process. In this case, the banks 410 and 420 may form a grid pattern. The banks 410 and 420 may include polyimide (PI).

[0098] In addition, although not shown in the drawings, at least some of the plurality of banks 410 and 420 may be disposed at the boundaries between the corresponding pixels PX to distinguish them from each other. In this case, the electrodes 210 and 220 may not be disposed on the banks 410 and 420 disposed at the boundaries between the corresponding pixels PX. These banks may be arranged in a substantially grid pattern together with the above-mentioned first bank 410 and second bank 420. At least some of the plurality of banks 410 and 420 disposed at the boundaries between the corresponding pixels PX may be disposed to cover the electrode lines of the display device 10.

[0099] Each of the plurality of dams 410 and 420 may have a structure in which at least a portion thereof protrudes from the insulating base layer 200. Each of the dams 410 and 420 may protrude upward relative to a plane on which the light emitting element 300 is disposed, and at least a portion of the protruding portion may have an inclination. Each of the dams 410 and 420 protruding with an inclination may reflect light incident on the reflective layers 211 and 221 disposed thereon, which will be described later. Light directed from the light emitting element 300 to the reflective layers 211 and 221 may be reflected and transmitted to the outside of the display device 10, for example, above the dams 410 and 420. The shape of each of the protruding dams 410 and 420 is not particularly limited. Although in Figure 2 4 shows that each of the embankments 410 and 420 has a protruding structure having an angular corner shape in which two side surfaces are flat and one upper side is flat, but the present invention is not limited thereto, and each of the embankments 410 and 420 may have a structure protruding in a curved shape.

[0100] Reflective layers 211 and 221 may be disposed on the plurality of banks 410 and 420 .

[0101] The first reflective layer 211 covers the first bank 410, and a portion of the first reflective layer 211 is electrically connected to the first drain electrode 123 of the first thin film transistor 120 through a fourth contact hole 319_1 penetrating the insulating base layer 200. The second reflective layer 221 covers the second bank 420, and a portion of the second reflective layer 221 is electrically connected to the power electrode 162 through a fifth contact hole 319_2 penetrating the insulating base layer 200.

[0102] The first reflective layer 211 may be electrically connected to the first drain electrode 123 of the first thin film transistor 120 through the fourth contact hole 319_1 in the pixel PX. Therefore, the first thin film transistor 120 may be disposed in a region overlapping the pixel PX. Figure 1 2 shows that the first reflective layer 211 is electrically connected to the first thin film transistor 120 through the first electrode contact hole CNTD disposed on the first electrode stem portion 210S. That is, the first electrode contact hole CNTD may be the fourth contact hole 319_1.

[0103] The second reflective layer 221 may also be electrically connected to the power electrode 162 through the fifth contact hole 319_2 in the pixel PX. Figure 2 FIG. 2 shows that the second reflective layer 221 is electrically connected to the power electrode 162 through the fifth contact hole 319_2 in one pixel PX. Figure 12 shows that the second electrode 220 of each pixel PX is electrically connected to the power wiring 161 through a plurality of second electrode contact holes CNTS on the second electrode stem portion 220S. That is, the second electrode contact holes CNTS may be fifth contact holes 319_2.

[0104] As mentioned above, in Figure 1 In the embodiment, the first electrode contact hole CNTD and the second electrode contact hole CNTS are respectively disposed on the first electrode trunk portion 210S and the second electrode trunk portion 220S. Figure 2 It is shown that in the cross-sectional view of the display device 10, the first electrode 210 and the second electrode 220 are electrically connected to the first thin film transistor 120 or the power wiring 161 through the fourth contact hole 319_1 and the fifth contact hole 319_2, respectively, in an area separated from the embankments 410 and 420 where the first electrode branch portion 210B and the second electrode branch portion 220B are provided.

[0105] However, the present invention is not limited thereto. Figure 1 In some embodiments, the second electrode contact hole CNTS may be disposed at various positions on the second electrode trunk portion 220S, and in some cases, the second electrode contact hole CNTS may be disposed on the second electrode branch portion 220B. In addition, in some embodiments, the second reflective layer 221 may be connected to one second electrode contact hole CNTS or one fifth contact hole 319_2 in an area other than the pixel PX.

[0106] The display device 10 may include a region other than the light emitting region provided with the light emitting element 300, for example, a non-light emitting region not provided with the light emitting element 300. As described above, the second electrodes 220 of each pixel PX are electrically connected to each other through the second electrode stem portion 220S to receive the same electrical signal.

[0107] In some embodiments, in the case of the second electrode 220, the second electrode stem portion 220S may be electrically connected to the power electrode 162 through one second electrode contact hole CNTS in a non-light emitting region located outside the display device 10. Figure 1 Unlike the display device 10 of the present invention, even when the second electrode trunk portion 220S is connected to the power electrode 162 through one contact hole, the second electrode trunk portion 220S extends to the adjacent pixel PX and is electrically connected, so that the same electrical signal can be applied to the second electrode branch portion 220B of each pixel PX. In the case of the second electrode 220 of the display device 10, the position of the contact hole for receiving the electrical signal from the power electrode 162 may vary according to the structure of the display device 10.

[0108] In addition, refer again Figure 1 and Figure 2 Each of the reflective layers 211 and 221 may include a high reflectivity material to reflect light emitted from the light emitting element 300. For example, each of the reflective layers 211 and 221 may include a material such as silver (Ag) or copper (Cu), but the present invention is not limited thereto.

[0109] The first electrode layer 212 and the second electrode layer 222 may be disposed on the first reflective layer 211 and the second reflective layer 221 , respectively.

[0110] The first electrode layer 212 is directly disposed on the first reflective layer 211. The first electrode layer 212 may have a pattern substantially the same as that of the first reflective layer 211. The second electrode layer 222 is directly disposed on the second reflective layer 221 and is spaced apart from the first electrode layer 212. The second electrode layer 222 may have a pattern substantially the same as that of the second reflective layer 221.

[0111] In an embodiment, the electrode layers 212 and 222 may respectively cover the underlying reflective layers 211 and 221. That is, the electrode layers 212 and 222 may be formed larger than the reflective layers 211 and 221 to cover the side surfaces of the ends of the reflective layers 211 and 221. However, the present invention is not limited thereto.

[0112] The first electrode layer 212 and the second electrode layer 222 can transmit the electrical signal transmitted to the first reflective layer 211 and the second reflective layer 221 connected to the first thin film transistor 120 or the power electrode 162 to the contact electrode to be described later. The electrode layers 212 and 222 may include a transparent conductive material. For example, the electrode layers 212 and 222 may include materials such as indium tin oxide (ITO), indium zinc oxide (IZO), or indium tin zinc oxide (ITZO), but the present invention is not limited thereto. In some embodiments, the reflective layers 211 and 221 and the electrode layers 212 and 222 may have a structure in which a transparent conductive layer (such as ITO, IZO, or ITZO) and a metal layer (such as silver or copper) are stacked as one or more layers. For example, the reflective layers 211 and 221 and the electrode layers 212 and 222 may have a stacked structure of ITO / silver (Ag) / ITO.

[0113] The first reflective layer 211 and the first electrode layer 212 disposed on the first bank 410 constitute the first electrode 210. The first electrode 210 may protrude to a region extending from both ends of the first bank 410, and thus the first electrode 210 may contact the insulating base layer 200 in the protruding region. The second reflective layer 221 and the second electrode layer 222 disposed on the second bank 420 constitute the second electrode 220. The second electrode 220 may protrude to a region extending from both ends of the second bank 420, and thus the second electrode 220 may contact the insulating base layer 200 in the protruding region.

[0114] The first electrode 210 and the second electrode 220 may be disposed to cover the entire area of ​​the first bank 410 and the entire area of ​​the second bank 420, respectively. However, as described above, the first electrode 210 and the second electrode 220 are spaced apart from each other and face each other. As will be described later, the first insulating material layer 510 may be disposed between the first electrode 210 and the second electrode 220 spaced apart from each other, and the light emitting element 300 may be disposed on the first insulating material layer 510.

[0115] In addition, the first reflective layer 211 may receive a driving voltage from the first thin film transistor 120, and the second reflective layer 221 may receive a power supply voltage from the power supply wiring 161, so that the first electrode 210 and the second electrode 220 receive a driving voltage and a power supply voltage, respectively. The first electrode 210 may be electrically connected to the first thin film transistor 120, and the second electrode 220 may be electrically connected to the power supply wiring 161. Therefore, the first contact electrode 261 and the second contact electrode 262 provided on the first electrode 210 and the second electrode 220 may receive a driving voltage and a power supply voltage. The driving voltage and the power supply voltage are transmitted to the light emitting element 300, and a predetermined current flows through the light emitting element 300 to emit light.

[0116] The first insulating material layer 510 is disposed on the first electrode 210 and the second electrode 220 to partially cover them. The first insulating material layer 510 may be disposed to cover most of the upper surfaces of the first electrode 210 and the second electrode 220, and may expose a portion of the first electrode 210 and a portion of the second electrode 220. The first insulating material layer 510 may be disposed in the space between the first electrode 210 and the second electrode 220. The first insulating material layer 510 may have an island shape or a line shape formed along the space between the first electrode branch portion 210B and the second electrode branch portion 220B in a plan view.

[0117] exist Figure 2 , it is shown that the first insulating material layer 510 is disposed in the space between one first electrode 210 (e.g., the first electrode branch portion 210B) and one second electrode 220 (e.g., the second electrode branch portion 220B). However, as described above, since the number of first electrodes 210 may be plural and the number of second electrodes 220 may be plural, the first insulating material layer 510 may also be disposed between one first electrode 210 and another second electrode 220 or between one second electrode 220 and another first electrode 210. In addition, the first insulating material layer 510 may be disposed on the side opposite to the facing side of the first electrode 210 and the second electrode 220 to partially cover them. That is, the first insulating material layer 510 may be disposed to expose the centers of the first electrode 210 and the second electrode 220.

[0118] The light emitting element 300 is disposed on the first insulating material layer 510. The first insulating material layer 510 may be disposed between the light emitting element 300 and the insulating base layer 200. The lower surface of the first insulating material layer 510 may be in contact with the insulating base layer 200, and the light emitting element 300 may be disposed on the upper surface of the first insulating material layer 510. In addition, both side surfaces of the first insulating material layer 510 may be in contact with the first electrode 210 and the second electrode 220 to electrically insulate them from each other.

[0119] The first insulating material layer 510 may overlap a portion of a region on each of the electrodes 210 and 220, for example, a portion of a region protruding in a direction in which the first electrode 210 and the second electrode 220 face each other. The first insulating material layer 510 may also be provided in a region where the inclined side surface and the flat upper surface of each of the banks 410 and 420 overlap each of the electrodes 210 and 220.

[0120] For example, the first insulating material layer 510 may cover each end portion protruding in the direction in which the first electrode 210 and the second electrode 220 face each other. The first insulating material layer 510 may be in contact with a portion of the upper surface of the insulating base layer 200, and may be in contact with the side surface of each of the electrodes 210 and 220 and a portion of the upper surface of each of the electrodes 210 and 220. Therefore, the first insulating material layer 510 may protect the region overlapped with each of the electrodes 210 and 220, and electrically insulate the electrodes 210 and 220 from each other. In addition, the first insulating material layer 510 may prevent the first conductive semiconductor layer 310 and the second conductive semiconductor layer 320 of the light emitting element 300 from directly contacting other substrates to prevent damage to the light emitting element 300.

[0121] However, the present invention is not limited thereto, and the first insulating material layer 510 may be provided only in a region overlapping the inclined surfaces of the banks 410 and 420 among the regions on the first electrode 210 and the second electrode 220. In this case, the lower surface of the first insulating material layer 510 terminates at the inclined surface of each of the banks 410 and 420, and each of the electrodes 210 and 220 provided on a portion of the inclined surface of each of the banks 410 and 420 is exposed to contact the contact electrode 260.

[0122] In addition, the first insulating material layer 510 may be provided so that both ends of the light emitting element 300 are exposed. Therefore, the contact electrode 260 may contact the exposed upper surface of each of the electrodes 210 and 220 and both ends of the light emitting element 300, and the contact electrode 260 may transmit the electrical signal applied to the first electrode 210 and the second electrode 220 to the light emitting element 300.

[0123] At least one light emitting element 300 may be disposed between the first electrode 210 and the second electrode 220. Figure 2 FIG. 4 shows a light emitting element 300 disposed between the first electrode 210 and the second electrode 220 in the cross section, but it is obvious that Figure 1 As shown in , a plurality of light emitting elements 300 may be arranged along different directions (eg, the second direction D2 ) on a plane.

[0124] Specifically, one end of the light emitting element 300 may be electrically connected to the first electrode 210, and the other end thereof may be electrically connected to the second electrode 220. Both ends of the light emitting element 300 may contact the first contact electrode 261 and the second contact electrode 262, respectively.

[0125] In addition, despite Figure 1 , only the light emitting elements 300 emitting light of the same color are arranged in each pixel PX, but the present invention is not limited thereto. As described above, the light emitting elements 300 emitting light of different colors may be arranged in one pixel PX.

[0126] The light emitting element 300 may be a light emitting diode. The light emitting element 300 may be a nanostructure whose size is generally nanometers. The light emitting element 300 may be an inorganic light emitting diode including an inorganic material. In the case where the light emitting element 300 is an inorganic light emitting diode, when a light emitting material having an inorganic crystal structure is disposed between two electrodes facing each other and an electric field is formed in the light emitting material in a specific direction, the inorganic light emitting diode may be aligned between two electrodes having a specific polarity formed therein.

[0127] In some embodiments, the light emitting element 300 may include a first conductive semiconductor layer 310, an element active layer 330, a second conductive semiconductor layer 320, and an electrode material layer 370, which are sequentially stacked, and an insulating layer 380 surrounding the outer peripheral surface of these layers. In the stacking order of the above layers in the light emitting element 300, the first conductive semiconductor layer 310, the element active layer 330, the second conductive semiconductor layer 320, and the electrode material layer 370 are arranged in a horizontal direction relative to the insulating base layer 200. In other words, the light emitting element 300 in which a plurality of layers are formed may be arranged in a horizontal direction relative to the insulating base layer 200. However, the present invention is not limited thereto, and the light emitting element 300 may be aligned so that the above stacking direction is reversed between the first electrode 210 and the second electrode 220.

[0128] In addition, despite the Figure 2 , only one light emitting element 300 is shown to be provided, but as described above, a plurality of light emitting elements 300 having different diameters from each other may be arranged between the first electrode 210 and the second electrode 220. The details of the light emitting element will be described later.

[0129] The second insulating material layer 520 may be disposed to overlap at least a portion of a region on the light emitting element 300. The second insulating material layer 520 may protect the light emitting element 300 and may fix the light emitting element 300 between the first electrode 210 and the second electrode 220.

[0130] The second insulating material layer 520 is disposed only on the upper surface of the light emitting element 300 in a cross-sectional view, or as shown in FIG. Figure 2 As shown in , the second insulating material layer 520 may be provided to surround the outer surface of the light emitting element 300. That is, similar to the first insulating material layer 510, the second insulating material layer 520 may be provided to extend in the second direction D2 along the space between the first electrode branch portion 210B and the second electrode branch portion 220B to have an island shape or a line shape in a plan view.

[0131] Furthermore, a portion of the material of the second insulating material layer 520 may even be disposed in a region where the lower surface of the light emitting element 300 contacts the first insulating material layer 510. When manufacturing the display device 10, such a configuration may be formed when the light emitting element 300 is aligned on the first insulating material layer 510 and the second insulating material layer 520 is disposed on the first insulating material layer 510. When some voids are formed in the first insulating material layer 510 contacting the lower surface of the light emitting element 300, a portion of the material of the second insulating material layer 520 penetrates into the voids when the second insulating material layer 520 is formed to form such a configuration.

[0132] The second insulating material layer 520 is arranged so that the two side surfaces of the light emitting element 300 are exposed. That is, because the length of the second insulating material layer 520 measured in the uniaxial direction provided on the upper surface of the light emitting element 300 in the cross section is shorter than the length of the light emitting element 300, the second insulating material layer 520 can be recessed inward from the two side surfaces of the light emitting element 300. Therefore, the side surfaces of the first insulating material layer 510, the light emitting element 300, and the second insulating material layer 520 can be stacked in steps. In this case, the contact electrodes 261 and 262 to be described later can be in smooth contact with both ends of the light emitting element 300. However, the present invention is not limited thereto, and the length of the second insulating material layer 520 can match the length of the light emitting element 300 so that their two sides can be aligned with each other.

[0133] In addition, the second insulating material layer 520 may be provided to cover the first insulating material layer 510 and then patterned in the region where the light emitting element 300 is exposed to contact the contact electrode 260. The process of patterning the second insulating material layer 520 may be performed by a commonly used dry etching or wet etching method. Here, in order to prevent the first insulating material layer 510 from being patterned, the first insulating material layer 510 and the second insulating material layer 520 may include materials having different etching selectivities from each other. In other words, when the second insulating material layer 520 is patterned, the first insulating material layer 510 may be used as an etching stopper.

[0134] Therefore, even when the second insulating material layer 520 covers the outer surface of the light emitting element 300 and is patterned to expose both ends of the light emitting element 300, the material of the first insulating material layer 510 is not damaged. Specifically, the first insulating material layer 510 and the light emitting element 300 can form a smooth contact surface at both ends of the light emitting element 300, and the light emitting element 300 contacts the contact electrode 260 at the smooth contact surface.

[0135] A first contact electrode 261 disposed on the first electrode 210 and overlapping at least a portion of the second insulating material layer 520 and a second contact electrode 262 disposed on the second electrode 220 and overlapping at least a portion of the second insulating material layer 520 may be disposed on the second insulating material layer 520 .

[0136] The first contact electrode 261 and the second contact electrode 262 may be disposed on the upper surface of the first electrode 210 and the upper surface of the second electrode 220, respectively. Specifically, the first contact electrode 261 and the second contact electrode 262 may be in contact with the first electrode layer 212 and the second electrode layer 222, respectively, in a region where the first insulating material layer 510 is patterned to expose a portion of the first electrode 210 and a portion of the second electrode 220. Each of the first contact electrode 261 and the second contact electrode 262 may be in contact with one end side surface of the light emitting element 300 (e.g., the first conductive semiconductor layer 310, the second conductive semiconductor layer 320, or the electrode material layer 370). Therefore, the first contact electrode 261 and the second contact electrode 262 may transmit an electrical signal applied to the first electrode layer 212 and the second electrode layer 222 to the light emitting element 300.

[0137] The first contact electrode 261 may be disposed on the first electrode 210 to partially cover the first electrode 210, and may partially contact the light emitting element 300, the first insulating material layer 510, and the second insulating material layer 520. One end of the first contact electrode 261 in the direction in which the second contact electrode 262 is disposed may be disposed on the second insulating material layer 520. The second contact electrode 262 may be disposed on the second electrode 220 to partially cover the second electrode 220, and may partially contact the light emitting element 300, the first insulating material layer 510, and the third insulating material layer 530. One end of the second contact electrode 262 in the direction in which the first contact electrode 261 is disposed may be disposed on the third insulating material layer 530.

[0138] Regions of the first and second electrodes 210 and 220 provided with the first and second insulating material layers 510 and 520 to cover the first and second electrodes 210 and 220 on the upper surfaces of the first and second banks 410 and 420 may be patterned. Thus, the first electrode layer 212 of the first electrode 210 and the second electrode layer 222 of the second electrode 220 are exposed to be electrically connected to the contact electrodes 261 and 262, respectively.

[0139] The first contact electrode 261 and the second contact electrode 262 may be disposed to be spaced apart from each other on the second insulating material layer 520 or the third insulating material layer 530. That is, the first contact electrode 261 and the second contact electrode 262 contact the second insulating material layer 520 or the third insulating material layer 530 and the light emitting element 300, but the first contact electrode 261 and the second contact electrode 262 are spaced apart from each other along the stacking direction on the second insulating material layer 520 to be electrically insulated from each other. Therefore, the first contact electrode 261 and the second contact electrode 262 may receive different power from the first thin film transistor 120 and the power wiring 161. For example, the first contact electrode 261 may receive a driving voltage applied from the first thin film transistor 120 to the first electrode 210, and the second contact electrode 262 may receive a common power voltage applied from the power wiring 161 to the second electrode 220. However, the present invention is not limited thereto.

[0140] The contact electrodes 261 and 262 may include a conductive material. For example, the contact electrodes 261 and 262 may include ITO, IZO, ITZO, or aluminum (Al). However, the present invention is not limited thereto.

[0141] In addition, the contact electrodes 261 and 262 may include the same material as that of the electrode layers 212 and 222. The contact electrodes 261 and 262 may be disposed on the electrode layers 212 and 222 in substantially the same pattern to contact the electrode layers 212 and 222. For example, the first contact electrode 261 contacting the first electrode layer 212 and the second contact electrode 262 contacting the second electrode layer 222 may receive an electrical signal applied from the first electrode layer 212 and the second electrode layer 222, and transmit the electrical signal to the light emitting element 300.

[0142] The third insulating material layer 530 may be disposed on the first contact electrode 261 to electrically insulate the first contact electrode 261 and the second contact electrode 262 from each other. The third insulating material layer 530 may be disposed to cover the first contact electrode 261, but may be disposed not to overlap a portion of the light emitting element 300, so that the light emitting element 300 contacts the second contact electrode 262. The third insulating material layer 530 may partially contact the first contact electrode 261, the second contact electrode 262, and the second insulating material layer 520 on the upper surface of the second insulating material layer 520. The third insulating material layer 530 may be disposed to cover one end of the first contact electrode 261 on the upper surface of the second insulating material layer 520. Therefore, the third insulating material layer 530 may protect the first contact electrode 261 and electrically insulate the first contact electrode 261 and the second contact electrode 262 from each other.

[0143] One end of the third insulating material layer 530 in the direction in which the second electrode 220 is provided may be aligned with one side surface of the second insulating material layer 520 .

[0144] In addition, in some embodiments, the third insulating material layer 530 may be omitted in the display device 10. Therefore, the first contact electrode 261 and the second contact electrode 262 may be disposed on substantially the same plane and may be electrically insulated from each other by a passivation layer 550 to be described later.

[0145] The passivation layer 550 may be formed on the third insulating material layer 530 and the second contact electrode 262 to protect the components disposed on the insulating base layer 200 from the external environment. When the first contact electrode 261 and the second contact electrode 262 are exposed, the problem of disconnection of the contact electrode material due to electrode damage may occur, so the passivation layer 550 may cover these components. That is, the passivation layer 550 may be provided to cover the first electrode 210, the second electrode 220, the light emitting element 300, etc. As described above, when the third insulating material layer 530 is omitted, the passivation layer 550 may be formed on the first contact electrode 261 and the second contact electrode 262. In this case, the passivation layer 550 may electrically insulate the first contact electrode 261 and the second contact electrode 262 from each other.

[0146] Each of the first insulating material layer 510, the second insulating material layer 520, the third insulating material layer 530, and the passivation layer 550 may include an inorganic insulating material. For example, the first insulating material layer 510, the second insulating material layer 520, the third insulating material layer 530, and the passivation layer 550 may include an inorganic insulating material such as silicon oxide (SiO x ), Silicon Nitride (SiN x ), silicon oxynitride (SiO x N y ), aluminum oxide (Al 2 O 3 ) or an inorganic insulating material such as aluminum nitride (AlN). The first insulating material layer 510, the second insulating material layer 520, the third insulating material layer 530, and the passivation layer 550 may include the same material or may include materials different from each other. In addition, various materials that impart insulating properties to the first insulating material layer 510, the second insulating material layer 520, the third insulating material layer 530, and the passivation layer 550 may be applicable.

[0147] In addition, as described above, the first insulating material layer 510 and the second insulating material layer 520 may have different etching selectivities. For example, when the first insulating material layer 510 includes silicon oxide (SiO x ), the second insulating material layer 520 may include silicon nitride (SiN x As another example, when the first insulating material layer 510 includes silicon nitride (SiN x ), the second insulating material layer 520 may include silicon oxide (SiO x ). However, the present invention is not limited thereto.

[0148] In addition, the light emitting element 300 may be manufactured on the substrate by an epitaxial growth method. The light emitting element 300 may be manufactured by forming a seed layer for forming a semiconductor layer on the substrate, and depositing a desired semiconductor material on the seed layer to grow the seed layer. Figure 3 The structure of the light emitting element 300 according to various embodiments is described in detail.

[0149] Figure 3 is a schematic perspective view of a light emitting element according to an embodiment.

[0150] Reference Figure 3 , the light emitting element 300 may include a plurality of conductive semiconductor layers 310 and 320, an element active layer 330, an electrode material layer 370, and an insulating layer 380. The electrical signal applied from the first electrode 210 and the second electrode 220 may be transmitted to the element active layer 330 through the plurality of conductive semiconductor layers 310 and 320 to emit light.

[0151] Specifically, the light emitting element 300 may include a first conductive semiconductor layer 310, a second conductive semiconductor layer 320, an element active layer 330 disposed between the first conductive semiconductor layer 310 and the second conductive semiconductor layer 320, an electrode material layer 370 disposed on the second conductive semiconductor layer 320, and an insulating layer 380. Figure 3 3 shows that the light emitting element 300 has a structure in which a first conductive semiconductor layer 310, an element active layer 330, a second conductive semiconductor layer 320, and an electrode material layer 370 are sequentially stacked, but the present invention is not limited thereto. The electrode material layer 370 may be omitted, and in some embodiments, the electrode material layer 370 may also be provided on at least one of the two side surfaces of the first conductive semiconductor layer 310 and the second conductive semiconductor layer 320. Hereinafter, the Figure 3 The light emitting element 300 of FIG. 1 is taken as an example, and it is apparent that even if the light emitting element 300 also includes other structures, the description of the light emitting element 300 to be described later can be equally applied.

[0152] The first conductive semiconductor layer 310 may be an n-type semiconductor layer. For example, when the light emitting element 300 emits light in the blue wavelength band, the first conductive semiconductor layer 310 may be an n-type semiconductor layer. x Al y Ga 1-x-yThe first conductive semiconductor layer 310 may be a semiconductor material having a chemical formula of N(0≤x≤1, 0≤y≤1, 0≤x+y≤1). For example, the semiconductor material may be at least one of InAlGaN, GaN, AlGaN, InGaN, AlN, and InN doped with an n-type conductive dopant. The first conductive semiconductor layer 310 may be doped with a first conductive dopant, for example, the first conductive dopant may be Si, Ge, Sn, etc. The length of the first conductive semiconductor layer 310 may be in the range of 1.5 μm to 5 μm, but is not limited thereto.

[0153] The second conductive semiconductor layer 320 may be a p-type semiconductor layer. For example, when the light emitting element 300 emits light in the blue wavelength band, the second conductive semiconductor layer 320 may be a p-type semiconductor layer. x Al y Ga 1-x-y The second conductive semiconductor layer 320 may be a semiconductor material having a chemical formula of N(0≤x≤1, 0≤y≤1, 0≤x+y≤1). For example, the semiconductor material may be at least one of InAlGaN, GaN, AlGaN, InGaN, AlN, and InN doped with a p-type conductive dopant. The second conductive semiconductor layer 320 may be doped with a second conductive dopant, for example, the second conductive dopant may be Mg, Zn, Ca, Se, Ba, etc. The length of the second conductive semiconductor layer 320 may be in the range of 0.08 μm to 0.25 μm, but is not limited thereto.

[0154] The element active layer 330 may be disposed between the first conductive semiconductor layer 310 and the second conductive semiconductor layer 320, and may include a material having a single quantum well structure or a multi-quantum well structure. When the element active layer 330 includes a material having a multi-quantum well structure, the multi-quantum well structure may be a structure in which a plurality of quantum layers and a plurality of well layers are alternately stacked. According to an electrical signal applied through the first conductive semiconductor layer 310 and the second conductive semiconductor layer 320, the element active layer 330 may emit light by the combination of electron-hole pairs. For example, when the element active layer 330 emits light in the blue band, it may include a material such as AlGaN or AlInGaN. Specifically, when the element active layer 330 has a multi-quantum well structure in which a plurality of quantum layers and a plurality of well layers are alternately stacked, the quantum layer may include a material such as AlGaN or AlInGaN, and the well layer may include a material such as GaN or AlGaN. However, the present invention is not limited thereto. The element active layer 330 may have a structure in which a semiconductor material having a high band gap energy and a semiconductor material having a low band gap energy are alternately stacked, and may include other III-V semiconductor materials according to the wavelength band of the emitted light. Therefore, the light emitted from the element active layer 330 is not limited to the light in the blue wavelength band, and in some cases, the element active layer 330 may emit light in the red wavelength band or light in the green wavelength band. The length of the element active layer 330 may be in the range of 0.05 μm to 0.25 μm, but is not limited thereto.

[0155] The light emitted from the element active layer 330 may be emitted not only to the outer surface of the light emitting element 300 in the length direction but also to both side surfaces thereof. That is, the direction of the light emitted from the element active layer 330 is not limited to one direction.

[0156] In addition, the element active layer 330 of the light emitting element 300 may have emission light of different wavelength bands according to the difference in components. Specifically, the element active layer 330 may emit light of different colors according to the type of active material of the element active layer 330, but even if the element active layer 330 includes the same type of active material, a deviation in the emission wavelength may occur according to the component ratio in the element active layer 330 and the lattice strain of the semiconductor crystal. In other words, the element active layer 330 may include the same type of active material to have any band gap energy, but when the light emitting element 300 is manufactured, the band gap energy varies according to the lattice strain of the active material crystal formed in the element active layer 330, and therefore, a deviation in the wavelength band of the emitted light may occur.

[0157] Here, when a plurality of light emitting elements 300 are formed to have different diameters from each other, the lattice strain of the active material crystals included in the element active layer 330 of each of the light emitting elements 300 may vary. The band gap energy of the element active layer 330 may vary according to the different lattice strains between the light emitting elements 300, and thus, the wavelength of the emitted light may vary.

[0158] Therefore, based on the light emitting element 300 emitting light in an arbitrary wavelength band, the emission wavelength of the light emitting element 300 that is deviated from the light in the wavelength band can be controlled by adjusting the diameter of the light emitting element 300 .

[0159] The electrode material layer 370 may be an ohmic contact electrode. However, the present invention is not limited thereto, and the electrode material layer 370 may be a Schottky contact electrode. The electrode material layer 370 may include a conductive metal. For example, the electrode material layer 370 may include at least one of aluminum (Al), titanium (Ti), indium (In), gold (Au), and silver (Ag). The electrode material layer 370 may include the same material, and may also include different materials. However, the present invention is not limited thereto.

[0160] The insulating layer 380 may be formed outside the first conductive semiconductor layer 310, the second conductive semiconductor layer 320, the element active layer 330, and the electrode material layer 370 to protect these components. For example, the insulating layer 380 is formed to surround the side surface of the component, and thus may not be formed at both ends of the light emitting element 300 in the length direction, for example, at both ends of the light emitting element 300 where the first conductive semiconductor layer 310 and the electrode material layer 370 are provided. However, the present invention is not limited thereto.

[0161] The insulating layer 380 may include a material having insulating properties, such as silicon oxide (SiO x ), Silicon Nitride (SiN x ), silicon oxynitride (SiO x N y ), aluminum nitride (AlN) or aluminum oxide (Al 2 O 3 ). Therefore, the insulating layer 380 can prevent an electrical short circuit that may occur when the element active layer 330 is in direct contact with the first electrode 210 or the second electrode 220. In addition, since the insulating layer 380 can protect the outer peripheral surface of the light emitting element 300 including the element active layer 330, the insulating layer 380 can prevent a decrease in light emitting efficiency.

[0162] Although the insulating layer 380 is shown in the drawings as extending in the length direction to cover the first conductive semiconductor layer 310 to the electrode material layer 370, the present invention is not limited thereto. The insulating layer 380 may cover only the first conductive semiconductor layer 310, the element active layer 330, and the second conductive semiconductor layer 320, or may cover only a portion of the outer surface of the electrode material layer 370 to expose a portion of the outer surface of the electrode material layer 370.

[0163] The thickness of the insulating layer 380 may be in the range of 0.5 μm to 1.5 μm, but is not limited thereto.

[0164] In addition, in some embodiments, the outer peripheral surface of the insulating layer 380 may be surface treated. As described above, when the light emitting element 300 is aligned between the electrodes 210 and 220, the light emitting element 300 may be coated in a dispersed state in a solution. Here, the insulating layer 380 may be subjected to a hydrophobic or hydrophilic surface treatment so that the light emitting element 300 may be maintained in a state in which the light emitting elements 300 are dispersed with each other in a solution. Therefore, when the light emitting element 300 is aligned, the light emitting element 300 may be aligned between the first electrode 210 and the second electrode 220 without being aggregated.

[0165] The light emitting element 300 may be cylindrical. Therefore, a cross-sectional view of the light emitting element 300 taken along the length direction passing through both ends of the light emitting element 300 may have a rectangular shape. However, the shape of the light emitting element 300 is not limited thereto, and may have various shapes such as a cube, a cuboid, and a hexagonal column. The length l of the light emitting element 300 may be in the range of 1 μm to 10 μm or 2 μm to 5 μm, and may preferably be about 4 μm. In addition, the diameter of the light emitting element 300 may be in the range of 300 nm to 700 nm, and as described above, the plurality of light emitting elements 300 included in the display device 10 may have different diameters from each other according to the differences in the components of the element active layer 330. Preferably, the diameter of the light emitting element 300 may be about 500 nm.

[0166] In addition, as described above, a plurality of light emitting elements 300 may have diameters different from each other. In an exemplary embodiment, the difference in diameter between any light emitting element 300 and another light emitting element 300 having a different diameter may be in the range of 2% to 16% of the diameter of any light emitting element 300. For example, when any light emitting element (e.g., the second light emitting element 302) has a diameter of 500nm, the first light emitting element 301 may have a diameter in the range of 420nm to 490nm, and the third light emitting element 303 may have a diameter in the range of 510nm to 580nm. However, the present invention is not limited thereto, and as will be described later, the diameter of the light emitting element 300 may vary depending on the difference in the components of the element active layer 330.

[0167] In the following, for convenience, Figure 3 The light emitting element 300 shown in FIG. 1 is taken as an example, but as described above, this case can be equally applied even to the case where a larger number of electrode material layers 370 are included or other structures are also included.

[0168] in addition, Figure 4 It is along Figure 1 A cross-sectional view taken along line IV-IV'.

[0169] Figure 1 The line IV-IV′ may be a line passing through the centers of both ends of the light emitting element 300 aligned along the first direction D1 between the first electrode 210 and the second electrode 220, Figure 4 It is a cross-sectional view taken along a line passing through the centers of both ends of the plurality of light emitting elements 300 .

[0170] Reference Figure 2 and Figure 4 The lower surfaces of the first light emitting element 301, the second light emitting element 302, and the third light emitting element 303 may partially contact the first insulating material layer 510 and the second insulating material layer 520, and the upper surfaces of the first light emitting element 301, the second light emitting element 302, and the third light emitting element 303 may be fixed between the first electrode 210 and the second electrode 220 by the second insulating material layer 520. The third insulating material layer 530 and the passivation layer 550 may be formed on the second insulating material layer 520, Figure 4 The structure shown in the reference Figure 1 and Figure 2 The structure described is the same.

[0171] The plurality of light emitting elements 300 included in the display device 10 may include a first light emitting element 301, a second light emitting element 302, and a third light emitting element 303 having different diameters from each other. The first light emitting element 301, the second light emitting element 302, and the third light emitting element 303 have different diameters from each other but may emit light of substantially the same wavelength band.

[0172] The diameter r2 of the second light emitting element 302 may be larger than the diameter r1 of the first light emitting element 301, but smaller than the diameter r3 of the third light emitting element 303. In other words, the first light emitting element 301, the second light emitting element 302, and the third light emitting element 303 may be formed so that the diameters increase sequentially. This may mean that the diameters of the light emitting elements 300 are adjusted when the light emitting elements 300 are manufactured so that the wavelength band of the light emitted from the element active layer 330 of each of the light emitting elements 300 is shifted.

[0173] As described above, when manufacturing the light-emitting element 300, the element active layers 330 of the plurality of light-emitting elements 300 may have different components from each other, and therefore, the light-emitting elements 300 may have different band gap energies from each other. For example, when the first light-emitting element 301, the second light-emitting element 302, and the third light-emitting element 303 grown on the same wafer substrate all have the same diameter, the element active layers 330 of the light-emitting elements may emit light of different wavelengths. The element active layer 330 of the first light-emitting element 301 may emit the first light L1 of the first wavelength band, the element active layer 330 of the second light-emitting element 302 may emit the second light L2 of the second wavelength band, and the element active layer 330 of the third light-emitting element 303 may emit the third light L3 of the third wavelength band.

[0174] Here, when the second light L2, which is the light emitted by the element active layer 330 of the second light emitting element 302, is set as a reference, the light emitted by the element active layer 330 of the first light emitting element 301 and the third light emitting element 303 may have a wavelength band deviation from the second light L2. However, in order to minimize the deviation of the wavelength of the light emitted by the light emitting element 300, the light emitting element 300 may have different diameters so that the emission wavelength can be frequency shifted. By controlling the lattice strain of the element active layer 330 by varying the diameter of each of the light emitting elements 300, the first light emitting element 301, the second light emitting element 302, and the third light emitting element 303 can be frequency shifted to emit light having substantially the same wavelength.

[0175] As an example, the diameter r1 of the first light emitting element 301 may be smaller than the diameter r2 of the second light emitting element 302, and the light emitted from the element active layer 330 of the first light emitting element 301 may be blue-shifted, so that its wavelength becomes shorter from the first light L1 to the second light L2. In addition, the diameter r3 of the third light emitting element 303 may be larger than the diameter r2 of the second light emitting element 302, and the light emitted from the element active layer 330 of the third light emitting element 303 may be red-shifted, so that its wavelength becomes longer from the third light L3 to the second light L2. Therefore, the first light emitting element 301, the second light emitting element 302, and the third light emitting element 303 may emit light of substantially the same wavelength band (e.g., the second light L2). However, the present invention is not limited thereto, and the plurality of light emitting elements 300 included in the display device 10 may include a greater number of light emitting elements 300 having different diameters.

[0176] As described above, when the light emitting element 300 is manufactured, the nano patterns 1710, 1720, and 1730 (shown in FIG. Figure 8 The etching pattern layer 1700 (shown in Figure 8) to manufacture the first light emitting element 301, the second light emitting element 302 and the third light emitting element 303 having different diameters. When vertically etching the semiconductor structure 3000 grown on the wafer substrate (shown in Figure 6 In the step of forming the nanopatterns 1710, 1720, and 1730 having different diameters from each other, the light emitting elements 300 finally manufactured have different diameters but can emit light of substantially the same wavelength band. Therefore, the plurality of light emitting elements 300 can minimize the deviation of the emission wavelength, and the display device 10 according to the embodiment can improve the purity and reliability of the light emitted from each pixel PX.

[0177] In the following, reference will be made to Figures 5 to 16 The method of manufacturing the light emitting element 300 according to the embodiment is described in detail.

[0178] Figures 5 to 16 is a cross-sectional view or a flowchart schematically illustrating a method of manufacturing a light emitting element according to an embodiment.

[0179] Figure 5 and Figure 6 is a cross-sectional view schematically illustrating a method of forming a semiconductor structure according to an embodiment.

[0180] First, refer to Figure 5 , prepare a lower base layer 1000, the lower base layer 1000 includes a base substrate 1100 and a buffer material layer 1200 formed on the base substrate 1100. Figure 5 As shown in , the lower substrate layer 1000 may have a structure in which a base substrate 1100 and a buffer material layer 1200 are sequentially stacked.

[0181] The base substrate 1100 may be a sapphire substrate (Al 2 O 3 ) or a transparent substrate such as a glass substrate. However, the present invention is not limited thereto, and the base substrate 1100 may be a conductive substrate including GaN, SiC, ZnO, Si, GaP, or GaAs. Hereinafter, the base substrate 1100 will be described as a sapphire substrate (Al 2 O 3 The thickness of the base substrate 1100 is not particularly limited, but for example, the base substrate 1100 may have a thickness in the range of 400 μm to 1500 μm.

[0182] A plurality of conductive semiconductor layers are formed on the base substrate 1100. A plurality of conductive semiconductor layers grown by an epitaxial method can be grown by forming a seed crystal and depositing a crystalline material thereon. Here, the conductive semiconductor layer can be formed by electron beam deposition, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma laser deposition (PLD), dual-type thermal evaporation, sputtering or metal organic chemical vapor deposition (MOCVD), preferably, the conductive semiconductor layer can be formed by metal organic chemical vapor deposition (MOCVD). However, the present invention is not limited thereto.

[0183] The precursor material for forming the plurality of conductive semiconductor layers is not particularly limited within the range that can be generally selected to form the target material. For example, the precursor material may be a metal precursor containing an alkyl group such as a methyl group or an ethyl group. For example, the precursor material may be a precursor such as trimethylgallium (Ga(CH 3 ) 3 ), trimethylaluminum (Al(CH 3 ) 3 ) or triethyl phosphate ((C 2 H 5 ) 3 PO 4 ) compounds, but not limited thereto. Hereinafter, the method of forming a plurality of conductive semiconductor layers, its process conditions, etc. will be omitted, and the order of the method of manufacturing the light emitting element 300 and the stacked structure of the light emitting element 300 will be described in detail.

[0184] A buffer material layer 1200 is formed on the base substrate 1100. Although it is shown in the drawings that one buffer material layer 1200 is stacked, the present invention is not limited thereto, and a plurality of buffer material layers 1200 may be formed. The buffer material layer 1200 may be provided on the base substrate 1100 to reduce a difference in a lattice constant of the first conductive semiconductor layer 3100. In a step to be described later, the buffer material layer 1200 may provide a seed crystal so that crystals of the first conductive semiconductor layer 3100 may be easily grown thereon.

[0185] As an example, the buffer material layer 1200 may include an undoped semiconductor, and may include a material substantially the same as that of the first conductive semiconductor layer 3100, but may include a material not doped with an n-type or p-type dopant. In an exemplary embodiment, the buffer material layer 1200 may include at least one of undoped InAlGaN, GaN, AlGaN, InGaN, AlN, and InN, but the material thereof is not limited thereto.

[0186] In addition, despite Figure 5, but a separation layer 1300 (shown in FIG. Fig.21 As will be described later, a separation layer 1300 may be provided on the buffer material layer 1200 to perform a chemical separation method (chemical peeling, CLO) for removing the separation layer 1300 when separating the element rod ROD from the lower substrate layer 1000. Therefore, the end surface of the manufactured light emitting element 300 may be formed to be relatively flat. For a more detailed description, reference is made to other embodiments.

[0187] Next, refer to Figure 6 , a first conductive semiconductor layer 3100 , an active material layer 3300 , a second conductive semiconductor layer 3200 , and a conductive electrode material layer 3700 are formed on the buffer material layer 1200 of the lower substrate layer 1000 to form a semiconductor structure 3000 .

[0188] The semiconductor structure 3000 may be partially etched in a step to be described later to form an element rod ROD (shown in FIG. Fig.13 ). A plurality of material layers included in the semiconductor structure 3000 may be formed by performing conventional processes as described above. A first conductive semiconductor layer 3100, an active material layer 3300, a second conductive semiconductor layer 3200, and a conductive electrode material layer 3700 may be sequentially formed on the separation layer 1300, and the first conductive semiconductor layer 3100, the active material layer 3300, the second conductive semiconductor layer 320, and the conductive electrode material layer 3700 may include the same materials as the first conductive semiconductor layer 310, the element active layer 330, the second conductive semiconductor layer 320, and the electrode material layer 370 of the light emitting element 300, respectively.

[0189] Although not shown in the drawings, the light emitting element 300 may omit the electrode material layer 370, or may further include another electrode material layer 370 below the first conductive semiconductor layer 310. Figure 6 Differently, in the semiconductor structure 3000, the conductive electrode material layer 3700 may be omitted, or another conductive electrode material layer may be formed under the first conductive semiconductor layer 3100. However, hereinafter, a case where the semiconductor structure 3000 includes the conductive electrode material layer 3700 will be described as an example.

[0190] Figure 7 1 is a flowchart showing a step of forming an element rod in a method of manufacturing a light emitting element according to an embodiment.

[0191] Reference Figure 7According to the embodiment, the method for manufacturing a light emitting element may include the following steps: (S100) forming a semiconductor structure 3000 on a lower substrate layer 1000; (S200) measuring light having different wavelength bands emitted from the semiconductor structure 3000 to define a wavelength area WA on the semiconductor structure 3000; and (S300) forming nano-patterns 1710, 1720 and 1730 having different diameters and spaced apart from each other on the semiconductor structure 3000 according to the wavelength area WA, and etching the semiconductor structure 3000 to form an element rod ROD.

[0192] Depending on the performance or quality of manufacturing equipment, the semiconductor structure 3000 formed on the lower substrate layer 1000 may have a region where its composition is partially non-uniform depending on its spatial position. For example, when the semiconductor structure 3000 is formed by metal organic chemical vapor deposition (MOCVD), the precursor material disposed on the lower substrate layer 1000 may be in the form of a gas phase. The precursor material in the gas phase may be disposed on the lower substrate layer 1000 in an uneven distribution, and therefore, the semiconductor structure 3000 formed by depositing the precursor material may have a non-uniform composition depending on the spatial position.

[0193] Here, when the composition of the active material layer 3300 differs according to the spatial position, a plurality of light emitting elements 300 manufactured to have the same diameter may include element active layers 330 having different compositions from each other. In this case, a plurality of light emitting elements 300 manufactured at different positions in the semiconductor structure 3000 may have a deviation in the wavelength band of emitted light.

[0194] Therefore, in order to minimize the deviation of the emission band that may occur in the plurality of light emitting elements 300, the method for manufacturing the light emitting element 300 according to the embodiment may further include the following steps: in the step of etching the semiconductor structure 3000 in a direction perpendicular to the lower substrate layer 1000, forming an etching pattern layer 1700 having sizes different from each other, thereby forming a plurality of element rods ROD having diameters different from each other. Therefore, even if the element active layers 330 of the light emitting elements 300 have components different from each other, the plurality of light emitting elements 300 manufactured by performing the following steps can emit light of substantially the same band because they have different diameters.

[0195] The method of manufacturing a light emitting element according to the embodiment may include the following steps: ( S200 ) before forming the etching pattern layer 1700 to define the wavelength area WA on the semiconductor structure 3000 , measuring lights having wavelength bands different from each other emitted from the semiconductor structure 3000 .

[0196] As described above, the semiconductor structure 3000 (e.g., the active material layer 3300) formed on the lower substrate layer 1000 can emit light of different wavelength bands according to the spatial position. The wavelength area WA for emitting light of different wavelength bands is defined on the semiconductor structure 3000, and thus, nano patterns 1710, 1720, and 1730 having different diameters can be formed. In the steps to be described later, the element rods ROD formed by the nano patterns 1710, 1720, and 1730 having different diameters can shift the wavelength band of the emitted light according to the diameter.

[0197] Figures 8 to 16 is a cross-sectional view schematically illustrating a method of manufacturing a light emitting element according to an embodiment.

[0198] First, refer to Figures 8 to 13 The first conductive semiconductor layer 3100, the active material layer 3300, the second conductive semiconductor layer 3200, and the conductive electrode material layer 3700 are etched in a direction perpendicular to the lower substrate layer 1000 to form element rods ROD. Here, the element rods ROD may be formed to have different diameters from each other.

[0199] The step of forming the element rod ROD by vertically etching the semiconductor structure 3000 may include a patterning process that may be conventionally performed. According to an embodiment, the step of forming the element rod ROD by etching the semiconductor structure 3000 may include the steps of forming an etching mask layer 1600 and an etching pattern layer 1700 on the semiconductor structure 3000, etching the semiconductor structure 3000 according to the pattern of the etching pattern layer 1700, and removing the etching mask layer 1600 and the etching pattern layer 1700.

[0200] The etch mask layer 1600 may be used as a mask for sequentially etching the first conductive semiconductor layer 3100, the active material layer 3300, the second conductive semiconductor layer 3200, and the conductive electrode material layer 3700 of the semiconductor structure 3000. The etch mask layer 1600 may include a first etch mask layer 1610 including an insulating material and a second etch mask layer 1620 including a metal.

[0201] The insulating material included in the first etching mask layer 1610 of the etching mask layer 1600 may be an oxide or a nitride. For example, the insulating material may be silicon oxide (SiO x ), Silicon Nitride (SiN x ) or silicon oxynitride (SiO x N y ). The thickness of the first etch mask layer 1610 may be in the range of 0.5 μm to 1.5 μm, but is not limited thereto.

[0202] The material of the second etching mask layer 1620 is not particularly limited as long as it is a conventional material that can be used as a mask for continuous etching of the semiconductor structure 3000. For example, the second etching mask layer 1620 may include chromium (Cr), etc. The thickness of the second etching mask layer 1620 may be in the range of 30 nm to 150 nm, but is not limited thereto.

[0203] The etching pattern layer 1700 formed on the etching mask layer 1600 may be provided to have one or more nano-patterns 1710, 1720, and 1730 spaced apart from each other. The etching pattern layer 1700 may be used as a mask for continuous etching of the semiconductor structure 3000. The method of forming a pattern is not particularly limited as long as it can form a pattern using the etching pattern layer 1700 including a polymer, polystyrene balls, silica balls, etc.

[0204] For example, when the etching pattern layer 1700 includes a polymer, a conventional method capable of forming a pattern using a polymer may be used. For example, the etching pattern layer 1700 including a polymer may be formed by a method such as photolithography, electron beam lithography, or nanoimprint lithography.

[0205] In an exemplary embodiment, the etching pattern layer 1700 may be formed by nanoimprint lithography, and the nano patterns 1710, 1720, and 1730 of the etching pattern layer 1700 may include a nanoimprint resin. Examples of the resin may include, but are not limited to, fluorinated monomers, acrylate monomers, dipentaerythritol hexaacrylate, dipropylene glycol diacrylate, polyethylene glycol phenyl ether acrylate, butylated hydroxytoluene (BHT), and 1-hydroxy-cyclohexyl phenyl ketone (Irgacure 184).

[0206] The structure, shape, and spacing of the nano-patterns 1710, 1720, and 1730 may be related to the shape of the finally manufactured light emitting element 300. However, as described above, since the light emitting element 300 may have different diameters, the sizes of the nano-patterns 1710, 1720, and 1730 may be various.

[0207] In an exemplary embodiment, the diameter rn2 of the second nanopattern 1720 may be larger than the diameter rn1 of the first nanopattern 1710, but may be smaller than the diameter rn3 of the third nanopattern 1730. In other words, the first nanopattern 1710, the second nanopattern 1720, and the third nanopattern 1730 may be formed such that their diameters sequentially increase.

[0208] Specifically, Figure 8As shown in , the active material layer 3300 may have a difference in the composition of its material according to its spatial position, and a strong strain is applied to the lattice of the active material when the active material layer 3300 is deposited. Therefore, the band gap energy of the active material may vary according to the position of the active material layer 3300, and the wavelength band of the emitted light may have a deviation. As shown in the drawings, the semiconductor structure 3000 including the active material layer 3300 may include any space defined by a first wavelength region WA1 in which the first light L1 is emitted, a second wavelength region WA2 in which the second light L2 is emitted, and a third wavelength region WA3 from which the third light L3 is emitted. The active material layer 3300 may have a difference in the composition of the active material according to each wavelength region WA, or may have different strains applied to the lattice of the active material.

[0209] A first nano pattern 1710 , a second nano pattern 1720 , and a third nano pattern 1730 having diameters different from each other may be formed on the first wavelength area WA1 , the second wavelength area WA2 , and the third wavelength area WA3 , respectively.

[0210] Fig. 9 When viewed from above Figure 8 A cross-sectional view of an etching pattern layer formed on a semiconductor structure. Fig. 9 The semiconductor structure 3000 grown on the lower substrate layer 1000 and the etching pattern layer 1700 formed thereon are partially shown. Fig. 9 , only some of the nano-patterns 1710 , 1720 , and 1730 included in the etch pattern layer 1700 are shown, and it is apparent that a greater number of the nano-patterns 1710 , 1720 , and 1730 may be formed on the semiconductor structure 3000 .

[0211] like Fig. 9 As shown in , the central portion of the semiconductor structure 3000 may be defined as the third wavelength region WA3, and the second wavelength region WA2 and the first wavelength region WA1 may be defined as surrounding the third wavelength region WA3. The third nano pattern 1730 may be formed on the third wavelength region WA3, the second nano pattern 1720 may be formed on the second wavelength region WA2, and the first nano pattern 1710 may be formed on the first wavelength region WA1. Fig. 9 , in which the wavelength region of light emitting different wavelength bands may be defined as it goes outward based on the center of the semiconductor structure 3000. Light emitted from the second wavelength region WA2 may have a shorter wavelength than the wavelength of light emitted from the first wavelength region WA1, and may have a longer wavelength than the wavelength of light emitted from the third wavelength region WA3. In other words, the wavelength band of the emitted light may increase from the center of the semiconductor structure 3000 toward the outside.

[0212] At least one first nano pattern 1710, at least one second nano pattern 1720, and at least one third nano pattern 1730 may be respectively disposed in the wavelength region, and the nano patterns may be disposed to be spaced apart from each other. The space or structure in which the plurality of nano patterns 1710, 1720, and 1730 are spaced apart from each other is not particularly limited. Fig. 9 In the embodiment of the present invention, the plurality of nanopatterns 1710, 1720, and 1730 may be arranged so that other nanopatterns surround any one nanopattern. Here, six other nanopatterns are arranged to surround the outer surface of a centered nanopattern, and the six nanopatterns may be divided and arranged at regular intervals. In other words, the region formed by the plurality of nanopatterns may have a regular hexagonal shape. However, the present invention is not limited thereto, and the region formed by the plurality of nanopatterns may have a circular shape, a polygonal shape, etc.

[0213] The spacing between the plurality of nano patterns 1710, 1720, and 1730 is not particularly limited. For example, the spacing between the plurality of nano patterns 1710, 1720, and 1730 may be larger than the diameter of each of the nano patterns 1710, 1720, and 1730. In an exemplary embodiment, the spacing between the plurality of nano patterns 1710, 1720, and 1730 may be two to four times or three times the diameter of each of the nano patterns 1710, 1720, and 1730. The structure of each of the nano patterns 1710, 1720, and 1730 and the spacing between the nano patterns 1710, 1720, and 1730 are not particularly limited. For example, when the nano patterns 1710, 1720, and 1730 have a polygonal shape in which they are spaced apart from each other, the light emitting element 300 manufactured by vertically etching the semiconductor structure 3000 may have the shape of a polygonal column. However, the present invention is not limited thereto.

[0214] In addition, as described above, the first nano pattern 1710, the second nano pattern 1720, and the third nano pattern 1730 may have diameters different from each other. For example, among the light emitting elements manufactured by the semiconductor structure 3000, based on the second light emitting element 302 manufactured to have a diameter of the second nano pattern 1720 on the second wavelength region WA2 emitting the second light L2, nano patterns of different diameters may be formed according to the difference in the wavelength bands of the light emitted from the first wavelength region WA1 emitting the first light L1 and the light emitted from the third wavelength region WA3 emitting the third light L3. That is, the first nano pattern 1710 and the third nano pattern 1730 may have diameters different from the diameter of the second nano pattern 1720.

[0215] In an exemplary embodiment, a diameter rn1 of the first nano-pattern 1710 formed on the first wavelength area WA1 emitting the first light L1 having a longer wavelength than the second light L2 may be smaller than a diameter rn2 of the second nano-pattern 1720, and a diameter rn3 of the third nano-pattern 1730 formed on the third wavelength area WA3 emitting the third light L3 having a shorter wavelength than the second light L2 may be larger than the diameter rn2 of the second nano-pattern 1720. In other words, the diameters of the nano-patterns 1710, 1720, and 1730 formed on the semiconductor structure 3000 may decrease from the center to the outside of the semiconductor structure 3000. In addition, the diameters of the nano-patterns 1710, 1720, and 1730 may increase along a uniaxial direction passing through the center of the semiconductor structure 3000, and then decrease after passing through the center of the semiconductor structure 3000. In other words, the diameters of the nanopatterns 1710, 1720, and 1730 may increase from one end of an axis passing through the center of the semiconductor structure 3000 toward the center of the semiconductor structure 3000, but the diameters of the nanopatterns 1710, 1720, and 1730 may decrease from the center of the semiconductor structure 3000 toward the other end of the axis.

[0216] However, the present invention is not limited thereto. In the drawings, the first nano pattern 1710, the second nano pattern 1720, and the third nano pattern 1730 having diameters different from each other are shown, but the present invention is not limited thereto and may include a larger number of nano patterns. That is, when the active material layer 3300 includes a larger number of regions emitting light of different wavelength bands, a larger number of nano patterns may be formed.

[0217] Therefore, the element rods ROD manufactured in the steps to be described later may have different diameters from each other. According to the diameters of the first nano pattern 1710, the second nano pattern 1720, and the third nano pattern 1730, the element rods ROD formed in the first wavelength region WA1, the second wavelength region WA2, and the third wavelength region WA3 may have different diameters from each other, and may include active material layers 3300 having different components from each other.

[0218] In the element rod ROD formed by etching the semiconductor structure 3000 in a direction perpendicular to the lower substrate layer 1000, different lattice strains are applied to the active material layer 3300, respectively. In the element rod ROD including the active material layer 3300 having components different from each other, the active material has different lattice strains according to the diameter of the element rod ROD, and the band of the emitted light (e.g., the first light L1 and the third light L3) can be frequency-shifted. In other words, the diameters of the nano-patterns 1710, 1720, and 1730 can be adjusted so that the wavelength of the emitted light can be frequency-shifted according to the band of the wavelength region WA.

[0219] Therefore, the finally manufactured light-emitting element, for example, the first light-emitting element 301 manufactured in the first wavelength region WA1 by the first nanopattern 1710 can emit the second light L2 due to the blue shift of the light emitted from the element active layer 330, and the third light-emitting element 303 manufactured in the third wavelength region WA3 by the third nanopattern 1730 can emit the second light L2 due to the red shift of the light emitted from the element active layer 330.

[0220] Next, if Figures 10 to 13 As shown in , the semiconductor structure 3000 is etched according to the nano patterns 1710, 1720 and 1730 of the etching pattern layer 1700 to form the element rod ROD. The step of forming the element rod ROD may include: a first etching step of vertically etching the region of the etching pattern layer 1700 in which the plurality of nano patterns 1710, 1720 and 1730 are spaced apart from each other to pattern the etching mask layer 1600 and the conductive electrode material layer 3700 to form the first hole h1; a step of removing the etching pattern layer 1700; a second etching step of patterning the second conductive semiconductor layer 3200, the active material layer 3300 and the first conductive semiconductor layer 3100 along the first hole h1 to form the second hole h2; and a step of removing the etching mask layer 1600.

[0221] The step of forming the first hole h1 and the step of forming the second hole h2 may be performed by a commonly used etching method. For example, as an etching method, dry etching, wet etching, reactive ion etching (RIE), inductively coupled plasma reactive ion etching (ICP-RIE) may be used. In the case of dry etching, anisotropic etching is possible, so it may be suitable for forming the hole h by vertical etching. When the above etching method is used, the etchant may be Cl 2 or 2 However, the present invention is not limited thereto.

[0222] In some embodiments, the semiconductor structure 3000 may be etched by a combination of dry etching and wet etching. For example, first, etching in the depth direction may be performed, and then the etched sidewalls may be placed on a plane perpendicular to the surface by wet etching as isotropic etching.

[0223] Then, the etching mask layer 1600 or etching pattern layer 1700 remaining on the vertically etched semiconductor structure 3000 may be removed to form an element rod ROD. The etching mask layer 1600 or etching pattern layer 1700 may be removed by a common method (eg, dry etching or wet etching).

[0224] As described above, according to the nano patterns 1710 , 1720 , and 1730 having different diameters from each other in the etching pattern layer 1700 , the formed element rods ROD may have different diameters from each other, but light emitted from the element rods ROD may have substantially the same wavelength band.

[0225] In addition, in the step of forming the element rod ROD by etching the semiconductor structure 3000, in addition to the first etching step and the second etching step, patterning processes different from each other may be performed, and one patterning process may be performed to pattern the first conductive semiconductor layer 3100 along the etching pattern layer 1700. However, the present invention is not limited thereto.

[0226] Next, refer to Figures 14 to 16 , an insulating film 3800 is formed to partially surround the outer surface of the element rod ROD, and the element rod ROD is separated from the lower substrate layer 1000 to manufacture the light emitting element 300.

[0227] First, refer to Fig.14 and Fig.15 , the insulating film 3800 may be formed by coating or impregnating an insulating material on the outer surface of the vertically etched element rod ROD, but the present invention is not limited thereto. For example, the insulating film 3800 may be formed by atomic layer deposition (ALD). The insulating film 3800 may form the insulating layer 380 of the light emitting element 300. As described above, the insulating film 3800 may include silicon oxide (SiO x ), Silicon Nitride (SiN x ), silicon oxynitride (SiO x N y ), aluminum oxide (Al 2 O 3 ) or aluminum nitride (AlN).

[0228] Reference Fig.14 , the insulating film 3800 may be formed on the side surfaces and the upper surface of the element rods ROD spaced apart from each other, and thus may be formed even on the buffer material layer 1200 exposed to the outside. In order to expose the two end side surfaces of the element rods ROD, it is necessary to remove the insulating film 3800 formed on the upper surface of the element rods ROD. Therefore, the insulating film 3800 formed in a direction perpendicular to the length direction of the element rods ROD (i.e., in a direction parallel to the base substrate 1100) may be partially removed. That is, as Fig.15 As shown in , the insulating film 3800 disposed on at least the upper surface of the element rod ROD and the buffer material layer 1200 may be removed to expose the upper surface of the element rod ROD. To this end, a process such as dry etching or etch-back as anisotropic etching may be performed.

[0229] Finally, if Fig.16 As shown in , the element rods ROD grown on the lower substrate layer 1000 are separated from the lower substrate layer 1000 , thereby manufacturing the light emitting element 300 .

[0230] In the step of separating the element rod ROD, the separation method is not particularly limited as long as it can be generally performed, such as a physical separation method (mechanical peeling (MLO) or a chemical separation method (chemical peeling (CLO)). However, according to some embodiments, in the method of manufacturing the light emitting element 300, a separation layer 1300 may be further provided between the buffer material layer 1200 and the first conductive semiconductor layer 3100, and the separation layer 1300 may be removed by the chemical separation method (CLO) in the step of separating the element rod ROD. In order to remove the separation layer 1300, a separation etchant such as hydrofluoric acid (HF) or a buffered oxide etchant (BOE) may be used to perform a wet etching process, but the present invention is not limited thereto. In addition, the light emitting element 300 manufactured by the chemical separation method (CLO) can maintain a flat and smooth end surface, and at the same time, a plurality of light emitting elements 300 can ensure the uniformity of the end surface.

[0231] like Fig.16 As shown in FIG. 1 , the plurality of light emitting elements 300 may include a first light emitting element 301, a second light emitting element 302, and a third light emitting element 303 having diameters different from each other. The light emitting elements 300 include element active layers 330 having components different from each other and have diameters different from each other, and thus may emit light having the same wavelength band by shifting the wavelength of the emitted light.

[0232] although Fig.16 Only the first light emitting element 301, the second light emitting element 302, and the third light emitting element 303 having diameters different from each other are shown, but the present invention is not limited thereto. In some cases, a greater number of light emitting elements 300 having diameters different from the diameter of any light emitting element 300 may be included, and when there are fewer divided regions formed on the active material layer 3300 due to differences in components, only two light emitting elements 300 having diameters different from each other may be included.

[0233] As described above, in the method of manufacturing the light emitting element 300 according to the embodiment, such light emitting elements can be manufactured: having a difference in composition between the element active layers 330, but having different diameters from each other to emit light of substantially the same wavelength band. These light emitting elements 300 can be manufactured by forming the etching pattern layer 1700 having different sizes from each other in the step of vertically etching the semiconductor structure 3000 to form the element rod ROD. Since the light emitting elements 300 according to the embodiment are manufactured to have different diameters from each other, the difference in emission wavelength that may occur according to the difference in composition of the element active layer 330 can be compensated, and the display device 10 including the light emitting element 300 can minimize the deviation of the emission wavelength between the light emitting elements 300 in each pixel PX, and improve the color purity and light emission reliability of each pixel PX.

[0234] In addition, in the step of forming the element rod ROD, the shape or arrangement of the etching pattern layer 1700 in its cross section may be various. The shape or arrangement of the etching pattern layer 1700 may vary according to the divided areas formed due to the difference in the components of the semiconductor structure 3000 formed on the lower substrate layer 1000. Figures 17 to 19 The shape of the etch pattern layer 1700 according to other embodiments is described.

[0235] Fig.17 is a schematic diagram showing a cross-sectional shape of an etching pattern layer formed on a semiconductor structure when viewed from above in a method for manufacturing a light emitting element according to another embodiment.

[0236] exist Fig. 9 3 shows that the wavelength area WA defined on the semiconductor structure 3000 changes from the center to the outside of the semiconductor structure 3000. In this case, the nano-patterns 1710, 1720, and 1730 of the etching pattern layer 1700 may have different diameters from the center to the outside of the semiconductor structure 3000.

[0237] On the contrary, Fig.17 1 shows that the wavelength area WA defined on the semiconductor structure 3000 changes from one side of the semiconductor structure 3000 to the other side of the semiconductor structure 3000. In this case, the nano-patterns 1710_1, 1720_1, and 1730_1 of the etching pattern layer 1700 may have different diameters from one side of the semiconductor structure 3000 to the other side of the semiconductor structure 3000.

[0238] As described above, when the semiconductor structure 3000 is formed by depositing a precursor material on the lower substrate layer 1000, the distribution of the precursor material disposed on the lower substrate layer 1000 may be non-uniform. The arrangement of the wavelength area WA defined on the active material layer 3300 of the semiconductor structure 3000 may vary depending on the uniformity of the distribution of the precursor material.

[0239] exist Fig.17 , the first wavelength area WA1 is formed on one side of the semiconductor structure 3000, and the second wavelength area WA2 and the third wavelength area WA3 are sequentially formed toward the other side of the semiconductor structure 3000 which is the opposite side of the one side of the semiconductor structure 3000. Therefore, the arrangement of the nano-patterns 1710_1, 1720_1, and 1730_1 formed on the semiconductor structure 3000 may also be changed.

[0240] The first nano pattern 1710_1 may be formed on the first wavelength region WA1, the second nano pattern 1720_1 may be formed on the second wavelength region WA2, and the third nano pattern 1730_1 may be formed on the third wavelength region WA3. Therefore, based on an axis direction passing through the center of the semiconductor structure 3000, the diameters of the nano patterns 1710_1, 1720_1, and 1730_1 may increase from one side to the other side. In other words, the diameters of the nano patterns 1710_1, 1720_1, and 1730_1 may increase from one end of an axis passing through the center of the semiconductor structure 3000 to the other end thereof. However, the present invention is not limited thereto, and vice versa. The shapes, arrangement structures, diameters, etc. of the nano patterns 1710, 1720, and 1730 may vary according to the wavelength region WA defined on the semiconductor structure 3000.

[0241] Fig.18 and Fig.19 FIG. 1 is a schematic diagram showing a cross-sectional shape of an etching pattern layer in a method for manufacturing a light emitting element according to another embodiment.

[0242] Reference Fig.18 and Fig.19 As described above, the nano-patterns 1710, 1720, and 1730 of the etching pattern layer 1700 do not necessarily have a circular shape, but may have a polygonal shape. Fig.18 FIG. 1 shows that the nanopatterns 1710_2, 1720_2, and 1730_2 have a triangular shape. Fig.19 FIG. 1 shows that the nano patterns 1710_3, 1720_3, and 1730_3 have a rhombus shape or a rectangular shape. However, the present invention is not limited thereto.

[0243] according to Fig.18 and Fig.19The light emitting element 300 manufactured by the nano patterns 1710, 1720 and 1730 may have a polygonal column shape. The light emitting element 300 may be aligned between the first electrode 210 and the second electrode 220 of the display device 10, and both ends of the light emitting element 300 may contact the contact electrodes 261 and 262. Therefore, the light emitting element 300 may have various shapes within the range that does not cause adhesion failure when the light emitting element 300 contacts the contact electrodes 261 and 262.

[0244] In addition, as described above, in some embodiments, a plurality of layers may be formed on the buffer material layer 1200 , and the separation layer 1300 may be disposed between the buffer material layer 1200 and the plurality of layers. Fig. 20 and Fig.21 are cross-sectional views illustrating some processes of a method of manufacturing a light emitting element according to another embodiment.

[0245] Reference Fig. 20 and Fig.21 , a separation layer 1300 may be further provided on the lower substrate layer 1000. The separation layer 1300 may have the first conductive semiconductor layer 3100 formed thereon. That is, the separation layer 1300 may be disposed between the first conductive semiconductor layer 3100 and the buffer material layer 1200, and the separation layer 1300 may include a material for growing crystals of the first conductive semiconductor layer 3100. The separation layer 1300 may include at least one of an insulating material and a conductive material. For example, the separation layer 1300 may include silicon oxide (SiO x ), Silicon Nitride (SiN x ) or silicon oxynitride (SiO x N y ) as an insulating material, and may include ITO, IZO, IGO, ZnO, graphene or graphene oxide as a conductive material. However, the present invention is not limited thereto.

[0246] The separation layer 1300 may be etched and removed in a step to be described later, thereby separating the light emitting element 300 from the lower substrate layer 1000. The step of removing the separation layer 1300 may be performed by the chemical separation method (CLO) as described above, and thus, the end surface of the light emitting element 300 may have a shape substantially the same as that of the surface of the separation layer 1300. That is, the end surface of the light emitting element 300 may have a flat surface.

[0247] In addition, in the process of etching the semiconductor structure 3000, the separation layer 1300 can be used as an etching stopper between the semiconductor structure 3000 and the buffer material layer 1200. That is, when etching the semiconductor structure 3000, the separation layer 1300 can be patterned simultaneously in one process, or the separation layer 1300 can be patterned separately in another process. The method of manufacturing the light emitting element 300 is not particularly limited thereto.

[0248] However, the present invention is not limited thereto. A greater number of separation layers 1300 may be arranged in the semiconductor structure 3000 or the lower substrate layer 1000 , and the separation layers 1300 may be provided in a region other than the interface between the buffer material layer 1200 and the first conductive semiconductor layer 3100 .

[0249] At the end of the detailed description, it will be appreciated by those skilled in the art that many variations and modifications may be made to the preferred embodiments without departing substantially from the principles of the invention. Therefore, the disclosed preferred embodiments of the invention are used in a general and descriptive sense only and not for purposes of limitation.

Claims

1. A method for manufacturing a light-emitting element, the method comprising: Providing a semiconductor structure formed on a substrate, the semiconductor structure including different wavelength regions, the different wavelength regions emitting light having wavelength bands different from each other; After providing the semiconductor structure, measuring the semiconductor structure to determine the different wavelength regions; After measuring the semiconductor structure, forming nano-patterns having diameters different from each other and spaced apart from each other on the semiconductor structure based on respective wavelength regions; etching the semiconductor structure to correspond to the nano-patterning element rods, The element rods formed by the different wavelength regions and having different diameters emit light of the same wavelength band.

2. The method according to claim 1, wherein: The wavelength region includes: a first wavelength region, from which first light having a first wavelength band is emitted; a second wavelength region from which second light having a second wavelength band shorter than the first wavelength band is emitted; and A third wavelength region from which third light having a third wavelength band shorter than the second wavelength band is emitted.

3. The method according to claim 2, in, In the step of forming the nano-pattern, the nano-pattern is formed on the wavelength region with an increasing diameter as a wavelength band of light emitted from the wavelength region decreases.

4. The method according to claim 3, in, The nano-pattern includes a first nano-pattern, a second nano-pattern, and a third nano-pattern, the second nano-pattern having a diameter larger than that of the first nano-pattern, the third nano-pattern having a diameter larger than that of the second nano-pattern, and The first nano-pattern is formed on the first wavelength region, the second nano-pattern is formed on the second wavelength region, and the third nano-pattern is formed on the third wavelength region.

5. The method according to claim 4, wherein: The element rod comprises: a first element rod formed in a region overlapping the first wavelength region; a second element rod formed in a region overlapping the second wavelength region; and The third element rod is formed in a region overlapping the third wavelength region.

6. The method according to claim 5, in, The second element rod is larger in diameter than the first element rod but smaller in diameter than the third element rod, and The first element rod, the second element rod and the third element rod emit light of the same wavelength band.

7. The method according to claim 4, in, The third wavelength region is disposed at the center of the semiconductor structure, the second wavelength region is disposed around an outer surface of the third wavelength region, and The first wavelength region is disposed around an outer surface of the second wavelength region.

8. The method according to claim 7, in, The semiconductor structure comprises a first axis passing through the center of the semiconductor structure, The diameter of the nano-pattern increases from one end of the first axis toward the center of the semiconductor structure, and The diameter of the nano-pattern decreases from the center of the semiconductor structure toward the other end of the first axis.

9. The method according to claim 4, in, The semiconductor structure includes a second axis passing through a center of the semiconductor structure, The first wavelength region is disposed at one end of the second axis, The second wavelength region partially surrounds the outer surface of the first wavelength region and extends in the direction of the other end of the second axis, and The third wavelength region partially surrounds an outer surface of the second wavelength region and extends to the other end of the second axis.

10. The method according to claim 9, in, The diameter of the nano-pattern disposed along the second axis increases from the one end of the second axis toward the other end of the second axis.

11. A method for manufacturing a light-emitting element, the method comprising: providing a substrate and a semiconductor structure, the semiconductor structure being disposed on the substrate and comprising a first conductive semiconductor layer, an active material layer, and a second conductive semiconductor layer, so that the semiconductor structure comprises different wavelength regions, the different wavelength regions emitting light having wavelength bands different from each other; After providing the semiconductor structure, measuring the semiconductor structure to determine the different wavelength regions; After measuring the semiconductor structure, forming an etching mask layer and an etching pattern layer including one or more nano-patterns on the semiconductor structure based on respective wavelength regions, the etching mask layer being formed on the semiconductor structure, the one or more nano-patterns being formed on the etching mask layer, having diameters different from each other according to the wavelength regions and being spaced apart from each other; Etching the semiconductor structure in a direction perpendicular to the substrate along a region where the nano patterns are spaced apart from each other to form element bars; as well as separating the element rod from the substrate to form a light-emitting element, The element rods formed by the different wavelength regions and having different diameters emit light of the same wavelength band.

12. The method according to claim 11, wherein: The nano pattern comprises: The first nanopattern; a second nano-pattern having a diameter larger than that of the first nano-pattern; and The third nano-pattern has a diameter larger than that of the second nano-pattern.

13. The method according to claim 12, wherein: The light emitting element comprises: a first light emitting element having a diameter equal to the diameter of the first nano-pattern; a second light emitting element having a diameter equal to the diameter of the second nano-pattern; and The third light emitting element has a diameter equal to the diameter of the third nano-pattern.

14. The method according to claim 13, in, A difference in diameter between the first light emitting element and the second light emitting element is in a range of 2% to 16% of the diameter of the second light emitting element.

15. The method according to claim 14, in, A pitch between the one or more nano-patterns spaced apart from each other is in a range of 2.5 to 3.5 times the diameter of each of the nano-patterns.

16. The method according to claim 15, in, The nano-pattern has a circular shape or a polygonal shape.

17. The method according to claim 11, in, A separation layer is further provided between the substrate and the first conductive semiconductor layer, and The step of forming the light emitting element includes the step of removing the separation layer to separate the element rod from the substrate.

18. A display device, comprising: substrate; at least one first electrode and at least one second electrode extending along a first direction on the substrate and spaced apart from each other along a second direction different from the first direction; at least one light emitting element disposed in a space between the first electrode and the second electrode; a first contact electrode partially covering the first electrode and contacting the first end of the light emitting element; as well as a second contact electrode partially covering the second electrode and contacting a second end of the light emitting element, the second end of the light emitting element being positioned opposite to the first end of the light emitting element, wherein the light emitting element comprises a first light emitting element and a second light emitting element, the second light emitting element having a diameter larger than that of the first light emitting element, and The first light emitting element and the second light emitting element emit light of the same wavelength band.

19. The display device according to claim 18, in, A difference in diameter between the first light emitting element and the second light emitting element is in a range of 2% to 16% of the diameter of the second light emitting element.

20. The display device according to claim 19, in, The light emitting element further includes a third light emitting element, and The third light emitting element has a diameter larger than that of the second light emitting element, and emits light in the same wavelength band as that of the second light emitting element.

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